Fampridine

Association between brain atrophy and cognitive motor interference in multiple sclerosis

INTRODUCTION

Cognitive motor interference (CMI) is performance impairment due to simultaneuous task execution and is measured using the dual task cost (DTC). No pathological feature of MS has to date been associated with CMI.

AIM

To assess the relationship between brain volumes and CMI, as measured using the DTC, in a cross-sectional study.

METHODS

A group of persons with MS (pwMS) and an age- and sex-matched healthy control (HC) group underwent 3D gait analysis during using the dual task paradigm. Brain volumes were measured on T1-weighted gradient echo scans using SIENAX software. The relationships between brain volumes and the DTCs of spatial temporal parameters were evaluated using Pearson correlation. A multiple regression model was used to evaluate the ability to predict the DTC of cadence based on brain volume and grey matter (GM) volume.

RESULTS

Forty-four patients and 16 HCs underwent MRI and gait analysis. The mean expanded disability status scale (EDSS) was 2.4 ± 1.5. Significant relationships between brain volumes and DTC were found only in the pwMS group, with higher rho scores for the DTC of mean velocity, DTC of cadence, and DTC of stride time. A statistically significant regression equation with an R² value of 0.684 was found using GM and Z-score on the Stroop test as predictors of the DTC of cadence (p < 0.001).

CONCLUSION

Brain atrophy, especially than in the GM, is a major determinant of DTC, although other pathological markers also contribute to CMI in patients with MS.

Restoring Axonal Function with 4-Aminopyridine: Clinical Efficacy in Multiple Sclerosis and Beyond

The oral potassium channel blocker 4-aminopyridine has been used in various neurological conditions for decades. Numerous case reports and studies have supported its clinical efficacy in ameliorating the clinical presentation of certain neurological disorders. However, its short half-life, erratic drug levels, and safety-related dose restrictions limited its use as a self-compounded drug in clinical practice. This changed with the introduction of a prolonged-release formulation, which was successfully tested in patients with multiple sclerosis. It was fully approved by the US FDA in January 2010 but initially received only conditional approval from the European Medicines Agency (EMA) in July 2011. After additional clinical studies, this conditional approval was changed to unrestricted approval in August 2017. This article reviews and discusses these recent studies and places aminopyridines and their clinical utility into the context of a broader spectrum of neurological disorders, where clinical efficacy has been suggested. In 2010, prolonged-release 4-aminopyridine became the first drug specifically licensed to improve walking in patients with multiple sclerosis. About one-third of patients across disease courses benefit from this treatment. In addition, various reports indicate clinical efficacy beyond multiple sclerosis, which may broaden its use in clinical practice.