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Neurorehabilitation of Persistent Sport-Related Post-Concussion Syndrome

  • Carolina Neuropsychological Service


Background: Persistent Sport-Related Post-Concussion Syndrome is often diagnosed with any type of prolonged PCS symptoms. However, there are not specific diagnostic criteria for PPCS such that misdiagnosis often occurs. Further, the signs and symptoms of PCS overlap with other common illnesses such as depression, anxiety, migraines, ADHD and others. Misdiagnosis may lead to less than efficacious treatment, resulting in prolonged symptoms. Objective: This article will review relevant evidence-based literature on PCS, pointing out the lack of a systemic diagnostic framework. It will also provide evidence that highlights the multiple conflicting findings in the literature. This article will posit the BioPsychoSocial framework as the best diagnostic framework for understanding the impact of concussions on the person and to generate individualized and personal interventions. Methods: A narrative review of sport concussion-related articles was conducted, after extensive searches of relevant and non-relevant literature by each author, as well as articles recommended by colleagues. Articles varied from American Academy of Neurology Class I to IV for evaluation and critique. Class IV articles were reviewed, as there is much public misconception regarding sport and other concussion treatment that needed identification and discussion. Results: Articles reviewed varied by quality of research design and methodology. Multiple symptoms, recovery patterns and rehabilitation treatment approaches are purported in the sport-related concussion literature. Current consensus data as well as the mixed and contradictory findings were explored. Conclusions: Persistent Sport-Related Post-Concussion Syndrome is a topic of great interest to both professionals and the general public. There is much misunderstanding about the etiology, causation, diagnostic formulations, symptom presentation, prolonging factors and treatment involved in this syndrome. This article posits an individualized multi-system diagnostic formulation, examining all relevant factors, as generating the best interventions for neurorehabilitation of Persistent Sport-Related Post-Concussion Syndrome.
NeuroRehabilitation 46 (2020) 167–180
IOS Press
Neurorehabilitation of Persistent
Sport-Related Post-Concussion Syndrome
Alanna Condera, Robert Condera,and Christopher Friesenb
aCarolina Neuropsychological Service, Raleigh, NC, USA
bNiagara Neuropsychology, Grimsby, Ontario, Canada
BACKGROUND: Persistent Sport-Related Post-Concussion Syndrome is often diagnosed with any type of prolonged PCS
symptoms. However, there are not specific diagnostic criteria for PPCS such that misdiagnosis often occurs. Further, the
signs and symptoms of PCS overlap with other common illnesses such as depression, anxiety, migraines, ADHD and others.
Misdiagnosis may lead to less than efficacious treatment, resulting in prolonged symptoms.
OBJECTIVE: This article will review relevant evidence-based literature on PCS, pointing out the lack of a systemic
diagnostic framework. It will also provide evidence that highlights the multiple conflicting findings in the literature. This
article will posit the BioPsychoSocial framework as the best diagnostic frameworkfor understanding the impact of concussions
on the person and to generate individualized and personal interventions.
METHODS: A narrative review of sport concussion-related articles was conducted, after extensive searches of relevant
and non-relevant literature by each author, as well as articles recommended by colleagues. Articles varied from American
Academy of Neurology Class I to IV for evaluation and critique. Class IV articles were reviewed, as there is much public
misconception regarding sport and other concussion treatment that needed identification and discussion.
RESULTS: Articles reviewed varied by quality of research design and methodology. Multiple symptoms, recovery patterns
and rehabilitation treatment approaches are purported in the sport-related concussion literature. Current consensus data as
well as the mixed and contradictory findings were explored.
CONCLUSIONS: Persistent Sport-Related Post-Concussion Syndrome is a topic of great interest to both professionals
and the general public. There is much misunderstanding about the etiology, causation, diagnostic formulations, symptom
presentation, prolonging factors and treatment involved in this syndrome. This article posits an individualized multi-system
diagnostic formulation, examining all relevant factors, as generating the best interventions for neurorehabilitation of Persistent
Sport-Related Post-Concussion Syndrome.
Keywords: Concussion, sport concussion, mild traumatic brain injury, Post-Concussion Syndrome, biofeedback
1. Introduction
Persistent sport-related concussion (SRC) is
widely discussed both in the academic literature and
popular press. Many academic review papers cite
pre-existing medical and psychosocial factors for
Address for correspondence: Robert Conder, Carolina Neu-
ropsychological Service, Raleigh, NC, USA. Tel.: +1 919 859
9040; E-mail:
prolonging what should be a time-limited neuro-
physiological condition. Moreover, while traditional
neuroimaging and clinical biomarkers typically do
not show positive findings, experimental measures
of brain functioning reveal abnormalities for weeks
to months post-injury, even after clinical symptoms
have resolved (Institute of Medicine, 2013). Over
the past two decades, the field of concussion has
progressed from a propensity to under-diagnose con-
cussions and minimize their potential for persistent
ISSN 1053-8135/20/$35.00 © 2020 – IOS Press and the authors. All rights reserved
168 A. Conder et al. / Neurorehabilitation of Persistent Sport-Related Post-Concussion Syndrome
sequelae, to rapid and global expansions in concus-
sion awareness, detection and formal protocols for
response. In its latest dialectic iteration, there is now
almost paranoia in popular press articles suggesting
that even a minor impact head strike sustained in any
sport, at any age, by any person could potentially
lead to persistent SRC or dire progressive degenera-
tive neurologic illness known under the moniker of
Chronic Traumatic Encephalopathy (CTE). Former
staunch advocates for collision sports and “playing
hard” are now questioning the safety and value of
youth participation in sports with concussion poten-
tial. Within this context, there is a need for frank,
data-driven appraisal and interpretation of extant data
to inform views on factors that influence concus-
sion risk, management and recovery. The two-fold
purpose of this article is to: (a) review the evidence-
based literature that establishes the incidence and
prevalence of sport concussion and examines its
neuropathophysiology, sequelae, and factors influ-
encing risk for protracted recovery; and (b) critically
review established and emerging rehabilitation inter-
ventions for ameliorating persistent symptoms or
deficits resulting from refractory SRC. Given the lim-
ited extent of Class 1 empirical data available, this
article also will evaluate research regarding persis-
tence of SRC and proposed rehabilitation treatment
alternatives which may be promising but currently
lack scientific rigor.
1.1. Definitions of sport concussion and post
concussion syndrome
An updated consensus definition of sport con-
cussion was developed at the 5th International
Conference on Concussion in Sport held in Berlin,
October 2016 (hereafter referred to as the “2016
Berlin Consensus Statement”). This document pro-
vides an international foundation that can help in
establishing reliability of diagnosis across profes-
sional disciplines, sports, and geographic locations.
This lengthy, empirically and clinically-driven con-
sensus statement document should be consulted in
its entirety (McCrory et al, 2017). This document
delineates four core criteria for diagnosing a sport
concussion: (a) a TBI injury induced by biome-
chanical forces including direct or indirect trauma
to the head, face, neck or elsewhere on the body
with an impulsive force transmitted to the head;
(b) rapid onset of short-lived impairment of neuro-
logic function that resolves spontaneously, although
sometimes symptoms evolve over a time period; (c)
negative standard neuroimaging reflecting a func-
tional rather than structural injury and with or without
a loss of consciousness; and (d) resolution of clin-
ical and cognitive features typically following a
sequential course, although in some cases symp-
toms may be prolonged. The accepted etiology of
SRC is that postulated by Giza and Hovda (2001)
of a neurometabolic cascade at a cellular level that
essentially is based on a mismatch between glu-
cose metabolism and hyper-glycolysis and reduced
cerebral blood flow. In a majority of these animal
studies, the metabolic cascade restores to homeosta-
sis in about a seven-day period, with no irreversible
damage at a cellular level in these animal models.
This phenomenon has been extended to humans based
on similar time courses for symptom presentation
and resolution (McCrea, Prichep, Powell, & Chabot,
2010). The 2016 Berlin Consensus in Sport position
paper is useful on a number of fronts, but has yet to
be fully disseminated by medical practitioners and
researchers, even those familiar with the consensus
guidelines promulgated by the previous 2012 Zurich
Consensus Statement (McCrory et al., 2013).
The lack of consistent and reliable diagnostic con-
cussion criteria also has added to confusion and
misdiagnosis of the condition termed Post Concus-
sion Syndrome (PCS). Initially, a symptom course
lasting three months after a diagnosed concussion was
the standard required to meet diagnostic criteria for
PCS. More recently, PCS has problematically been
clinically diagnosed within a matter of days or weeks
based primarily on mechanism of injury and resulting
symptoms. This lack of diagnostic rigor is problem-
atic with regard to tracking prevalence and recovery
patterns, as well as researching PCS subtypes and
response to treatment intervention. The American
Medical Society for Sports Medicine (Harmon et al,
2013) as well as the recent 2016 Berlin Consensus
in Sport Group and other professional organizations’
position papers differ slightly, but shared features
among all diagnostic formulae identify PCS as: (a)
a physical hit or concussive force impact with gener-
ally immediate sequelae; (b) core resulting symptoms
including headaches, balance problems, dizziness,
fatigue, sleep disturbance (either sleeping too little
or too much), noise/light sensitivity, visual changes,
and dysregulated mood; (c) symptom course persist-
ing beyond the expected recovery period of weeks to
months post-injury, (d) with refractory symptoms not
better explained by another etiology or maintained
A. Conder et al. / Neurorehabilitation of Persistent Sport-Related Post-Concussion Syndrome 169
by secondary factors such as litigation or psychoso-
cial gain. Despite general agreement on these criteria,
there is a dire need for consensus in PCS diagnostic
1.2. Prevalence and demographics of sport
concussion injuries
Overall, the CDC estimates 3 to 5 million con-
cussions per year, a majority of which are due to
accidents such as automobile accidents, falls in the
elderly, and 17 percent due to sports (Centers for
Disease Control and Prevention, 2011 & 2013).
Of the estimated 45 million children and adoles-
cents participating in organized or recreational sports
(Ewing & Seefeldt, 2002), an estimated 5 to 10%
receive a SRC with an emergency room presenta-
tion (Gilchrist, Thomas, Xu, McGuire, & Coronado,
2011). An additional 15 million adults participate in
organized recreational sports. These figures are esti-
mates based upon emergency room admissions which
are acknowledged to underestimate prevalence, as
many SRC do not receive medical care, especially
at the level of emergency room presentation. At the
college level of the 450,000 players participating in
all sports, over 160,000 participate in sports iden-
tified as concussion generating (NCAA, 2012). At
the professional level, there are fewer but more elite
athletes participating, with an estimated 1600 play-
ers at some level in the National Football League,
and about the same number in the National Hockey
League. Concussion risk potential from such partici-
pation must be weighed against the well documented
positive gains provided by sports participation
on physical, social and intellectual development
(Rieck, Jackson, Martin, Petrie & Greenleaf, 2013;
Weiss, Kipp & Bolter, 2012) and mental health
(Ahn & Fedewa, 2011).
Breakdown by sport and age indicates that a major-
ity of youth concussions presenting to Emergency
Departments and recorded as part of the surveillance
studies in the United States are from playground and
bicycle accidents. Once organized sports begin in the
US public and private school settings, SRC preva-
lence data follow age and gender demographics for
participation in contact/collision sports. Accordingly,
American football and hockey in males and Soc-
cer (European football), field hockey and volleyball
injuries in females are primary SRC generators in the
high school and collegiate population. At the profes-
sional level, males still dominate American football
while soccer may be equally distributed, with SRC
prevalence following these patterns.
1.3. Typical SRC recovery patterns
The 2016 Berlin Consensus statement cited most
severe SRC symptoms in the first 24–72 hours post-
injury, with a majority of balance, cognitive deficits
and symptoms improving in the first two weeks post-
injury. This typical SRC recovery course parallels
the animal model research of Hovda and Giza cited
above. However, further studies have shown proto-
typical but differing recovery courses based on prior
SRC status, age and gender variables. In response
to such, the Berlin Consensus acknowledged that
“a sizable minority of youth, high school and col-
legiate athletes take much longer than 10 days to
clinically recover and return to sport.” The Con-
sensus statement goes on to state: “At present it is
reasonable to conclude that the large majority of
injured athletes recover, from a clinical perspective,
within the first month of injury.” Development of sub-
acute problems including depression and migraine
headaches and pre-injury history of mental health
problems or migraines were identified in this docu-
ment as risk factors for symptom persistence of more
than a month. Finally, teenage athletes, particularly
of high school age, were identified as being most
vulnerable for a persistent symptom course, with
greater risk for female than male athletes. Consistent
with these consensus statements, Neidecker, Gealt,
Luksch & Weaver (2017) performed a retrospective
medical record analysis of 11 to 18 year-old ath-
letes who sustained first time SRC between 2011 and
2013 and found females remained symptomatic for
longer time periods when compared with male ath-
letes of similar age, regardless of sport played. Other
studies have found that female concussed athletes
generally report a higher number of symptoms than
males, although there are confounding factors noted
in these studies. Research has also examined how
post-injury athlete symptom report varies depending
on gender of the examiner, with data suggesting that
a female examiner may elicit more symptoms than a
male interviewer; whereas male athlete/male exam-
iner dyads may yield the lowest symptom reports
(Frommer, Gurka, Cross, Ingersoll, Comstock, & Sal-
iba, 2011). These athlete-examiner gender dyads may
present a confound when examining gender effects on
concussion severity and recovery.
170 A. Conder et al. / Neurorehabilitation of Persistent Sport-Related Post-Concussion Syndrome
Nevertheless, the usual recovery course for a sin-
gle, uncomplicated sport concussion in a collegiate or
older athlete usually follows a consistent pattern of
remission of symptoms in both frequency and sever-
ity over a time course extending from 7 to 10 days
to a few weeks. Of course, this assumes that the ath-
lete is following the current recommended treatment
guidelines, which include immediate diagnosis and
removal from sport.
1.4. Prolonged SRC recovery patterns
With regard to prolonged recovery, much research
and clinical activity has focused on examining risk
factors to explain why some athletes have prolonged
sequelae and others do not. As with many aspects of
science, the data is incomplete and sometimes contra-
dictory, but currently is being guided by better studies
on larger groups of concussed athletes (McCrea,
McAllister, Hammeke, Powell, Barr & Kelly, 2009;
Henry, Elbin, Collins, Marchetti & Kontos, 2016;
Collins, Lovell, Leddy, Kozlowski, Fung, Pendergast
& Willer, 2007). This article will examine prolonged
recovery probability across three categories: premor-
bid, comorbid, and postmorbid risk factors.
1.4.1. Premorbid risk factors for prolonged
Premorbid factors need to be investigated in any
athlete with persistent PCS, as they may add to symp-
tom burden or prolonged symptoms. Most frequently
studied and cited in the Berlin Consensus is a personal
or family history of migraine headaches, especially
in female athletes (Kuczynski et al, 2013). Pre-
existing personal and/or family history of migraines
and/or headaches has been identified as a primary
risk factor for posttraumatic migraines, which can
be especially debilitating for a student-athlete Choe
& Blume, 2016). Concern is noted that the diagnos-
tic formulations of the International Classification
of Headaches be followed and that the practitioner
does not confuse chronic daily headache, tension or
musculoskeletal headache, and migraine headache.
Zasler (2015) and Arnold (2018) should be con-
sulted as expert references for differential headache
classification. More broadly, almost any pre-existing
neurologic vulnerability should be recognized and
examined as a premorbid risk factor, given that a con-
cussion is a neurologic injury at its core. This would
include any sort of early birth complications, seizure
disorder, developmental delay or deviation, or history
of sleep pathology. A history of depression or anxiety
or other psychological disorder in the athlete or in first
degree relatives may be a premorbid risk factor for
prolonged concussion recovery (Broshek, DeMarco
& Freeman, 2015; Hou, Moss-Morris, Peveler, Mogg,
Bradley & Belli, 2012). Corollary to this, concussive
injuries may exacerbate the expression and symptom
burden of a pre-existing condition, such as ADHD,
LD, migraines, depression, anxiety or visual dysfunc-
tion (Conder, 2018). More recent resiliency studies
have identified pre-existing psychological coping
resources of the athlete and his/her family as an
important factor in mitigating the development or
maintenance of symptoms. A person with flexible
and adaptive psychological coping resources and a
family system that is supportive but not symptom-
reinforcing typically is better equipped to handle any
injury, whether neurologic or orthopedic, than is the
athlete without well-developed psychological coping
1.4.2. Comorbid risk factors for prolonged
Comorbid factors also can influence PCS severity,
course and recovery. These include active and current
modifying factors such as concurrent psychosocial
stressors within the athlete and/or his or her family
system (Broshek, DeMarco & Freeman, 2015); pres-
ence or loss of support from the athlete’s teammates
and/or peer group; impact of athlete’s injury on team
performance; financial implications; and new-onset
psychosocial responses of the athlete to changes in
their sense of resiliency or control.
1.4.3. Post-morbid risk factors for prolonged
Post-morbid factors include anything that may
inadvertently prolong the frequency, severity or
persistence of PCS symptoms or recovery. While his-
torically not a factor in the treatment of athletes, now
the specter of litigation has to be considered with
prolonged symptoms if there is a context of gain (Mil-
lis, 2015). Ponsford and Kinsella (1992) followed
Emergency Department admissions from concussion
by etiology and found that over a course of three
months, symptom presentation dropped significantly
for the sports concussion athletes, while those in liti-
gation continued to report a high symptom burden.
To a lesser extent, stressors within a psychosocial
group may prolong symptom burden. Even within
the primary family group, family dynamics in terms
A. Conder et al. / Neurorehabilitation of Persistent Sport-Related Post-Concussion Syndrome 171
of the meaning of symptoms and their function may
be important to evaluate. For example, a young child
evaluated by one of the authors and followed for
a period of time continued to report a high symp-
tom burden, although almost all objective measures
indicated a return to premorbid baseline. Clinical
investigation of psychosocial factors eventually led
to the child’s candid acknowledgement of worry that
“If I get better, my parents will divorce.” While dra-
matic, this emphasizes the need to look “between
the ears” to the larger nexus of the athlete’s existen-
tial situation (Conder & Conder, 2015a). The astute
clinician should carefully elucidate the above premor-
bid, comorbid, and post-morbid factors which may be
prolonging concussion symptom report or expression
(Iverson, Gardner, Terry, Ponsford, Sills, Broshek &
Solomon, 2017).
1.5. Post concussive syndrome
As discussed above, there is a poignant need for
a clear and consensus-based diagnostic schema for
delineating a syndrome which can be diagnosed reli-
ably across sports and geographic locations (Legome,
2018). Based on the PCS definition offered in a
prior section, its diagnosis de facto predicts the need
for treatment interventions beyond the passive heal-
ing effects of time and physical or cognitive rest
to address refractory PCS symptoms. Predominant
among these symptoms are migraines/headaches;
sleep disturbance (sleeping too much or too little);
mood instability such as anxiety, sadness or irritabil-
ity; balance/vestibular symptoms; oculomotor/vision
symptoms; and neurocognitive problems such as
declines in attention/concentration, memory and pro-
cessing speed. Lumba-Brown et al (2019) reviewed
the efficacy of various PCS rating scales in organiz-
ing symptoms and found a lack of consistency and
comprehensiveness among the scales. Additionally,
Iverson (2006) points out that none of these symp-
toms are unique to PCS, and many may be driven by
psychological etiologies including depression.
Assessment of symptom meaning and mainte-
nance is best done by an experienced clinician
undertaking a diagnostic investigation from the
Bio-Psycho-Social formulation elucidated by many
authors (Conder & Conder, 2015b; Yeates, 2010;
Engel, 1997). A BioPsychoSocial assessment is
a holistic formulation which examines symptoms
and signs at multiple levels, as well as interac-
tion among multiple systems which may prolong
symptoms. It posits that a concussion will begin
with a physiologic event (the concussive injury)
which may trigger secondary biological seque-
lae (headaches, vestibular-oculomotor dysfunction)
especially in those with premorbid vulnerabilities,
with concomitant psychological and psychosocial
factors at any stage likely to impact or mediate symp-
tom expression and maintenance.
Kontos, Sufrinko, Sandel, Emami & Collins (2019)
have postulated six rationally derived categories for
characterizing potential sub-types of post concus-
sive experience. These include: cognitive/fatigue,
oculomotor; vestibular; cervical; migraine; and anx-
iety/mood. The utility of these sub-types is that they
help group symptoms into meaningful clusters and
focus treatment interventions, depending on the pri-
mary area of symptom report. These categories are
not orthogonal and many times symptom clusters may
be overlapping. Nevertheless, this approach has util-
ity for assisting the clinician in marshaling treatment
resources. More research is needed to establish the
empirical validity of these sub-types.
2. Neurorehabilitation and treatment of SRC
2.1. Guiding principles for rehabilitation:
Regulation, resilience and mindfulness
While concussions are primarily assumed to be
a central nervous system etiology, there are parallel
Autonomic Nervous System (ANS) alterations asso-
ciated with the concussive event (Goodman, Vargas,
& Dodick, 2013, Hanna-Pladdy, Berry, Bennett &
Phillips, 2001). These may be generated by brainstem
injury but affect multiple levels of functioning. Other
physiological concussion sequelae can also impact
functioning. For example, research has identified
EEG changes (Thatcher, 2006) and cardiac correlates
including alteration in Heart Rate Variability (HRV)
following concussion (Conder & Conder, 2014; Gall,
Parkhouse & Goodman, 2004; Len, Nearly, Asmund-
son, Goodman, Bjornson & Bhambhani, 2011). All
of these psychophysiological sequelae pinpoint Reg-
ulation as a primary function disrupted by concussion
and amenable to targeted psychological, neuropsy-
chological, or psychophysiological PCS treatment
interventions and rehabilitation.
Resilience is defined as an enduring quality of
proactive adaptation to adversity (Sisto, Vicinanza,
Campanozzi, Ricci, Tartaglini, & Tambone, 2019).
The concept of resilience has been widely studied
in the field of Sport Psychology (Fletcher & Sarkar,
172 A. Conder et al. / Neurorehabilitation of Persistent Sport-Related Post-Concussion Syndrome
2012), focusing on factors that enhance performance
and protect against or ameliorate negative outcomes
in the face of adverse circumstances such as injury
or poor performance. Just as risk factor analysis tar-
gets athletes with higher likelihood of prolonged
PCS recovery, resilience data can identify protec-
tive factors to reduce symptom burden or promote
coping post-injury. LeUnes (2008) posits a gradient
in physiologic resilience as athletes progress from
recreational to more elite levels, with professional or
elite athletes more invulnerable to potentially career-
ending injuries. Treatment techniques which foster
resilience can be integrated with other rehabilitation
interventions to maximize recovery.
Mindfulness is a new “buzz” word with a very old
basis. Mindfulness as a meditative technique dates
back to the 14th century, emerging from monas-
tic and Buddhist traditions. Mindfulness meditation
endorses observing phenomenon without judging
or reacting. Its focus on accepting and allowing,
rather than trying to actively control, undesirable
experiences and symptoms fosters ANS regulation
by activating the parasympathetic nervous system
critical for rest and recovery functions (Criswell,
2017). In doing so, Mindfulness-based interventions
can have desirable physiological and psychologi-
cal effects which foster resilience in the face of
adversity and enhance treatment response. Currently,
mindfulness is being used not only for every day
psychological enhancement but as part of treat-
ment approaches for stress; chronic illnesses such
as cardiac disease or cancer; and chronic and post-
traumatic headaches or migraines. Inna Khazan at
Harvard Medical School (Khazan, 2013) recom-
mends combining mindfulness meditation techniques
with biofeedback or with HRV in the treatment of
2.2. Education as PCS treatment
One of the most benign treatments offered has
been education, provided primarily by means of
hand-outs supplied by Emergency Departments and
healthcare personnel with a background in mild trau-
matic brain injury. Used in isolation, this treatment
approach traditionally has had limited efficacy, as
many concussed athletes may not present to these
facilities and not all primary care physicians were
aware of new guidelines. This challenge has been
admirably addressed over the past 15 years by
efforts from the CDC to widely disseminate free
downloadable, comprehensive educational resources
including the CDC “Heads Up!” Concussion materi-
als ( geared toward players,
coaches, sports officials, and parents. The Heads Up
materials are particularly suitable for K-12 sports par-
ticipants and are made readily available to coaches,
trainers, emergency rooms, urgent care clinics, sports
medicine centers, physicians and youth sports organi-
zations. With US state legislation mandates regarding
concussion education and management in all 50 states
and the District of Columbia, there is incentive by
schools, trainers and concussion health care providers
to document their own education and training and
that they have taken steps to educate participants and
parents. In the latest iteration, education efforts have
extended to on-line training programs that document
various stakeholders have received and understand
concussion education and/or concussion manage-
ment training.
Collegiate/NCAA and professional sports orga-
nizations have specific SRC training programs for
their healthcare personnel based on the consensus
data from the Zurich and Berlin conferences1. The
National Football League, National Hockey League,
and Major League Soccer also use a neuropsy-
chological concussion evaluation model (Lovell,
2006). Similary, many professional organizations
have developed specific concussion education and
management guidelines for their disciplines, such as
the American Medical Society for Sports Medicine,
the American Academy of Neurology and the
National Association of Athletic Trainers (NATA)
(Echemendia, Giza, & Kutcher, 2015). Of the above,
the NATA position statement is one of the most
comprehensive and pragmatic documents available,
readily implemented across medical and neuropsy-
chological disciplines (Broglio et al., 2014). Overall,
education plays a crucial first step in treatment, as
evidence-based knowledge prompts players, parents
and coaches to quickly recognize and appropriately
manage a concussive injury.
2.3. Cognitive behavior therapy and
psychotherapeutic interventions
Cognitive Behavioral Therapy (CBT) has long rec-
ognized efficacy in the treatment of depression (Beck
& Beck, 2011) and was one of the initial approaches
to be is utilized as a first line treatment for anxiety
and depressive reactions in athletes with refrac-
tory sports concussion (Hou, Moss-Morris, Peveler,
A. Conder et al. / Neurorehabilitation of Persistent Sport-Related Post-Concussion Syndrome 173
Mogg, Bradley, & Belli, 2012). Using a modified
CBT framework, the first stage in working with the
injured athlete is to educate and alert them to iden-
tify maladaptive cognitions and distortions such as
Overgeneralization and Catastrophizing that either
result from the injury, or prolong recovery by main-
taining symptoms. For example, athletes may see
their concussion and need for supports as a sign of
weakness, may stress that protracted recovery will
transform into a career-ending event, or harbour a
catastrophic fear that they will develop CTE, the
latter not helped by distorted media attention. For
elite athletes reluctant to consider pharmacotherapy,
a modified CBT approach may have the added advan-
tage of symptom control based on procedures that
foster an internal locus of control over the recovery
process and formulation of action plans congruent
with an athlete’s natural preference for self-efficacy
(Feltz, 1984; Beauchamp, Jacksons & Morton, 2012).
Another application of CBT in concussion rehabili-
tation addresses insomnia and parasomnias, as sleep
disturbance is increasingly recognized as prominent
in refractory SRC (Kostyun, Milewski, & Hafeez,
2014). CBT for Insomnia (CBT-I) protocols (Jacobs
et al., 2004) are an alternative for those athletes
who do not like or tolerate the sedating properties
of sleep medication, or have poor sleep hygiene
impacting recovery. CBT-I also could be paired with
pharmacotherapy or relaxation training to potentiate
normalization of sleep.
2.4. Behavioral medicine approaches in SRC
Behavioral Medicine approaches including train-
ing in relaxation and stress management are readily
used by athletes to optimize sports performance and
manage undesirable post-injury symptoms. In refrac-
tory concussion, athletes respond well to training in
breathing exercises, progressive relaxation, positive
imagery, autogenic phrases and mindfulness medi-
tation (Brown & Gerbang, 2009; Jacobson, 1938;
Norris, Fahrion & Oikawa, 2003) to reduce acute
stress, headaches and autonomic arousal. Many elite
and Olympic athletes know the value of breathing
for enhancing performance and self-regulation and
have worked with various breathing routines (Wil-
son & Cummings, 2011) so they respond well to
yogic or diaphragmatic breathing training. Specific
relaxation and/or hypnotic induction tapes or CDs are
commercially available or can be individually made
by a therapist for the athlete’s specific circumstances
(Schwartz, 2003). The latter tend to be more effective
due to personalization of the athlete’s situation and
needs. These audio files can be made in the office with
the athlete present, then an MP3 file can be given to
the athlete for use outside of the office. Similarly, once
trained in the relaxation response, injured athletes
can implement breathing, imagery and/or meditation
strategies in the naturalistic setting to reduce PCS
2.5. Cognitive rehabilitation
Cognitive rehabilitation (CR) is the use of cogni-
tive techniques to rehabilitate impaired information
processing after a neurologic event such as a concus-
sion, TBI, or CVA (Conder et al., 1988; Conder 1992).
Kreutzer, Conder, Wehman and Morrison (1989)
were early researchers examining the use of cog-
nitive rehabilitation to enhance independent living
and vocational outcome post mTBI. More recently,
Cicerone and colleagues (Cicerone et al., 2011;
Cicerone et al., 2005) have elucidated a cognitive
rehabilitation schema in association with the Ameri-
can Congress of Rehabilitation Medicine. Most often
PCS sequelae include problems with basic atten-
tion and concentration functions. Not only are these
deficits problematic in their own right, but from
an information processing view of cognition, atten-
tion/concentration are the gateways for information
to flow to higher levels of cognitive processing
including memory, problem-solving and executive
functioning. An everyday example of this com-
plex relationship is the injured student-athlete who
experiences trouble attending to detail and maintain-
ing focus upon returning to school or remembering
specific plays on the field, which in turn creates cog-
nitive fatigue and problems remembering reading
assignments, studying effectively or executing plays.
Without CR support, attempts to “gut it out” are likely
to trigger headaches and stress, which in a cyclic
manner further diminish strained attention resources.
In the initial phases of recovery, direct teaching
and practicing of strategies to remediate attention
and working memory is advocated. After the athlete
is symptom free, tolerating computer or screen-
time activities, computerized cognitive rehabilitation
programs targeting specific impaired/altered neu-
rocognitive functions can also be efficacious both in
an office setting and remotely for home use. Helmich
(2010) presents a consensus conference review of
cognitive rehabilitation for military personnel with
refractory PCS and mTBI injuries.
174 A. Conder et al. / Neurorehabilitation of Persistent Sport-Related Post-Concussion Syndrome
2.6. Academic and work modifications
In conjunction with the cognitive rehabilitation
interventions reviewed above, academic and work
modifications can be critical in addressing persis-
tent post-concussive functional declines in vocational
and educational settings. Most common yet complex
are the problems experienced by injured student-
athletes in the classroom, especially those enrolled in
more demanding academic pursuits such as college
students or high school students taking Advanced
Placement or International Baccalaureate courses.
At the other end of the spectrum, student-athletes
with pre-existing ADHD or learning disabilities often
experience magnified impairments that severely com-
promise post-SRC academic re-entry. Given that
concussions at a neurophysiological level affect the
information-processing capacities of the brain, any
activity dependent upon the integrity of the brain may
be attenuated. Academic settings not only primar-
ily focus on brain-based processes for new learning
consolidation (which are generally harder than post-
injury resumption of routine vocational skills), but
have the added age burden of a population where
brain development is not yet complete at the time
of injury.
Within this context, recent efforts have focused on
Return-to-Learn (RTL) needs of concussed student-
athletes (Halstead, McAvoy, Devorc, Carl, Lee, &
Logan, 2013). Cognitive re-entry is more successful
with tailored supports to address cognitive-academic
functions still recovering at the time of school
re-entry (Conder, 2011). Typical academic mod-
ifications to reduce the compromising impact of
PCS-related declines in attention, memory, pro-
cessing speed, visual tracking/accommodation, or
cognitive stamina include: provision of class notes
and Power-Points; reduced screen time and reading
activities, modified assignments and extended assign-
ment deadlines, more frequent breaks and repetition,
and test modifications (Conder, 2013; Conder, 2018).
A tailored, practical problem-solving approach is
indicated in these situations rather than uniform or
global recommendations that may actually hinder
recovery or add to academic stress. For example,
exemption from all assignments or prolonged medi-
cal leave may be detrimental in a majority of cases,
whereas successful school re-entry benefits from
analysis of which activities for what duration trigger
symptoms or require impaired resources in a particu-
lar student. A recent study by Reiger, Lewandowski,
Potts, and Shea (2019) highlighted the need for inter-
ventions to target anxiety and stress about academic
concerns as an integral part of PCS recovery.
2.7. Biofeedback interventions in SRC
Biofeedback (BFB) interventions, also known as
psychophysiological intervention, have a long and
efficacious history in the behavioral medicine lit-
erature (Norris et al., 2003; Schwartz & Andrasik,
2016) and in the sports psychology literature (Wil-
son & Cummings, 2011; Blumenstein & Orbach,
2012; Conder & Conder, 2014; Wilson & Somers,
2011). They provide an adjunct treatment for somatic
complaints that have a psychophysiological compo-
nent or provide information that can improve optimal
performance in elite athletes (Beauchamp, Harvey
& Beauchamp, 2012). Traditionally, BFB methods
such as temperature biofeedback in the peripheries,
galvanic skin response/electrodermal response, and
electromyography have been used successfully with
medical conditions such as chronic headaches or
vestibular problems, and psychological conditions
including depression or anxiety. It is unsurprising,
therefore, that these techniques have applicability to
these same complaints presenting in the context of a
refractory PCS process.
A primary advantage of psychophysiological BFB
protocols in post-concussion treatment is their provi-
sion of sensitive, objective physiologic measures of
interest, which can provide data independent of sub-
jective symptom report. There are no true biomarkers
for concussion that are generally accepted. How-
ever, the Institute of Medicine report notes alteration
on numerous neurophysiologic parameters post-
concussion, such as fMRI, DTI, MEG, and Evoked
Potentials. BFB data can be instrumental in objectify-
ing athlete symptom report, identifying dysregulated
systems, and identifying targets for BFB and
psychotherapeutic treatment intervention, with the
ultimate goal of teaching self-regulation. After a
concussion, post-traumatic headaches and cardiovas-
cular changes may cause vasoconstriction leading to
significant alterations in temperature regulation in the
extremities, which can be assessed and intervened
with traditional thermal biofeedback. Muscle con-
traction headaches can be treated effectively with
electromyography BFB measuring tension at the
frontalis and masseter muscle sites. Finally, electro-
dermal response (GSR) is very sensitive to negative
thinking, making it possible to objectively measure
changes in GSR within seconds of a maladaptive
A. Conder et al. / Neurorehabilitation of Persistent Sport-Related Post-Concussion Syndrome 175
thought or awareness of a stressor (Mann & Janelle,
2.8. Heart rate variability biofeedback (HRV-B)
An evidence-based form of psychophysiological
biofeedback for sports performance and SRC reha-
bilitation is heart rate variability (HRV) training,
discussed in detail by Conder and Conder, 2014; Tan,
Fink, Dao, Hebert, Farmer, Sanders, A.,. . . Gevirtz,
2009. As noted above, there are cardiac consequences
of a concussion. These most often include reduced
cerebral perfusion with exertion post-concussion
(needed by athletes attempting to perform at their
normal strenuous competitive level). Essentially, the
healthy heart has variability in heart rate, measured by
the R-wave intervals, which may reflect an alteration
between input from the sympathetic and parasym-
pathetic branches of the ANS (Strack & Gevertz,
2011). In cardiopathology, there is reduced vari-
ability between R-waves which reflects illness and
which can predict serious cardiac events. Multi-
ple studies have shown that an athlete’s heart rate
variability is reduced post-concussion (Gall, Park-
house & Goodman, 2004), reflecting ANS changes
driven by the vagus nerve, both at rest and more
importantly at exertion. Post-concussive changes in
cardiac inter-beat variability can be measured with
the traditional biofeedback protocol in the labora-
tory, such as using the protocol of Leddy with the
Buffalo Treadmill Test (Leddy, Haider, & Willer,
2018). This reduction in heart rate variability post-
concussion may have implications for changes in
cardiac demand while performing sports, as well as
reduced cerebrovascular perfusion. Lagos, Thomp-
son, and Vaschillo (2013) modified Lehrer’s heart
rate variability training successfully with concussed
adolescents. In HRV-B training, an athlete learns to
increase variability through respiratory sinus arrhyth-
mia resonant frequency breathing. While the resonant
frequency varies by individual physiology, gender
and age, it is usually between four to seven breaths
per minute (BPM), with six BPM as the modal
rate. Cognitive correlates of heart rate variability
training, especially in the low frequency band, have
shown improvement in complex neurocognitive per-
formance including executive functioning. There are
portable instruments to assess and treat not only heart
rate variability but also temperature and EDR that the
athletes can use in everyday life, including during ath-
letic practice. HRV-B treatment provides an objective
measure of heart-brain connectivity impacting per-
sistent SRC, and preliminary studies by the military
and clinical researchers suggest promising efficacy in
promoting a quicker return to pre-injury status.
3. Conclusions
As noted above, there is a need for reliable and
valid diagnostic schema for identifying concussions
and diagnosing Persisting Post Concussive Syndrome
that can be adopted by all practitioners for all sports
in all geographic regions. This reliable diagnos-
tic formulation would help with understanding and
studying the phenomenon of PCS, perhaps leading
to more effective and focussed treatment. As also
noted and discussed, PCS is not an entity unto itself
and its symptoms are shared with other disorders,
particularly depression and anxiety. Consequently,
a comprehensive differential diagnostic approach
from the Bio-Psycho-Social formulation is needed to
understand not only the degree of biological injury,
but the syndrome’s manifestation based on premorbid
and comorbid psychological factors occurring within
a psychosocial context. These phenomena should be
examined for their role in prolonging presentation of
symptom degree and frequency. Not only is analysis
of secondary gain needed, but also analysis of pri-
mary gain to better understand intrapsychic, social
and family systems factors impacting the PCS pre-
sentation. Unfortunately, the specter of litigation also
must be factored in as a component that can pro-
long symptom presentation. Further, a fundamental
misunderstanding of PCS and concussions, in gen-
eral, is promulgated by the popular media and/or by
persons who may have an interest in prolonging the
symptoms, and are not cognizant of relevant, rapidly
evolving neuroscience literature. Appreciation and
attention to all of these factors can improve concus-
sion management and protect the health and safety of
Future directions should include further investiga-
tion of objective biomarkers. Evoked Potentials have
been shown to be altered for up to a year in con-
cussed collegiate athletes and may serve as a viable
biomarker (Broglio, 2009). However, not all prac-
titioners may have the availability of equipment to
measure this. A discussion of computerized testing
is out of the scope of this paper but other studies
should be consulted which elucidate the problems
with reliability and validity of such forms of adminis-
tration (Schatz & Maelender, 2013; Maelender et al,
2013; Malerlender et al, 2010). The authors would
176 A. Conder et al. / Neurorehabilitation of Persistent Sport-Related Post-Concussion Syndrome
generally advocate that computerized testing results
in and of themselves be interpreted cautiously, due
to general problems with reliability. From a philos-
ophy of science perspective, they provide one level
of data to be considered within an overall clinical
formulation undertaken and synthesized by a quali-
fied practitioner in their diagnostic decision-making.
Ultimately, the diagnosis of Persistent Sports Related
Concussion is the burden of a skilled diagnostician,
as inappropriate diagnosis of this syndrome can lead
to symptom burden and morbidity, when not neces-
sary. Going forward and guided by better research
studies, it is hoped that clinicians will be more
inclined to rely on a variety of assessment modalities,
including objective physiological and psychophysio-
logical data in addition to the clinical examination
and neurocognitive assessment, assist in diagnostic
formulation and treatment intervention development
for concussed athletes. While concussive injury is
a physiologic and neurophysiologic entity, persis-
tent sport related concussion should be recognized
as a psychophysiological entity best elucidated using
a BioPsychoSocial diagnostic formulation to guide
diagnostic accuracy and formulate treatment and neu-
rorehabilitation interventions to maximize symptom
Conflict of interest
All of the authors declare they have no conflict of
interest. No sources of funding nor outside support
was received for this project.
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... Often, re-evaluating SRCs' symptoms is insufficient during the surveillance period by medical personnel. In many cases, no follow-up treatment is applied to the patients, although they need a detailed second or ongoing evaluation with strict guidelines [14,20,21]. In other situations, patients themselves are sometimes not aware of the symptoms due to a lack of knowledge, while others want to enforce a fast discharge and return to work or sport. ...
... In particular, successful athletes may take a higher risk to conceal symptoms in order to avoid a longer break from training [1]. Long-term signs of concussions are a major cause of prolonged observation and longer hospitalization [1,14,20,21]. Depending on the type of sport, rates of persistent symptoms between 10 and 30% have been described in the literature. In particular, contact sports and younger athletes showed an increased risk [22,23]. ...
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Sports-related concussions (SRC) have developed into a highly discussed topic in sports medicine over the last few years and demonstrate a severe issue in the personalized treatment of patients. This retrospective cohort study investigated 86 patients with sports-related concussions in a level 1 trauma center, relating to the mechanism, symptoms, medical history, acute therapy including first assessment and the return to sport. The research is based on medical records as well as questionnaires six months after hospitalization. Loss of consciousness for under 30 min (41.2%), headache (36.5%) and amnesia (29.4%) were the most frequent symptoms when presenting in the emergency room. During the hospitalization, mainly headache and vertigo were documented. Most concussions occurred after incidents in equitation and cycling sports; the most common mechanism was falling to the ground with a subsequent impact (59.3%). At the time of discharge from hospital, in 13.4% of all cases, concussion symptoms were still documented in medical records, in contrast to 39.5% of the concerned athletes who reported symptoms for longer than 24 h, and 41.0% who reported ongoing post-concussion symptoms after six months. Concussions are difficult-to-treat disorders with a challenging diagnostic process and many symptoms in various values and levels of persistence. Therefore, a patient-involving treatment with a complaint-dependent return to sport process should be applied to concerned athletes.
... Knecht and Studer[5] conducted a study where they observed that neurorehabilitation even improves the overall prognosis of all critically ill patients during their rehabilitation period, irrespective of interventions performed[5]. Related to that published by Heslot et al.[1], Conde et al.[8] conducted a comprehensive review on the impact of neurorehabilitation in the management of post-concussion syndrome secondary to repetitive traumatic brain injury in athletes, finding that the neurorehabilitation plan, starts from the evaluation of the risk of neurological involvement, prediction of the pattern of neurological injury, protection and early diagnosis, as well as follow-up of the post-concussion syndrome and implementation of cognitive-behavioral therapy, psychotherapeutic interventions, education, resilience and adaptation to rehabilitation[8].As pointed out by Heslot et al.[1], there is limited evidence on cognitive rehabilitation[1], and therefore limited evidence on neurorehabilitation. In this order of ideas, it is necessary to carry out studies of better quality conformed by international collaborations, to evaluate the behavior and effect that would have on the disease burden of neurological disorders, working on the prevention, management and monitoring of neurological disorders and sequelae, especially in the post-pandemic period where it has been observed the emergence of a new condition that is postulated as a new challenge in the rehabilitation of the COVID-19 patient, the post-COVID-19 neurological syndrome[9]. ...
... Knecht and Studer[5] conducted a study where they observed that neurorehabilitation even improves the overall prognosis of all critically ill patients during their rehabilitation period, irrespective of interventions performed[5]. Related to that published by Heslot et al.[1], Conde et al.[8] conducted a comprehensive review on the impact of neurorehabilitation in the management of post-concussion syndrome secondary to repetitive traumatic brain injury in athletes, finding that the neurorehabilitation plan, starts from the evaluation of the risk of neurological involvement, prediction of the pattern of neurological injury, protection and early diagnosis, as well as follow-up of the post-concussion syndrome and implementation of cognitive-behavioral therapy, psychotherapeutic interventions, education, resilience and adaptation to rehabilitation[8].As pointed out by Heslot et al.[1], there is limited evidence on cognitive rehabilitation[1], and therefore limited evidence on neurorehabilitation. In this order of ideas, it is necessary to carry out studies of better quality conformed by international collaborations, to evaluate the behavior and effect that would have on the disease burden of neurological disorders, working on the prevention, management and monitoring of neurological disorders and sequelae, especially in the post-pandemic period where it has been observed the emergence of a new condition that is postulated as a new challenge in the rehabilitation of the COVID-19 patient, the post-COVID-19 neurological syndrome[9]. ...
... 38,45,48 A small number of athletes may also experience persisting symptoms beyond the expected recovery time. 16,31 However, ensuring timely assessment, targeted treatment, and academic adjustments may minimize the risks of the negative effects of concussion, ensure safe participation in sport, and successful return to sport and learning. 3,21,31 Notwithstanding the fact that appropriate concussion management may improve recovery, 3 nondisclosure of concussions to coaches and medical staff is commonly reported. ...
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Background Concussion nondisclosure and poor management after a concussion are a concern in Irish collegiate sports. How athletes perceive concussions and appraise their own concussion may affect their decisions and behaviors after a suspected concussion. However, this has yet to be examined in an Irish context. This study aimed to (1) establish concussion perceptions and associated anxiety in Irish collegiate athletes; (2) examine how sex, concussion, and mood disorder history influenced their perceptions; and (3) investigate factors associated with higher anxiety perceptions. Hypothesis Irish collegiate athletes will display negative concussion perceptions and anxiety related to concussion, especially in female athletes and those without a concussion history. Study Design Cross-sectional study. Level of Evidence Level 3. Methods Irish collegiate athletes [n = 268 (141 women,127 men), mean age = 21.5 ± 2.2 years] from high-risk sports completed a survey including the Perceptions of Concussion Inventory for Athletes (PCI-A), demographics, diagnosed concussion history, self-reported mood disorder history, and a concussion knowledge assessment. Differences in concussion perceptions by sex, concussion history, mood disorder history were examined using Mann-Whitney U tests, and factors associated with anxiety-related concussion perceptions were identified using multivariate logistic regression. Results Over half (53.0%, n = 142) of participants reported concerns regarding concussion. The thoughts of sustaining a concussion made participants feel upset (63.4%, n = 170), fearful (47.7%, n = 128), and anxious (35.1%, n = 94). Women reported significantly higher anxiety ( P < 0.01, r = 0.23), effects ( P = 0.04, r = 0.12), and clarity ( P = 0.01, r = 0.16) perception scores. Participants with a diagnosed concussion history displayed greater symptom variability perception scores ( P = 0.04, r = 0.12), but lower anxiety ( P = 0.03, r = 0.13) and treatment ( P < 0.01, r = 0.19) beliefs on the PCI-A. No differences were observed for those with a history of a mood disorder ( P > 0.05). A significant multivariate model was established (χ ² = 55.44, P < 0.01), with female sex [odds ratio (OR) = 1.53], concussion history (OR = 0.63), effects (OR = 1.31), and treatment (OR = 1.15) subscales associated with greater anxiety. Conclusion Concerns about sustaining a concussion are prevalent in Irish collegiate athletes. Women displayed more negative perceptions and those with a concussion history displayed fewer perceived benefits of treatment. Clinical Relevance The findings support the need for concussion awareness campaigns to provide accurate concussion information to mitigate anxiety-related concussion perceptions and injury belief misconceptions.
... However, symptoms are poor, non-specific indicators of underlying cognitive and physiological disturbances, and evidence suggests that recovery extends beyond symptom resolution. 2 Autonomic nervous system dysfunction is postulated as one factor producing clinical symptoms during recovery following mTBI. 1 Heart rate variability (HRV) (see Figure 1) is reportedly reduced following TBI. 3 A reduction in HRV following mTBI may have implications for changes in cardiac demand while performing physically arduous tasks, accelerating fatigue and worsening recovery status, in addition to reducing cerebrovascular perfusion. 4 HRV has shown promise as an objective noninvasive, clinically useful tool to monitor mTBI recovery, thereby helping to facilitate clinical decision making. ...
... It appears that physiologic recovery and clinical recovery may be related, but more research is needed in this area (14,15). Patients who experience persistent symptomology, cognitive, and/or postural stability deficits are often diagnosed with Post-Concussion Syndrome (PCS), but it is not clear if this is physiologically distinct from the initial injury (16). If physiological healing may still be occurring it is important to monitor for any potential clinical deficits beyond the initial recovery window. ...
Primary objective: The objective of this study was to examine neurocognition, postural control, and symptomology at multiple timepoints following concussion. We hypothesized that collegiate athletes would perform similar to or better than their baseline in terms of each outcome at both timepoints. Research design: This was a retrospective study of 71 collegiate athletes (18.3 ± 0.89 years old; 182.2 ± 10.05 cm; 84.2 ± 20.07 kg) to observe changes in outcomes from a previously established clinical protocol. Methods and procedures: Participants were administered ImPACT™, the Sensory Organization Test (SOT), and the revised head injury scale (HIS-r) prior to their seasons (baseline); upon reporting symptom-free following concussion (post-injury); and approximately 8-months after return-to-play to establish a new baseline. Main outcomes and results: There were no changes in ImPACT scores or HIS-r reporting over time. ImPACT total symptom score (TSS) decreased over time (p = .002, ηp2 = 0.08). Significant main effects occurred for the SOT equilibrium score (p < .01, ηp2 = 0.34) and Vestibular sensory ratio (p < .001, ηp2 = 0.22). Conclusions: Our data suggest no decline in neurocognition, balance, or symptom burden approximately eight months post-injury. As clinicians continue to explore "best practices" for concussion management and potential long-term implications of these injuries it is important to monitor outcome measures longitudinally.
The aim of this article is to provide an up-to-date review of psychological changes in association with postconcussive athletes. In particular, this article focused on the symptomatology, risk factors, and treatment of psychiatric diagnoses in patients who suffered a sports-related concussion (SRC). After an extensive review of prior and current literature, there is significant evidence that demonstrates an association of changes in mood and behavior, including new or worsening symptoms of anxiety, depression, and difficulty with attention and concentration in those who are recovering from a concussion. The goal of care in these patients is to identify and treat these psychological symptoms early to have more favorable long-term outcomes. Primary treatment should focus on psychotherapy; however, other considerations may be warranted in certain cases, such as selective serotonin reuptake inhibitors for depression and tricyclic antidepressants and gabapentin for short-term cognitive symptom improvement.
Purpose of review: This review provides the reader with an overview of concussion and mild traumatic brain injury (TBI). Key aspects of the pathophysiology, signs, and symptoms, treatment and rehabilitation, and recovery from concussion/mild TBI are reviewed with an emphasis on the variety of factors that may contribute to cognitive concerns following injury. Recent findings: Concussion remains a clinical diagnosis based on symptoms that occur in the immediate aftermath of an applied force and in the hours, days, and weeks thereafter. Although advances have been made in advanced diagnostics, including neuroimaging and fluid biomarkers in hopes of developing objective indicators of injury, such markers currently lack sufficient specificity to be used in clinical diagnostics. The symptoms of concussion are heterogeneous and may be seen to form subtypes, each of which suggests a targeted rehabilitation by the interdisciplinary team. Although the majority of patients with concussion recover within the first 30 to 90 days after injury, some have persistent disabling symptoms. The concept of postconcussion syndrome, implying a chronic syndrome of injury-specific symptoms, is replaced by a broader concept of persistent symptoms after concussion. This concept emphasizes the fact that most persistent symptoms have their basis in complex somatic, cognitive, psychiatric, and psychosocial factors related to risk and resilience. This framework leads to the important conclusion that concussion is a treatable injury from which nearly all patients can be expected to recover. Summary: Concussion/mild TBI is a significant public health problem in civilian, military, and organized athletic settings. Recent advances have led to a better understanding of underlying pathophysiology and symptom presentation and efficacious treatment and rehabilitation of the resulting symptoms. An interdisciplinary team is well-positioned to provide problem-oriented, integrated care to facilitate recovery and to advance the evidence base supporting effective practice in diagnosis, treatment, and prevention.
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Introduction. Vestibular rehabilitation (VR) represents an evolving area of physical therapy practice and is therefore pertinent to entry-level education. Currently, there is no consensus regarding the extent of content that should be covered in entry-level Doctor of Physical Therapy (DPT) programs. The first step in establishing standards of education in VR is to determine what content is currently taught and what is perceived to be important. The purpose of this study was to survey entry-level DPT programs as to what VR content is included in their curriculum and their perceptions of importance of VR examination and intervention techniques. Methods. Directors of 229 accredited physical therapy education programs in the United States were contacted to complete the survey. A task force of 3 clinicians and 4 faculty used a modified Delphi process to select survey items to examine content exposure, student assessment, and a rating for overall expected expertise. Modifications were made to the final survey for clarity and time requirements based on pilot survey data. Descriptive and correlational statistics were applied to the data. Results. Ninety-nine programs (43.23%) responded to the survey. More than 90% rated 7 vestibular conditions (unilateral vestibular hypofunction, posterior semicircular canal canalithiasis and cupulolithiasis, vestibular neuritis, labyrinthitis, bilateral vestibular hypofunction, and horizontal semicircular canal canalithiasis) as essential for entry-level practice. More than 90% of respondents rated all elements of clinical application and decision-making as essential for entry-level education except for billing/diagnosis codes. Most respondents expected students to perform at the intermediate or advanced beginner level in vestibular assessment and rehabilitation on graduation. Discussion and Conclusion. Disparities in VR content, expected level of performance, and the amount of time dedicated to VR exist. Vestibular rehabilitation education may not match current clinical practice. Future research should determine the level of education clinicians expect of entry-level DPT graduates.
Conference Paper
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Pancreatic cancer presents a unique challenge for the development of effective oncotherapies. The tumor microenvironment (TME) of this type of tumor typically contains a dense desmoplastic barrier composed of aberrant extracellular matrix proteins, as well as an acidic hypoxic and necrotic core. Additionally, the immune system surrounding this type of tumor has often been suppressed by the TME. Hence, choosing the correct model of the tumor microenvironment within which to test a potential anti-cancer therapy is a critical experimental design decision. While the typical solid tumor contains a complex microenvironment including both phenotypic and genotypic heterogeneity, the methods used to model this disease state often do not reflect this complexity. This simplistic approach may have contributed to stagnant five-year survival rates experienced over the past four decades. Oncolytic bacteria, a class of bacteria with the innate ability to seek and destroy solid tumors has been revived from historical anecdotes in an attempt to overcome these challenges. Regardless of the promise of oncolytic bacteria, accurate assessment of their potential requires choosing the proper tumor model. This study explores the impact of cancer cell lines co-cultures with Wild-Type C. novyi to establish the efficacy of this oncolytic bacteria in a monolayer culture.
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Background and objectives: This paper addresses psychological resilience, a multidisciplinary theoretical construct with important practical implications for health sciences. Although many definitions have been proposed in several contexts, an essential understanding of the concept is still lacking up to now. This negatively affects comparisons among research results and makes objective measurement difficult. The aim of this review is to identify shared elements in defining the construct of resilience across the literature examined in order to move toward a conceptual unification of the term. Materials and methods: A literature review was performed using the electronic databases ‘PubMed’ and ‘PsycINFO’. Scientific studies written in English between 2002 and May 2019 were included according to the following key terms: ‘Psychological’, ‘resilience’, and ‘definition’. Results: The review identifies five macro-categories that summarize what has been reported in the recent literature concerning the resilience phenomenon. They serve as a preliminary and necessary step toward a conceptual clarification of the construct. Conclusions: We propose a definition of psychological resilience as the ability to maintain the persistence of one’s orientation towards existential purposes. It constitutes a transversal attitude that can be understood as the ability to overcome the difficulties experienced in the different areas of one’s life with perseverance, as well as good awareness of oneself and one’s own internal coherence by activating a personal growth project. The conceptual clarification proposed will contribute to improving the accuracy of research on this topic by suggesting future paths of investigation aimed at deeply exploring the issues surrounding the promotion of resilience resources.
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Aim: Postconcussion symptom-rating scales are frequently used concussion assessment tools that do not align directly with new expert, consensus-based concussion subtype classification systems. This may result in delays in concussion diagnosis, subspecialty referral and rehabilitative strategies. Objective: To determine the representation of subtype-directed symptomatology in common postconcussion symptom-rating scales. Methods: Literature review and expert consensus were used to compile commonly used concussion symptom-rating scales. Statistics were generated to describe the degree of representation of the consensus symptom set. Results: The percentage of symptoms representing each subtype/associated condition is low overall (15-26%). The ocular-motor (11%) and vestibular subtypes (19%) and cervical strain (5%)-associated condition were the most under-represented and also had the greatest unmet needs. Conclusion: Concussion subtypes do not have equal representation on commonly used concussion symptom-rating scales. There is a need for a subtype-directed symptom assessment to allow for increased accuracy of diagnosis and to guide management.
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Sport-related concussion (SRC) is a physiological brain injury that produces cerebral and systemic effects, including exercise intolerance. Exercise intolerance after concussion is believed to be the result of autonomic nervous system (ANS) dysfunction. Ventilation is inappropriately low for the level of exercise intensity, raising arterial carbon dioxide (PaCO2) levels. Elevated PaCO2 increases cerebral blood flow (CBF) out of proportion to exercise intensity, which is associated with symptoms that limit exercise performance. Thus, elevated exercise PaCO2 may signal incomplete recovery from SRC. This article reviews recent observational and experimental data and presents the evidence that subthreshold aerobic exercise normalizes the cerebrovascular physiological dysfunction and is "medicine" for patients with concussion and persistent postconcussive symptoms (PPCS). It discusses the systematic evaluation of exercise tolerance after concussion using the Buffalo Concussion Treadmill Test (BCTT) and reviews the utility of the Buffalo Concussion Bike Test (BCBT), the data from which are used to establish an individualized heart rate "dose" of subthreshold exercise to safely speed recovery, which also may work in the acute recovery phase after SRC with the potential to reduce the incidence of PPCS. Evaluation and treatment approaches based on the physiology of concussion suggest that exercise is medicine for concussion, potentially adding a new dimension to concussion care to help safely speed recovery and prevent PPCS in some patients.
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Third edition of the International Classification of Headache Disorders
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Background: Recent evidence suggests that autonomic nervous dysfunction may be one of many potential factors contributing to persisting post-concussion symptoms. Objective: This is the first systematic review to explore the impact of concussion on multiple aspects of autonomic nervous system functioning. Methods: The methods employed are in compliance with the American Academy of Neurology (AAN) and PRISMA standards. Embase, MEDLINE, PsychINFO, and Science Citation Index literature searches were performed using relevant indexing terms for articles published prior to the end of December 2016. Data extraction was performed by two independent groups, including study quality indicators to determine potential risk for bias according to the 4-tiered classification scheme of the AAN. Results: Thirty-six articles qualified for inclusion in the analysis. Only three studies (one Class II and two Class IV) did not identify anomalies in measures of ANS functioning in concussed populations. Conclusions: The evidence supports the conclusion that it is likely that concussion causes autonomic nervous system anomalies. An awareness of this relationship increases our understanding of the physical impact of concussion, partially explains the overlap of concussion symptoms with other medical conditions, presents opportunities for further research, and has the potential to powerfully inform treatment decisions.
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Background: Concussion is one of the most common injuries in athletes. Current concussion consensus statements propose that female sex may be a modifying factor in concussion management and recovery. Objective: To determine whether female athletes in middle school and high school with a first-time, sports-related concussion remained symptomatic longer than their male counterparts. Methods: A retrospective medical record analysis was performed among athletes who sustained a concussion between 2011 and 2013. Inclusion criteria consisted of age between 11 and 18 years and diagnosis of first-time concussion sustained while playing organized sports. Using the documented notes in the medical record, length of time that each athlete was symptomatic from his or her concussion was calculated. Results: A total of 110 male and 102 female athletes (N=212) met the eligibility criteria for the study. A significant difference was found in the median number of days female athletes remained symptomatic (28 days) when compared with male athletes (11 days) (P<.001). No statistically significant difference was found in symptom duration between age groups. When matched for sex, no statistically significant differences were found in symptom duration between the type of sports played. Conclusion: Female athletes aged 11 to 18 years with first-time, sports-related concussions remained symptomatic for a longer period when compared with male athletes of similar age, regardless of sport played. The mechanism behind this difference needs to be further elucidated.
Objective: The purpose of this study was to compare adolescent students with and without concussion on a battery of academic, neurocognitive, and socioemotional measures and assess the aftereffects of concussion across domains of functioning. Methods: Twenty-four adolescents (ages 13-17) reporting postconcussion symptoms were compared to 24 controls matched for age and gender across a battery of tests and surveys. Results: After correcting for multiple comparisons, there were no significant differences on any neuropsychological measures. Similarly, there were no significant group differences on academic measures of vocabulary, word recognition, or reading comprehension. Self-reported concussion symptoms were much greater for students with concussion, as were self-reports of anxiety, depression, and somatization symptoms. Parents also rated those with concussion as having greater depression and somatization symptoms, but not to a degree that survived Bonferroni correction. Lastly, those with concussion reported a significantly greater number of school problems and academic concerns. Conclusions: Results indicated that adolescents who reported postconcussion symptoms do not perform differently from peers on most neurocognitive and academic tasks, yet they showed considerably more worry, somatization, academic concerns, and feelings of inadequacy than matched controls. The findings suggest that interventions to address psychological and academic stress may be indicated for adolescents symptomatic from concussion.
Sport-related concussion (SRC) is a heterogeneous injury that involves varied symptoms and impairment that presents a significant clinical challenge to sports medicine professionals. In response to this challenge, clinical researchers have proposed clinical profiles or subtype models for assessing and treating athletes with SRC. One such model emphasizes five concussion clinical profiles including cognitive/fatigue, vestibular, ocular, migraine, and anxiety/mood. Sleep is a common modifier that co-occurs across these clinical profiles. A combination of medical history, risk factors, injury information, clinical characteristics, and assessment outcomes can inform each clinical profile. Preliminary data involving 236 patients from a concussion specialty clinic indicate that the migraine (26%) and anxiety/mood (24%) profiles are the most common, with vestibular and ocular profiles combined representing more than one third (35%) of clinical profiles. Findings also support several relationships among different clinical profiles including vestibular and migraine, suggesting that many athletes present with multiple clinical profiles. Targeted, active treatments for each profile are discussed.