Multiple Sclerosis Cognition Abstracts - 3

Background
With the use of comprehensive NeuroPsychological assessments, a substantial proportion of patients with Multiple Sclerosis have been found to have substantial Cognitive Impairment.

Although data generated from comprehensive examinations are useful in making recommendations for treatment interventions and compensatory strategies, the cost of such assessments prohibits their use with all patients.

Objective
To develop a screening battery to detect Cognitive Impairment in patients with Multiple Sclerosis that is sensitive, specific, brief, and cost-effective, and could identify patients who might benefit from a more comprehensive NeuroPsychological examination.

Design
On the basis of a comprehensive NeuroPsychological assessment battery, the presence of significant Cognitive Impairment was determined in patients with Multiple Sclerosis.

The screening battery consisted of a subset of tests from the comprehensive battery.

Performance on the screening battery was then used to predict presence of Cognitive Impairment on the comprehensive battery in validation and cross-validation samples.

Severity of impairment on the screening battery was also regressed on ratings of functional impairment derived from the Expanded Disability Status Scale.

Results
In the validation sample, the screening battery had 100% sensitivity, 80% specificity, and 88.1% overall diagnostic accuracy.

In the cross-validation sample, the screening battery had 100% sensitivity, 81.8% specificity, and an overall diagnostic accuracy rate of 90.7%.

chi 2 tests showed that the accuracy of the screening battery was significantly better than chance in both samples. Performance on the screening battery also predicted the level of disability ratings on the Expanded Disability Status Scale and Functional Systems Scales.

Conclusions
The screening battery had a high degree of sensitivity, specificity, and diagnostic accuracy, while maintaining a brief administration time and high cost-effectiveness.

The screening battery also predicted higher levels of disability and functional impairment as assessed by the Expanded Disability Status Scale, thereby enhancing its clinical utility.

Despite its advantages, the findings do not suggest that the screening battery may be an effective substitute for a more detailed examination.

Comments:

• Comment in: Arch Neurol 1997 Apr;54(4):352

The nature, prevalence, and course of Cognitive and Emotional disturbances in Multiple Sclerosis (MS) are described in this article.

Mild to moderate Cognitive Impairment is common in MS and may be more incapacitating than physical symptoms for some patients.

Although existing Neurologic and NeuroImaging procedures can detect some Cognitively impaired patients, they lack sensitivity.

Development of a brief NeuroPsychological screening battery, suitable for routine clinical use, is an important objective that may be achieved in the near future.

Cognitive Impairment affects 40 to 70% of patients with Multiple Sclerosis (MS).

But its occurrence cannot be predicted from knowledge of the individual patient's age, level of physical disability, duration of disease, disease type, or performance on standard mental status examinations.

To evaluate the usefulness of a brief screening battery, the Screening Examination for Cognitive Impairment (SEFCI), 103 community-dwelling MS patients and 32 healthy normal controls received the SEFCI and a 2-hour battery of other NeuroPsychological tests chosen for their sensitivity to the Cognitive Impairments most often observed in MS.

Performance on the SEFCI correctly identified 86% of the patients with impairment on any of the 11 measures from the longer battery, 100% of the patients with impairments in at least three Cognitive domains, and 90% of the patients without Cognitive Impairment.

Because the SEFCI is sensitive, specific, and easily administered and scored, it should aid the physician in deciding whether to refer an MS patient for a complete evaluation.

The purpose of this study was to illustrate how Cognitive functioning evolves over time in patients with Multiple Sclerosis.

We followed the evolution of Cognitive performances in two clinically and demographically similar Multiple Sclerosis groups, the 'Cognitively preserved' (n = 20) and the 'Cognitively mildly deteriorated' (n = 22), and in healthy controls (n = 34).

We conducted the follow-up examination using the Mild Deterioration Battery, the Mini-Mental State Examination, and a set of additional NeuroPsychological measures after an interval of 3 years. The drop-out rate in our study was only 5%.

The 'Cognitively preserved' Multiple Sclerosis group showed substantial NeuroPsychological stability by performing as well as the controls both at baseline and at follow-up.

By contrast, the initially 'Cognitively mildly deteriorated' group demonstrated Progressive Cognitive decline on many NeuroPsychological tests.

The intermediate-length screening battery, the Mild Deterioration Battery, was sensitive to this decline, whereas the briefer Mini-Mental State Examination was not. The Progressive Cognitive decline could not be predicted from other disease variables.

The study demonstrated that intact Cognitive functioning in Multiple Sclerosis may remain stable, whereas incipient Cognitive decline seems to be widespread and Progressive in nature.

Thus, Progressive Cognitive deterioration should be considered as one of the characteristics of Multiple Sclerosis.

To assess the nature and magnitude of Memory Impairment in Multiple Sclerosis (MS), the authors analyzed quantitatively 36 studies comparing the Memory performance of MS participants to healthy controls.

The authors studied:

1. The pattern of Impairment across Short-Term Memory (STM), Working Memory (WM), and Long-Term Memory (LTM)
2. The moderating influence of Retrieval support on LTM Impairment
3. The CoVariation of WM and LTM impairment
4. The moderating influence of clinical characteristics of the MS sample on Memory Impairment

The analyzes revealed significant Impairment across all Memory domains and failed to support a Retrieval-based account of LTM dysfunction in MS patients.

In addition, robust associations were found between clinical features of MS and Memory Impairment.

The findings suggest a more global pattern of Memory deficits in MS than has been previously believed, with deficits clearly associated with Neurological Disability and disease course.

Objectives
To assess the evolution of Cognitive Dysfunction in early-onset Multiple Sclerosis, to identify clinical predictors of mental decline, and to determine its impact on a patient's everyday life.

Design
The Cognitive performance of 50 patients with Multiple Sclerosis on a NeuroPsychological battery was compared with that of 70 control subjects initially and again after a 4-year interval.

Clinical predictors of Cognitive Impairment and its effect on daily life were analyzed by stepwise linear regression.

Setting & Participants
The research clinic of a University department of Neurology.

A consecutive sample of 50 inpatients and outpatients with Multiple Sclerosis (mean disease duration, 1.58 years) and 70 demographically matched healthy control subjects selected from the patients' relatives and friends.

Main Outcome Measures
Mean psychometric test scores of both groups at the initial and follow-up testing.

Regression coefficients measuring the relationship between clinical parameters and Cognitive capacity and between mental decline and performance of common tasks measured by the Environmental and the Incapacity Status scales.

Results
Multiple Sclerosis-related deficits in Verbal Memory and Abstract Reasoning on initial testing remained more or less stable on the retest.

At which time Linguistic disturbances on the Set and Token tests also emerged.

A patient's initial disability level predicted decreased performance on only four of 13 Cognitive variables, and disease duration did so on only two.

Extent of intellectual decline on initial testing, initial disability level, and Progressive course were independent determinants of handicap in a patient's work and social activities.

Conclusions
Cognitive and Neurological deficits appear not to develop in parallel.

Yet Cognitive Dysfunction proves to be a predictor of handicap in everyday life, even in patients in the incipient phase of Multiple Sclerosis.

The purpose of this study was to explore further the hypothesis that changes in Cognitive function may occur in the mild stages of Multiple Sclerosis (MS) by determining whether Ventricular enlargement was related to Cognitive function.

Ten measures of Ventricular size were made in a sample of 123 MS patients with mild disability and 60 well-matched healthy controls.

In addition, sixteen tests of Cognitive function and the Beck Depression Inventory were administered.

For the MS group, there were significant correlations between the Ventricular measures and Cognitive performance but not for the normal controls.

Scores on the Beck Depression Inventory were not correlated with either Cognitive performance or Ventricular enlargement.

These findings suggest that for the MS group Cognitive Impairment was related to the disease process but not to the level of Depression.

We examined Short-Term Memory (STM) among a group of 23 definite, Chronic/Progressive Multiple Sclerosis (MS) patients, all of whom had experienced recent significant disease activity, and a control group matched closely on age and education.

MS patients were impaired, relative to controls, on the majority of the measures used.

Although there were no significant differences between groups on the Mini Mental State Examination, patients performed more poorly on digits forward and backward, the Brown-Peterson test, and the Logical Memory Scale of the Revised Wechsler Memory Scale (both Immediate and Delayed).

Performance on tests sensitive to Central Processing capacity was significantly correlated with measures of STM. Working Memory was significantly impaired in this sample of Chronic/Progressive MS patients.