Influence of continuous photostimulation on catecholamine urinary excretion in patients with cerebral hemorrhage.

: Hypertensives with (25 cases) or without (27 cases) cerebral hemorrhage (CH) and normotensives (25 cases) were exposed from 7 to 8.30 a.m. to a low light input and from 8.30 to 10 to a high light input (HLI), and urinary epinephrine (E) and norepinephrine (NE) were measured at the end of these periods. In normotensives HLI had no effect on E and NE excretion; in hypertensives with and without CH it increased E excretion and depressed NE excretion. Light activation of E release may be responsible for the daytime occurrence of CH in hypertensives.