Emilio Portaccio

Multiple sclerosis-related cognitive changes: A review of cross-sectional and longitudinal studies

Prevalence estimates of cognitive impairment in multiple sclerosis (MS) range from 40% to 65%, depending on the research setting. Cognitive dysfunction virtually encompasses all the disease stages and types of clinical course, although it is generally less frequent in relapsing-remitting (RR) patients compared with secondary progressive (SP) patients, and tends to be less frequent in primary progressive (PP) patients. Moreover, it causes role limitations in work and social life, independently of the degree of physical disability. Relatively little is known about the evolution of cognitive impairment in MS, particularly starting from the early stages of the disease. Controlled studies, however, have clearly shown that cognitive deterioration tends to progress over time. Among clinical predictors, incipient cognitive decline seems to be the major risk factor for further deterioration in the short-term. In the long-term, the likelihood increases that also patients with initial cognitive preservation may deteriorate. As for magnetic resonance imaging (MRI), there are consistent, albeit moderate, correlations between the progression of cognitive impairment and increasing brain lesion load and brain atrophy. The aim of this paper is to provide a review of existing cross-sectional and longitudinal studies on cognitive deterioration in MS.

Neocortical volume decrease in relapsing-remitting MS patients with mild cognitive impairment.

Objective: To assess neocortical changes and their relevance to cognitive impairment in early relapsing–remitting (RR) multiple sclerosis (MS). Methods: Conventional MR was acquired in 41 patients with RR MS and 16 demographically matched normal control subjects (NCs). An automated analysis tool was used with conventional T1-weighted MRI to obtain measures of cortical brain volumes normalized for head size. Neuropsychological performance of MS patients was assessed using the Rao Brief Repeatable Battery. Relationship between volumetric MR measures and neuropsychological scores was assessed. Results: Neuropsychological assessment allowed for the identification of 18 cognitively preserved (MS-cp) and 23 cognitively impaired (MS-ci) MS patients. The whole MS sample showed lower values of normalized cortical volumes (NCVs) than did the NC group (p = 0.01). Upon grouping of MS patients according to cognitive performance, NCV values were lower (p = 0.02) in MS-ci patients than in both MS-cp patients and NCs. Moreover, there were positive correlations between NCV values and measures of verbal memory (r = 0.51, p = 0.02), verbal fluency (r = 0.51, p = 0.01), and attention/concentration (r = 0.65, p < 0.001) in MS-ci patients. Furthermore, NCV values were decreased in patients who scored lower on a greater number of tests (r = −0.58, p < 0.01) in the MS-ci group. None of the neuropsychological measures correlated to NCV values in the MS-cp patient group. Conclusions: Cortical atrophy was found only in cognitively impaired patients and was significantly correlated with a poorer performance on tests of verbal memory, attention/concentration, and verbal fluency. Gray matter pathology may contribute to the development of cognitive impairment in MS from the earliest stages of the disease.

New natural history of interferon‐β–treated relapsing multiple sclerosis

To investigate the impact of interferon‐beta (IFNβ) on disease progression in relapsing‐remitting multiple sclerosis patients.

The Rao's Brief Repeatable Battery and Stroop Test: normative values with age, education and gender corrections in an Italian population.

The Brief Repeatable Battery of Neuropsychological Tests (BRB) is by far the most widely used instrument to estimate cognitive dysfunction in multiple sclerosis (MS) patients. However, the paucity of normative data currently limits its applicability. We administered the BRB to 200 healthy subjects to obtain normative values. Moreover, we assessed the influence of demographic factors on the test scores and calculated corrections for these relevant factors. To test executive functions not explored by the BRB, we also included the Stroop word-color task (ST). Higher educational level was associated with better performance on all the tests, except for the world list generation (WLG) and the ST, considering version A, and on Symbol Digit Modalities Test (SDMT), Paced Auditory Serial Addition Test (PASAT) and Selective Reminding Test-Delayed (SRT-D), considering version B. Females performed better than males on the WLG considering version A, and on the SRT-Long Term Storage (SRT-LTS) and SRT-Consistent Long Term Retrieval (SRT-CLTR) considering version B. Increasing age was associated with worse performance on the ST in version A, and on the SRT-LTS, SRT-CLTR and WLG in version B. Our data can improve the applicability of the BRB for both clinical and research purposes.

Cognitive and psychosocial features of childhood and juvenile MS

Objective: To assess the impact of multiple sclerosis (MS) on cognitive and psychosocial functioning in childhood and juvenile cases. Methods: We used an extensive neuropsychological battery assessing IQ, memory, attention/concentration, executive functions, and language. Fatigue and depression were also measured. An interview on school and daily living activities was obtained from the parents. Performance of cases was compared with that of demographically matched healthy controls. Results: Sixty-three patients and 57 healthy controls were assessed. Five patients (8%) exhibited a particularly low IQ (<70). Criteria for cognitive impairment (failure on at least three tests) were fulfilled in 19 patients (31%), whereas 32 patients (53%) failed at least two tests. Beyond deficits in memory, complex attention, and executive functions, the profile of deficits was characterized by involvement of linguistic abilities. In the regression analysis, the only significant predictor of cognitive impairment was an IQ score lower than 90 (odds ratio [OR] 18.2, 95% CI 4.6–71.7, p < 0.001). Considering the IQ score as a dependent variable, the only significant predictor was represented by younger age at onset (OR 0.7, 95% CI 0.5–0.9, p = 0.009). Depressive symptoms were reported by 6% of the cases, and fatigue was reported by 73% of the cases. MS negatively affected school and everyday activities in 56% of the subjects. Conclusions: In childhood and juvenile cases, multiple sclerosis (MS) is associated with cognitive impairment and low IQ scores, the latter related to younger age at onset. These aspects are of critical importance in helping children and adolescents with MS to manage their difficulties and psychosocial challenges.

Cognitive and psychosocial features in childhood and juvenile MS Two-year follow-up

Objective: To assess the evolution of cognitive and psychosocial functioning in a cohort of childhood and juvenile multiple sclerosis (MS) cases after a mean period of 2 years had elapsed since baseline evaluation. Methods: In this cohort study, we used the same extensive neuropsychological battery with alternative versions of the tests assessing memory, attention/concentration, executive functions, and language. Fatigue and depression were also measured. An interview on school and daily living activities was obtained from the parents. The cognitive performance of the patients was compared with that of demographically matched healthy controls (HC). Results: Fifty-six patients and 50 HC were assessed. At follow-up, criteria for cognitive impairment (failure on at least 3 tests) were fulfilled in 39 patients (70%) and 75% of the cases were classified as having a deteriorating cognitive performance. Changes were prominent in tests of verbal memory, complex attention, verbal fluency, and receptive language. In the regression analysis, the only significant predictor of cognitive deterioration was older age of the subject (odds ratio 1.9, 95% confidence interval 1.2–2.9, p = 0.003). Psychiatric disorders, most frequently depression, were diagnosed in 12 patients (30.5%). Fatigue was reported by 21% of the patients. MS negatively affected school and everyday activities in 30% to 40% of the subjects. Conclusions: Our findings confirm the importance of systematic assessment of cognitive and psychosocial issues in children and teens with MS. The progressive nature of the cognitive difficulties emphasizes the need for developing effective treatment strategies.

Pregnancy and fetal outcomes after interferon-β exposure in multiple sclerosis

Objective: To assess pregnancy and fetal outcomes after in utero exposure to interferon-β (IFNβ) in all pregnancies occurring in women with multiple sclerosis (MS) during the study period, with a specific focus on the risk of spontaneous abortion. Methods: In this cohort study, data were gathered through a standardized, semi-structured interview. Patients who discontinued IFNβ less than 4 weeks from conception (exposed) were compared with those who had discontinued the drug at least 4 weeks from conception or who were never treated (not exposed). Possible confounders were handled through multivariate analyses adjusted for propensity score (PS). Results: We collected data on 396 pregnancies in 388 women, 88 classified as exposed (mean exposure 4.6 ± 5.8 weeks). IFNβ exposure was not associated with an increased risk of spontaneous abortion (PS-adjusted odds ratio [OR] 1.08, 95% confidence interval [CI] 0.4 to 2.9, p = 0.88), although it was associated with both lower baby weight (PS-adjusted β −113.8, p < 0.0001) and length (PS-adjusted β −1.102, p < 0.0001). Proportion of spontaneous abortion in exposed patients fell within the range expected for the Italian population in the same period. IFNβ exposure (PS-adjusted OR 2.11, 95% CI 1.18 to 3.78, p = 0.012) and cesarean delivery were the only predictors of preterm delivery. In the exposed group, we did not observe any significant fetal complications, malformations, or developmental abnormalities over a median follow-up of 2.1 years. Conclusions: Our findings point to the relative safety of IFNβ exposure times of up to 4 weeks and can assist neurologists facing therapeutic decisions in women with MS with a pregnancy plan.

Cognitive impairment predicts conversion to multiple sclerosis in clinically isolated syndromes

Significant cognitive impairment has been found in 20—30% of patients with clinically isolated syndromes suggestive of multiple sclerosis. In this study we aimed to assess the prognostic value of the presence of cognitive impairment for the conversion to multiple sclerosis in patients with clinically isolated syndromes. All patients with clinically isolated syndromes consecutively referred to our centre since 2002 and who had been followed-up for at least one year underwent cognitive assessment through the Rao’s Battery and the Stroop test. Possible predictors of conversion to clinically definite multiple sclerosis were evaluated through the Kaplan Meier curves and Cox regression analysis. A total of 56 patients (41 women; age 33.2 ± 8.5 years; expanded disability scale score 1.2 ± 0.7) were recruited. At baseline, 32 patients (57%) fulfilled McDonald’s criteria for dissemination in space. During the follow-up (3.5 ± 2.3 years), 26 patients (46%) converted to a diagnosis of multiple sclerosis. In particular, 64% of patients failing ≥ 2 tests and 88% of patients failing ≥ 3 tests converted to multiple sclerosis. In the Cox regression model, the failure of at least three tests (HR 3.3; 95% CI 1.4—8.1; p = 0.003) and the presence of McDonald’s dissemination in space at baseline (HR 3.8; 95% CI 1.5—9.7; p = 0.005), were found to be predictors for conversion to multiple sclerosis. We conclude that cognitive impairment is detectable in a sizable proportion of patients with clinically isolated syndromes. In these subjects cognitive impairment has a prognostic value in predicting conversion to multiple sclerosis and may therefore play a role in therapeutic decision making.

Cognitive changes in multiple sclerosis

Cognitive dysfunction (CD) affects 40–65% of multiple sclerosis (MS) patients and can have a great functional impact. It can be detected in all the disease phenotypes from the early stages of the disease and tends to progress over time. Memory, complex attention, information processing speed and executive functions are most commonly involved. The relationship between cognitive changes and MRI findings may involve changes in different areas, including white matter lesions, normal appearing brain tissue on conventional MRI, cortical and deep gray matter. The search for effective therapeutic strategies is a major undertaking. Evidence of a possible effect of anticholinesterasics and cognitive rehabilitation is still preliminary. In this article, we review the current knowledge on CD in MS and highlight areas of special importance for future research in the field.

Cognitive assessment and quantitative magnetic resonance metrics can help to identify benign multiple sclerosis.

Background: The definition of benign multiple sclerosis (B-MS) is still controversial. This mainly takes into account the subject’s motor ability, with little or no relevance to other important features such as cognition. Moreover, no paraclinical markers are currently available to reliably identify patients who will remain benign in the long term. Objectives: To assess, by using quantitative magnetic resonance (MR) metrics, differences in tissue damage between B-MS patients after dividing them into two groups on the basis of their cognitive performance. Methods: Forty-seven B-MS patients (Expanded Disability Status Scale score ≤3.0 and disease duration ≥15 years) underwent neuropsychological assessment through the Rao Brief Repeatable Battery and the Stroop Test. At that time, B-MS patients underwent conventional brain MR and magnetization transfer (MT) imaging. White matter lesion load, global and regional brain volumes, and MT ratio (MTr) in lesions and normal-appearing brain were measured. Quantitative MR measures were compared in cognitively impaired (CI-MS) and cognitively preserved (CP-MS) patients and in 24 demographically matched healthy controls. Test performance was correlated with MR changes in specific cortical regions. Results: Eleven patients were classified as CI-MS, and 36 were classified as CP-MS. Both T2-weighted and T1-weighted lesion loads were higher (p = 0.05 and 0.001) in CI-MS than in CP-MS patients. Furthermore, CI-MS patients were characterized by more pronounced decrease in neocortical volume (p = 0.005) and cortical MTr (p = 0.02) values than CP-MS patients. Finally, test performance correlated significantly with MR changes in relevant cortical regions. Conclusions: Cognitive assessment and quantitative magnetic resonance can help to reliably identify benign multiple sclerosis patients.