Schröder R, Keller E, Flacke S, Schmidt S, Pohl C, Klockgether T, Schlegel U
Neurologische Klinik und Poliklinik, Universität Bonn, Germany.
J Neurol. 1999 Nov;246(11):1069-74. doi: 10.1007/s004150050514.
Hirayama's disease is a benign juvenile form of focal amyotrophy affecting the upper limbs. Previous studies have suggested that the disorder is a neck flexion induced cervical myelopathy. We report clinical and magnetic resonance imaging findings in nine patients with Hirayama's disease. Cervical imaging of seven patients revealed spinal cord changes consisting of focal atrophy and foci of signal alterations. On neck flexion a forward movement and mild reduction in the anteroposterior diameter of the lower cervical cord against the vertebral bodies was noted in affected individuals as well as in five normal controls. In contrast to earlier reports, none of our patients showed complete obliteration of the posterior subarachnoid space. Measurement of the anteroposterior spinal cord diameter in each vertebral segment (C4-C7) revealed no significant differences in the degree of spinal cord flattening between the two groups. Furthermore, two of our patients had significant degenerative changes in the cervical spine (disc herniation, retrospondylosis) contralateral to the clinically affected side. These degenerative changes resulted in a marked cord compression on neck flexion but were not associated with ipsilateral clinical abnormalities or spinal cord alterations. Our results argue against a flexion-induced cervical myelopathy and support the view that Hirayama's disease is an intrinsic motor neuron disease.
平山病是一种影响上肢的良性青少年型局灶性肌萎缩。以往研究提示该疾病是一种颈屈诱发的颈椎病。我们报告了9例平山病患者的临床及磁共振成像结果。7例患者的颈椎成像显示脊髓改变，包括局灶性萎缩和信号改变灶。在颈屈时，受累个体以及5名正常对照者均可见下颈段脊髓相对于椎体向前移动且前后径轻度减小。与早期报告不同，我们的患者均未出现蛛网膜下腔后部完全闭塞。测量每个椎体节段（C4 - C7）的脊髓前后径显示，两组之间脊髓扁平程度无显著差异。此外，我们的2例患者在临床受累侧对侧的颈椎有明显退变改变（椎间盘突出、椎体后缘骨质增生）。这些退变改变在颈屈时导致明显的脊髓受压，但与同侧临床异常或脊髓改变无关。我们的结果反对颈屈诱发颈椎病的观点，并支持平山病是一种原发性运动神经元病的观点。
