脊髄小脳変性症における脳幹機能の電気生理学的検討

Abstract

In order to evaluate brainstem function in spinocerebellar degeneration (SCD), brainstem auditory evoked potentials (BAEP) and blink reflex (BR) were recorded in 63 cases of SCD (M:F=39:24, 52.8±10.4 y. o.) : 13 cases of Menzel type olivo-ponto-cerebellar atrophy (MOPCA), 26 of sporadic olivo-ponto-cerebellar atrophy (SOPCA), 5 of Holmes type cortical cerebellar atrophy (HCCA) and 19 of late cortical cerebellar atrophy (LCCA). Atrophy of the brainstem was also checked by using the MRI in 42 out of 63 cases (M:F=28:14, 52.4±9.9 y. o.). Age-sex matched persons with muscle contraction headache or cervical spondylosis war used as controls. Latencies of Ⅰ, Ⅲ, Ⅴ, Ⅰ-Ⅲ, Ⅰ-Ⅴ and Ⅲ-Ⅴ were measured on BAEP. Amplitudes of Ⅰ (ampⅠ), Ⅲ (ampⅢ) and Ⅴ (ampⅤ) and ratios of amplitude (Ⅲ/Ⅰ, Ⅴ/Ⅰ and Ⅴ/Ⅲ) were obtained. R1 latencies of BR were estimated. Then facial nerve distal latencies (D) were measured to calculate R1/D. Right-left differences of R1 (ΔR1), D (ΔD) and R1/D (ΔR1/D) were calculated. Area ratios of pons to posterior fossa (Po) and 4th ventricle to posterior fossa (Ve) were evaluated by using the MRI. Diameter ratios of midbrain tegmentum to cerebral cortex (Te) were also calculated. Correlation coefficients of these parameters were examined. Prolongations of Ⅲ, Ⅰ-Ⅲ and Ⅰ-Ⅴ, decrease of ampⅢ and Ⅲ/Ⅰ and increase of Ⅴ/Ⅲ were statistically significant in BAEP of MOPCA and SOPCA. A remarkable difference of R1 and R1/D in MOPCA and SOPCA from normal controls was observed. Significant correlations of Ve to ampⅢ, Ⅲ/Ⅰ, Ⅴ/Ⅲ, R1 and R1/D were observed. Po had significant correlations to Ⅲ, Ⅴ, Ⅰ-Ⅲ, Ⅰ-Ⅴ, ampⅢ, Ⅲ/Ⅰ, Ⅴ/Ⅲ, R1 and R1/D, AmpⅢ, Ⅲ and Ⅲ/Ⅰ showed remarkable correlations to R1 and R1/D. From these results MOPCA and SOPCA have the brainstem dysfunction, which can be evaluated by Ⅲ, Ⅰ-Ⅲ, ampⅢ, Ⅲ/Ⅰ, R1 and R1/D. Pontine atrophies judged in MRI have significant correlations to these parameters in SCD.