title: An investigation of attention, executive, and psychomotor aspects of cognitive fatigability.
abstract: OBJECTIVE
  Self-perceived mental fatigue is a common presenting symptom in many neurological diseases. Discriminating objective fatigability from self-perceived mental fatigue might facilitate neuropsychological diagnosis and treatment programs. However clinically valid neuropsychological instruments suitable for assessment of fatigability are still lacking. The prime aim of the study was to investigate aspects of cognitive fatigability and to identify properties of neuropsychological tests suitable to assess fatigability in patients with persistent cognitive complaints after mild brain injury. Another aim was to investigate whether cognitive fatigability captured by neuropsychological measures is influenced by depression or sleep disturbances.
  
  
  METHODS
  Twenty-four patients with persistent cognitive symptoms after mild traumatic brain injury (mTBI), (aged 18-51 years) and 31 healthy controls (aged 20-49 years) underwent neuropsychological testing measuring three cognitive fatigability domains: Attention fatigability was assessed using the Ruff 2 & 7 Selective Attention Test, executive fatigability using the Color Word Test (Stroop), and psychomotor fatigability using the Digit Symbol Substitution Test from the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III). Subjective fatigue was measured using the Fatigue Severity Scale and a questionnaire of everyday consequences of fatigue. Depression was screened using the Hospital Anxiety and Depression Scale and sleep disturbances using the Pittsburgh Sleep Quality Index.
  
  
  RESULTS
  The patients reported significantly more mental fatigue and performed worse on tests of psychomotor and executive fatigability than the healthy controls. Furthermore, the cognitive fatigability measures were not influenced by depression or sleep disturbances, as was the case in self-reported fatigue.
  
  
  CONCLUSIONS
  Tests demanding executive or simultaneous processing of several neuropsychological functions seem most sensitive in order to capture cognitive fatigability. Clinical tests that can capture fatigability enable a deeper understanding of how fatigability might contribute to cognitive complaints and problems in maintaining daily activities.
authors: a Centre for Clinical Research Sörmland, Uppsala University , Uppsala , Sweden.
authors: Marika Christina
authors: MC
authors: Möller
authors: Catharina
authors: C
authors: Nygren de Boussard
authors: Christian
authors: C
authors: Oldenburg
authors: Aniko
authors: A
authors: Bartfai
mesh_terms: D000293:Adolescent; D000328:Adult; D001288:Attention / Q000502:physiology*; D001930:Brain Injuries / Q000150:complications; D003863:Depression / Q000503:physiopathology; D059026:Diagnostic Self Evaluation; D056344:Executive Function / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D005222:Mental Fatigue / Q000175:diagnosis* / Q000209:etiology; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000592:standards*; D011597:Psychomotor Performance / Q000502:physiology*; D012720:Severity of Illness Index; D012893:Sleep Wake Disorders / Q000503:physiopathology; D055815:Young Adult
keywords: Depression; Fatigue; Neuropsychological tests; Sleep disturbances; Traumatic brain injury