Category: Cognitive Dysfunction

Cognitive deficits in patients suffering from chronic fatigue syndrome, acute infective illness or depression

Abstract:

BACKGROUND: Patients with chronic fatigue syndrome (CFS) report neuro-psychological symptoms as a characteristic feature. We sought to assess cognitive performance in patients with CFS, and compare cognitive performance and subjective workload experience of these patients with that of two disease comparison groups (non-melancholic depression and acute infection) and healthy controls.

METHOD: A computerized performance battery employed to assess cognitive functioning included tests of continuous attention, response speed, performance accuracy and memory. Severity of mood disturbance and subjective fatigue were assessed by questionnaire.

RESULTS: All patient groups demonstrated increased errors and slower reaction times, and gave higher workload ratings than healthy controls. Patients with CFS and non-melancholic depression had more severe deficits than patients with acute infection. All patient groups reported more severe mood disturbance and fatigue than healthy controls, but patients with CFS and those with acute infection reported less severe mood disturbance than patients with depression.

CONCLUSIONS: As all patients demonstrated similar deficits in attention and response speed, it is possible that common pathophysiological processes are involved. The differences in severity of mood disturbance, however, suggest that the pathophysiological processes in patients with CFS and acute infection are not simply secondary to depressed mood.

 

Source: Vollmer-Conna U, Wakefield D, Lloyd A, Hickie I, Lemon J, Bird KD, Westbrook RF. Cognitive deficits in patients suffering from chronic fatigue syndrome, acute infective illness or depression. Br J Psychiatry. 1997 Oct;171:377-81. http://www.ncbi.nlm.nih.gov/pubmed/9373430

 

Post-Lyme syndrome and chronic fatigue syndrome. Neuropsychiatric similarities and differences

Abstract:

BACKGROUND: Patients with chronic fatigue syndrome (CFS) and post-Lyme syndrome (PLS) share many features, including symptoms of severe fatigue and cognitive difficulty.

OBJECTIVE: To examine the neuropsychiatric differences in these disorders to enhance understanding of how mood, fatigue, and cognitive performance interrelate in chronic illness.

METHODS: Twenty-five patients with CFS, 38 patients with PLS, and 56 healthy controls participated in the study. Patients with CFS met 1994 criteria for CFS and lacked histories suggestive of Lyme disease. Patients with PLS were seropositive for Lyme disease, had met the Centers for Disease Control and Prevention criteria, or had histories strongly suggestive of Lyme disease and were experiencing severe fatigue that continued 6 months or more following completion of antibiotic treatment for Lyme disease. All subjects completed self-report measures of somatic symptoms and mood disturbance and underwent neuropsychological testing. All patients also underwent a structured psychiatric interview.

RESULTS: Patients with CFS and PLS were similar in several somatic symptoms and in psychiatric profile. Patients with CFS reported more flulike symptoms than patients with PLS. Patients with PLS but not patients with CFS performed significantly worse than controls on tests of attention, verbal memory, verbal fluency, and motor speed. Patients with PLS without a premorbid history of psychiatric illness did relatively worse on cognitive tests than patients with PLS with premorbid psychiatric illness compared with healthy controls.

CONCLUSIONS: Despite symptom overlap, patients with PLS show greater cognitive deficits than patients with CFS compared with healthy controls. This is particularly apparent among patients with PLS who lack premorbid psychiatric illness.

 

Source: Gaudino EA, Coyle PK, Krupp LB. Post-Lyme syndrome and chronic fatigue syndrome. Neuropsychiatric similarities and differences. Arch Neurol. 1997 Nov;54(11):1372-6. http://www.ncbi.nlm.nih.gov/pubmed/9362985

 

Patients with chronic fatigue syndrome and accurate feeling-of-knowing judgments

Abstract:

Many Chronic Fatigue Syndrome (CFS) patients complain of memory impairments which have been difficult to document empirically. Subjective complaints of memory impairment may be due to a deficit in metamemory judgment. CFS patients and matched controls were tested with a computerized Trivia Information Quiz that required them to rate their confidence about correctly recognizing an answer in a multiple choice format that they had been unable to remember in a fact-recall format. Even though CFS patients reported significantly greater amounts of fatigue, cognitive, and physical symptoms, the accuracy of their confidence levels and recognition responses were similar to controls. This finding suggests that a metamemory deficit is not the cause of the memory problems reported by CFS patients.

 

Source: Lakein DA, Fantie BD, Grafman J, Ross S, O’Fallon A, Dale J, Straus SE. Patients with chronic fatigue syndrome and accurate feeling-of-knowing judgments. J Clin Psychol. 1997 Nov;53(7):635-45. http://www.ncbi.nlm.nih.gov/pubmed/9356893

 

Neuropsychology of chronic fatigue syndrome: a critical review

Abstract:

This article provides a comprehensive and critical review of the neuropsychological and related literature on chronic fatigue syndrome (CFS). Despite the methodological limitations observed in several studies, some consistent findings are noted.

The most consistently documented neuropsychological impairments are in the areas of complex information processing speed and efficiency. General intellectual abilities and higher order cognitive skills are intact. Emotional factors influence subjective report of cognitive difficulty, whereas their effect on objective performance remains uncertain.

Although the neuropathological processes underlying cognitive dysfunction in CFS are not yet known, preliminary evidence suggests the involvement of cerebral white matter. Directions for future research are outlined.

 

Source: Tiersky LA, Johnson SK, Lange G, Natelson BH, DeLuca J. Neuropsychology of chronic fatigue syndrome: a critical review. J Clin Exp Neuropsychol. 1997 Aug;19(4):560-86. http://www.ncbi.nlm.nih.gov/pubmed/9342690

 

Cognitive functioning is impaired in patients with chronic fatigue syndrome devoid of psychiatric disease

Abstract:

OBJECTIVE: To examine the effect of the presence or absence of psychiatric disease on cognitive functioning in chronic fatigue syndrome.

METHODS: Thirty six patients with chronic fatigue syndrome and 31 healthy controls who did not exercise regularly were studied. Subgroups within the chronic fatigue syndrome sample were formed based on the presence or absence of comorbid axis I psychiatric disorders. Patients with psychiatric disorders preceding the onset chronic fatigue syndrome were excluded. Subjects were administered a battery of standardised neuropsychological tests as well as a structured psychiatric interview.

RESULTS: Patients with chronic fatigue syndrome without psychiatric comorbidity were impaired relative to controls and patients with chronic fatigue syndrome with concurrent psychiatric disease on tests of memory, attention, and information processing.

CONCLUSION: Impaired cognition in chronic fatigue syndrome cannot be explained solely by the presence of a psychiatric condition.

 

Source: DeLuca J, Johnson SK, Ellis SP, Natelson BH. Cognitive functioning is impaired in patients with chronic fatigue syndrome devoid of psychiatric disease. J Neurol Neurosurg Psychiatry. 1997 Feb;62(2):151-5. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC486726/ (Full article)

 

The effects of fatigue on neuropsychological performance in patients with chronic fatigue syndrome, multiple sclerosis, and depression

Abstract:

The effects of fatigue on neuropsychological performance were examined in patients with fatiguing illnesses. Repeated testing with the Paced Auditory Serial Addition Test (PASAT; Gronwall, 1977) was employed over the course of a demanding neuropsychological testing session. It was hypothesized that if fatigue affects performance, one would expect to observe “blunting” of the PASAT practice effect.

Fifteen of the study participants live with chronic fatigue syndrome (CFS), 15 with multiple sclerosis (MS), 14 with depression (DEP), and 15 are healthy, sedentary controls. Overall PASAT performance was significantly reduced for CFS and DEP participants compared to controls, whereas mean performance did not differ across the three fatiguing illness groups. Degree of improvement across trials (i.e., practice effect) for the groups did not differ from controls’. Neither subjective fatigue or DEP were significantly related to PASAT performance.

These findings suggest that fatigue does not universally impair performance during neuropsychological assessment even in groups in which fatigue is a prominent symptom.

 

Source: Johnson SK, Lange G, DeLuca J, Korn LR, Natelson B. The effects of fatigue on neuropsychological performance in patients with chronic fatigue syndrome, multiple sclerosis, and depression. Appl Neuropsychol. 1997;4(3):145-53. http://www.ncbi.nlm.nih.gov/pubmed/16318477

 

Sudden vs gradual onset of chronic fatigue syndrome differentiates individuals on cognitive and psychiatric measures

Abstract:

To examine the influence of mode of illness onset on psychiatric status and neuropsychological performance, 36 patients with CFS were divided into two groups: sudden vs gradual onset of symptoms.

These two CFS subgroups were compared to each other and to sedentary healthy controls on standardized neuropsychological tests of attention/concentration, information processing efficiency, memory, and higher cortical functions. In addition, the distribution of comorbid Axis I psychiatric disease between the two CFS groups was examined.

The rate of concurrent psychiatric disease was significantly greater in the CFS-gradual group relative to the CFS-sudden group. While both CFS groups showed a significant reduction in information processing ability relative to controls, impairment in memory was more severe in the CFS-sudden group. Because of the significant heterogeneity of the CFS population, the need for subgroup analysis is discussed.

 

Source: DeLuca J, Johnson SK, Ellis SP, Natelson BH. Sudden vs gradual onset of chronic fatigue syndrome differentiates individuals on cognitive and psychiatric measures. J Psychiatr Res. 1997 Jan-Feb;31(1):83-90. http://www.ncbi.nlm.nih.gov/pubmed/9201650

 

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

 

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

 

Cognitive functioning in patients with chronic fatigue syndrome

Abstract:

A comprehensive battery of neuropsychological tests was administered to 35 outpatients suffering from Chronic Fatigue Syndrome (CFS). They were compared to 33 normal controls matched for age, gender, intelligence, and education.

The patients displayed psychomotor slowing and impaired attention. The learning rate of verbal and visual material for patients with CFS was slower, and delayed recall of verbal and visual information was impaired. Because there was a high variability in cognitive impairment within the CFS group, it would be inappropriate to generalize results to the entire CFS population. Two neuropsychological variables indicating aspects of psychomotor performance and verbal memory were found to discriminate best between patients and controls.

 

Source: Michiels V, Cluydts R, Fischler B, Hoffmann G, Le Bon O, De Meirleir K. Cognitive functioning in patients with chronic fatigue syndrome. J Clin Exp Neuropsychol. 1996 Oct;18(5):666-77. http://www.ncbi.nlm.nih.gov/pubmed/8941852