Changes in the Soleus H-reflex Test and Correlations between Its Results and Dynamic Magnetic Resonance Imaging Abnormalities in Patients with Hirayama Disease

Publication date: Available online 3 October 2017
Source:Clinical Neurophysiology
Author(s): Chaojun Zheng, Yu Zhu, Feizhou Lu, Dongqing Zhu, Shuo Yang, Xiaosheng Ma, Xinlei Xia, Robert Weber, Jianyuan Jiang
ObjectiveTo investigate changes in soleus H-reflex tests in patients with Hirayama disease (HD) and to analyse correlations between these changes and forward-shifting of the cervical cord during neck flexion.MethodsThe amplitude of the soleus H-reflex with and without vibration on the Achilles tendon was recorded bilaterally in 81 HD patients and 34 controls to measure both the vibratory inhibition index (VII) and the Hmax/Mmax ratio. The maximum forward-shifting degree of cervical cord during neck flexion was measured using dynamic magnetic resonance imaging in all HD patients.ResultsSignificantly higher VII was recorded in 6/81 (7.4%) HD patients, along with abnormal Hmax/Mmax ratios in 5 of 6 cases. Compared to illness duration (r = 0.29-0.36, p < 0.05), the maximum forward-shifting degree of the cervical cord was more strongly correlated with both VII and the Hmax/Mmax ratio (r = 0.51-0.81, p < 0.05).ConclusionsHD patients may develop cervical spinal cord injury with disease progression, and these lesions may be more likely to occur in cases with relatively severe cervical-flexion structural abnormalities even during early stages.SignificanceMore caution should be taken when managing HD patients with severe cervical-flexion abnormalities because of the possible early occurrence of upper motor neuron lesions.



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