起立失調症候群の皮膚微小循環血流量の検討—レーザードップラー法による評価と塩酸ミドドリンの影響

Study on the Blood Flow of Cutaneous Microcirculation in Orthostatic ataxia Syndrome:Evaluation by the laser Doppler method and the effect of midodrine hydrochloride

　起立失調症候群の皮膚交感神経機能障害を皮膚血流量測定により明らかにすることを目的とした．さらに，交感神経刺激作用を有する塩酸ミドドリンの皮膚血流量に対する影響を検討した．対象は起立失調症候群9例，健常者12例．方法は，血圧はトノメトリ法，皮膚血流量はレーザードップラー法，心電図は第II誘導で記録．安静時160秒間，head-up tilt試験1分間の測定を行った．起立失調症候群に対しミドドリンを4週間投与し，投与前後で比較した．結果は安静時は両群で差を認めなかった．head-up tilt試験では，健常者群は負荷時に血圧，皮膚血流量は不変，心拍数は上昇．起立失調症候群ミドドリン投与前は，負荷時に血圧，皮膚血流量は低下，心拍数は上昇．ミドドリン投与4週間後は，体位変換時に血圧，皮膚血流量は不変，心拍数は上昇．起立失調症候群は体位変換時の皮膚交感神経活動の反応性低下があり，ミドドリンは，この反応性低下を改善した．

This study was conducted in order to clarify the skin sympathetic nervous disorder in the syndrome of orthos-tatic by determining the skin blood flow. Additionally, the effect of midodrine hydrochloride which simulates the sympathetic nervous system on skin blood flow was examined. Nine patients with orthostatic syndrome and 12 healthy subjects were used. Blood pressure was recor-ded by a tonometric method, skin blood flow by a laser Doppler method, and electrocardiogram by the II lead. Systolic blood pressure at rest, skin blood flow and heart beat were determined for 180 seconds, and head-up tilt test was conducted for 1 minute. To the patients with orthostatic syndrome, midodrin was administered for 4weeks, and the above values were compared between, before and after administration. It was found that there were no differences in systolic blood pressure, skin blood flow and heat rate between healthy subject and patients with orthostatic syndrome at rest. In the head-up tilt test, the healthy-subjects group showed unchanged blood pressure and skin blood flow and increased heart rate on change of posture. The group with orthostatic syndrome showed decreased blood pressure and skin blood flow and increased heart rate on change of posture before administration of midodrine. At 4 weeks after administration, there was unchanged blood pressure, unchanged skin blood flow, and increased heart rate on change of posture. In the group with orthostatic syn-drome, a decrease in reactivity of skin sympathetic activity was observed on change of posture, but mido-drine improved this decreased reactivity.