脳血管炎と考えられた2例

Two Cases of What was Regarded as Cerebral Vasculitis

I．はじめに

　脳血管炎は様々な全身性疾患や原因によって2次的に引き起こされることが知られている^17）．しかし，明らかな基礎疾患や原因がなく，病態や病因の不明な中枢神経系に限局する血管炎の報告も見られるが，極めて稀な疾患である．今回，われわれはこのような原因不明の中枢神経系に限局する脳血管炎と考えられる2例を経験したので症例を供覧するとともに若干の文献的考察を加えて報告する．

Two cases of cerebral vasculitis of the central ner-vous system are reported. In our cases, systemic inves-tigation found no underlying cause for vasculitis.

Case 1: A 59-year-old female presented severe headache due to subarachnoid hemorrhage. CT scan obtained one month later demonstrated a low density area with ring-like enhancement in the right frontal lobe. A surgical specimen revealed inflammation of the leptomenigeal vessels with many lymphocytes.

Case 2: A 64-year-old female came to us with dysar-thria and slight left hemiparesis. CT scan and MRI obtained after admission demonstrated an abnormal mass lesion with enhancement in the right frontal lobe. The histological examination revealed vasculitis. After systemic disease and central nervous system infection were excluded, we diagnosed this case as cerebral vas-culitis of unknown origin.

In this paper, the clinical and pathological features of cerebral vasculitis and differential diagnosis were dis-cussed.