Correlation of electrophysiological parameters of peripheral nerves and manual dexterity in patients with amyotrophic...

Introduction: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease affecting upper and lower motor neurons, presenting with various manifestations, leading to progressing disability, with poor prognosis, and with no options for successful treatment. In its classic form the central and peripheral motor neurons are simultaneously affected at the beginning; the bulbar-onset ALS successively involving other parts of the nervous system is slightly less common. The aim: To demonstrate a correlation between electrophysiological parameters of peripheral nerves and loss of manual dexterity in the ALS.

Materials and methods: The analysis covered results of electrophysiological tests of motor conductivity in median and ulnar nerves, and results of the Mira Stambak and Rene Zazzo tests normally used to evaluate lateralisation, while in this study they were adapted to verify manual dexterity. The study covered 20 patients with clinically confirmed or possible ALS determined on the basis of the EI Escorial criteria. Half (10 people) of the studied group had limb-onset ALS, while the other half had the bulbar-onset ALS.

Results: When evaluating a correlation between the results of electrophysiological tests and the results of the Mira Stambak and Rene Zazzo tests, a significant relationship was found between a reduction in an amplitude of the compound muscle action potential (CMAP) and deterioration in manual dexterity in the subjects, with a tendency for progression in these deviations, but with their interdependency maintained.

Conclusions: 1. A loss of motor cells in the anterior horns of the spinal cord is reflected in the deterioration of manual dexterity in ALS patients. 2. A significant correlation is found between a loss in manual dexterity and an increase in changes in motor conductivity.