Familial adult myoclonus epilepsy: A comprehensive diagnostic strategy for clinical practice

Abstract

Familial adult myoclonus epilepsy (FAME) is a genetic neurological disorder characterized by cortical myoclonus and epileptic seizures with clinical features that overlap with other movement disorders and epileptic syndromes, particularly essential tremor (ET), progressive myoclonic epilepsy (PME), and juvenile myoclonic epilepsy (JME). The key clinical manifestations include an autosomal dominant family history, tremorlike cortical myoclonus, generalized tonic-clonic seizures, photosensitivity, mild cognitive impairment, and other associated symptoms. Electrophysiological examinations are essential in demonstrating cortical hyperexcitability and confirming the cortical origin of myoclonus. Neuroimaging studies typically show mild cerebellar atrophy or nonspecific structural changes on magnetic resonance imaging. Notably, photosensitivity is confirmed by clinical, electrophysiological, and neuroimaging evidence, highlighting its significant yet underestimated role in the underlying etiology of FAME. Genetic analysis, particularly long-read genome sequencing, is recognized as the gold standard for definitive diagnosis. We propose an integrated and clinically oriented diagnostic approach for FAME, including clinical assessment, electrophysiological tests, neuroimaging studies, and genetic analysis. The differential diagnosis of FAME, ET, PME, and JME is also thoroughly discussed. Antiseizure medications are the cornerstone of FAME treatment, with a combination of valproate or levetiracetam with benzodiazepines serving as the first-line therapy. A detailed review and a well-established diagnostic workflow for FAME can enhance the understanding of FAME; the identification of specific biomarkers for FAME requires further investigation.

Keywords: FAME; cortical myoclonus; diagnosis; photosensitivity; seizure.