A Distinct EEG Marker of Celiac Disease-Related Cortical Myoclonus.

BACKGROUND

Celiac disease is associated with motor cortex hyperexcitability and neurological manifestations including cortical myoclonus. Electroencephalography abnormalities have been described, but no distinct pattern has been reported.

METHODS

We describe the neurophysiological characteristics of 3 patients with celiac-associated cortical myoclonus using electroencephalography, magnetoencephalography, and transcranial magnetic stimulation.

RESULTS

Electroencephalography in all cases demonstrated lateralized low-amplitude, electropositive beta-frequency polyspike activity over the central head region, corresponding to motor cortex contralateral to the myoclonic limb. Jerk-locked back-averaging demonstrated a preceding cortical potential; magnetoencephalography source localization revealed a cortical generator in the posterior wall of the precentral gyrus for the back-averaged potential and oscillatory abnormality. In 1 patient, cerebellar inhibition of the motor cortex was physiologically normal.

CONCLUSIONS

Central head oscillatory, low-amplitude, electropositive electroencephalography polyspike activity may be a distinct marker of celiac-related cortical myoclonus and is consistent with celiac-related motor cortex hyperexcitability, which may not necessarily result from cerebellar disinhibition. © 2020 International Parkinson and Movement Disorder Society.