INTRODUCTION: Hirayama disease is a rare focal motor neuron disorder that manifests as slowly progressive unilateral or bilateral hand weakness and atrophy. METHODS: The case report of a young man who presented with the phenotype of Hirayama disease indicated an extensive anterior cervical epidural arachnoid cyst. RESULTS: A 34-year-old man presented with a 5-year history of slowly progressive hand and forearm weakness and atrophy. Nerve conduction studies demonstrated low median and ulnar motor amplitudes, and EMG demonstrated fibrillation potentials and long-duration, high-amplitude motor unit potentials in C6-T4-innervated muscles. MRI demonstrated a longitudinally extensive anterior spinal epidural cyst extending from C2 to L1. The patient had improved hand strength after surgery. CONCLUSIONS: Anterior cervical epidural spinal cysts should be considered in the differential diagnosis in patients who present with slowly progressive hand weakness.
INTRODUCTION:Hirayama disease is a rare focal motor neuron disorder that manifests as slowly progressive unilateral or bilateral hand weakness and atrophy. METHODS: The case report of a young man who presented with the phenotype of Hirayama disease indicated an extensive anterior cervical epidural arachnoid cyst. RESULTS: A 34-year-old man presented with a 5-year history of slowly progressive hand and forearm weakness and atrophy. Nerve conduction studies demonstrated low median and ulnar motor amplitudes, and EMG demonstrated fibrillation potentials and long-duration, high-amplitude motor unit potentials in C6-T4-innervated muscles. MRI demonstrated a longitudinally extensive anterior spinal epidural cyst extending from C2 to L1. The patient had improved hand strength after surgery. CONCLUSIONS:Anterior cervical epidural spinal cysts should be considered in the differential diagnosis in patients who present with slowly progressive hand weakness.