Cognitive dysfunction relates to subjective report of mental fatigue in patients with chronic fatigue syndrome.
Neuropsychopharmacology. 2006-01-04; 31(8): 1777-1784
DOI: 10.1038/sj.npp.1301005
Read on PubMed
1. Neuropsychopharmacology. 2006 Aug;31(8):1777-84. Epub 2006 Jan 4.
Cognitive dysfunction relates to subjective report of mental fatigue in patients
with chronic fatigue syndrome.
Capuron L(1), Welberg L, Heim C, Wagner D, Solomon L, Papanicolaou DA, Craddock
RC, Miller AH, Reeves WC.
Author information:
(1)Department of Psychiatry and Behavioral Sciences, Emory University School of
Medicine, Atlanta, GA, USA.
Patients with chronic fatigue syndrome (CFS) frequently complain of cognitive
dysfunction. However, evidence of cognitive impairment in CFS patients has been
found in some, but not other, studies. This heterogeneity in findings may stem
from the relative presence of mental fatigue in the patient populations examined.
The present study assessed this possibility in a population-based sample of CFS
patients. In all, 43 patients with CFS defined by the criteria of the 1994
research case definition using measurements recommended by the 2003 International
CFS Study Group, and 53 age-, sex-, and race/ethnicity-matched nonfatigued
subjects were included in the study. Mental fatigue was assessed using the mental
fatigue subscale of the multidimensional fatigue inventory. Cognitive function
was evaluated using an automated battery of computerized tests (Cambridge
neuropsychological test automated battery (CANTAB)) that assessed psychomotor
function, planning and problem-solving abilities, and memory and attentional
performance. CFS patients with significant complaints of mental fatigue (score of
mental fatigue 2 standard deviations above the mean of nonfatigued subjects)
exhibited significant impairment in the spatial working memory and sustained
attention (rapid visual information processing) tasks when compared to CFS
patients with low complaints of mental fatigue and nonfatigued subjects. In CFS
patients with significant mental fatigue, sustained attention performance was
impaired only in the final stages of the test, indicating greater cognitive
fatigability in these patients. CFS patients with low mental fatigue displayed
performance comparable to nonfatigued subjects on all tests of the CANTAB
battery. These findings show strong concordance between subjective complaints of
mental fatigue and objective measurement of cognitive impairment in CFS patients
and suggest that mental fatigue is an important component of CFS-related
cognitive dysfunction.
DOI: 10.1038/sj.npp.1301005
PMID: 16395303 [Indexed for MEDLINE]