A Case Report of Congenital Hyperekplexia in Twin

Hyperekplexia or startle disease is a hereditary neurological disorder characterized by an abnormally exaggerated startle response to tactile, auditory and visual stimuli, together with a global muscular hypertonia and hyperactive tendon reflexes. This disease is a rare, genetically determined disorder, with an autosomal dominant inheritance with variable expression, first described by Suhren, et al. We report two cases of familial hyperekplexia, who developed hypertonia and pathologic startle response to tactile stimulation in the immediate neonatal period. The infant showed a marked improvement of the startle response and muscular hypertonia with low-dose clobazam.