Orthostatic hypotension following spinal cord injury: impact on the use of standing apparatus.

INTRODUCTION: Upright posture confers numerous medical and social benefits to a spinal cord injured (SCI) patient. Doing so is limited by symptoms of orthostatic hypotension. This is a common secondary impairment among tetraplegic sufferers. OBJECTIVE: Establish the proportion of SCI patients who are restricted from using standing apparatus, such as standing frames and standing wheelchairs, because of inducing symptomatic orthostatic hypotension or the fear of developing these disabling symptoms. STUDY DESIGN: Survey conducted by Internet-accessible electronic questionnaire. Questionnaire validated for reliability and accuracy. RESULTS: 293 respondents. Mean age 44.6; 76% male. Median time from injury: 7 years. 38% suffered with orthostatic hypotension; majority were complete injuries and all (except one - T12) were T5 or above level. 52% replied that they were using standing wheelchairs or frames. Of these, 59 (20% of total) stated that orthostatic hypotension symptoms were limiting the use of their upright apparatus. Of those who did not use standing wheelchairs or frames, 16 (5.5% of total) reported that this was because of the fear of worsening their orthostatic hypotension. CONCLUSION: Orthostatic hypotension restricts standing apparatus use in a large proportion (a total of 25.5% of respondents in this survey) of SCI patients.

Pressure changes under the ischial tuberosities of seated individuals during sacral nerve root stimulation.

Neuromuscular stimulation via the sacral nerve roots is proposed for prevention of ischial pressure ulcers following a spinal cord injury (SCI). Acute effects of sacral functional magnetic stimulation (FMS) on seat interface pressure changes were investigated in five nondisabled volunteers. Similar effects were demonstrated with functional electrical stimulation in people with SCI who used a sacral anterior root stimulator implant. The results indicated that sacral nerve root stimulation, either by FMS or implanted electrical stimulation, induced gluteus maximus contraction and mild pelvic tilt sufficient for clinically significant reductions in ischial pressures during sitting.

Interface pressure and cutaneous hemoglobin and oxygenation changes under ischial tuberosities during sacral nerve root stimulation in spinal cord injury.

Noninvasive functional magnetic stimulation (FMS) of the sacral nerve roots can activate gluteal muscles. We propose the use of sacral anterior root stimulator (SARS) implants to prevent ischial pressure ulcers in the spinal cord injury (SCI) population. In this study, we (1) investigated the acute effects of sacral FMS on ischial pressure, skin blood content, and oxygenation changes in people with SCI and demonstrated the utility of FMS as an assessment tool, and (2) showed that similar effects are possible with electrical stimulation via a SARS implant. Results indicated that sacral nerve root stimulation, either by FMS or implanted electrical stimulation, induced sufficient gluteus maximus contraction to significantly change subjects' ischial pressures and cutaneous hemoglobin and oxygenation during sitting. In addition to these beneficial acute effects, chronic stimulation via a SARS implant may build gluteal muscle bulk and prevent or reduce pressure ulcers in the SCI population.