A comparison of memory performance in relapsing-remitting, primary progressive and secondary progressive, multiple sclerosis.

OBJECTIVE: The current investigation was designed to examine the influence of disease course on the specific patterns of acquisition and retrieval impairments in multiple sclerosis (MS). BACKGROUND: Recent investigations of learning and memory in MS have shown that many subjects have impaired verbal and visual new learning abilities, but normal long-term recall and recognition. However, heterogeneity in the learning and memory abilities of subjects has been documented. Some evidence in the literature suggests that this heterogeneity may be in part attributable to clinical variables, such as disease course. METHODS: Verbal and visual learning and memory tests, modified to equate MS groups with healthy controls on initial acquisition of information, were administered to 64 individuals with clinically definite MS (relapse-remitting = 21; primary progressive = 18; secondary progressive = 25), and to 20 healthy control participants. Recall and recognition performance then was evaluated at 30 minutes, at 90 minutes, and at 1 week for the verbal learning task, and at 30 minutes and at 90 minutes for the visual learning task. RESULTS: Results indicate that the two progressive forms of MS result in significantly greater deficits in regard to the acquisition of new verbal information, with the secondary progressive group showing a significantly higher failure rate in regard to meeting the learning criterion. Performance for recognition measures was not significantly different among groups, whereas recall performance of the primary progressive group was significantly below that of the control group and of the secondary progressive group. When testing new learning with visuospatial information, individuals with relapse-remitting MS and secondary progressive MS required more trials than control participants to learn the same amount of visual information. Visual recall and recognition performance did not differ between groups. No group differences in rates of forgetting for visuospatial material was observed after equating for acquisition. CONCLUSIONS: Results of the current study indicate that the primary problem in MS with regard to memory functioning is in the acquisition of new information. Our findings support previous research showing verbal memory deficits with a progressive disease course and visuospatial memory deficits in relapse-remitting MS. However, the detailed analysis of new learning and memory performed in the current study indicated that the primary progressive group may be showing difficulty in their ability to use newly learned information. The pattern of new learning deficits observed between MS disease subtypes in the current study was determined to be unrelated to the duration of MS and to the physical severity of the disease. The degree of physical disability observed in patients with MS does not appear to be related to the degree of cognitive decline because of the distinct patterns and severity of memory dysfunction noted within each disease type, independent of physical disability.

Development of the Functional Assessment Taxonomy.

The development of the Functional Assessment Taxonomy is described and the taxonomy is presented. The taxonomy provides a method to classify and organize constructs that are used to assess the functional abilities of people with medical impairments to determine work disability. The taxonomy has 131 constructs that are organized into 33 conceptual factors that are nested in 5 domains. Each construct is defined and is categorized in terms of the work disability model and the unit of analysis that is commonly used to measure the construct. The use of the taxonomy in the Disability Methodology Redesign Project is described. Other possible uses for the taxonomy are presented.

Learning impairment is associated with recall ability in multiple sclerosis.

Recent evidence suggests that persons with multiple sclerosis may experience deficits in verbal and visuospatial acquisition rather than recall. The present study was designed to determine whether this finding generalized to a broader range of neuropsychological tests of learning and memory. To control for group differences in information acquisition, healthy controls (HCs) and persons with multiple sclerosis (MS) were trained to specific learning criteria on both verbal (i.e., paragraph learning and paired associates) and visuospatial (i.e., facial recognition) memory tasks. Persons with MS required significantly more learning trials to meet criteria on the paragraph learning and facial recognition tasks, but not the paired associates test. However, after learning comparable amounts of information, the MS and HC groups recalled statistically similar amounts of information at 30-minutes, 90-minutes, and up to 1-week on the paragraph learning and paired associate tests. This suggests that persons with MS may have deficits in acquisition rather than recall per se. Results are discussed in terms of possible rehabilitation strategies to improve memory functioning in persons with MS.

Speed of information processing as a key deficit in multiple sclerosis: implications for rehabilitation.

Speed of information processing was assessed in patients with multiple sclerosis and healthy controls using both an auditory and visual task designed to control for accuracy of performance across groups. After controlling for accuracy of performance, patients with multiple sclerosis were found to have significantly slower speed of information processing relative healthy controls, irrespective of the modality of stimulus presentation (auditory or visual). When given an adequate amount of time to process information, however, the patients performed similarly to controls. These results suggest that persons with multiple sclerosis experience deficits specifically in processing speed but not performance accuracy. Results are discussed in terms of rehabilitative guidelines for the cognitive improvement of persons with multiple sclerosis.

Examination of Cloninger's basic dimensions of personality in fatiguing illness: chronic fatigue syndrome and multiple sclerosis.

Relatively few studies have examined the personality characteristics of patients with chronic fatigue syndrome (CFS). The personality profiles of 38 CFS subjects were compared with 40 healthy controls and 40 subjects with multiple sclerosis (MS), a chronic illness that shares many symptoms with CFS (e.g., fatigue), but has a known neurological substrate. Subjects were examined within Cloninger's biosocial theory of personality, which delineates basic dimensions of temperament. Both illness groups displayed similarly elevated levels of Harm Avoidance, and lower levels of Reward Dependence as compared with healthy controls. The MS group showed a lower level of Persistence than controls and CFS subjects. Implications for the relationship between chronic illness and personality are discussed.

Acquisition and storage deficits in multiple sclerosis.

This study examined whether verbal and visual memory impairments in multiple sclerosis (MS) are attributable to deficits in acquisition, storage, or retrieval. Volunteers with MS (n = 40) and healthy controls (n = 20) rehearsed a word list and a checkerboard pattern using a selective reminding procedure until two consecutive error-free trials were attained. Recall and recognition were assessed after 30 min and 90 min (and 1 week for verbal material) delays. The MS group required significantly more trials to attain criterion on both learning tests. Once equated for acquisition, both groups performed similarly on verbal recall and recognition. However the MS group performed significantly worse on measures of visual recall and recognition. The results suggest that the verbal memory impairment in MS is due to deficient acquisition, while the visual memory impairment in MS is attributable to deficits in acquisition and storage.

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

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.

ECT and non-memory cognition: a review.

The literature on the effects of electroconvulsive therapy (ECT) on non-memory cognitive functions is reviewed. It is concluded that with early methods of ECT administration (sine wave, high dose), these effects are larger than those of depression. They are less pronounced, and usually do not exceed the effects of depression, when modern methods of ECT administration (brief pulse, moderate or low dose) are used. Following ECT, these functions progressively improve. At one week to seven months after ECT, performance is better than before ECT, probably because of the alleviation of both the effects of depression and of ECT. The time course to full recovery of the non-memory effects resembles that of the recovery of amnesic effects, although the latter are more pronounced. With bilateral ECT, as with right unilateral ECT, there is evidence that right hemisphere effects are more pronounced. The results of this review argue that clinicians should take the non-memory cognitive effects of ECT into account, and patients should be informed of their existence before they sign consent for ECT.

Construct validity in the Trail Making Test: what makes Part B harder?

The Trail Making Test (TMT) is primarily a test of motor speed and visual attention. In Trail Making, Part A, the subject's task is to quickly draw lines on a page connecting 25 consecutive numbers. In Part B, the subject must draw the lines alternating between numbers and letters. To determine what makes Part B harder than Part A, variations of the standard Trail Making Test were assessed. Forty college students (20 male, 20 female) were given four forms of the Trail Making Test. The results show that Trail Making, Part B with just numbers took longer to complete than the standard Part A with numbers. Part B is 56 cm longer and has more visually interfering stimuli than Part A. These results indicate that Part B is more difficult than Part A not only because it is a more difficult cognitive task, but also because of its increased demands in motor speed and visual search.