before. Drs. Natelson, Lange and DeLuca have published in this area.
Without pre-morbid functioning data it is also difficult to determine
whether a test score is "normal" for that individual. Other researchers
have found problems with areas these researchers did not, but variables
such as definition and disease stage may account for some of the
differences as might which tests were used and how they were scored.
Although the evidence is preliminary, researchers have shown that people
with viral infections have more cognitive performance issues as do people
when the immune system or gut microflora are abnomal.
This study is behind a paywall, but the fee to acquire it is $11.95 which
is a relatively low fee compared to other journals.
Cognitive deficits in chronic fatigue syndrome and their relationship to
psychological status, symptomatology, and everyday functioning.
Cockshell, Susan J.; Mathias, Jane L.
Neuropsychology, Vol 27(2), Mar 2013, 230-242.
Objective: To examine cognitive deficits in people with chronic fatigue
syndrome (CFS) and their relationship to psychological status, CFS
symptoms, and everyday functioning.
Method: The current study compared the cognitive performance (reaction
time, attention, memory, motor functioning, verbal abilities, and
visuospatial abilities) of a sample with CFS (n = 50) with that of a sample
of healthy controls (n = 50), all of whom had demonstrated high levels of
effort and an intention to perform well, and examined the extent to which
psychological status, CFS symptoms, and everyday functioning were related
to cognitive performance.
Results: The CFS group showed impaired information processing speed
(reaction time), relative to the controls, but comparable performance on
tests of attention, memory, motor functioning, verbal ability, and
Moreover, information processing speed was not related to psychiatric
status, depression, anxiety, the number or severity of CFS symptoms,
fatigue, sleep quality, or everyday functioning.
Conclusion: A slowing in information processing speed appears to be the
main cognitive deficit seen in persons with CFS whose performance on effort tests is not compromised. Importantly, this slowing does not appear to be
the consequence of other CFS-related variables, such as depression and
fatigue, or motor speed.
(PsycINFO Database Record (c) 2013 APA, all rights reserved)