Two Cases of Hirayama Disease in a Pediatric Clinic / 대한소아신경학회지

We report two pediatric cases with Hirayama disease—a 16-year-old boy with a left wrist drop and a 14-year-old-boy with weakness and muscle atrophy of right hand. Motor nerve conduction study revealed decreased motor nerve action potential amplitudes in the ulnar nerve and radial nerve of the affected hands. The former patient showed normal magnetic resonance imaging (MRI) of the cervical spine, but the latter showed mild, asymmetric thinning of the anterior spinal cord at levels C5 to C7. Following active rehabilitation and avoidance of neck flexion, no further progression of neurological findings was noticed. These clinical findings were typical of Hirayama disease. We show that timely and accurate diagnosis for Hirayama disease is possible with awareness of disease history, careful physical examination, and the use of neurophysiological studies and MRI studies.

Rare case of Hirayama’s disease.

Hirayama‟s disease is a rare benign neurological disorder also known as monomelic amyotrophy, Sobue disease, Juvenile Muscular Atrophy of Distal Upper Extremity (JMADUE). It mainly affects young males in their second or third decades and is most commonly seen in Asian countries like Japan, Malaysia and India. In majority of the cases the cause of the disease is unknown. An 18 year male came with weakness in his right hand and forearm since 1 year. Examination revealed weakness and wasting of muscles of forearm and hand without lower limb involvement and normal deep tendon reflexes. MRI showed focal short segment hyperintense signal in the ventral and right lateral aspect of the cervical cord at C5-C6 level with the involved segment measuring 4x3mm in size. Based on clinical and radiological features a diagnosis of focal amyotrophy was made. Patient is given a cervical collar to prevent flexion at the neck and physiotherapy in the form of hand and forearm exercises were started. Regular follow up of the patient once every 2 months is being done. Hirayama‟s disease is a rare, benign, self-limiting neurological disorder. Early diagnosis and management by preventing cervical flexion with the help of a cervical collar has shown to halt the progression of the disease.

Response of Hirayama disease to surgical intervention: case report.

Hirayama disease also known as monomelic amyotrophy, primarily involves distal upper limb extremities. It differs from the known types of motor neuron diseases because of its nonprogressive behavior and pathologic findings of focal ischemic changes in the anterior horn of the lower cervical cord. We present a young male with Hirayama disease who had a left upper extremity involvement which was progressive in nature. He didn’t respond with initial treatment of cervical collar. Consequently surgical intervention improves muscle weakness and decrease the neurological deficit.