A clinical neurophysiology study of Hirayama disease.

Abstract

BACKGROUND:

Hirayama disease is a rare disease characterized by juvenile-onset of asymmetric amyotrophy, of which etiology has not been clarified. The aim of our study was to investigate the clinical and neurophysiologic characteristics of Hirayama disease.

METHODS:

Neurophysiological tests, including nerve conduction studies (NCS), F-wave and routine electromyography (EMG), were performed in seventy-three patients with Hirayama disease. EMG was selectively performed on upper and lower extremities, sternocleidomast and thoracic paravertebral muscles according to the clinical features of the patients.

RESULTS:

Abnormal NCS parameters, including decreased compound muscle action potentials or delayed distal motor latency, were found in 34.2% (25/73) and 12.3% (9/73) of the patients, respectively. A total of 24.6% (18/73) of the patients showed decreased F-wave frequency. EMG demonstrated the presence of neurogenic lesions in all patients with spontaneous potentials, prolonged duration or augmentation of amplitude in motor unit potentials (MUPs), or a single pattern of MUP recruitment. About 17.8% (13/73) of the patients showed neurogenic lesions, mostly in the C7-8 level of the cervical cord, only in the upper extremity of affected side, whereas 35.6% (26/73) of the patients possessed lesions in the upper extremities bilaterally. A total of 46.6% (34/73) of patients exhibited abnormalities in the lower extremities, sterno- cleidomast or thoracic paravertebral muscle. Changes in motor NCS were significantly correlated with muscle strength.

CONCLUSIONS:

EMG detects diffused subclinical neurogenic lesion in a high proportion of patients with Hirayama disease. Results of our study challenge the hypothesis that Hirayama disease is a type of cervical myelopathy.

• Authors: Xin-ning Wang, Li-ying Cui, Ming-sheng Liu, Yu-zhou Guan, Ben-hong Li, Hua DU
• Journal: Chinese medical journal (Chin Med J (Engl)) Vol. 125 Issue 6 Pg. 1115-20 (Mar 2012) ISSN: 2542-5641 [Electronic] China
• PMID: 22613540 (Publication Type: Journal Article)

Topics

• Adolescent
• Adult
• Electromyography
• Female
• Humans
• Magnetic Resonance Imaging
• Male
• Neural Conduction
• Spinal Muscular Atrophies of Childhood (pathology, physiopathology)
• Young Adult