Hyperekplexia is a rare, autosomal dominant neurological disorder characterized by hypertonia, especially in infancy, and by an exaggerated startle response. This disorder is caused by mutations in the alpha 1 subunit of the inhibitory glycine receptor (GLRA1). We previously reported two GLRA1 point
OBJECTIVE
Myoclonus remains a challenging movement phenotype to characterize, evaluate, and treat. A systematic assessment of the temporal sequence, phenomenology, and distribution of movements can assist in the rational approach to diagnosis and management.
RESULTS
Cortical forms of myoclonus are