多発性硬化症の神経心理学的検討

Neuropsychological Investigation in Multiple Sclerosis

　最近，多発性硬化症（MS）の認知障害と大脳病巣との関連が注目されている。10例のMS例において神経心理学的検査とMRIを施行しその関連にっいて検討した。MS例全体では，9項目の神経心理検査上，三宅式記銘力検査，かなひろいテスト，語想起テストの3検査は対照群に比し成績が有意に低下していた。MRI上大脳に多巣性・融合性の脱髄巣を認めたA群5症例中4例では4項目以上の心理検査で対照群に比較して有意に成績が低下していたが，散在性・非融合性の脱髄巣を認めるB群3例および病巣を認めないC群2例では有意な成績低下は2項目以下であった。MS例では，記銘力障害，情報処理速度の遅延が顕著で，いわゆる皮質下性痴呆の病態を呈し，MRI上の大脳病巣と神経心理学的所見の程度に対応が認められた。

We studied neuropsychological performance in 10 patients with multiple sclerosis (MS). Neuropsy-chological test batteries consisted of Mini-Mental State Examination, Digist Span, Paired Associate Learning Test (PAL), Benton Visual Retention Test, Kohs Block -Design Test, Digit Symbol Subtest in WAIS, `Kanahi-roi" Test, Verbal Fluency and Wisconsin Card Sorting Test. In accordance with cerebral lesions on MRI, patients were devided into three groups. A : Multiple-confluent lesions, B : Discrete lesions, C: No lesion

In MS patients as a whole, performance of PAL, "Kanahiroi" Test and Verbal Fluency were significantly impaired compared with 10 age and education matched normal controls (p＜0.05), while other tests were not. In four out of five patients of A group, more than four neuropsychological tests showed bellow mean -2SD score of normal controls, whereas in patients of B and C group, less than three neuropsychological tests showed bellow -2SD score of normal controls.

In conclusion, severity of cognitive impairment in patients with MS correlated with lesion extent on MRI. Patients with MS exhibited significant cognitive impair-ment on tasks of recent memory and mental processing speed. It is suggested that MS patients show the features of subcortical dementia.