Functional electrical stimulation effect on orthostatic hypotension after spinal cord injury.

OBJECTIVE

To investigate the possibility of using functional electrical stimulation (FES) to control orthostatic hypotension in patients with spinal cord injury (SCI) and to clarify the mechanism of the response.

DESIGN

Subjects were tilted by 10 degree increments with varying intensities of lower-extremity FES. Stimulation over muscles was compared to stimulation over noncontractile sites.

SETTING

Physical therapy department of a major rehabilitation center.

PATIENTS: Six patients with SCI above T6 (3 with recent injury recruited consecutively from an inpatient spinal cord rehabilitation unit, and 3 from the community with longstanding injury, recruited as volunteers).

MAIN OUTCOME MEASURES: Blood pressure, heart rate, and perceived presyncope score recorded at each tilt angle and analyzed using a multivariate analysis of variance statistical methodology.

RESULTS

Systolic and diastolic blood pressure increased with increasing stimulation intensities (systolic, p = .001; diastolic, p = .0019) and decreased with increasing angle of tilt (p < .001) regardless of the site of stimulation. Subjects tolerated higher angles of incline with electrical stimulation than without (p = .03).

CONCLUSIONS

FES causes a dose-dependent increase in blood pressure independent of stimulation site that may be useful in treating orthostatic hypotension.