眼球運動障害，不随意運動，筋萎縮，痴呆を伴った家族性脊髄小脳変性症の1家系—臨床症候分析による一考察

A FAMILY OF SPINO-CEREBELLAR DEGENERATION WITH DISTURBANCE OF OCULAR MOVEMENT, CHOREO-ATHETOSIS, AMYOTROPHY AND DEMENTIA: A CONSIDERATION IN CLINICAL FEATURES

　抄録上方注視障害，slow eye movementなど眼球迷動障害，choreo-athetosis，著明な萎縮，痴呆，sleep apneaなどの多彩な臨床症状を呈した遺伝性家族性脊髄小脳変性症の1家系を報告した。本家系の病型分類上の位置づけとしては，病理学的に歯状核赤核淡蒼球ルイ体萎縮症（DRPLA）と呼ばれる疾患に類似すると考えられるが，臨床症状からは，本家系はataxo-choreoathetoid formとpseudo-Huntingtonformのちょうど中間に位置し，しかもその家系内発症者の大半が比較的均一な症状を呈した点は注目すべきである。このような疾患で，著明な筋萎縮を伴った症例は稀であり，筋生検によって，前根ないし末梢神経障害型と考えられる神経原性変化を認めており，病変分布の多系統性を考える上で示唆に富む所見といえる。

Seven cases in a family of hereditary spino-cerebellar degeneration (SCD) similar to dentato-rubro-pallido-Luysian atrophy (DRPLA) were re-ported. The clinical features of these cases were disturbance of ocular movement (limitation of ocu-lar movement and slow eye movement (SEM)), remarkable amyotrophy, choreo-athetosis, dementia and sleep apnea. The brain CT's revealed marked atrophy in pons and cerebellum.

Amyotrophy had been reported in the case of DRPLA, particular ataxo-choreoathetoid form (by Hirayama). Muscle biopsy was performed in these cases, which showed scattered small angu-lated fiber, severe atrophic fiber with pyknotic nuclear clump, fiber type grouping and small rounded fiber were mixed. These findings indi-cates neurogenic change of radiculo-neuropathy type (by Tanabe). In many reported cases of DRPLA and SCD with amyotrophy, this type of muscle biopsy had not been recognized.

In SCD with amyotrophy, a main lesion had exsisted on peripheral nerve. In this case, there was no definite clinical findings (sensory distur-bance, delay of conduction nerve velocity, peri-pheral neuropathy in nerve biopsy).

In recent years, several unclassified cases of SCD with amyotrophy had been reported, which had multi-system degeneration involving peri-pheral neuropathy. This case is similar to these cases, which is speculates multi-systemic lesions, not only DRPLA but also peripheral nerve in-volvement. On neuro-otological study, velocity of saccade was slow and persuit was reserved in proband case. In younger onset case, disturbance of saccade and pursuit was mild. In older pro-gressive case, disturbance of saccade and pursuit was progressive and accompanied with severe limitation of ocular movement. Several autopsy cases of SEM had been reported. No neuronal loss of paramedian pontine reticular formation had been found in these cases.

On polysomnography of all day long, sleep apnea was noticed, which was occured in light sleep. This finding is compatible for sleep apnea of SCD. Mechanism of sleep apnea in SCD is regarded as disturbance of auto-regulation system in respiration and sleep-awakefulness rhythm due to monoamine hypothesis. It indicates neuronal loss of locus coeruleus middle pontine to medullary raphe nuclei.

In this family, various clinical findings are recog-nized, which is featured by uniformity of clinical symptom and anticipation of heredity.