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Neurofeedback Therapy of Attention Deficits in Patients with Traumatic Brain Injury

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  • Neurozentrum Arabellapark

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Background. Impairments of attention are a frequent and well documented consequence of head injury. The purpose of this study was to evaluate if Neurofeedback Therapy (NFT) can enhance remediation of attention deficits in patients with closed head injuries (CHI) who are still in the phase of spontaneous recovery.Method. Feedback of beta-activity (13–20 Hz) was used for the treatment of attentional impairments in twelve patients with moderate closed head injuries. A matched control group of nine patients was treated with a standard computerized training. All patients were tested before and after treatment with a set of attention tests.Results. After ten sessions the analyses of beta activity showed that eight patients were able to increase their beta activity while the remaining four patients showed a decrease of beta activity. Mean duration of beta activity was prolonged about 50% after training. Patients who received NFT improved significantly more in the attention tests than control patients.Conclusion. The results suggest that neurofeedback is a promising method for the treatment of attentional disorders in patients with traumatic brain injuries. It is suggested that NFT should focus not only on the enhancement of beta activity, but also on the duration patients are able to hold beta activity. It is proposed to use NFT also with patients in the early phase of rehabilitation.
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Neurofeedback Therapy
of Attention Deficits in Patients
with Traumatic Brain Injury
Ingo Keller, PhD
ABSTRACT. Background. Impairments of attention are a frequent and
well documented consequence of head injury. The purpose of this study
was to evaluate if Neurofeedback Therapy (NFT) can enhance remed-
iation of attention deficits in patients with closed head injuries (CHI)
who are still in the phase of spontaneous recovery.
Method. Feedback of beta-activity (13-20 Hz) was used for the treat-
ment of attentional impairments in twelve patients with moderate closed
head injuries. A matched control group of nine patients was treated with
a standard computerized training. All patients were tested before and af-
ter treatment with a set of attention tests.
Results. After ten sessions the analyses of beta activity showed that
eight patients were able to increase their beta activity while the remaining
four patients showed a decrease of beta activity. Mean duration of beta ac-
tivity was prolonged about 50% after training. Patients who received NFT
improved significantly more in the attention tests than control patients.
Conclusion. The results suggest that neurofeedback is a promising
method for the treatment of attentional disorders in patients with trau-
matic brain injuries. It is suggested that NFT should focus not only on the
enhancement of beta activity, but also on the duration patients are able to
hold beta activity. It is proposed to use NFT also with patients in the
early phase of rehabilitation. [Article copies available for a fee from The
Haworth Document Delivery Service: 1-800-342-9678. E-mail address:
<getinfo@haworthpressinc.com> Website: <http://www.HaworthPress.com>
2001 by The Haworth Press, Inc. All rights reserved.]
Ingo Keller has been Head of the Department of Neuropsychology, Neurological
Clinic in Bad Aibling, Germany since 1994. He is a member of the German Neuro-
psychological Association and the German Association of Neurotraumatology and
Clinical Neuropsychology.
Address correspondence to: Ingo Keller, Department of Neuropsychology, Neuro-
logical Clinic, Kolbermoorer Strasse 72, D-83043, Bad Aibling, Germany.
Journal of Neurotherapy, Vol. 5(1/2) 2001
2001 by The Haworth Press, Inc. All rights reserved. 19
KEYWORDS. Attention deficit, closed head injury, neurofeedback
therapy, rehabilitation
INTRODUCTION
Since the first publication by Conkey (1938), it is well documented
that one major consequence of brain injury is an impairment of atten-
tion. A manifestation of this impairment is a reduction of information
processing speed, reflected in lengthened reaction times, which has of-
ten been reported for injuries of different aetiologies (Miller, 1970; Van
Zomeren & Deelman, 1976; Brouwer, 1985; Braun, Daigneault & Cham-
pagne, 1989; Tartaglione, Inglese, Bandini, Spandavecchia, Hamsher &
Favale, 1991; Keller, Schlenker & Pigache, 1995). In addition to im-
paired information processing speed, many studies have shown deficits
of divided attention (Miller, 1970; Gronwall & Sampson, 1974; Van
Zomeren & Deelman, 1976; Levin, High, Goldstein & Williams, 1988;
Keller, 1998) and of sustained attention (Cohen, Semple, Gross, Holcomb,
Dowling & Nordahl, 1988; Deutsch, Papanicolaou, Bourbon & Eisenberg,
1988; Levin et al., 1988; Parasuraman, Mutter & Molloy, 1991), mainly
in patients with closed head injuries (CHI).
There is good evidence that attentional impairments in head injured
patients are connected to specific changes in the electroencephalogram
(EEG). Thatcher, Biver, McAlaster and Salazar (1998) compared data
from conventional magnetic resonance tomography (MRT) with EEG
coherence in two independent groups of patients with closed head in-
jury. The analysis showed that lengthened 1H T2 relaxation times of the
cortical gray and white matter were related to decreased EEG coherence
between short interelectrode distances (e.g., 7 cm) and increased EEG
coherence between long interelectrode distances (e.g., 28 cm). Differ-
ences in EEG frequency in which T2 relaxation time was most strongly
related to the gray matter in the delta and theta frequencies in CHI pa-
tients, and increased T2 relaxation time and decreased short-distance
EEG coherence were related to reduced cognitive function. The results
were interpreted in terms of reduced integrity of protein/lipid neural
membranes and the efficiency and effectiveness of short- and long-dis-
tance neural synchronization following traumatic brain injury.
Hoffman, Stockdale, Hicks and Schwaninger (1995) proposed that
changes in coherence and phase-shift of the EEG in patients mainly lead
to a decrease of multi-tasking and slowing of mental processing. One
reason for these abnormalities of the EEG are axonal injuries which
20 JOURNAL OF NEUROTHERAPY
produce a diffuse slowing of the EEG with an enhancement of slow
theta (4-7 Hz) activity and suppression of fast beta (13-20 Hz) activity
(Schaul, 1998).
There are several studies showing that Neurofeedback Therapy (NFT)
can improve cognitive and emotional deficits in patients with mild head
injury. Ayers (1993) compared 12 patients treated with NFT and psy-
chotherapy with a group of six patients exclusively treated with psycho-
therapy. The patients in this study were trained to enhance beta (15-18
Hz) while suppressing the slower theta (4-7 Hz) activity. Individuals
who received only psychotherapy did not improve in symptomatology,
whereas patients who received NFT with psychotherapy had symptom-
atology subside and reported progress in therapy. Byers (1995) trained a
58-year-old female with a mild traumatic head injury with NFT. The
treatment consisted of 31 sessions designed to enhance the sensori-
motor rhythm of 12-15 Hertz and the beta (15-18 Hz) frequency bands
of the EEG while at the same time suppressing the theta (4-7 Hz) fre-
quency band. Efficiency of the NFT was supported with neuropsy-
chological evaluations and quantified electroencephalograms (QEEG).
The comparison of the pre- and post-measures as well as the process
measures showed several improvements. Especially tests on cognitive
flexibility and executive functioning improved significantly after NFT.
Hoffman and Stockdale (1996) treated 50 patients with mild traumatic
brain injury beyond the time interval when one would expect treatment
changes to be attributed to spontaneous recovery. They tracked 24
physical, emotional and cognitive symptoms at regular intervals and
observed significant improvements in 78 percent of the patients.
The NFT procedures used in most of these studies were designed to
enhance the EEG frequency band in the range of 12-20 Hz while at the
same time suppressing a slower frequency band in the range of 4-8 Hz.
However, none of these studies was designed for patients admitted to
an inpatient neurorehabilitation program defined as an interdisciplinary
approach for the intensive remediation of motor-deficits as well as defi-
cits of language, cognition and psychological functions. Although most
patients with brain injuries suffer from deficits of attention, none of the
previous studies focused on attentional impairments. Therefore, the
purpose of the present investigation was to determine if NFT can also
enhance remediation of attention deficits in CHI patients who are still in
the phase of spontaneous recovery. Since patients in the early phase of
recovery from a head trauma are not able to perform complex tasks, the
feedback procedure was made as simple as possible providing a training
to enhance beta activity only.
Scientific Articles 21
METHODS
Patients
All patients were recruited from the Neurological Clinic Bad Aibling,
Germany. The sample included 21 moderate CHI patients (mean age:
31.9, range 21 to 42 years; mean years of education: 13.4, range 9 to 18
years). Severity of brain damage was classified with the initial Glasgow
Coma Score (GCS, Teasdale and Jenett, 1974). The mean GCS was
11.8 (range 7 to 12). Computerized tomography (CT) scans showed the
following lesions: bilateral haematoma (4), frontoparietal haematoma
(5), temporal lobe contusions (7), frontotemporal contusions (13) and
bilateral contusions (8). The CT scans of the remaining eight CHI pa-
tients were normal. It can be assumed that as a result of traumatic rota-
tion and white matter shearing, all CHI patients were likely to have
suffered diffuse brain damage which is known to disconnect neural
transmission. Except one, none of the patients sustained lesions of the
midbrain or brainstem. For all patients, the mean injury-to-test interval
was 3.8 months (range one to eight months), the mean duration of
posttraumatic amnesia (PTA) was 6 days (range 5 minutes to 20 days).
All patients were examined by a clinical neuropsychologist and in all
cases a normal level of intelligence was ascertained by the Raven Pro-
gressive Matrices (Raven, 1996), a nonverbal test of intelligence. The
mean IQ for CHI patients was 108 (range 90 to 133). None of the pa-
tients showed signs of aphasia. All patients performed within the nor-
mal range in tests sensitive to working memory (Digit Span, Block
tapping, free recall of a 57-unit story, Shuri, 1993). Some patients
showed slightly subaverage performance in a verbal learning task (Au-
ditory Verbal Learning Test, Spreen & Strauss, 1998). Deficits in verbal
learning were associated to attentional problems and did not signifi-
cantly interfere with the task demands. All patients showed attention
deficits in three different attention tasks. Subjects with a similar initial
GCS (±2 scores) and time since injury (±1 week) were alternately as-
signed to receive NFT or participated in a computer-based attention
training (control group).
Attention Tasks
Three different attention tests were presented before and after treat-
ment. The first procedure was a letter cancellation task (d2; Bricken-
22 JOURNAL OF NEUROTHERAPY
kamp, 1962). The test presents rows of b’s and d’s while some of these
letters were labeled with primes. Using a pencil, the patient was re-
quired to cross out only labeled d’s as rapidly as possible. The number
of crossed out stimuli during 280 seconds was taken as a measure of
speed of information processing. The sum of ommission and commis-
sion errors served as a measure for accuracy.
The second task was a simple choice reaction task (DR2; Bukasa &
Wenninger, 1986). The test material comprised 48 visual and/or acous-
tic signals. The signals or combination of signals “red,” “yellow,”
“beeper,” “red and beeper” appeared eight times each, “yellow and
beeper” 16 times. The patient was required to react only to the signals
“yellow and beeper.” The number of errors indicated accuracy of per-
formance.
The third task tested for sustained attention (TAP; Zimmermann &
Fimm, 1989). Patients had to listen for 15 minutes to alternating tones
of different frequences (1000 and 440 Hz). They were asked to press a
response key whenever the same tone appeared two times. The proba-
bility for the appearance of the critical stimuli was five percent.
EEG Recording
EEG recording was performed with a FlexCompEEG feedback
system. The Fz scalp location was used as the active lead (according to
the international 10/20 system) with linked ear reference (both ears are
used as a reference to the active lead with a ground on the forehead).
Connections were made using an electrode cap (Mind Media Feedback
Systems) and electrogel was inserted through each sensor to improve
conductance. Impedance measures for all channels were less than 3 K
Ohms. The EEG of all patients was recorded for 30 minutes during an
eye-open listening condition after the first, fifth and tenth training ses-
sion.
PROCEDURE
Neurofeedback
Twelve CHI patients participated in the NFT. Before treatment all
patients signed a consent for treatment. Following preparation, a five
minute baseline-EEG was recorded for an eye-open listening condition.
The mean amplitude of beta-activity (13-20 Hz) during baseline was
Scientific Articles 23
then used as the threshold during NFT. The first aim of beta training
was to increase the mean amplitude of 13-20 Hz EEG activity. The sec-
ond aim was to extend the time in which patients were able to hold their
beta activity above the threshold. The training was conducted with eyes
open watching a bar graph on the monitor for beta activity. The thresh-
old was superimposed as a dotted line on the bar graph. The patients
were instructed about the concept of attention and beta-activity. Then
they were asked to exceed the pre-set beta amplitude threshold setting.
Patients were told to learn to discover the mental set or strategy that
would keep the bar above the threshold. When beta-activity dropped be-
low the threshold, patients had to perform silent arithmetics (e.g.,
counting backwards from 200 in steps of 7) or to detect defined words in
an acoustically presented story. This was done until the beta amplitude
exceeded the threshold again. Ten NFT sessions were conducted in two
weeks. Each session lasted 30 minutes. During NFT, patients were in-
structed to avoid eye movements and motor acts of their limbs.
Computer-Based Attention Training
Nine patients took part in a computerized attention training. Only
commercially available training programs designed for the remediation
of patients with cognitive impairments were used (COGPACKby
Marker; 1996; Neurosoftby Siegmund, 1999). Ten different tasks se-
lected for the training of speed of information processing and selective
attention were applied. The complexity of each task could be adjusted to
improvements in performance. Feedback concerning speed and accu-
racy was immediately provided by the microcomputer during the task.
At the end of each task a score indicating the overall level of perfor-
mance was administered. Patients had to write down the score to track
their performance from trial to trial. Participants progressed from one
difficulty level to the next if performance in speed and accuracy was
considered to be stabilized for three consecutive trials. Ten 30-minute
training sessions were conducted in two weeks.
RESULTS
Because electrophysiological and behavioral data of patients were
not symmetrically distributed and mean values would have been af-
fected by extreme scores, all statistical analyses were performed using
nonparametric statistics. Statistical analyses within groups were calcu-
24 JOURNAL OF NEUROTHERAPY
lated with the Wilcoxon test for matched samples (Wilcoxon & Wilcox,
1964). Trend analysis was calculated by the Friedman two-way analysis
of variance. A time series analysis using ARIMA (auto-regressive inte-
grated moving average) models (Box & Jenkins, 1970) was used to esti-
mate significance of change of beta activity duration following onset of
treatment. The statistical analysis of demographical data (age, years of
education, injury-test interval, IQ) indicated no significant differences
between the patient groups.
Table 1 shows the median values of the beta amplitude for the first,
fifth and tenth training session for all patients.
Eight patients of the neurofeedback group started with low beta am-
plitudes which then increased continuously (NFT+). The increase of
beta amplitude from the fifth to the tenth training session was statisti-
cally significant (p = 0.028; Friedman two-way analysis of variance).
The remaining four patients of this group started with a high level of
beta amplitudes which then decreased from the first to the tenth training
session (NFT). The beta amplitudes of control patients did not show
any systematic variation.
Figure 1 shows that patients of the NFT group increased the duration
they were able to sustain beta activity above the threshold. This increase
was statistically significant (p = 0.012; t-test of ARIMA).
The results of accuracy in the attention tasks showed improvements
for both patient groups (Table 2). The average number of errors in the
choice reaction task and sustained attention task decreased after NFT
and computer-based treatment, although this decrease was not statisti-
Scientific Articles 25
TABLE 1. Mean Values and Standard Deviation (SD) in Microvolts (µV) of Beta
Amplitudes for the First, Fifth and Tenth Session for Patients Who Increased
Their Beta Amplitude (NFT+), Patients Who Decreased Their Beta Amplitude
(NFT) and Control Patients Treated with a Computer-Based Therapy. The
Difference Between the Fifth and Tenth Session in the NFT+ Group Was Sta-
tistically Significant.
NFT+
N = 8
NFT
N = 4
Control
N = 9
Mean SD Mean SD Mean SD
First Session 2.6 µV 0.6 µV 3.7 µV 0.5 µV 2.6 µV 0.4 µV
Fifth Session 2.9 µV 0.7 µV 3.5 µV 0.6 µV 2.4 µV 0.3 µV
Tenth Session 3.6 µV* 0.6 µV 3.5 µV 0.6 µV 2.5 µV 0.5 µV
*p = 0.028; Friedman two-way analysis of variance
cally significant. In contrast, the number of errors in the cancellation
task significantly decreased in the NFT group (p = 0.032, Wilcoxon test
for matched samples).
Speed of information processing also improved in both groups (Table 3).
The number of detected stimuli in the cancellation task as well as reac-
tion times in the choice reaction task decreased significantly (p = 0.009,
p = 0.013 for the NFT group; p = 0.012, p = 0.04 for the control group,
Wilcoxon-test for matched samples). Nevertheless, a statistically sig-
nificant decrease of reaction time in the sustained attention task was
only observed for patients treated with NFT (p = 0.006, Wilcoxon test
for matched samples).
DISCUSSION
Eight of twelve patients treated with NFT learned to increase their
beta amplitudes. In contrast, four patients starting with a high level of
beta activity showed a decrease of amplitudes after NFT. Nevertheless,
patients of the NFT group doubled the duration of beta activity above
threshold from the first to the tenth training session. This result sug-
gests, that amplitudes may not be the most important factor in cognitive
change. The time patients are able to hold beta activity may describe the
26 JOURNAL OF NEUROTHERAPY
20
15
10
5
Duration of Beta Activity
Session
Minutes
1 23 4 567 8910
FIGURE 1. Mean (±Standard Deviation) of Duration Patients Were Able to
Hold Beta Activity Above the Threshold for Each Session.
process of focusing attention more precisely than a model of intensity.
Being able to hold beta activity for a certain period of time also corre-
sponds to the data of the sustained attention task, where patients of the
NFT group improved more than patients of the control group. The pre-
requisite for a sustained attention task is the ability to maintain a certain
amount of arousal for a long period of time. Although duration of beta
activity has not been measured in patients of the control group, it seems
plausible that this may have been the advantage of patients who re-
ceived NFT.
In agreement with other studies (Ayers, 1993; Byers, 1995; Hoffman &
Stockdale, 1996) NFT led to significant improvements of cognitive
functions. However, patients treated with a computer-based attention
training also improved in some of the attention tests, although their beta
amplitudes did not change over time. One possible explanation for this
result is that treatment effects can be attributed to spontaneous recov-
Scientific Articles 27
TABLE 2. Means and Standard Deviations (SD) of Errors Before and After
Treatment for All Attention Tasks in the NFT Group and Computer-Based
Training Group.
Neurofeedback Group (N = 12)
Pre-Treatment Post-Treatment Level of
Significance
Mean SD Mean SD
Number of Errors in the
Cancellation Task
17.2 3.2 6.2 2.1 p = 0.032
Number of Errors in the
Choice Reaction Task
2.7 1.1 1.9 0.9 Not Significant
Number of Errors in the
Sustained Attention Task
6.6 2.1 4.0 2.5 Not Significant
Wilcoxon test for matched samples
Computer-Based Training Group (N = 9)
Pre-Treatment Post-Treatment Level of
Significance
Mean SD Mean SD
Number of Errors in the
Cancellation Task
13.5 4.8 11.5 2.8 Not Significant
Number of Errors in the
Choice Reaction Task
2.5 1.2 1.5 0.7 Not Significant
Number of Errors in the
Sustained Attention Task
8.5 3.3 5.5 0.9 Not Significant
Wilcoxon test for matched samples
ery. Although spontaneous recovery cannot be ruled out as a variable
influencing the results partly, each therapy showed specific training ef-
fects. Patients treated with the computer-based therapy, improved mainly
in computerized attention tests requiring them to focus their attention
for short periods of time. This indicates that the benefit of this training
procedure seems to be limited to tasks resembling those patients had ex-
ercised during therapy. In contrast, patients who received NFT im-
proved in computer-based tests as well as in a paper-pencil task.
Additionally, these patients showed a significant improvement in the
sustained attention task. This provides convincing evidence that NFT
had a more extensive effect on attention deficits than the computer-
based therapy. Furthermore, patients of the NFT group did not have
much experience with computerized reaction tasks which rules out the
28 JOURNAL OF NEUROTHERAPY
TABLE 3. Means and Standard Deviations (SD) of Number of Crossed Out
Stimuli in the Cancellation Task and Reaction Times (ms) Before and After
Treatment for the Choice Reaction and Sustained Attention Tasks in the NFT
Group and Computer-Based Training Group.
Neurofeedback Group (N = 12)
Pre-Treatment Post-Treatment Level of
Significance
Mean SD Mean SD
Numer of Crossed Out
Stimuli in the Cancellation
Task
175.3 11.3 268.3 18.5 p = 0.009
Choice Reaction Time (ms) 645.4 79.1 484.1 66.2 p = 0.013
Reaction Time (ms) in the
Sustained Attention Task
756.0 84.3 569.2 77.1 p = 0.006
Wilcoxon test for matched samples
Computer-Based Training Group (N = 9)
Pre-Treatment Post-Treatment Level of
Significance
Mean SD Mean SD
Numer of Crossed Out
Stimuli in the Cancellation
Task
166.1 13.2 235.6 15.6 p = 0.012
Choice Reaction Time (ms) 620.2 75.4 488.9 68.3 p = 0.04
Reaction Time (ms) in the
Sustained Attention Task
715.3 79.8 616.6 78.2 Not Significant
Wilcoxon test for matched samples
possibility of a simple transfer effect due to the similarity between train-
ing tasks and evaluation tests (as proposed for the control group).
As a consequence of diffuse axonal injury there is a loss of myelin in-
tegrity, possibly leading to a decrease of speed of information process-
ing and change of the signal to noise ratio. This suggestion is in
agreement with results obtained from reaction time experiments (Klensch,
1983; MacFlynn, Montgomery, Feton & Rutherford, 1984; Miller,
1970; Norman & Svahn, 1961; Van Zomeren, 1981; Van Zomeren &
Deelman, 1976). Brouwer (1985) proposed that brain injuries lengthen
the access time to stored knowledge by weakening the strengths be-
tween nodes of the knowledge net. Tromp and Mulder (1991) modified
this theory by suggesting that the reduced access to knowledge results
from a loss of redundant pathways in the knowledge net. The effect of
this would be pervasive, but the retrieval of novel new information
would be especially slow since it is linked by fewer redundant connec-
tions. The research of Thatcher et al. (1998) supports the suggestion that
changes in coherence and time delay between different areas of the
brain represent the link between observed deficits of attention and al-
tered brain activity. The neural network which deploys attention and di-
rects it to representations of extrapersonal space (Baleydier & Mauguière,
1980; Mesulam, 1981) includes the cingulate cortex, the frontal eye
fields, the rostral bank of the intraparietal sulcus, and the reticular for-
mation (raphe nuclei, nucleus coeruleus and intralaminar thalamic nu-
clei). Recent findings have extended this network to include widespread
locations of the right dorsolateral prefrontal and the right superior parietal
cortices (Pardo, Fox & Raichle, 1991). The anterior cingulate cortex is
activated during visual and auditory discrimination tasks (Pardo, Pardo,
Janer & Raichle, 1990; Cohen, Semple, Gross, Holcomb, Dowling &
Nordahl, 1988), in the semantic processing of speech (Petersen, Fox,
Posner, Mintun & Raichle, 1988), and when complex targets are pre-
sented at high rates (Petersen et al., 1988). The frontal eye fields are ac-
tivated during visual or auditory discriminations tasks (Crowne, 1983;
Roland, 1982, 1984) and the rostral intraparietal cortex (area 7a/PG in
monkeys) secures, maintains and disengages the direction of visual at-
tention and covert orienting (Lynch, Mountcastle, Talbot & Yin, 1977;
Bushnell, Goldberg & Robinson, 1981; Posner, Walker, Friedrich &
Rafal, 1984). The right prefrontal and superior parietal cortices are acti-
vated during sustained visual and somatosensory vigilance tasks (Pardo
et al., 1991); and a right-sided dominance is manifested in the inner-
vation of cortex by the reticular formation and locus coeruleus (Oke,
Keller, Mefford & Adams, 1978). Pfurtscheller (1992) and Sterman
Scientific Articles 29
(1996) demonstrated that the brain’s ability to desynchronize and re-
synchronize defines its capacity to process an ongoing task and to reen-
ter a state of readiness for the next task. It seems obvious that a
disruption of coherence and timing within the described network results
in a severe deficit of attention. NFT may be seen as a method to restore
the mechanisms that underlie the management of rhythmic brain activ-
ity demonstrating thereby the brain’s capacity for restoring homeosta-
sis. Therefore, it might be of interest to offer EEG-based therapy also
for CHI patients in the earliest time after injury (e.g., intensive care
units). By stimulating (e.g., acoustic stimulation with white noise) or
deprivating the brain, arousal can be regulated to an optimum level, thus
providing a necessary basis for information processing.
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32 JOURNAL OF NEUROTHERAPY
... Interventions such as neurofeedback training and action observation training have been reported to improve the concentration of brain injured patients [11][12][13][14]. These interventions have been reported to improve motor function through improved concentration, but the application of these interventions in clinical practice is not easy [6]. ...
... While performing tasks that require attention, alpha waves are suppressed and beta waves increase [22]. Keller (2001) reported improved concentration when beta-wave activation training was applied to patients with traumatic brain injury with reduced concentration. This is because the activity of beta waves corresponds to the improved continuous attention task data [12]. ...
... Keller (2001) reported improved concentration when beta-wave activation training was applied to patients with traumatic brain injury with reduced concentration. This is because the activity of beta waves corresponds to the improved continuous attention task data [12]. In addition, Rozelle & Budzynski (1995) reported that concentration improved after beta-wave activation training [23]. ...
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PURPOSE: The purpose of this study was to investigate the changes of electroencephalography (EEG) activity on balance and gait while physiotherapy in stroke patients.METHODS: General physiotherapy was applied to 18 stroke patients for 30 minutes per session, 5 times a week, for a total 4 weeks. EEG measured for one week while intervention. Based on the attention score, group was classified into high and low attention groups. We used functional reaching test to measure dynamic balance and GAITRite to measure spatiotemporal variables during gait.RESULTS: In the high attention group, the sensorimotor rhythm wave was high and the dynamic balance was significantly increased (p<.05). There were significant differences in stance time, single support time, and double support time among temporal variables (p<.05). There were significant differences in step length, stride length, swing % of cycle, stance % of cycle, single support % of cycle, and double support % of cycle among the spatial gait variables (p<.05).CONCLUSIONS: The high attention during physiotherapy helps improvement of balance and gait ability in stroke patients, therefore, it may be considered in intervention.
... Participants. Three source studies applied NFT interventions to traumatic brain injury (TBI) populations (Keller, 2001;Reddy, Rajeswaran, Devi, & Kandavel, 2013;Schoenberger, Shiflett, Esty, Ochs, & Matheis, 2001), while one applied NFT to a post-stroke population (Cho, Kim, Lee, & Jung, 2015). TBI severity ranged from mild to severe across source study samples. ...
... Two studies reported no group differences in brain injury severity (Keller, 2001;Schoenberger et al., 2001). Baseline MMSE performance was equivalent between Cho et al.'s treatment and control groups (Cho et al., 2015). ...
... Control paradigm differed between source studies. Reddy et al. (2013) and Schoenberger et al. (2001) employed wait-list control, Keller (2001) employed alternative treatment control, and Cho et al. (2015) employed treatment as usual. ...
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Objectives Interest in neurofeedback therapies (NFTs) has grown exponentially in recent years, encouraged both by escalating public interest and the financial support of health care funding agencies. Given NFTs’ growing prevalence and anecdotally reported success in treating common effects of acquired brain injury (ABI), a systematic review of the efficacy of NFTs for the rehabilitation of ABI-related cognitive impairment is warranted. Methods Eligible studies included adult samples (18+ years) with ABI, the use of neurofeedback technology for therapeutic purposes (as opposed to assessment), the inclusion of a meaningful control group/condition, and clear cognitive–neuropsychological outcomes. Initial automated search identified n = 86 candidate articles, however, only n = 4 studies met the stated eligibility criteria. Results Results were inconsistent across studies and cognitive domains. Methodological and theoretical limitations precluded robust and coherent conclusions with respect to the cognitive rehabilitative properties of NFTs. We take the results of these systematic analyses as a reflection of the state of the literature at this time. These results offer a constructive platform to further discuss a number of methodological, theoretical, and ethical considerations relating to current and future NFT–ABI research and clinical intervention. Conclusions Given the limited quantity and quality of the available research, there appears to be insufficient evidence to comment on the efficacy of NFTs within an ABI rehabilitation context at this time. It is imperative that future work increase the level of theoretical and methodological rigour if meaningful advancements are to be made understanding and evaluating NFT–ABI applications.
... On the other hand, there is a vast amount of research regarding the possibility of improving several aspects of cognitive performance through EEG biofeedback training, also known as neurofeedback (Dessy et al. 2018;Naas et al. 2019;Norris and Currieri 1999;Vernon et al. 2003;Yamashita et al. 2017). It is reported that SMR-Beta1 (in the range of 12-18 Hz frequency bands) neurofeedback (NFB) training improves attentional processes in ADHD (Arns et al. 2015;Kaiser and Othmer 2000;Nazari et al. 2011), traumatic brain injury (Keller 2001), autistic (Holtmann et al. 2011) and healthy populations (Gruzelier 2014). Furthermore, it has been suggested that arousal levels might also be increased after SMR-Beta1 neurofeedback training (Faller et al. 2019; Communicated by Francesca Frassinetti. ...
... Over the past four decades research has indicated that NFB training of SMR-Beta1 (12-18 Hz) activity has beneficial effects on the attentional processing and arousal levels of healthy and clinical participants (Kaiser and Othmer 2000;Keller 2001). The feasibility of learned self-regulation via NFB has been reported for EEG frequency components Kamiya 1968;Vernon et al. 2003). ...
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The timing ability plays an important role in everyday activities and is influenced by several factors such as the attention and arousal levels of the individuals. The effects of these factors on time perception have been interpreted through psychological models of time, including Attentional Gate Model (AGM). On the other hand, research has indicated that neurofeedback (NFB) training improves attention and increases arousal levels in the clinical and healthy population. Regarding the link between attentional processing and arousal levels and NFB and their relation to time perception, this study is a pilot demonstration of the influence of SMR–Beta1 (12–18 Hz) NFB training on time production and reproduction performance in healthy adults. To this end, 12 (9 female and 3 males; M = 26.3, SD = 3.8) and 12 participants (7 female and 5 males; M = 26.9, SD = 3.1) were randomly assigned into the experimental (with SMR–Beta1 NFB) and control groups (without any NFB training), respectively. The experimental group underwent intensive 10 sessions (3 days a week) of the 12–18 Hz up-training. Time production and reproduction performance were assessed pre and post NFB training for all participants. Three-way mixed ANOVA was carried out on T-corrected scores of reproduction and production tasks. Correlation analysis was also performed between SMR–Beta1 and time perception. While NFB training significantly influenced time production (P < 0.01), no such effect was observed for the time reproduction task. The results of the study are finally discussed within the frameworks of AGM, dual-process and cognitive aspects of time perception. Overall, our results contribute to disentangling the underlying mechanisms of temporal performance in healthy individuals.
... Hz) is usually divided into high beta, mid beta and low beta. Within the low beta range, we can differentiate the sensorimotor rhythm (SMR) (13)(14)(15), the activation of the SMR is correlated with movement inhibition [4], and improvement of concentration, sustained attention [15], semantic memory [16], working memory [17], and information processing facilitation [4]. Beta and theta band fluctuations have been correlated with memory and attention. ...
... Hz) is usually divided into high beta, mid beta and low beta. Within the low beta range, we can differentiate the sensorimotor rhythm (SMR) (13)(14)(15), the activation of the SMR is correlated with movement inhibition [4], and improvement of concentration, sustained attention [15], semantic memory [16], working memory [17], and information processing facilitation [4]. Beta and theta band fluctuations have been correlated with memory and attention. ...
Article
Severe traumatic brain injury residual cognitive impairments significantly impact the quality of life. EEG-based neurofeedback is a technique successfully used in traumatic brain injury and stroke to rehabilitate cognitive and motor sequelae. There are not individualized comparisons of the effects of EEG-based neurofeedback versus conventional neuropsychological rehabilitation. We present a case study of a traumatic brain injury subject in whom eight sessions of a neuropsychological rehabilitation protocol targeting attention, executive functions, and working memory as compared with a personalized EEG-based neurofeedback protocol focused on the electrodes and bands that differed from healthy subjects (F3, F1, Fz, FC3, FC1, and FCz), targeting the inhibition of theta frequency band (3 Hz−7 Hz) in the same number of sessions. Quantitative EEG and neuropsychological testing were performed. Clear benefits of EEG-based neurofeedback were found in divided and sustained attention and several aspects related to visuospatial skills and the processing speed of motor-dependent tasks. Correlative quantitative EEG changes justify the results. EEG-based neurofeedback is probably an excellent complementary technique to be considered to enhance conventional neuropsychological rehabilitation.
... These findings are in line with the previous studies where EEG-NFT resulted in enhanced attention and response accuracy in a group of patients with mild TBI (Tinius & Tinius, 2000). Similar findings were also observed in patients with moderate TBI where EEG-NFT led to enhanced accuracy in a processing speed test and faster reaction time in a sustained attention task (Keller, 2001). Another study from the southern Indian peninsula reported similar findings where 20 sessions of EEG-NFT with a similar alpha-theta protocol were effective in improving various cognitive domains in patients with mild to severe TBI (Reddy et al., 2013). ...
Article
Full-text available
Introduction: Traumatic brain injury (TBI) is associated with physical, cognitive, emotional, and behavioral disturbances. The cognitive deficits are common after TBI, and a holistic approach to neuropsychological rehabilitation is recommended in these patients. EEG neurofeedback training (EEG-NFT) is a state-of-the-art technique for neuropsychological rehabilitation. There is a paucity of studies exploring the use of EEG-NFT integrated with holistic neuropsychological rehabilitation. Method: Single case design was adopted for the present study. A 25-year-old single male, diagnosed with severe TBI, presented with physical, cognitive, and emotional-behavioral disturbances after 17 months of injury. A comprehensive neuropsychological assessment was carried out. The neuropsychological rehabilitation using EEG-NFT along with psychosocial interventions with the patient and the parents was carried out for 9 months. Results: The patient showed significant improvement in cognitive deficits such as attention, executive functions, and visuospatial ability. Emotional-behavioral problems such as irritability, sadness, and overall dysfunction also improved significantly. Conclusion: The present case study highlights that integrating EEG-NFT along with holistic neuropsychological rehabilitation helps to improve cognitive, emotional, and behavioral disturbances after TBI.
... The small sample size of the study and the difference in the overall beta activity of the NFT receiving group prevent this study's findings to be conclusive for all PCS and mTBI patients. [19] ...
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The growing number of concussions and mild traumatic brain injuries (mTBI) with the lack of evidence-based treatment options is a continuous health concern. This creates problems when evaluating and providing efficacious symptom management to patients suffering from post-concussion syndrome (PCS). Numerous pharmacological and non-pharmacological agents have been utilized in an attempt to treat PCS. Some of these approaches include physical therapy, analgesics, antidepressants, and nutraceuticals. Although these treatments have had some success, there has been inconsistent outcomes, with some examples of patients’ symptoms worsening. Among pharmaceutical agents, fluoxetine has been a popular choice for the symptom management of PCS. Although some patients have had symptom resolution with the use of fluoxetine, there is still a lack of conclusive data. Of the several biochemical changes that occur in a patient’s brain following a concussion, an increase in reactive oxygen species (ROS) is of particular concern. In order to counteract the responses of the brain, antioxidants, such as ascorbic acid, have been utilized to reverse the damaging cellular effects. However, this may inadvertently cause an increase in ROS, rather than a reduction. Although there is a lack of consistency in exactly when each treatment was used in the post-injury interval, it is important that we analyze the strengths and weaknesses of the most commonly used agents due to the lack of a set protocol. The studies were chosen in a non-exhaustive manner and were not consistent in patients’ post-injury intervals, in addition to other baseline characteristics. However, over-arching claims that some treatments may benefit more than others can be made. This review evaluates both the pharmaceutical and non-pharmaceutical protocols that are most commonly utilized in post-concussive patients for their efficacy in treatment of post-concussive syndrome (PCS).
... EEG-NFT has shown promising effects for ameliorating cognitive, behavioral, emotional, and physical dysfunctions among patients with TBI (Bennett et al., 2018;Keller, 2001;Munivenkatappa, Rajeswaran, Indira Devi, Bennet, & Upadhyay, 2014;Reddy, Rajeswaran, Devi, & Kandavel, 2013;Schoenberger, Shiflett, Esty, Ochs, & Matheis, 2001). ...
Article
Full-text available
Traumatic brain injury (TBI) is a leading cause of death, and its survivors with a disability are considered to be an important global health priority. In view of a diverse range of disability and its impact on TBI survivors, the need for effective rehabilitation modalities is on a high rise. Therefore, the present study was aimed to investigate the efficacy of EEG neurofeedback training (EEG-NFT) in moderate-severe TBI patients on their clinical and electrophysiological outcomes. The study was an experimental longitudinal design with a pre-post comparison. A total of 14 TBI patients in a postinjury period between 3 months to 2 years were recruited. All participants received twenty sessions of EEG-NFT. Baseline and post-NFT comparisons were made on postconcussion symptoms (PCS) and electrophysiological variables. The result indicates a significant reduction in the severity of PCS following EEG-NFT. A consistent pattern of reduced slow waves and fast waves amplitude ratios was also noted at post-NFT, although it was not significant across all the brain regions. The present study suggests EEG-NFT as a contributing factor in improving PCS and normalization of qEEG in TBI patients, which holds an implication for clinical decision-making of EEG-NFT as a viable alternative to be offered to TBI patients.
Article
Objective Persistent post-concussive symptoms (PPCS) often include attention deficits, particularly orienting and executive attention. Research in other clinical populations has demonstrated that neurofeedback therapy (NFT) is effective at improving orienting and executive attention, although its effects on attentional networks in patients with PPCS are unknown. Method In this single-group pilot study, we examined attention-related event-related potentials (ERPs) – N1 and P3 – and cognitive outcomes following Live Z-score training (LZT), a variant of NFT. Results No changes in early selective attention, as indexed by N1 amplitude, were observed; however, P3 amplitude, which indexes neural resource allocation, increased following LZT and returned to baseline by 3 months. Cognitive performance improved following treatment, which was sustained at 3 months. The magnitude of change in P3 and ANT performance did not differ between orienting or executive attention, suggesting LZT improved general attentional processing efficiency. Conclusion Our results suggest that LZT may positively affect attention globally, but does not target specific attention networks. These pilot data warrant the initiation of a clinical trial evaluating the effectiveness of LZT for treating attention deficits in patients with PPCS.
Article
The restoration of motor function is important in daily life in patients with brain damage. Although attentional concentration can affect motor function, most physical therapists focus only on therapeutic exercise. Therefore, we investigated changes in motor function in patients with high attentional concentration during our intervention. A total of 21 subjects diagnosed with stroke participated in the study. They were divided into the high attentional concentration group and low attentional concentration group based on the self-programmed attention index. The subjects underwent trunk strengthening and gait training for 30 min per session, twice a day, 5 days a week, for a total of 4 weeks. All patients wore electroencephalogram (EEG) devices during the treatment to enable EEG examinations. Diagnostic ultrasound was used to measure muscles of the abdomen: external oblique abdominal, internal oblique abdominal, transversus abdominis, and rectus abdominal muscles. A trunk impairment scale was used to evaluate trunk control. We used Gaitrite to measure the spatial and temporal components during gait. The group with high attentional concentration showed significant differences in abdominal muscle strength and trunk control. In gait, there was a significant difference in swing cycle, stance cycle, single cycle, double support cycle, stance time, and double support time. Therefore, attentional concentration should be considered to improve motor function as a part of therapeutic exercises for stroke patients.
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Objective: As life expectancy increases, the incidence of degenerative diseases such as osteoarthritis also increases. Dynamic balance is one of the essential factors that affect the mobility and daily living activity of patients suffering from knee osteoarthritis after undergoing Bilateral Total Knee Replacement (BTKR) surgery. Traditional rehabilitation approaches are based on reducing pain and increasing muscle strength, which are applied topically on the knee area. One of the new methods used to improve balance is neurofeedback, which acts at the central nervous system level. This pilot study aims to examine the effect of neurofeedback on dynamic stability and sustained attention in women who underwent BTKA. Materials & Methods: This is a quasi-experiment study with a pre-test/post-test design and no control group. The study population consisted of all patients with BTKA referred to the outpatient clinic of the Department of Occupational Therapy at Shahid Beheshti University of Medical Sciences from April 2017 to September 2017. Of these patients, 8 female patients with a mean age of 67.5 years (3 months had passed since their surgery) were selected using a convenience sampling method and based on the inclusion and exclusion criteria. Results: The inclusion criteria were being over 55 years old; having a history of BTKR surgery in the last 2 to 4 months; being able to walk independently; using a cement prosthesis; lacking a record of cognitive problems (mini-mental state exam score> 20), cardiovascular diseases, uncontrolled high blood pressure, visual impairment, drug abuse or alcohol use, vestibular disorders that can impair balance, use of neuroleptics and sedatives; not receiving neurofeedback before this study, or undergoing surgery in other joints of lower limbs, such as ankle or hip. The exclusion criteria were the absence of more than two sessions from therapeutic protocol and unwillingness to collaborate in the research process. All patients received 8 sessions of standard neurofeedback training. Assessments were done at three times: before the intervention, and at the 4th and 8th sessions using vigilance subscale of Vienna test system and Biodex balance system (dynamic stability level 6 test). Data analysis was done in SPSS V. 22 using repeated-measures ANOVA and paired-samples t test. P
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Twenty-two closed head injury (CHI) patients and 22 normals matched for age sex, education and socio-economic status were compared using several reaction time tasks. The study did not support the notions of a complexity effect, nor of a modality effect in CHI. Reaction time was generally more sensitive than error rate which was more sensitive than intra-individual variance. However, paradigms designed to elicit commission errors (a go no-go paradigm, and a paradigm with prestimulus warning on a random inter-stimulus interval) were the most sensitive, particularly error rate measures for these tasks. Traditional indicatores of morbidity (coma duration, post-traumatic amnesia duration, post-onset time, neuropsychological test impairment and symptom reports) were not correlated and did not predict performances on reaction time tasks. It is concluded that computer-based reaction time paradigms are more promising than the tradittional indicators of morbidity for the further elucidation of functional impairment following CHI, particularly with regards to the analysis of commission versus omission error patterns to further test the hypothesis of frontal disinhibition as a prevalent sequel of CHI.
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The cognitive act of shifting attention from one place in the visual field to another can be accomplished covertly without muscular changes. The act can be viewed in terms of three internal mental operations: disengagement of attention from its current focus, moving attention to the target, and engagement of the target. Our results show that damage to the parietal lobe produces a deficit in the disengage operation when the target is contralateral to the lesion. Effects may also be found on engagement with the target. The effects of brain injury on disengagement of attention seem to be unique to the parietal lobe and do not appear to occur with our frontal, midbrain, and temporal control series. These results confirm the close connection between parietal lobes and selective attention suggested by single cell recording. They indicate more specifically the role that parietal function has on attention and suggest one mechanism of the effects of parietal lesions reported in clinical neurology.
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Recent neurophysiological findings in relation to thalamocortical mechanisms for sensory processing, together with established anatomical and expanding functional evidence, have provided a rational theoretical framework for the interpretation of normal and abnormal EEG rhythmic activities. This perspective is integrated here with earlier animal studies which were the foundation for many current applications of EEG self-regulation as a clinical tool. Basic evidence concerning the origins, frequency modulation, and functional significance of normal EEG rhythmic activities is reviewed here in an effort to provide guiding principles for the interpretation of clinical abnormalities and their remediation with EEG feedback training.
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According to clinical experience a frequent consequence of head injury is an impairment of auditory attention. We investigated the possibility that patients with either closed head injuries (CHI), or cerebrovascular accidents (CVA) of the right hemisphere, would be impaired by comparison to healthy subjects on an objective test of auditory attention. We used an experimental paradigm that consisted of four subtests which comprised strings of auditory digits heard either diotically or dichotically, at either fast or slow presentation rates, respectively. Omission and commission errors were scored for each subtest and combined by an index of errors. The results showed that CHI patients were significantly impaired initially by the fast stimulus presentation conditions, whereas CVA patients made significantly more errors on the dichotic subtests independent of the speed of presentation. It is proposed that the observed selective attention deficits of these patients were due to differential disruptions of an interactive cortical network incorporating prefrontal, anterior cingulate, and temporoparietal structures of the right hemisphere. Statistically significant correlations between the error index scores and subjectively perceived attention deficits suggested that the auditory attention task measured clinically relevant aspects of attention.
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