OBJECTIVE:The 'repetition effect' stipulates that recall ability improves as the number of learning trials that a person receives increases. While the repetition effect has been supported through many empirical investigations in healthy individuals, it has not yet been applied to clinical populations. The present study tested the hypothesis that an increased number of learning trials improves recall ability in persons with a neurological disorder, namely multiple sclerosis (MS).DESIGN:Prospective between-group design with 30-minute, 90-minute and one-week assessments.SETTING:Private, nonprofit, research facility.SUBJECTS:Sixty-four MS subjects; 20 healthy control subjects (HC).INTERVENTIONS:Subjects were given a modified Selective Reminding Test (SRT), a list of 10 words to remember in a selective reminding format. To control for the amount of information initially learned, the learning trials were repeated until the subject recalled all 10 words on two consecutive trials.MAIN OUTCOME MEASURES:SRT word recall and recognition was tested 30 minutes, 90 minutes and one week subsequent to initial acquisition.RESULTS:Interestingly, the antithesis of our hypothesis was found. That is, persons with MS who required more learning trials to reach the perfect learning criterion performed significantly worse on the recall trials. However, this was not the case in a sample of healthy individuals undergoing the same protocol.CONCLUSIONS:These results indicate that individuals with MS may not benefit from repetition in isolation, but rather require the use of more intensive cognitive rehabilitation strategies (i.e., increased organization) to help improve their depth of encoding of new information.

OBJECTIVEThe current investigation was designed to examine the influence of disease course on the specific patterns of acquisition and retrieval impairments in multiple sclerosis (MS).BACKGROUNDRecent 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.METHODSVerbal 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.RESULTSResults 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.CONCLUSIONSResults 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.

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 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.

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.

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.