Mental fatigue and impaired information processing after mild and moderate traumatic brain injury.
OBJECTIVE
Mental fatigue is a common symptom after brain injury. Its mechanisms are not fully understood and it has been difficult to find an objective way of measuring it. The aim was to compare cognitive tests with a new self-assessment questionnaire about mental fatigue.


METHODS
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, working memory 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 than controls. A significantly decreased information processing speed (digit symbol-coding, reading speed, trail making test) was found in those on sick leave due to MTBI or TBI, compared to controls. Divided attention was affected to a lesser extent and no effect was detected on working memory.


CONCLUSIONS
Mental fatigue after MTBI can last for several years. It can be profoundly disabling and affect working capacity as well as social activities. Subjective mental fatigue following brain injury is suggested to mainly correlate with objectively measured information processing speed.
Johansson
Birgitta
B
Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Sweden. birgitta.johansson2@vgregion.se
Berglund
Peter
P
Rönnbäck
Lars
L
D000328:Adult; D001930:Brain Injuries / Q000150:complications / Q000503:physiopathology* / Q000523:psychology; D003072:Cognition Disorders / Q000209:etiology / Q000503:physiopathology* / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D005222:Mental Fatigue / Q000209:etiology / Q000503:physiopathology* / Q000523:psychology; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000502:physiology*; D011795:Surveys and Questionnaires