Features of Hirayama Disease on Fully Flexed Position Cervical MRI

The Journal of International Medical Research 2011; 39: 222 – 228 222 Features of Hirayama Disease on Fully Flexed Position Cervical MRI B YIN, L LIU AND D-Y GENG Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China This study reports on cervical magnetic resonance imaging (MRI) performed in the fully flexed position in 13 male patients with Hirayama disease and 12 normal controls (males). The anterior– posterior diameter of the cervical cord at the superior margin of the C6 vertebral body was measured, as well as the angle between adjacent cervical bodies. Localized lower cervical-cord atrophy, cord flattening and abnormal signals in the posterior epidural space were studied. Patients demonstrated an increased angle between C5 and C6, and C6 cord lesions. There were significant differences between patients and controls in localized lower cervical-cord atrophy and cord flattening. Many patients were found to have a crescent-shaped high-intensity mass on T2WI MRI and a low-intensity mass on T1WI MRI in the posterior epidural space. In patients, there were specific imaging features of Hirayama disease on fully flexed MRI. Cervical MRI in the fully flexed position has significant value in the clinical diagnosis of Hirayama disease. KEY WORDS: HIRAYAMA DISEASE; MAGNETIC RESONANCE IMAGING; MRI; FULLY FLEXED POSITION Introduction Juvenile muscular atrophy of the distal upper limb (Hirayama disease) is a rare disease that predominantly occurs in young men. 1 It is an anterior horn cell disorder, characterized by muscular weakness and atrophy in the hand and forearm. The onset is insidious, and is followed by spontaneous relief after about 5 years. 1 Diagnosis of Hirayama disease depends mainly on clinical presentation and electromyogram examination; 2 – 5 traditional imaging via plain anteroposterior and lateral cervical spine radiography is generally inconclusive. Magnetic resonance imaging (MRI), however, has significant value in the diagnosis of Hirayama disease. 4 The present study was designed to compare the features of fully flexed cervical MRI in Hirayama patients and healthy controls. Patients and methods PATIENTS Patients with clinical manifestations and electromyogram examination findings compatible with Hirayama disease presenting to the Department of Neurology at Huashan Hospital, Fudan University, Shanghai, China, between January 2006 and June 2008 were included in the study. Volunteer control subjects with normal medical histories were recruited from students of Fudan University. The study protocol was approved by the Institutional Review Board of Huashan Hospital, and written informed consent was

Features of Hirayama Disease on Fully Flexed Position Cervical MRI

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