皮膚単一知覚点を中心とした触覚及び痛覚の臨床生理学的研究

Clinico-physiological Studies on Cutaneous Sensory Spots, Especially on Tactile and Pain Spots.

　知覚受容機構の解明にあたつて末梢皮膚受容機構の関与するところ極めて大であり，且末梢より中枢に至る広い知覚神経系の中で，皮膚はヒトに於て臨床実験の可能な殆んど唯一の場でもある。

　本論文は皮膚知覚受容機構の中に於て重要な位置を示めている単一知覚点に関する最近の研究が主として形態解剖学的方面からのみ行われていて詳細な臨床生理学的な面よりの研究が比較的乏しいことに鑑み，この方面から新たに吾々の考案せるOptical lever esthesio-algesiometer^21）を用いて，触，痛覚を中心として検討を試み，皮膚単一知覚点の機能を検討し併せて知覚の臨床検査法の限界にもふれようとするものである。

　Clinico-physiological studies on single tactileand pain spots were made by means ofnewly devised Abe's optical lever esthesio-algesiometer upon the volar surface offorearm of normal subjects.

On tactile spots:

　1) By mechanical stimulations on minute skinarea, it is confirmed that the spots especially sensitive to tactile stimuli are scatteredover the skin surface.

　2) Tactile thresholds of these spots even withinthe limited skin area, are not constant, butthere is gradation in these thresholds; fromthe lowest value to the highest one. Thehigher the threshold value the characteristicsof the tactile spots become less distinct.

On pain spots;

　1) Threshold for pricking pain is higher thanthat for touch on a given spot.

　2) Dense distribution of "pain spots" wasdescribed by v. Frey and has been supportedby many authors. We, however, failed tofind such localized spots especially sensitiveto painful stimuli. Increasing the quantityof mechanical stimulation on the minuteskin area, any point on the skin surfacemay give rise to pricking pain.

　3) It is considered that factor inducing painto mechanical stimulation is distortion ofthe skin.

　4) No double pain response was obtained bymeans of our minute mechanical stimulations.

　5)"Specific sensory spots" of very rare distribution, hitherto not described, were found, which, in contrast with the pricking painspots described above, respond to very weakneedle stimulation with burning or penetrating pain of unpleasant character, withoutany tactile response, and hardly respond topressure stimuli.