Cortical hyperexcitability in progressive myoclonus epilepsy: A study with transcranial magnetic stimulation

Abstract

In progressive myoclonus epilepsy (PME), responses to afferent input are frequently abnormal. It is unclear whether the abnormality lies at the cortical, subcortical, or segmental level. To obtain evidence for an exaggerated effect on motor cortical excitability, we used peripheral nerve and transcranial magnetic stimulation in controts and subjects with idiopathic generalized epilepsy and PME. Mean threshold intensity was higher in those with idiopathic generalized epilepsy and PME than in controls, probably as a result of anticonvulsant treatment. A long-latency response to peripheral stimulation and an exaggerated facilitatory effect of peripheral stimulation on the motor evoked potential..