Hirayama disease is an uncommon and rarely seen lower motor neuron disease. It is usually seen during periods of rapid growth (15-25 years). Distal upper extremities characteristically show weakness and atrophy. The disease has an insidious onset with slow progression in the first 2-5 years, then progresses more rapidly at approximately 5 years after onset. In this paper a case is presented of this rare, and difficult to diagnose disease, not previously reported in this age group, and the findings are discussed in the light of information of earlier cases in Turkey.
A 53-year old male patient presented at Inonu University Neurology Polyclinic with complaints of motion tremor and atrophy in the left arm, which had been ongoing for 4 years. Clinical examination revealed low amplitude in the left musculocutaneus and axillary nerves. After electromyography, the deltoid, biceps, triceps, extensor digitorum communis, abductor pollicis brevis and abduction digiti minimi muscles were identified in the upper left limb and further neurological motor unit potential tests were applied. Subsequently, cervical cord atrophy, asymmetric cord flattening, parenchymal signal changes in the lower cervical cord, and abnormal cervical curvature were observed on magnetic resonance imaging. A diagnosis of Hirayama disease was made from the anamnesis and clinical / radiological findings. Hirayama disease is a motor neuron disease that can be difficult to diagnose. It is important to know the differential diagnosis of amyotrophic lateral sclerosis in respect of the prognosis of the patient. This case report presents information about the differential diagnosis, detailed symptoms and treatment methods of a Hirayama patient applying for physical therapy.
Key words: Hirayama Disease, Lower Motor Neuron, Tremor, Atrophy, Physiotherapy, Function