Familial cortical tremor with epilepsy.

Area of Science:

• Neurology
• Genetics
• Neurophysiology

Background:

• Essential tremor is a common movement disorder.
• Epilepsy can present with various seizure types.
• Cortical reflex myoclonus is a rare neurological condition.

Purpose of the Study:

• To describe a novel dominantly inherited disorder characterized by adult-onset tremor and epilepsy.
• To investigate the underlying neurophysiological mechanisms of the observed symptoms.

Main Methods:

• Clinical examination of affected family members across three generations.
• Electrophysiological studies including somatosensory evoked potentials (SEPs) and jerk-locked averaging.
• Assessment of treatment response to anticonvulsants and beta-blockers.

Main Results:

• Five family members exhibited non-progressive adult-onset tremor and epilepsy.
• Electrophysiology revealed giant SEPs, enhanced C-reflex, and positive premovement cortical potentials, indicative of cortical reflex myoclonus.
• Tremor and seizures responded well to anticonvulsants but not beta-blockers.

Conclusions:

• This family presents a unique, dominantly inherited disorder with features of cortical reflex myoclonus.
• The condition should be considered in the differential diagnosis of essential tremor.
• Anticonvulsants are effective treatments for both tremor and seizures in this disorder.