Mental Fatigue and Attention Problems Due to Brain Injury

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Brain Injury, December 2009; 23(1314): 10271040

Mental fatigue and impaired information processing after mild andmoderate traumatic brain injury

BIRGITTA JOHANSSON, PETER BERGLUND, & LARS RONNBACK

Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, The Sahlgrenska

Academy, University of Gothenburg, Gothenburg, Sweden

(Received 4 March 2009; revised 8 October 2009; accepted 18 October 2009)

AbstractPrimary objective: Mental fatigue is a common symptom after brain injury. Its mechanisms are not fully understood andit has been difficult to find an objective way of measuring it. The aim was to compare cognitive tests with a newself-assessment questionnaire about mental fatigue.

Methods and procedures: Individuals reporting mental fatigue for 6 months or more after mild traumatic brain injury (MTBI)or traumatic brain injury (TBI) and controls were assessed for subjective fatigue, information processing speed, workingmemory and attention. Depression and anxiety were also assessed in the individuals with brain injury.Results: Individuals with MTBI or TBI reported significantly more problems with mental fatigue and related symptoms thancontrols. A significantly decreased information processing speed (digit symbol-coding, reading speed, trail making test) wasfound in those on sick leave due to MTBI or TBI, compared to controls. Divided attention was affected to a lesser extentand no effect was detected on working memory.Conclusion: Mental fatigue after MTBI can last for several years. It can be profoundly disabling and affect working capacityas well as social activities. Subjective mental fatigue following brain injury is suggested to mainly correlate with objectively

measured information processing speed.

Keywords: Mental fatigue, TBI, MTBI, self-assessment questionnaire, information processing speed, working memory, digit

symbol-coding, reading speed, TMT

Introduction

Fatigue is a common symptom after both a mild

traumatic brain injury (MTBI) and traumatic brain

injury (TBI). Mental fatigue is characterized by

concentration and memory difficulties as well as

increased fatigability after mental activities, withdepletion of energy which can take days to recover

from. For most individuals the problem disappears

within a year, but for some, mental fatigue becomes

a chronic problem that affects daily life. The

mechanisms that cause mental fatigue are not fully

understood and no clear treatment guidelines have

been developed. Therefore, it is important to find

appropriate assessment methods to increase knowl-

edge of mental fatigue.

Concern about the different aspects of mental

fatigue has been addressed for neurological diseases

and injuries [1] and an investigation revealed thatit is the most common problem following TBI, as it

can last for many years and influences daily activities

[2]. One third of the patients who suffered from

MTBI complained of severe fatigue at 6 months as

well as a decrease in physical and social activities [3],

while 40% complained of headache and fatigue

Correspondence: Dr Birgitta Johansson, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, The Sahlgrenska

Academy, University of Gothenburg, Per Dubbsgatan 14, 1tr, SE 413 45 Gothenburg, Sweden. Tel: 46-31-34210 00. E-mail: birgitta.johansson2@

vgregion.se

ISSN 02699052 print/ISSN 1362301X online

2009 Informa Healthcare Ltd.DOI: 10.3109/02699050903421099


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1 year after concussion [4]. After 5 years, 73%

reported still having a problem with fatigue, which

affected them in everyday life [5]. Even after 10

years, fatigue was still present, irrespective of injury

severity [6]. Improvement was reported during the

first year, after which it was limited [7]. Fatigue after

brain injury has a significant effect on well-being and

quality of life and is suggested to be due to the brain

injury, as it cannot be explained as an effect of

depression, pain or sleep-disturbance [8]. In addi-

tion, the degree of fatigue is not related to the

severity of the injury, age or time since injury [9, 10].

Mental fatigue is central to many neurological

disorders and biological models have been proposed

as a means of understanding pathophysiological

mechanisms. Chaudhuri and Behan [1] formulated

a hypothesis suggesting that metabolic and structural

lesions that disrupt the usual process of activation

in pathways interconnecting the basal ganglia,

thalamus, limbic system and higher cortical centreare implicated in the pathophysiological process

of central fatigue. Another hypothesis proposed

that functions of the glial cells in the brain are out

of balance [11, 12]. Inflammatory activity with

microglial activation and the production of cytokines

could be responsible for an attenuated astroglial

fine-tuning and support of the neuronal glutamate

signalling, which is of the utmost importance for

information processing in the brain. In addition,

other systems have been found to be affected.

Recent research results demonstrate that there is

an imbalance in the regulation of the hypothalamus-

hypophysis-adrenal cortex (HPA)-axis, which isunder the control of the excitatory neurotransmitter

glutamate [13]. It was also shown that glutamate can

activate the amygdala to release the corticotropine-

releasing factor [14], which in turn can lead to

increased glucocorticoid levels. Moreover, it has

been suggested that genetic variation is

important [15].

It has proved difficult to relate cognitive functions

such as attention and memory to mental fatigue

[10]. However, mental fatigue theories suggest that

cognitive activities require more resources than

normal [16] and subjective assessment of fatigue

has been found to correlate with complex selectiveattention [9] and information processing speed [17].

Higher neuronal activity compared to controls

during a mental activity may also indicate an

increased cerebral effort after brain injury [18] and

support for the theory above [16].

There are a large number of different scales for

assessing fatigue, of which several were designed

for a specific disease [19] as well as for patients with

brain injury [10]. This means that different scales

report varying effects and accordingly it is difficult

to conduct intervention studies due to the lack of

validated tests [20]. The aim of this project was to

find better ways to determine mental fatigue. Both

subjective and objective measurements were used

with the intention of more clearly identifying

items associated with mental fatigue. A new self-

assessment scale was employed for the subjective

rating of mental fatigue and related symptoms [21]

in combination with objective tests of information

processing speed, working memory and divided

attention.

Method

Participants

The main purpose was to study subjectively reported

mental fatigue and cognitive functions and not the

frequency of mental fatigue. Participants with MTBI

or TBI who were reporting long-term mental fatigue

were recruited by means of an advertisement in alocal newspaper. Some subjects were also recruited

by a Swedish patient association for people with

brain injury and from the department of neurology at

the Sahlgrenska University hospital. The inclusion

criteria were MTBI or TBI with no other neurolog-

ical or psychiatric illnesses, no dyslexia and hav-

ing sustained the injury over 6 months prior to

inclusion. All MTBI participants had been diag-

nosed with commotion/concussion (ICD-10 S06.0).

Participants with TBI were not differentiated

between moderate and severe, but they all described

a moderate-to-severe head trauma and had been

hospitalized for varying lengths of time (months to ayear) and had received rehabilitation in specialized

units. The subjects with MTBI or TBI had no

motor complaints and all were living independently.

Some were working full time, while others were on

sick leave, most of them 100%, but some to a lesser

extent such as 25, 50 and 75%. MTBI working full

time were analysed separately, as it was assumed that

they could give valuable information about working

capacity and about severity of mental fatigue.

Control participants with no history of head injury,

no neurological disturbance or psychiatric illness,

no limitation in working capacity and of similarage, education and gender were recruited from the

general community. The study was approved by

the regional Ethics Committee in Gothenburg. The

participants gave their informed written consent

before the assessment.

Self-assessment of mental fatigue

The self-reported questionnaire contains 15 ques-

tions and was adapted from Rodholm et al. [22].

The questions cover the most common symptoms

occurring after brain injury [23, 24]. Each item

1028 B. Johansson et al.


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comprises examples of common activities to be

related to four response alternatives (see Appendix).

The rating is based on intensity, frequency and

duration. Higher scores reflect more severe symp-

toms. A rating of 0 corresponds to normal function,

1 indicate a problem, 2 a pronounced symptom and

3 a maximal symptom. It is also possible to indicate

a score between the given alternatives (0.5, 1.5, 2.5).

The intention was to construct an assessment scale

with response alternatives that can help the subjects

to be clearer and more consistent in their judgement.

The questions concern fatigue in general, lack of

initiative, mental fatigue, mental recovery, concen-

tration difficulties, memory problems, slowness of

thinking, sensitivity to stress, increased tendency to

become emotional, irritability, sensitivity to light and

noise, decreased or increased sleep as well as 24-hour

variations. The construction of the questionnaire

resemble the Comprehensive Psychopathological

Rating Scale (CPRS) designed to measure changesin psychopathology over a short period [25].

A clinical interview was performed based on the

questions from the self-assessment scale as well as

the CPRS to measure the presence of depression

and anxiety. Participants with brain injury were

also asked about changes in their leisure and social

activities, both at home and outside the home

according to the structured interview for the

Glasgow Coma Scale [26].

Neuropsychological tests

The neuropsychological tests measured informationprocessing speed (the time required to execute

a cognitive task within a finite time period) [27],

attention, working memory, verbal fluency and

reading speed, which are common problems after

MTBI. The tests included were digit symbol-coding

from the WAIS-III NI [28], measuring information

processing speed. Attention and working memory,

both auditory and visual, were measured by means

of the digit span and spatial span [28]. Both tests

included repetition of forward series of random

numbers or blocks in order as well as in reverse.

The verbal fluency test (FAS) measures the ability to

generate as many words as possible beginning witha specific letter within 1 minute [29]. Parts A and B

of the Trail Making Test (TMT) were administered

according to the published guidelines [30] in order

to measure visual scanning, divided attention and

motor speed [31]. The test consists of a series of

connect-the-circle tasks, part A with a numerical

order of 125 and part B comprising letters and

digits in alternating numerical and alphabetical

order, which have to be completed as quickly as

possible. In order to evaluate higher demands such

as dual tasks, a series of new tests was constructed

with three and four factors, respectively. The same

number of circles (25) was used in all parts. The

alternation between factors was similar to part B

except for the fact that months were added in part C

and both months and days of the week in chrono-

logical order in part D. In the latter, the order of

letters and digits was changed (A: 125, B: 1-A-2-

B-3-C, C: 1-A-January-2-B-February-3-C-March,

D: A-1-January-Monday-B-2-February-Tuesday).

The reading speed was measured using the DLS

reading speed test [32]. The participants were

instructed to read the text silently and mark the

correct word that corresponded to the meaning of

the sentence from 36 evenly distributed parentheses

containing three words, which serves as a check of

reading comprehension. The whole text contains

887 words and the time taken to read each page was

recorded. The average number of words per second

and page was measured. The native language of the

healthy controls was Swedish, with the exceptionof one individual whose first language was English,

but who had lived in Sweden for 10 years and

spoke Swedish fluently. None of the healthy controls

reported any reading problems or dyslexia. One

MTBI participant reported dyslexia and was

excluded from the analysis of reading speed.

The assessment was made in the following order:

self-assessment of fatigue, Trail Making Test, assess-

ment by the examiner, i.e. a neuropsychologist or

psychiatrist, of subjective fatigue, depression and

anxiety, digit symbol-coding, digit span, spatial span,

verbal fluency, reading speed and social function.

The instruments were administered according to therespective published guidelines.

Statistical analysis

The self-assessment questions and binominal data

were analysed by the non-parametric Kruskal-

Wallis, Mann-Whitney and Chi-squared tests.

Bonferroni adjustment was used after multiple

comparisons. ANOVA, ANCOVA and regression

analysis were employed for the parametric data and

Bonferroni served as a post-hoc test. Spearmans

rank correlation was used for the analysis of the

subjective assessments and cognitive tests. Theinternal consistency reliability of the self-assessment

questions was analysed by means of Cronbachs

alpha. SPSS 16.0 for Windows was used for data

analysis.

Results

Demographics

The participants were divided into four groups;

controls (Group 1), persons with MTBI in full time

Mental fatigue, TBI and information processing 1029


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employment (Group 2), persons with MTBI who

were on sick leave (Group 3) and persons with TBI

who were on sick leave (Group 4). As no statistical

difference was found between the groups with

different degrees of sick leave (25, 50, 75 or

100%), they were therefore combined. Sick leaveof 100% was the most common. Demographic data

are presented in Table I. More women than men

participated in the study, but there was no significant

difference in number of men and women between

the healthy control and brain injured groups.

A significant age difference emerged (F9.01,

p


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injury were found for reading speed, where group 2

was faster than group 4, and for the TMT D, where

group 2 was faster than group 3. Reading speed and

digit symbol-coding were maintained at almost the

same speed in both tests.

No significant difference in auditory (digit span)and visual (spatial span) working memory for total

and backward scores or visual span forward were

detected between groups. The only significant

difference was that group 3 scored fewer digits

forward compared to the control group (p


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significantly decreased their outdoor physical activ-

ity, activity at home and even social life outside and

in the home compared to MTBI working full time

(all questions, p


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one participant was assessed as being depressed.

Aches and pain from the CPRS was above 0.5 in

groups 3 and 4 and both increased and decreased

sleep was reported (Figure 5).

Discussion

Mental fatigue after MTBI is a common problem

and it often limits working capacity as well as the

ability to participate in social activities. The present

study aimed at investigating mental fatigue after

MTBI or TBI and examining whether it can be

related to cognitive functions. The authors wereunable to draw any conclusion about frequency,

as the participants were recruited on the basis of

reporting mental fatigue following brain injury.

Subjective effects

Subjects with MTBI and TBI, irrespective of work-

ing capacity and severity, reported significantly more

problems, both for total sum of scores and for all

separate items in the self-assessment questionnaire

compared to controls. In particular, mental fatig-

ability, mental recovery and stress sensitivity were

rated as high. The self-assessment scale includeditems with a high internal consistency and the

questions also correlated significantly with each

other. The scale was also relevant for different

diseases [21]. This indicates that the core problem

with mental fatigue comprise a broader spectrum

of relevant items with either primary or secondary

symptoms. The response alternatives may also make

the self-reports more consistent and might have

resulted in a more definite deviation from the healthy

controls. Social and leisure activities were also

affected and many of the participants had reported

mental fatigue for many years. This is in agreement

with other studies reporting that fatigue plays aprominent role in the lives of many people a long

time after a TBI [25].

Individuals with MTBI who were working full

time did not change their leisure and social activities,

although they rated their mental fatigue and related

items on the same level as the participants with

MTBI and TBI who were on sick leave. This may

appear strange but, depending on their mental load

during the day, subjects working full time might

need to devote more attention to mental work and

use more energy than is normal.

Figure 3. The figure shows the significant negative correlation for

the total sum score and digit symbol-coding (scale score used here

is adjusted for age in accordance with the WAIS-III manual).

Figure 4. Changes in leisure and social activities. Participants

with MTBI who were on sick leave had significantly decreased

their leisure and social activities both outside the home and at

home compared to those with MTBI who were working full time

(yesdecreased activity).

Figure 5. Selected items from the expert assessment with CPRS

and the self-assessment scale, showing median rating of depres-

sion, anxiety, pain, sleep, mental fatigue and sensitivity of stress.



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If they had the same mental effort, those on sick

leave might become more easily fatigued, but sick

leave or part time work probably helps them to

conserve their energy, which is crucial, as today rest

is the most important restorative factor for indivi-

duals who suffer from mental fatigue. If, as

suggested, mental activities require more cognitive

or cerebral effort than normal [16, 18, 34], this

would explain the similar subjective ratings among

individuals with brain injury. Unlike in the case of

those on sick leave, objective cognitive tests did not

differ between healthy subjects and those with

MTBI who were working full time and individuals

with MTBI who were working full time read faster

than both the MTBI group on sick leave and the TBI

group and were faster in the TMT D than the MTBI

group on sick leave, indicating a difference in injury

severity.

Objective effects

Objective tests dependent on information processing

speed were significantly impaired in the participants

with MTBI on sick leave and the TBI group

compared to controls. The working memory tests

were not affected, with the exception of a significant

decrease in group 3 on digit forward. Age correlated

with digit symbol-coding [28] as well as with TMT

A and B [35] and also with the total sum score for

the self-assessment scale. However, after controlling

for age (ANCOVA), significant differences remained

for information processing speed. Regression analy-

sis also indicated that age contributed to the varia-tion in self-assessment, but to a lesser extent than

information processing speed. It is therefore sug-

gested that information processing speed is a signif-

icant factor related to mental fatigue in persons with

MTBI and TBI, even when taking account of age.

Age is thus significant in the self-assessment of

fatigue and comparison between groups or interven-

tion studies must control for age. The order of the

tests cannot explain the slower information process-

ing speed as due to fatigability during the test

session, as the TMT, which was administered at the

beginning of the assessment, was also characterized

by decreased speed.The result is in agreement with studies that

describe information processing speed as the most

prominent function to be affected after brain injury

[27, 36] and other neurological diseases [37, 38].

Martin et al. [39] reported decreased information

processing speed, but no effect on working memory

after TBI. Reaction time increased when a more

difficult information processing test was used [40].

Spatial and digit span were in accordance with

previous reports and spatial span forward and

backward were on nearly the same level, while digit

span forward was higher than backward among

both healthy controls [41] and participants with mild

injury [42]. The TMT results of parts A and B were,

in the case of the control participants, close to the

normative data presented by Tombaugh [35]. When

compared with the WISC-III manual, the control

group accords well with what is expected for a

healthy group.

Reading is a complex activity, involving automa-

ticity, information processing speed and working

memory. It is also an important activity in daily life

and the most realistic test used in the present study.

Reading is also commonly reported as tiresome and

slow by patients after brain injury. However, it is

usually employed for assessing dyslexia and not for

testing cognitive disorders after brain injury or

neurological diseases. This study demonstrates that

reading speed can be a useful test for further

exploration of the mechanisms involved in mental

fatigue. TMT C and D, requiring a high load oninformation processing and divided attention, may

also be valuable as this more complex and sensitive

test makes it possible to capture milder cognitive

deficits after brain injury with co-occurring mental

fatigue.

Aspects on mental fatigue and cognitive function

A multi-factorial approach is most often used to

describe the occurrence of mental fatigue. DeLuca

et al. [43] discussed the problem of relating cognitive

tests to fatigue and demonstrated increased neuronal

activity after mental activity in patients with multiplesclerosis (MS). Similar results were also reported by

Kohl et al. [18] for patients with TBI. Furthermore,

a working memory task after brain injury was

associated with increased neuronal activity [44].

Azouvi et al. [16] proposed that mentally tiresome

activities after brain injury were related to reduced

resources and that patients with brain injury also

described mental activity as more energy demanding

than healthy persons. The same was reported after a

divided attention task [34]. Moreover, a simultane-

ous load on working memory that demands total

control of the situation was more tiresome than an

automatic activity [45]. The participants with MTBIwho were working full time also had a significantly

higher total sum score of the self-reporting items

than the controls, thus indicating that mental activity

is more energy demanding than normally expected.

The correlation here between mental fatigue and

information processing speed is also in agreement

with other studies [17, 46, 47]. Thumb pressing as

an objective test of speed did not differ between

control and TBI groups but was correlated with

subjective fatigue [46]. Ziino and Ponsford [47]

reported significantly slower performance on a



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complex selective attention task and suggested an

association with subjective fatigue. Furthermore,

information processing improved after a repeated

computerized test for healthy controls, something

not found in the subjects with brain injury [17].

Information processing speed is known to have an

important influence on higher order cognitive func-

tions such as working memory, episodic memory,

executive function, reasoning, problem-solving,

visual spatial as well as academic skills [27]. It is

also important for many jobs due to the high

demand on efficiency. A combination of subjective

and objective measures is suggested for assessing

mental fatigue, as it can provide a more specific

assessment of the level of mental fatigue and also be

of great value for estimating working capacity and

the need for rest and rehabilitation.

Depression

Depression is common after brain injury but, withthe exception of one individual, the participants who

voluntarily took part in this study were not found to

be depressed. Furthermore, the results were not

controlled for depression, as very low clinical ratings

close to normal (0 or 0.5) of core items of depression

were found for the participants with brain injury.

As questions overlap between CPRS and the

self-assessment of mental fatigue and related symp-

toms, it was decided to show the depression and

anxiety items separately in Figure 5. In the figure are

also some of the symptoms from the clinical rating

shown for a comparison with depression symptoms.

Depression is more common among MTBI and

TBI, but the inclusion criteria to this study and also

the subjects being recruited voluntarily may have

resulted in fewer depressed patients than would have

been found in an epidemiological study. A mixture

of fatigue, cognitive and depression items are often

included in different depression scales and, together

with other methodological discrepancies between

studies, can explain some of the variation in depres-

sion (from 677%) after brain injury [10]. Many

studies report increased susceptibility to depression

after brain injury, but the connection with mental

fatigue is less clear. Fatigue after brain injury wassuggested to be an effect of the brain injury itself and

not a result of pain, depression or sleep-deprivation

[8]. Therefore, the authors hold that mental fatigue

must be assessed thoroughly and needs to be

separated from depression, as both symptoms are

common and can co-occur but require different

intervention strategies [48].

Consideration of the study group and tests

Time since injury varied between participants,

but no significant correlation between cognitive

function, subjective assessment and years since

injury was found. In the case of 20 participants

(34%), mental fatigue remained for more than

10 years after the injury. This is in accordance with

other studies, reporting long-term visual spatial and

academic skill problems associated with fatigue after

brain injury [24, 7, 49, 50], for up to 10 years,

irrespective of injury severity [5]. Cognitive impair-

ments are also common 10 years after brain injury

[50].

A high proportion of the participants in group 3

had suffered two MTBI. Although it cannot be ruled

out that their problems were worse, no significant

difference was found when those reporting one

and two brain injuries in group 3 were compared.

No significant difference emerged between males

and females for the included items in the subjective

self-assessment scale for mental fatigue or in the

cognitive tests. There were, however, more female

participants in this study. One cannot draw anyconclusions about why more females volunteered

but, in other studies, more women than men

have reported subjective complaints after brain

injury [8, 51].

Limitations of the study

The differentiation of brain injury was not based on

commonly used classification systems, at it was

not possible to collect case records from different

hospitals. Furthermore, mental fatigue has not been

related to severity of the injury and it was therefore

decided to make this division into groups based onthe subjects description of the injury, if it has been

classified as a MTBI or a more severe injury and also

due to hospitalization. The estimation of depression

and anxiety is based on a clinical interview according

to CPRS and a self-assessment of depression

and anxiety is not done here, but would have been

valuable for adjustments and comparisons in statis-

tical analyses. The items included in the self-

assessment scale cover different areas such as sleep,

sensory, emotional and cognitive domains, which

all fit well together. Whether they are primary or

secondary effects to the brain injury is unknown

today, but will be important to explore in the future.In conclusion, mental fatigue after MTBI or TBI

remains in many cases for a very long time and can

be profoundly disabling, affecting working capacity

as well as recreation and social activities. It is

proposed that the self-assessment scale used here

in combination with tests that primarily measure

information processing speed and a high cognitive

load on attention might make it possible to capture

problems described by patients with mental fatigue

such as reading, participating in discussions and

activities involving an environment containing a



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large amount of stimuli. Subjective mental fatigue

after MTBI and TBI is thus suggested to primarily

correlate with objectively measured information

processing speed.

Acknowledgements

This work was supported by grants from The Health

& Medical Care Committee of the Region Vastra

Gotaland, Swedish Research Council, 21X-13015

and from Fyrbodalinstitutet.

Declaration of interest: The authors report no

conflicts of interest. The authors alone are respon-

sible for the content and writing of the paper.

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Appendix: Adjusted version

Self report of mental fatigue and related symptoms

This questionnaire will help us to find out how you perceive your health.

We are interested in your present condition, that is how you have felt during the past month.

Each question below is followed by four statements that describe: No (0), Slight (1), Fairly serious (2) and

Serious (3) problems.

We would like you to place a circle around the figure before the statement that best describes your problems.

Should you find that your problem falls between two statements, there are also figures to indicate this.

1. Fatigue

Have you felt fatigued during the past month? It does not matter if the fatigue is physical (muscular) or mental.

If you recently experienced something unusual (for example an accident or short illness) you should try to

disregard it when assessing your fatigue.0 I do not feel fatigued at all. (No abnormal fatigue, do not need to rest more than usual).

0.5

1 I feel fatigued several times every day but I feel more alert after a rest.

1.5

2 I feel fatigued for most of the day and taking a rest has little or no effect.

2.5

3 I feel fatigued all the time and taking a rest makes no difference.

2. Lack of initiative

Do you find it difficult to start things? Do you experience resistance or a lack of initiative when you have to start

something, no matter whether it is a new task or part of your everyday activities?



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0 I have no difficulty starting things.

0.5

1 I find it more difficult starting things than I used to. Id rather do it some other time.

1.5

2 It takes a great effort to start things. This applies to everyday activities such as getting out of bed, washing myself and eating.

2.5

3 I cant do the simplest of everyday tasks (eating, getting dressed). I need help with everything.

3. Mental fatigue

Does your brain become fatigued quickly when you have to think hard? Do you become mentally fatigued from

things such as reading, watching TV or taking part in a conversation with several people? Do you have to take

breaks or change to another activity?

0 I can manage in the same way as usual. My ability for sustained mental effort is not reduced.

0.5

1 I become fatigued quickly but am still able to make the same mental effort as before.

1.5

2 I become fatigued quickly and have to take a break or do something else more often than before.

2.5

3 I become fatigued so quickly that I can do nothing or have to abandon everything after a short period ($5 minutes).

4. Mental recoveryIf you have to take a break, how long do you need to recover after you have worked until you drop or are no

longer able to concentrate on what you are doing?

0 I need to rest for less than an hour before continuing whatever I am doing.

0.5

1 I need to rest for more than an hour but do not require a nights sleep.

1.5

2 I need a nights sleep before I can continue whatever I am doing.

2.5

3 I need several days rest in order to recover.

5. Concentration difficulties

Do you find it difficult to gather your thoughts and concentrate?

0 I can concentrate as usual.0.5

1 I sometimes lose concentration, for example when reading or watching TV.

1.5

2 I find it so difficult to concentrate that I have problems, for example reading a newspaper or taking part in a conversation with

a group of people.

2.5

3 I always have such difficulty concentrating that it is almost impossible to do anything.

6. Memory problems

Do you forget things more often than before, do you need to make notes or do you have to search for things

at home or at work?

0 I h ave no memory p roblems.

0.51 I forget things slightly more often than I should, but I am able to manage by making notes.

1.5

2 My poor memory causes frequent problems (for example forgetting important meetings or turning off the cooker).

2.5

3 I can hardly remember anything at all.

7. Slowness of thinking

Do you feel slow or sluggish when you think about something? Do you feel that it takes an unusually long time

to conclude a train of thought or solve a task that requires mental effort?



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0 My thoughts are neither slow nor sluggish when it comes to work involving mental effort.

0.5

1 My thoughts are a bit slow one or a few times each day when I have to do something that requires serious mental effort.

1.5

2 My thoughts often feel slow and sluggish, even when carrying out everyday activities, for example a conversation with a person or

when reading the newspaper.

2.5

3 My thoughts always feel very slow and sluggish.

8. Sensitivity to stress

Do you find it difficult to cope with stress, that is doing several things at the same time while under time

pressure?

0 I am able to cope with stress in the same way as usual.

0.5

1 I become more easily stressed, but only in demanding situations that I was previously able to manage.

1.5

2 I become stressed more easily than before. I feel stressed in situations that previously did not bother me.

2.5

3 I become stressed very easily. I feel stressed in unfamiliar or trying situations.

9. Increased tendency to become emotionalDo you find that you cry more easily than previously? Do you often burst into tears when, for example, you

watch a sad film or talk with your family members? If you recently experienced something unusual (for example

an accident or short illness) you should try to disregard it in your assessment.

0 I am not more emotional than I used to be.

0.5

1 I am more emotional than other people but it is something that is natural for me. I start to cry or my eyes fill with tears easily,

but only in relation to things that affect me deeply.

1.5

2 My emotions are problematic or embarrassing. I sometimes even start to cry about things that mean nothing to me. I try to avoid

certain situations because of this.

2.5

3 My emotions cause me great problems. They disturb my day-to-day relationship with members of my immediate family and

make it difficult for me to cope outside the home.

10. Irritability or a short fuse

Are you unusually short-tempered or irritable about things that previously did not bother you?

0 I am not more short-tempered or irritable than I used to be.

0.5

1 I become more easily irritated, but it does not last very long.

1.5

2 I become irritated very quickly about small things or things that do not bother other people.

2.5

3 I react with extreme anger or rage, which I find very difficult to control.

11. Sensitivity to light

Are you sensitive to strong light?0 I have no increased sensitivity to light.

0.5

1 I sometimes experience problems with strong light such as sunlight reflected by snow, water or glass, or strong lights at home,

but I am able to cope with it, for example by wearing sunglasses.

1.5

2 I am so sensitive to light that I prefer to carry out my daily activities in dim light. I find it difficult to leave the house without

sunglasses.

2.5

3 My sensitivity to light is so strong that I am unable to leave the house without sunglasses. I keep the blinds (or equivalent) drawn

at all times.



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12. Sensitivity to noise

Are you sensitive to noise?

0 I do not suffer from increased sensitivity to noise.

0.5

1 I sometimes have difficulty with loud noise (for example music, noise from the TV or radio or sudden, unexpected sounds),

but I can deal with it easily by turning down the volume. My sensitivity to noise does not disturb my everyday life.

1.5

2 I have a marked over-sensitivity to noise. I have to avoid loud noise or reduce it (for example by means of ear plugs) in order

to cope with everyday life.

2.5

3 My sensitivity to noise is so great that I find it difficult to manage at home, despite sound insulation.

13. Decreased sleep at night

Do you sleep badly at night? If you are sleeping more than before at night, please place a circle around the 0.

If you are taking sleeping tablets and sleep normally, please place a circle around the 0.

0 I do not sleep less than before.

0.5

1 I have slight problems falling asleep or my sleep is shorter, lighter or more restless than before.

1.5

2 I sleep at least 2 hours less than before and wake up frequently during the night without anything disturbing me.

2.53 I sleep less than 23 hours per night.

14. Increased sleep

Do you sleep longer and/or more deeply than before? If you are sleeping less than before, please place a circle

around the 0. NB: Please take account of time spent sleeping during the day.

0 I do not sleep more than usual

0.5

1 I sleep longer or deeper, but less than 2 hours more than usual, including naps during the day.

1.5

2 I sleep longer or deeper. At least 2 hours more than usual, including naps.

2.5

3 I sleep longer or deeper. At least 4 hours more than usual, and in addition I need to take a nap during the day.

15. 24-hour variations

Do you find that at certain times of the day or night the problems we asked about (for example tiredness, lack of

concentration) are better or worse? In the statements below, regularly means at least 34 days of the week.

0 I have not noticed that my problems are regularly better or worse at certain times, or I do not have any specific problems.

1 There is a clear difference between certain times of the day. I can predict that I will feel better at certain times and worse at other

times.

2 I feel unwell at all times of the day and night.

If you experience 24-hour variations:

When do you feel at your best? Morning Afternoon Evening Night

When do you feel at your worst? Morning Afternoon Evening Night



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Documents

Mental Fatigue and Attention Problems Due to Brain Injury