Objective: This study aims to investigate the role of cerebellum and the olivodentatorubral pathway in generating movement-related cortical potential (MRCP).

Background: Cerebellum and its connecting pathways play important roles on executing volitional movements. Since MRCP represents the cortical activation relevant to preparation and initiation of volitional movements, it is intriguing to know whether MRCP is altered in the patients with Holmes’ tremor and cerebellar degeneration.

Methods: Two patients presenting Holmes’ tremor at their right arm, four patients with cerebellar degeneration (two idiopathic type and two hereditary type) and four age-matched healthy subjects were studied. Scalp MRCP was recorded from multi-channel Ag/AgCl cup electrodes when the subjects performed self-paced, brisk extension of the right wrist at an approximate rate of once every 7 seconds. The latency and the amplitude of frontal peak of motor potential (fpMP) and the summated negativity of MRCP from 500 to 0 msec before the movement onset were measured. Data of the four central electrodes, FCz, Cz, C3 and C4, were analyzed and compared by one-way analysis of variance (ANOVA).

Results: The summated negativity of MRCP from 500 to 0 msec prior to the movement onset was significantly reduced in the group of the patients with cerebellar degeneration at FCz, Cz, and C3 (all p<0.05) but not in the group of the patients with Holmes’ tremor. The amplitude of fpMP at FCz was significantly reduced in the both patient groups. The latency of fpMP showed a tendency of delay in the cerebellar degeneration group (p=0.073). In brief, the patients with Holmes’ tremor showed normal MRCP activities except a reduced fpMP amplitude at FCz. By contrast, the patients with cerebellar degeneration presented abnormal MRCP activities not only in the summated negativity but also in fpMP.

Conclusions: Findings suggest that the cerebellum did play a pivotal role in generating MRCP, both the negative shifting before the movement onset and the motor potential after the movement onset. However, its connecting pathway leading to the clinical manifestation of Holmes’ tremor might only affect fpMP.

« Back to 2018 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/distinct-abnormality-of-movement-related-cortical-potential-between-patients-with-holmes-tremor-and-cerebellar-degeneration/