老年者の意識障害を伴わない卒中発作（軽発作）について

CEREBROVASCULAR STROKE WITHOUT IMPAIRED CONSCIOUSNESS (LITTLE STROKE) IN THE OLD AGE

I．緒言

　脳卒中は，脳の急性循環障害であり，臨床的には主として，急激な意識障害と，運動麻痺とを伴う症候群とされており，種々の病因によつて起るが，多くは脳出血，又は脳血栓或は脳軟化（以下脳血栓或は脳軟化を合わせて脳血栓と記す）によつて生ずる。従つて意識障害の存することは，脳卒中の診断に重要なものではあるが，明らかに卒中様症状が存するに拘らず，意識障害のない脳血管性傷害も，しばしば経験されるところである。

　一方，剖検所見よりみると，老年者の脳では，脳出血又は脳血栓を有するものが多く，そのなかでは，大病巣を有するものよりも，小病巣が認められるものの方が多い。かかる小病巣が，意識障害を伴わない卒中様発作を示すことの稀でないことは，既にP．Marieの説く所である。

A total number of 500 unselected autopsy cases of the aged were studied at the Yoku-fukai Asylum for the aged, and the follow-ing results were obtained in respect to lit-tle stroke (cerebrovascular stroke without impaired consciousness):

1) Among 500 cases, 209 had one or more little strokes during their life and the vascu-lar lesions leading to diagnosis of little strokes were noted in 194 (93% of 209 cases), and in additional two cases (1%) cerebral tumor was noted. Postmortem examination failed to reveal any parenchymal alteration in thirteen cases (6%).

2) Among 500 cases, 269 (54%) had one or more cerebrovascular accidents with or without impaired consciousness and corres-ponding cerebrovascular lesions were confirm-ed with postmortem examination. Among these 269 cases, the number of cases who had one or more little strokes (194 cases) was more frequent than that of cases who had one or more cerebral strokes with im-parired consciousness (155 cases).

3) Most of the lesions leading to diagno-sis of little strokes were noted to be small softenings in the areas of basal ganglia, but large softenings also caused not infrequently the manifestations of little stroke.