Sleep anomalies in the chronic fatigue syndrome. A comorbidity study

Abstract:

Polysomnographic findings were compared between a group of patients with the chronic fatigue syndrome (CFS; n = 49) and a matched healthy control (HC) group (n = 20).

Sleep initiation and sleep maintenance disturbances were observed in the CFS group. The percentage of stage 4 was significantly lower in the CFS group. A discriminant analysis allowed a high level of correct classification of CFS subjects and HC. Sleep-onset latency and the number of stage shifts/hour contributed significantly to the discriminant function.

The presence of these anomalies as well as the decrease in stage 4 sleep were not limited to the patients also diagnosed with fibromyalgia or with a psychiatric disorder. No association was found between sleep disorders and the degree of functional status impairment. The mean REM latency and the percentage of subjects with a shortened REM latency were similar in CFS and HC.

 

Source: Fischler B, Le Bon O, Hoffmann G, Cluydts R, Kaufman L, De Meirleir K. Sleep anomalies in the chronic fatigue syndrome. A comorbidity study. Neuropsychobiology. 1997;35(3):115-22. http://www.ncbi.nlm.nih.gov/pubmed/9170115

 

Cognitive performance and complaints of cognitive impairment in chronic fatigue syndrome (CFS)

Abstract:

Patients with chronic fatigue syndrome (CFS) complain that they have difficulties with concentration and memory but studies to date have not found consistent objective evidence of performance deficits.

Two groups of CFS patients, depressed and non-depressed, and healthy controls, were asked about concentration problems in general and specifically when reading. CFS subjects were more likely than controls to report that they had concentration problems when reading, that they needed to re-read text and that they failed to take in what they were reading.

Subjects then performed a task in which their reading behaviour and text recall was measured. While all CFS subjects complained of general cognitive failures and of difficulties with reading, only depressed CFS subjects recalled significantly less of the text than controls. Severity of complaints about reading problems was not related to amount of text recalled, but was related to severity of depressed mood. However, subjects were able to evaluate accurately their ability to remember the text immediately after reading it and before being tested for recall.

Additionally, subjects performed a paired-associate learning task on which no significant differences between the subject groups was found. It is concluded that deficits in cognitive functioning in CFS patients are more likely to be found on naturalistic than on laboratory tasks.

 

Source: Wearden A, Appleby L. Cognitive performance and complaints of cognitive impairment in chronic fatigue syndrome (CFS). Psychol Med. 1997 Jan;27(1):81-90. http://www.ncbi.nlm.nih.gov/pubmed/9122311

 

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

 

Screening for psychiatric disorders in chronic fatigue and chronic fatigue syndrome

Abstract:

Psychiatric disorders are common in chronic fatigue (CF) and chronic fatigue syndrome (CFS). To determine the usefulness of the General Health Questionnaire (GHQ), a self-report measure of psychological distress, in identifying those with psychiatric illnesses, a structured psychiatric interview and the GHQ were administered to 120 CF and 161 CFS patients seen in a referral clinic.

Overall, 87 (35%) patients had a current and 210 (82%) a lifetime psychiatric disorder. Compared to patients without psychiatric disorders, GHQ scores above the threshold (> or = 12) were more frequent among patients with current (p < 0.001) and lifetime (p < 0.05) diagnoses; scores among patients with CF and CFS were similar.

Longer illness duration, greater fatigue severity, and current psychiatric disorders were significant predictors of the GHQ score. In CF and CFS, the best sensitivity (0.69-0.76) and specificity (0.51-0.62) were achieved for current psychiatric diagnoses using a threshold score of > or = 12. Thus, patients scoring < 12 on the GHQ are significantly less likely to have a psychiatric disorder.

 

Source: Buchwald D, Pearlman T, Kith P, Katon W, Schmaling K. Screening for psychiatric disorders in chronic fatigue and chronic fatigue syndrome. J Psychosom Res. 1997 Jan;42(1):87-94. http://www.ncbi.nlm.nih.gov/pubmed/9055216

 

In vitro effects of echinacea and ginseng on natural killer and antibody-dependent cell cytotoxicity in healthy subjects and chronic fatigue syndrome or acquired immunodeficiency syndrome patients

Abstract:

Extracts of Echinacea purpurea and Panax ginseng were evaluated for their capacity to stimulate cellular immune function by peripheral blood mononuclear cells (PBMC) from normal individuals and patients with either the chronic fatigue syndrome or the acquired immunodeficiency syndrome.

PBMC isolated on a Ficoll-hypaque density gradient were tested in the presence or absence of varying concentrations of each extract for natural killer (NK) cell activity versus K562 cells and antibody-dependent cellular cytotoxicity (ADCC) against human herpesvirus 6 infected H9 cells. Both echinacea and ginseng, at concentrations > or = 0.1 or 10 micrograms/kg, respectively, significantly enhanced NK-function of all groups. Similarly, the addition of either herb significantly increased ADCC of PBMC from all subject groups.

Thus, extracts of Echinacea purpurea and Panax ginseng enhance cellular immune function of PBMC both from normal individuals and patients with depressed cellular immunity.

 

Source: See DM, Broumand N, Sahl L, Tilles JG. In vitro effects of echinacea and ginseng on natural killer and antibody-dependent cell cytotoxicity in healthy subjects and chronic fatigue syndrome or acquired immunodeficiency syndrome patients. Immunopharmacology. 1997 Jan;35(3):229-35. http://www.ncbi.nlm.nih.gov/pubmed/9043936

 

Chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) has emerged as a public health concern over the past decade. A working case definition was created in 1988 and revised in 1994, and this has been used to establish prevalence estimates using physician-based surveillance and an a random digit dial telephone survey. Although CFS has some characteristics of an infectious disease, so far no infectious agent has been associated with the illness. Studies of immune function in CFS patients failed to detect differences between cases and healthy controls. However, when cases were subgrouped according to whether they had a sudden or gradual onset, differences in immunologic markers were detected between cases and their matched controls.

 

Source: Mawle AC. Chronic fatigue syndrome. Immunol Invest. 1997 Jan-Feb;26(1-2):269-73. http://www.ncbi.nlm.nih.gov/pubmed/9037629

 

Cognitive slowing and working memory difficulties in chronic fatigue syndrome

Abstract:

OBJECTIVE: Patients with chronic fatigue syndrome (CFS) commonly report problems with attention, memory, learning, and speed of cognitive processing. This study attempted to evaluate these complaints using objective test criteria.

METHOD: A test battery composed of six tests assessing these cognitive functions was given on two consecutive days. Twenty CFS patients were compared with 20 healthy control subjects and 14 patients with a history of major depression or dysthymia matched by age, intelligence, education level, and sex.

RESULTS: Compared with control subjects, CFS patients consistently scored lower on tests in which motor and cognitive processing speeds were a critical factor, eg, reaction-time tasks. They also had more difficulty on working-memory tests in which rapid cognitive processing speed is also an important factor. The effort made on the first day of testing did not result in a decline in cognitive function on the following day. CFS patients did not qualify as having affective disorder by several different diagnostic criteria. Nonetheless, CFS patients’ test performances did not differ from patients with a history of major depression or dysthymia.

CONCLUSIONS: It is concluded that, although CFS and major depression and dysthymia have distinct clinical features, these disorders have slowed motor and cognitive processing speed in common.

Comment in: Cognitive slowing in chronic fatigue syndrome (CFS) [Psychosom Med. 1997]

 

Source: Marshall PS, Forstot M, Callies A, Peterson PK, Schenck CH. Cognitive slowing and working memory difficulties in chronic fatigue syndrome. Psychosom Med. 1997 Jan-Feb;59(1):58-66. http://www.ncbi.nlm.nih.gov/pubmed/9021867

 

Amantadine and L-carnitine treatment of Chronic Fatigue Syndrome

Abstract:

Carnitine is essential for mitochondrial energy production. Disturbance in mitochondrial function may contribute to or cause the fatigue seen inChronic Fatigue Syndrome (CFS) patients.

Previous investigations have reported decreased carnitine levels in CFS. Orally administered L-carnitine is an effective medicine in treating the fatigue seen in a number of chronic neurologic diseases. Amantadine is one of the most effective medicines for treating the fatigue seen in multiple sclerosis patients. Isolated reports suggest that it may also be effective in treating CFS patients. Formal investigations of the use of L-carnitine and amantadine for treating CFS have not been previously reported.

We treated 30 CFS patients in a crossover design comparing L-carnitine and amantadine. Each medicine was given for 2 months, with a 2-week washout period between medicines. L-Carnitine or amantadine was alternately assigned as first medicine.

Amantadine was poorly tolerated by the CFS patients. Only 15 were able to complete 8 weeks of treatment, the others had to stop taking the medicine due to side effects. In those individuals who completed 8 weeks of treatment, there was no statistically significant difference in any of the clinical parameters that were followed.

However, with L-carnitine we found statistically significant clinical improvement in 12 of the 18 studied parameters after 8 weeks of treatment. None of the clinical parameters showed any deterioration. The greatest improvement took place between 4 and 8 weeks of L-carnitine treatment. Only 1 patient was unable to complete 8 weeks of treatment due to diarrhea.

L-Carnitine is a safe and very well tolerated medicine which improves the clinical status of CFS patients. In this study we also analyzed clinical and laboratory correlates of CFS symptomatology and improvement parameters.

 

Source: Plioplys AV, Plioplys S. Amantadine and L-carnitine treatment of Chronic Fatigue Syndrome. Neuropsychobiology. 1997;35(1):16-23. http://www.ncbi.nlm.nih.gov/pubmed/9018019

 

Clinical improvement in chronic fatigue syndrome is not associated with lymphocyte subsets of function or activation

Abstract:

The relationship between markers of immune function and chronic fatigue syndrome (CFS) is controversial. To examine the relationship directly, 43 subjects with CFS entering a randomized controlled trial of a nonpharmacological treatment for CFS gave samples for immunological analysis before and after treatment. Percentage levels of total CD3+ T cells, CD4 T cells, CD8 T cells, and activated subsets did not differ between CFS subjects and controls. Naive (CD45RA+ RO-) and memory (CD45RA- RO+) T cells did not differ between subjects and controls.

Natural killer cells (CD16+/CD56+/CD3-) were significantly increased in CFS patients compared to controls, as was the percentage of CD11b+ CD8 cells.

There were no correlations between any immune variable and measures of clinical status, with the exception of a weak correlation between total CD4 T cells and fatigue. There was a positive correlation between memory CD4 and CD8 T cells and depression scores and a negative correlation between naive CD4 T cells and depression.

No immune measures changed during the course of the study, and there was no link between clinical improvement as a result of the treatment program and immune status. Immune measures did not predict response or lack of response to treatment.

In conclusion, we have been unable to replicate previous findings of immune activation in CFS and unable to find any important associations between clinical status, treatment response, and immunological status.

 

Source: Peakman M, Deale A, Field R, Mahalingam M, Wessely S. Clinical improvement in chronic fatigue syndrome is not associated with lymphocyte subsets of function or activation. Clin Immunol Immunopathol. 1997 Jan;82(1):83-91. http://www.ncbi.nlm.nih.gov/pubmed/9000046

 

Immune responses associated with chronic fatigue syndrome: a case-control study

Abstract:

An exploratory case-control study was conducted to assess whether the many reported differences in the immune function of chronic fatigue syndrome (CFS) patients are detectable in rigorously defined cases of CFS. Although many studies have reported differences between cases and controls in various measures of immune function, none of these differences were found in all studies.

In this study, no differences were found in white blood cell numbers; immune complex, complement, or serum immunoglobulin levels; delayed type hypersensitivity and allergic responses; NK cell function; and proliferative responses to mitogens and antigens. Marginal differences were detected in cytokine responses and in cell surface markers in the total CFS population.

However, when the patients were subgrouped by type of disease onset (gradual or sudden) or by how well they were feeling on the day of testing, more pronounced differences were seen

 

Source: Mawle AC, Nisenbaum R, Dobbins JG, Gary HE Jr, Stewart JA, Reyes M, Steele L, Schmid DS, Reeves WC. Immune responses associated with chronic fatigue syndrome: a case-control study. J Infect Dis. 1997 Jan;175(1):136-41. http://jid.oxfordjournals.org/content/175/1/136.long (Full article)