Hirayama Disease and the Importance of Magnetic Resonans Imaging for Diagnosis

Abstract

Hirayama disease is a benign disease of the lower motor neurons which is encuntered mostly in young adults. This disease is extremely rare and characterized by the wasting and weakness of the distal upper extremities. In this paper, we present a 20 year- old male patient with the complaint of weakness and muscle wasting of the hands and forearms. Neurological examination revealed no abnormality including reflexes, position and vibration sensations. Electromyographic examination of the patient showed acute and chronic denervation of the muscles which are innervted by C7-T1 segments. Non-flexion MRI examination was obtained showing spinal cord atrophy at C6-C7 vertebral segments. Then flexion cervical MRI examination was obtained in order to evaluate the relationship between the spinal cord and the posterior dura mater and characteristic MRI findings confirmed the diagnosis of Hirayama disease. Radiologists and the clinicians should be aware of this disease in order to prevent progression of the atrophy.