Hyperekplexia

Hyperekplexia is a rare neurological disorder characterized by exaggerated startle responses and muscle stiffness, usually due to mutations affecting glycine receptor function. Clinical features include neonatal hypertonia, startle-induced falls, and apnea in severe cases. Pathophysiology involves impaired inhibitory neurotransmission in the brainstem and spinal cord. Diagnosis is clinical, supported by genetic testing. Management includes clonazepam and supportive care; prognosis is generally favorable with early treatment.