Neuropsychological and psychological functioning in chronic fatigue syndrome

Abstract:

Although patients with chronic fatigue syndrome (CFS) typically present subjective complaints of cognitive and psychological difficulties, studies to date have provided mixed objective support for the existence of specific cognitive deficits. The present study was designed to examine differences in performance between individuals diagnosed with CFS and matched controls with respect to sustained attention, processing efficiency, learning, and memory.

Subjects included 17 patients meeting Centers for Disease Control research criteria for CFS and 17 control subjects. Subjects were administered six measures assessing attention, memory, and word-finding ability and two measures assessing psychological distress.

For the most part, the two groups did not differ on measures of neurocognitive functioning. Significant group differences were found on a single measure of attention and incidental memory. However, CFS patients differed markedly from controls with respect to reported psychological distress.

The results support previous findings of notable levels of psychological distress among CFS patients. They also suggest the need for alternative research paradigms to assess the cognitive abilities of CFS patients.

 

Source: Kane RL, Gantz NM, DiPino RK. Neuropsychological and psychological functioning in chronic fatigue syndrome. Neuropsychiatry Neuropsychol Behav Neurol. 1997 Jan;10(1):25-31. http://www.ncbi.nlm.nih.gov/pubmed/9118194

 

Cognitive functioning in chronic fatigue syndrome and depression: a preliminary comparison

Abstract:

This study used a brief battery of neuropsychological measures to examine the performance of patients with chronic fatigue syndrome (CFS) (N = 16) and patients in a major depressive episode (N = 23). The overall neuropsychological performance of the CFS group was not significantly different from depressed patients, and both groups scored within normal limits on most measures. Variability of neuropsychologic performance was in general unrelated to level of depressive symptoms. The results are discussed in terms of the validity of the cognitive criterion for the CFS diagnosis. Subjective complaints of cognitive dysfunction by CFS patients in light of the lack of objective evidence for the same are considered in terms of a somatic vigilance hypothesis.

 

Source: Schmaling KB, DiClementi JD, Cullum CM, Jones JF. Cognitive functioning in chronic fatigue syndrome and depression: a preliminary comparison. Psychosom Med. 1994 Sep-Oct;56(5):383-8. http://www.ncbi.nlm.nih.gov/pubmed/7809336

 

Cognitive functioning and depression in patients with chronic fatigue syndrome and multiple sclerosis

Abstract:

OBJECTIVE: To assess cognitive function in patients with chronic fatigue syndrome (CFS) and multiple sclerosis (MS) and to evaluate the role of depressive symptoms in cognitive performance.

DESIGN: Case-control. All subjects were given a neuropsychological battery, self-report measures of depression and fatigue, and a global cognitive impairment rating by a neuropsychologist “blinded” to clinical diagnosis. Patients with MS and CFS were additionally evaluated with a Structured Clinical Interview for DSM-III-R (Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition) disorders.

SETTING: Institutional and private neurological practices and the community at large.

PATIENTS: Twenty patients with CFS diagnosed in accord with the Centers for Disease Control and Prevention-revised criteria who had cognitive complaints; 20 patients with clinically definite MS who were ambulatory and were matched for fatigue severity, age, and education to CFS subjects; and 20 age- and education-matched healthy controls.

RESULTS: Patients with CFS had significantly elevated depression symptoms compared with patients with MS and healthy controls (P < .001) and had a greater lifetime prevalence of depression and dysthymia compared with MS subjects. Patients with CFS, relative to controls, performed more poorly on the Digit Symbol subtest (P = .023) and showed a trend for poorer performance on logical memory (P = .087). Patients with MS compared with controls had more widespread differences of greater magnitude on the Digit Span (P < .004) and Digit Symbol (P < .001), Trail Making parts A (P = .022) and B (P = .037), and Controlled Oral Word Association (P = .043) tests. Patients with MS also showed a trend of poorer performance on the Booklet Category Test (P = .089). When patients with CFS and MS were directly compared, MS subjects had lower scores on all measures, but the differences reached significance only for the Digit Span measure of attention (P = .035).

CONCLUSIONS: Patients with CFS compared with MS have more depressive symptoms but less cognitive impairment. Relative to controls, a subset of CFS subjects did poorly on tests of visuomotor search and on the logical memory measure of the Wechsler Memory Scale-revised. Poor performance of logical memory in CFS appears to be related to depression, while visuomotor deficits in CFS are unrelated. Cognitive deficits in patients with MS are more widespread compared with those in patients with CFS and are independent of depressive symptoms.

 

Source: Krupp LB, Sliwinski M, Masur DM, Friedberg F, Coyle PK. Cognitive functioning and depression in patients with chronic fatigue syndrome and multiple sclerosis. Arch Neurol. 1994 Jul;51(7):705-10. http://www.ncbi.nlm.nih.gov/pubmed/8018045

 

Neuropsychology and psychology of MCS

Abstract:

Neurological symptoms are frequently reported by patients with multiple chemical sensitivities (MCS). Methods to compare the psychiatric, personality, and neuropsychological function of patients with MCS, chronic fatigue syndrome (CFS), and normal controls are described. Increased rates of Axis I psychiatric diagnoses are observed in the literature for MCS and CFS subjects relative to controls.

Findings on the MMPI-2 and the Toronto Alexithymia Scale reveal profiles consistent with the tendency to report somatic rather than emotional symptoms in response to stress. However, many of the reported somatic symptoms also coincide with those found in neurologic disorders. The overall neuropsychological profile for MCS subjects does not reflect cognitive impairment.

Relative to normal controls, the only difference in neuropsychological performance observed is reduced recognition of nontarget designs on a visual memory task. More fruitful areas for future psychological research will include measurement of the interaction between behavioral response styles and attentional processes in cognition, as well as observations under controlled challenge conditions.

 

Source: Fiedler N, Kipen H, Deluca J, Kelly-McNeil K, Natelson B. Neuropsychology and psychology of MCS. Toxicol Ind Health. 1994 Jul-Oct;10(4-5):545-54. http://www.ncbi.nlm.nih.gov/pubmed/7778113

 

Neuropsychiatric status of patients with chronic fatigue syndrome: an overview

Abstract:

Chronic fatigue syndrome (CFS) is an illness that results in debilitating fatigue as well as rheumatological, infectious, and neuropsychiatric symptoms. The present paper is a brief overview of the neuropsychological and psychiatric research on CFS. Studies from our laboratory contrasting CFS with patients with multiple sclerosis, depression, and healthy controls are detailed. Our hypothesis of neuropsychological impairments in CFS is discussed.

 

Source: Deluca J, Johnson SK, Natelson BH. Neuropsychiatric status of patients with chronic fatigue syndrome: an overview. Toxicol Ind Health. 1994 Jul-Oct;10(4-5):513-22. http://www.ncbi.nlm.nih.gov/pubmed/7778111

 

Neuropsychological and psychiatric abnormalities in myalgic encephalomyelitis: a preliminary report

Abstract:

Ten patients attending one general medical hospital clinic who fulfilled operational criteria for the diagnosis of myalgic encephalomyelitis (ME) and with a history longer than three months, underwent a series of standardized neuropsychological and psychiatric tests. Nine were able to complete the tests and were individually matched with a normal control group for age, sex, educational background and premorbid intelligence. The ME subjects showed inferior performance to the controls on two tests of verbal memory. Their personality scores displayed less extraversion and less psychoticism. This is the first report of objective neuropsychological abnormalities in patients with ME, suggesting a discrete deterioration of short-term memory. The findings may also suggest a concurrent psychiatric component of the condition, but the direction of causality remains to be clarified.

 

Source: Riccio M, Thompson C, Wilson B, Morgan DJ, Lant AF. Neuropsychological and psychiatric abnormalities in myalgic encephalomyelitis: a preliminary report. Br J Clin Psychol. 1992 Feb;31 ( Pt 1):111-20. http://www.ncbi.nlm.nih.gov/pubmed/1559114