Brain Injury, July 2006; 20(8): 799–806
Symptoms and disability until 3 months after mild TBI
A. LUNDIN1, C. DE BOUSSARD2, G. EDMAN1, & J. BORG3
1Department of Psychiatry,2Department of Rehabilitation Medicine, Karolinska Institutet, Danderyd Hospital,
Stockholm, Sweden, and3Department of Neuroscience, Rehabilitation Medicine, Uppsala University Hospital,
(Received 13 July 2005; accepted 8 April 2006)
Objective: Examine frequency, character and course of symptoms until 3 months after MTBI and the relation between
symptoms and disability.
Methods: Prospective cohort study of 122 consecutive patients with MTBI. Symptom assessment after 1, 7 and 14 days and
3 months post-injury by use of Rivermead Post-concussional Questionnaire. Disability assessment by use of Rivermead
Head Injury Follow-up Questionnaire.
Results: Patients reporting one or more symptoms declined from 86% on day 1 to 49% 3 months post-injury, when 25% also
reported change in one or more domains of everyday activities. Poor memory, sleep disturbance and fatigue were most
commonly reported. Symptom and disability scores were correlated (? ¼0.60; p<0.001). Early symptom load correlated
with late symptom load (? ¼0.38; p<0.01).
Conclusions: Symptoms gradually decline post-injury. Symptoms correlate with disability at 3 months. Patients with early
high symptom load are at risk for developing persisting complaints.
Keywords: Mild TBI, symptoms, disability
Data on the prevalence, character and risk factors for
persisting symptoms and disability after mild trau-
matic brain injury (MTBI) are inconsistant [1, 2].
This might reflect variations with regard to study
settings and designs and probably explains the
currently weak evidence base for intervention to
prevent or treat persisting complaints [3, 4].
Almost all MTBI patients report symptoms
such as headache and forgetfulness in the early
phase after the injury [4, 5]. In the majority of
patients, these symptoms resolve within 3 months
[6, 7]. A sub-group of patients report persisting
symptoms at 3 months and later, such as head-
ache [5, 8–10], dizziness [8, 10], concentration
difficulties [5, 11, 12] and fatigue [5, 13, 14]. In
have occurred or exacerbated after the injury,
24–60% of MTBI patients report one or more
such symptoms at 3 months or later after the
injury [5, 10, 12]. Some of this variation is
probably relatedto methodological
inherent in studies of MTBI, such as different
case definitions, different outcome measures and
insufficient control of confounding factors .
The concept of a ‘post-concussional syndrome’,
used inmany reports
DSM-IV, has been questioned due to lack of
consistency of the symptom constellation , lack
of intervention data supporting a common under-
lying mechanism  and unspecificity of the
andthus assessingsymptoms that
Correspondence: Dr Anders Lundin, MD, Psychiatric clinic, R&D section, Karolinska Institutet, Danderyd Hospital, 182 87 Danderyd, Sweden.
Tel: 46-8-6555852. Fax: 46-8-7533421. E-mail: firstname.lastname@example.org
ISSN 0269–9052 print/ISSN 1362–301X online ? 2006 Informa UK Ltd.
with other injuries , in chronic pain patients
[16, 17] and in the general population .
Recent studies have also demonstrated different
outcome when the suggested DSM-IV criteria as
compared to the ICD-10 criteria are applied .
While several studies have reported persisting
symptoms after MTBI, only a few studies have
investigated the relationship between symptoms and
measures of disability. The Rivermead Head Injury
shown to be a simple and reliable disability measure
across the entire range of severity, but particularly
after mild-to-moderate head injury . Studies of
the relation between self-reported symptoms and
disability are important as a basis for an appro-
priate definition of poor outcome after MTBI, a
pre-requisite for studies of prognostic factors. The
aim of the present study was, therefore, to examine
the character, frequency and course of persisting
symptoms and their relation to disability in everyday
activities in a prospective cohort of surgically
uncomplicated MTBI patients until 3 months after
Subjects and methods
Inclusion and exclusion criteria
Inclusion required a history of blunt head trauma,
loss of consciousness (LOC) and/or post-traumatic
amnesia (PTA), admission to hospital within 24
hours after the trauma, a Glasgow Coma Scale
(GCS) score of 14–15 at first assessment in the
emergency department and an age of 15–65 years.
Exclusion criteria were
LOC>30 minutes, PTA>24 hours, other signifi-
cant physical injury or other major neurological
disorder, including previous significant head injury.
No financial incentives were offered for participants
and no specific intervention was attached to the
any of thefollowing:
Study setting and study sample
Patients were recruited from three emergency
Stockholm, Sweden, between January 2000 and
December 2001. The total catchment area for the
three emergency departments has about 800000
inhabitants aged 15–65 years. Mean age in the area
is 38 years and ?51% are women. Stockholm is
the capital of Sweden with a high percentage of
employment in white collar professions. Thirty-eight
per cent of the population between 15–65 years
of age have an education exceeding 12 years;
the corresponding figure for the total Swedish
population is 26%.
central and north
Recruitment was non-systematically interrupted
and covered in total 20 months at Danderyd
Hospital and 3–6 months in the two other hospitals
MTBI patients were consecutively considered for
inclusion. In total, 122 patients with MTBI fulfilled
inclusion criteriaand gave
The majority (75 patients) was recruited from
Danderyd Hospital, where detailed data on numbers
and reasons for non-participation were collected
during a 3 month period (from February to April
2001). During this period, 27% of the eligible
patients agreed to participate. Most common rea-
sons given for non-participation were lack of time
and lack of interest and motivation for the follow-up
program. Age and gender did not differ between
participants, hospitalization rate was 53%; CT scan
was performed in 60% of the cases, none of which
was abnormal. Of the participants 80% had been
hospitalized and 93% underwent a CT scan, 7% of
which were abnormal.
Patients with high velocity traumas were managed
according to a regional trauma protocol and were,
thus, not available for the study.
Seventy-one men (58%) and 51 (42%) women
fulfilled the inclusion criteria and volunteered to
participate in a follow-up study, including sex
assessment sessions, a CT scan and an MRI brain
scan. According to current routines, most patients
(80%) were hospitalized after admission for observa-
Withdrawal during study
Twenty patients (16%) dropped out from the study
during the first 3 months. Dropouts were compared
to non-dropouts with respect to age, gender,
hospital, education, occupation, PTA, LOC, initial
symptom severity, previous psychiatric history and
alcohol intoxication at admission. Dropouts did not
differ in any variable except for significantly fewer
years of education (mean difference 2.3 years).
Thirty-five subjects without injury, in good health
according to self-report and working in different
professions (25% health care workers) or studying
(14%) were recruited by means of local advertise-
ment for symptom assessment at three occasions
(a first visit, after 14 days and 3 months). Symptom
ratings were averaged over visits to obtain a robust
measure of symptom intensity in individuals not
A. Lundin et al.
exposed to head trauma. No time effects were
analysed as no head trauma had occurred.
GCS score, duration of LOC, PTA and retrograde
amnesia and results from breath alcohol test results
were recorded by the emergency ward staff accord-
ing to the study protocol. The emergency depart-
ments were checked for head injury patients by the
research group staff every day of the week. Included
patients were assessed after 1, 7 and 14 days and at
3 months post-injury.
reassessed by one of the authors (AL) during the
first week after the injury and revised if additional or
divergent information was reliably obtained by use of
data not available at the initial assessment. CT scan
of the brain was performed within 24 hours after the
trauma and an MRI scan of the brain was performed
within 1 week (mean 7.4 days).
Ratings of symptoms and disability
concussional Questionnaire (RPQ)  and the
Rivermead Head Injury Follow-up Questionnaire
assessment instruments ask the patient to state
change in symptom level and in social and occupa-
tional functioning, respectively, and have been
shown to reliably measure change in frequency and
severity of post-concussional symptoms and disabil-
ity after head injury of mild-to-moderate severity.
The RPQ score was calculated, as described by King
et al.  as the sum of all symptom scores
excluding ratings of 1, as these indicated that
symptoms had resolved. Mild symptoms were
scored as 2, moderate as 3 and severe as 4. RPQ
was administered at all occasions and RHFUQ at 3
months only. Symptoms in healthy controls were
assessed with the same instruments. The controls
were asked to state frequency and severity of
occurred. Number of sick listing days was also
registered as an additional measure of disability.
versionsof the RivermeadPost-
no head traumahad
descriptive statistics (means, SDs, frequencies).
Differences in discrete variables (e.g. sex and
education level) were analysed with the ?2-method
(Fisher’s exact test in case of expected cell frequen-
cies less than 6). Differences in continuous variables
were analysed with non-parametric Mann-Whitney
(independent comparisons) or Wilcoxon matched
distributions were positively skewed.
variableswere summarizedwith standard
The factor structure of the two rating scales, RPQ
and RHFUQ, was investigated with a principal
number of factors extracted was identical to the
number of eigenvalues greater than or equal to 1.0.
Analysis of the RPQ data was made for symptoms
reported at day 1. Analysis of the RHFUQ data was
made for disability reported at 3 months. The factor
analyses were only performed on the ratings of the
All comparisons were two-tailed with a signifi-
cance level of 5%.
The study was approved by the ethics committee.
Informed consent was obtained from all participat-
ing patients and controls.
Sociodemographic and clinical characteristics
There were no statistically significant differences
between patients and controls with regard to age,
sex, years of education or occupational status. The
most common cause for MTBI was fall (59%). Of
traffic accidents (19%), bicycle accidents were most
common. Alcohol intoxication was present in 25%.
In 7% of the patients signs of traumatic, intra-cranial
lesion on CT or MRI scan were found. Complete
data are presented in Table I.
Symptom character, frequency and course
Poor memory, sleep disturbance and fatigue were
the most commonly reported post-injury symptom
changes after 3 months, when frequency as well as
intensity were taken into account. At days 1, 7 and
14, respectively, 86, 74 and 56% of the patients
reported one or more MTBI-related symptoms. At 3
months, 49% of the patients reported at least one
such symptom. Reported symptoms and total RPQ
scores at 3 months are presented in Table II.
A principal component analysis of the symptoms
reported at day 1 yielded a four factor solution—
somatic (headache, dizziness, nausea/vomiting and
fatigue), cognitive (taking longer to think, poor
concentration and poor memory), affective (feeling
frustrated, restlessness, sleep disturbance, irritability
and feeling depressed) and a fourth ‘vision-related’
(blurred vision, double vision, sensitivity to light)
together with noise sensitivity, with a somewhat
weaker loading. This factor solution explained 66%
of the total matrix variance. The factor structure
period. The factor analysis is presented in Table III.
The course from day 1 to 3 months varied
between symptoms (see Figure 1). Some symptoms
Symptoms and disability until 3 months after mild TBI
(headache, fatigue, taking longer to think, dizziness,
sensitivity to light and nausea/vomiting) decreased
markedly from day 1 to the assessment at 3 months.
Other symptoms (sleep disturbance, poor concen-
tration, noise sensitivity, feeling frustrated, blurred
vision and double vision) decreased less, whereas a
few symptoms (irritability, restlessness and poor
memory) increased during the 3 months follow-up.
patients and controls was not feasible as the pre-
requisites for assessment were different—MTBI
patients assessed change from baseline, whereas
controls assessed symptoms at baseline. The most
obvious differences, however, between patients and
controls at 3 months were the higher frequency of
noise sensitivity, dizziness, blurred vision and slow-
ness of thought in the MTBI group. The rank order
of symptom intensity in MTBI patients differed from
that in healthy controls, where sleep disturbance and
headache had the highest load (see figure 1).
The course of symptoms within the four different
load. Somatic symptoms were initially more promi-
nent but declined faster than symptoms in the other
factors, resulting in a similar symptom load for
somatic, cognitive and affective factors at 3 months.
Vision-related symptoms were less prominent and
reported by few patients only. High symptom load
at day 1 was significantly correlated with high
symptom load at 3 months (? ¼0.38; p<0.01).
The course of symptoms are presented in Figure 2.
Symptoms and disability
A factor analysis of the functional disability assessed
with RHFUQ at 3 months yielded two factors,
Table I. Sociodemographic and clinical characteristics of MTBI
patients (n¼122) and controls (n¼35).
Characteristic MTBI patientsControls
Gender, n (%)
Occupation, n (%)
Type of accident, n (%)
Fall (from height)
Fall (same level)
Intoxicated by alcohol
GCS at first examination, n (%)
Injury-related CT and/or
MRI abnormalities, n (%)
Loss of consciousness, n (%)
Anterograde amnesia, n (%)
Retrograde amnesia, n (%)
*Other types of accidents were collision with other person (6; in
sports), hit by falling objects (6), run into objects (3), kicked by
Table II. Number and proportion of MTBI patients and controls
with symptoms after 3 months according to RPQ.
Taking longer to think
Sensitivity to light
RPQ total score
of symptoms (SD)
9 17 17
6.5 (11.28) 3.9 (7.02)
aAt 3 months post-injury.
bAverage rate (for further description, see text) (NB patients
report change in symptom load after MTBI whereas controls
report symptom load independent of head injury).
A. Lundin et al.
which explained 75% of the total matrix variance.
The first factor—‘activity factor’—embraced social
and professional activities outside the family and the
second factor—‘relation factor’—had reference to
closer relations, e.g. family and friends. Four items
had significant loadings, i.e. correlations, with more
than one factor and were, thus, insufficiently
separated by the factors. The only items that were
satisfactorily separated were item 5 (‘previous
leisure activities’) and item 9 (‘relationship with
partner’). The factor analysis is presented in
At 3 months, 25% of the patients reported
dysfunction in at least one domain of everyday life,
such as work, relations and social and leisure
activities. Subjects with high total RPQ also tended
to have high total RHFUQ (? ¼0.60; p<0.001).
The four symptom factors (somatic, affective,
cognitive, vision-related) showed similar correlation
with the two disability factors (relations, activity)
(? ¼0.23–0.42, p<0.01) with a marginally higher
correlation between the affective factor and the
relation factor as compared to the activity factor
(0.42 vs. 0.33) and vice versa for the somatic factor
(0.23 vs. 0.34).
Duration of sick-listing was less than 10 days in
76% of the patients, 10–30 days in 20% and more
than 30 days in 4% of the patients. After 3 months
only one person of those in labour force had not
returned to his job. Patients with sick-listing more
than 10 days had significantly higher total symptom
ratings than those with sick-listing less or equal to 10
days at all assessment occasions and for all symptom
Factor analysis yielded four symptom domains: a
somatic, a cognitive, an affective and a vision-related
domain. Somatic symptoms predominated in the
early phase but at 3 months somatic, cognitive and
affective symptoms had similar weight, whereas
vision-related symptoms were reported by only few
individuals and had lower total impact. Similar
findings have been reported in previous studies at
follow-up, but to the authors’ knowledge the early
time course of symptom constellations has not
previously been demonstrated. These findings are
roughly in agreement with one prior study of 71
MTBI patients at 10 days post-injury by Bohnen
et al.  in which a principal component analysis
of the symptoms yielded a two factor solution with
one post-concussive-cognitive and one emotional-
vegetative factor. The persistence of the factor
structure throughout the observation period in this
study indicates that symptom domains might be a
meaningful variable when categorizing outcome
The vast majority (86%) of the MTBI patients
reported one or more symptoms the day after the
injury and about half reported at least one persisting
symptom at 3 months after the injury. The most
prominent symptoms experienced after 3 months
were poor memory, sleep disturbance and fatigue.
This corresponds well with the findings of the
original studies with the RPQ, in which fatigue,
irritability, frustration and poor memory were the
most prevalent symptoms at 6 months [13, 14].
The findings differ, however, from other studies
reporting headache, dizziness, fatigue and difficulty
in concentration ; headache, irritability and
dizziness ; headache, decreased energy and
dizziness ; concentration problems and restless-
ness  or headache and concentration difficulties
 as the most common symptoms at follow-up.
One reason for this discrepancy might be that RPQ
assesses change in symptoms, whereas other studies
use assessment instruments capturing total symptom
load which, at least theoretically, is a combination of
Table III. Four factor structure of MTBI symptoms rated
at day 1. Factor loadings in italics indicate the highest factor
loading for that variable and those which are underscored
a significant loading (>0.40). The proportion of explained
variance for a variable is expressed as a communality index (h2).
SymptomI II III IV
Sensitivity to light
Taking longer to think
* Loadings in italics indicate the highest factor loading/correlation
for that variable and those which are underscored a significant
loading (>0.40). The proportion of explained variance for a
variable is expressed as a communality index (h2).
Symptoms and disability until 3 months after mild TBI