Reduced intracortical facilitation in patients with cerebellar degeneration.

Abstract

OBJECTIVES:

Transcranial magnetic stimulation (TMS) was used to study intracortical inhibitory and excitatory phenomena in patients with cerebellar ataxia.

METHODS:

Motor evoked potentials (MEP) following single and paired TMS were recorded from the first dorsal interosseus muscle (FDI) in 15 patients with autosomal-dominant or idiopathic cerebellar ataxia and 15 age matched normal controls.

RESULTS:

MEP amplitudes after paired TMS with short interstimulus intervals (1-4 ms) showing intracortical inhibition in the control group were not significantly different in the patient group. In contrast, with longer interstimulus intervals (8-20 ms) mean MEP amplitudes were significantly reduced in the patient group, indicating a decrease of intracortical facilitation. The mean postexcitatory inhibition after TMS was also significantly prolonged in the patient group.

CONCLUSION:

Our findings support the idea that the cerebellum physiologically exerts a facilitatory influence on the motor cortex which is decreased in patients with a cerebellar degeneration.

• Authors: J Liepert, K Wessel, P Schwenkreis, P Trillenberg, V Otto, M Vorgerd, J P Malin, M Tegenthoff
• Journal: Acta neurologica Scandinavica (Acta Neurol Scand) Vol. 98 Issue 5 Pg. 318-23 (Nov 1998) ISSN: 0001-6314 [Print] Denmark
• PMID: 9858101 (Publication Type: Journal Article)

Topics

• Action Potentials (physiology)
• Adult
• Aged
• Cerebellar Ataxia (pathology)
• Electroencephalography
• Electromagnetic Fields
• Evoked Potentials, Motor
• Female
• Humans
• Male
• Middle Aged
• Motor Cortex (pathology, physiology)