Tag: attentional deficits

Memory, attention, and executive function in chronic fatigue syndrome

Abstract:

OBJECTIVES: To examine cognitive function in chronic fatigue syndrome.

METHODS: Twenty patients with chronic fatigue syndrome recruited from primary care and 20 matched normal controls were given CANTAB computerised tests of visuospatial memory, attention, and executive function, and verbal tests of letter and category fluency and word association learning.

RESULTS: Patients with chronic fatigue syndrome were impaired, predominantly in the domain of memory but their pattern of performance was unlike that of patients with amnesic syndrome or dementia. They were normal on tests of spatial pattern recognition memory, simultaneous and delayed matching to sample, and pattern-location association learning. They were impaired on tests of spatial span, spatial working memory, and a selective reminding condition of the pattern-location association learning test. An executive test of planning was normal. In an attentional test, eight subjects with chronic fatigue syndrome were unable to learn a response set; the remainder exhibited no impairment in the executive set shifting phase of the test. Patients with chronic fatigue syndrome were also impaired on verbal tests of unrelated word association learning and letter fluency.

CONCLUSION: Patients with chronic fatigue syndrome have reduced attentional capacity resulting in impaired performance on effortful tasks requiring planned or self ordered generation of responses from memory.

Source: Joyce E, Blumenthal S, Wessely S. Memory, attention, and executive function in chronic fatigue syndrome. J Neurol Neurosurg Psychiatry. 1996 May;60(5):495-503. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC486360/ (Full article)

Behavioural problems associated with the chronic fatigue syndrome

Abstract:

Disturbances of memory, concentration and motor function are often reported by patients with the chronic fatigue syndrome (CFS). The present study objectively evaluated these behavioural problems using a computerized test battery measuring memory, attention and motor skills.

Fifty-seven CFS patients were compared with 19 matched controls and all subjects completed the performance test battery and filled in questionnaires measuring psychopathology and mood. The patients reported significantly higher levels of depression, anxiety, physical symptoms and cognitive failures than the controls. Similarly, they reported more negative affect at the time of testing.

The patients were slower on psychomotor tasks, showed increased visual sensitivity and impaired attention. Digit span and free recall were not impaired but retrieval from semantic memory and logical reasoning were slower. None of the performance differences between patients and controls could be attributed to differences in psychopathology. These results agree with recent findings from other laboratories, and it is now time to consider the nature of the neurological dysfunction underlying these effects.

 

Source: Smith AP, Behan PO, Bell W, Millar K, Bakheit M. Behavioural problems associated with the chronic fatigue syndrome. Br J Psychol. 1993 Aug;84 ( Pt 3):411-23. http://www.ncbi.nlm.nih.gov/pubmed/8401992

 

Sensory and cognitive event-related potentials in myalgic encephalomyelitis

Abstract:

Myalgic Encephalomyelitis (ME) is a form of post viral fatigue syndrome resulting in myalgia and fluctuating fatiguability. Symptoms reflecting central nervous system dysfunction are common and include muscle weakness, headache, sensory disturbances, poor short term memory and impairment of concentration.

In view of the fact that sensory and cognitive disturbances are experienced by many patients objective evidence was sought with multi-modality sensory evoked potentials and auditory event-related cognitive potentials in a group of ME patients both with and without the enteroviral antigen, VP1 test positive.

The auditory brainstem, median nerve somatosensory and pattern reversal checkerboard visual potentials were normal for all 37 patients tested. In contrast to the sensory potentials significant differences in the mean latencies of the cognitive potential N2 and P3 were found. Reaction times were also significantly prolonged but the performance in terms of error was not significantly affected. No significant difference emerged in any of the parameters for the VP1 test. P3 was abnormal in latency or amplitude in 36% of the VP1 positive patients for the frequency discrimination task and 48% for the more difficult duration discrimination task.

The abnormalities indicate attentional deficits in some patients and slower speed of information processing in others. The prolonged latencies observed in these patients have not been observed in patients with depression in many other studies.

 

Source: Prasher D, Smith A, Findley L. Sensory and cognitive event-related potentials in myalgic encephalomyelitis. J Neurol Neurosurg Psychiatry. 1990 Mar;53(3):247-53. http://www.ncbi.nlm.nih.gov/pubmed/2324756

Note: You can read the full article here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1014138/