Disturbances of sensation occasioned by experimental arrest of blood flow

[摘要] Disturbances of sensation in the hand were studied during and after experimental arrest of circulation to the arm. Blockage of circulation was performed as outlined by Lewis and Pochin, by putting the cuff of a sphygmomanometer on the upper arm and bringing the pressure rapidly up to 200 mm/Hg. The experiments listed below were intended to demonstrate the variability of a central reaction brought about by fairly definite disturbances of the ischaemic periphery. All experiments were made on the present writers and repeated on nine other subjects, none of whom had systolic pressure reaching 150 mm/Hg. I - Blockage of circulation in both arms led to symmetrical phenomena in both hands (thermal paresthesias, tingling and hyposthesia), both under symmetrical experimental circumstances, and under the following variations: So long as the cuff pressure on both arms was above the systolic blood pressure, differences as great as 300 mm/Hg in one cuff and 150 mm in the other did not alter the symmetry of the effects. Neither was symmetry and synchronism of paresthesias affected when compression on one side preceded equal compression on the other up to 20 seconds. II - When a punctate pressure is applied to the paresthetic field the paresthesias disappear around that point and the latter is clearly brought out from the indifferent background produced in the area of depressed skin. On the basis of Kugelberg's findings, it seems that this occurs because the impulses caused by pressure have a higher frequency and substitute the spontaneous abnormal discharges of the ischaemic nerve fibers. III - Repeated mechanical stimulation of a fingertip during the experiment failed to show any influence on sensory (touch) thresholds, in contrast, therefore, to what would be expected on the basis of the physiologic experiments which show rapid fatigue of ischaemic structures. IV - In contrast to what might be expected from the intense changes undergone by receptors in the muscles during ischaemia, as observed by Matthews, weight discrimination and the capability of hitting targets with objects of different weights were not significantly altered, even during the painful phase of fatigue.