STUDY: Use of neuroprosthetic device may maintain blood pressure after spinal cord injury

Paralysis and sensory deficits are the most obvious consequences of spinal cord injury (SCI). But many people also experience orthostatic hypotension — an inability to maintain blood pressure when moving from lying to sitting or standing. This problem has now been circumvented, by artificially recreating a reflex essential for blood-pressure stability using a neuroprosthetic strategy that minimizes orthostatic hypotension caused by SCI.

Orthostatic hypotension is typically managed by lifestyle changes (such as using compression bandages on the legs and sleeping in a semi-upright position) and drugs such as fludrocortisone (a blood-volume expander) or midodrine (which activates the receptors that normally mediate the effect of the sympathetic nerves on the heart and vascular muscles). However, these drugs can have untoward effects. Other approaches include electrical stimulation of skeletal muscles in the lower limbs, which activates the muscle pump and aids cardiac filling, and abdominal constriction belts. Both of these strategies have been used therapeutically, but their effectiveness has not been clearly demonstrated.

Could neuroprosthetic devices be a better alternative? The principle is to restore function by electrically stimulating the neural pathways that have become unresponsive as a result of SCI. Ideally, the stimulation should closely approximate the pattern of activity that normally controls the targeted function. Such an approach has already been used to partially restore locomotion in primates. It has also been used to activate the leg muscles to improve blood-pressure control in people with an SCI, although the reasons for its apparent success in this setting were unclear.

You can read more about this research HERE.