平山症的臨床診斷與預後探討：病例報告

Clinical Diagnosis and Prognosis of Hirayama Disease: A Case Report

吳旻容(Min-Jung Wu) ； 邱然偉(Jan-Wei Chiu) ； 周正亮(Chen-Liang Chou) ； 詹瑞棋(Rai-Chi Chan)

《台灣復健醫學雜誌》 38卷2期 (2010/06) Pp. 123-130

https://doi.org/10.6315/2010.38(2)07

摘要

平山症(Hirayama disease)是一種罕見但具有其特殊臨床表現的疾病。此病最早由日本平山醫師觀察到並作描述，多好發於十至二十來歲的青少年，尤以男性居多。主要影響到下頭部脊髓的前角細胞，而有非對稱性的遠端上肢肌肉萎縮或無力表現。此症病程通常是緩慢的變化，在最初幾年內的惡化之後，會自行達到一個穩定的階段，爲一良性且自限性的疾病。目前致病機轉仍不甚明確，推測可能原因有二：反覆或持續性的頭部彎曲使下頭後部之脊硬膜不正常往前位移而造成下頭脊髓的壓迫；反覆的脖子彎曲造成脊髓前角細胞產生慢性創傷性局部缺血變化。診斷工具除了善加利用肌電學檢查，在影像學上亦可利用頭部動態核磁共振造影幫助診斷。本文報告一個14歲男孩的平山症案例，藉由其典型的臨床表現，肌電學檢查及影像學診斷，讓臨床醫師能更了解此類疾病病理機轉及預後，並探討目前的治療建議。

關鍵字

平山症 ； 頭部脊髓病變 ； 肌肉萎縮 ； 電生理學 ； 動態核磁共振影像

並列摘要

Hirayama disease is a rare disease with unique clinical manifestations. It was first reported by Japanese physician Keizo Hirayama, and tends to develop in young people in their teens and early twenties, predominantly in men. The lower cervical spinal anterior horn cells are usually involved, resulting in asymmetric muscular atrophy or weakness of distal upper extremity. The onset is insidious and gradual. It ends up in a stable status after years of progression. By now the mechanism is still unclear, and two hypotheses are discussed. One is anterior displacement of the cervical dural sac from repeated or sustained neck flexion, resulting in direct lower cervical cord compression. The other is chronic traumatic focal ischemic change in the anterior horn cells caused by repeated neck flexion. It is very important to make the correct diagnosis because Hirayama disease has a benign and self-limited course. It should be distinguished from other motor neuron diseases or cervical myeloradiculopathy, to prevent unnecessary operations or interventions. Electrodiagnostic tests are needed. The cervical dynamic magnetic resonance imaging is also useful to detect cervical cord compression on neck flexion. We reported a 14-year-old boy with Hirayama disease to demonstrate the typical clinical manifestations, electrophysiological tests, and diagnostic imaging studies, and to discuss current therapeutic options. Some experts suggest application of a temporary cervical collar in early stage of disease to prevent hyperflexion of neck and symptom progression. Surgical stabilization has inconsistent outcomes in long term studies, and is only recommended for advanced cases.

並列關鍵字

Hirayama disease ； cervical myelopathy ； muscular atrophy ； electrophysiology, dynamic magnetic resonance imaging