NEUROMODULATION OF DETRUSOR HYPER-REFLEXIA BY FUNCTIONAL MAGNETIC STIMULATION OF THE SACRAL ROOTS

Objective To investigate the acute effects of functional magnetic stim ulation (FMS) on detrusor hyper-reflexia using a multi-pulse magnetic stimulator. Patients and methods Seven male patients with established and intractable detrusor hyper-reflexia following spinal cord injury w ere studied, No patient was on medication and none had had previous su rgery for detrusor hyper-reflexia. After optimization of magnetic stim ulation of S2-S4 sacral anterior roots by recording toe flexor electro myograms, unstable detrusor activity was provoked during cystometry by rapid infusion of fluid into the bladder. The provocation test produc ed consistent and predictable detrusor hyper-reflexia. On some provoca tions, supramaximal FMS at 20 pulses/s for 5 s was applied at detrusor pressures which were >15 cmH(2)O. Results Following FMS there was an obvious acute suppression of detrusor hyper-reflexia. There was a prof ound reduction in detrusor contraction, as assessed by the area under the curves of detrusor pressure with time. Conclusions Functional magn etic stimulation applied over the sacrum can profoundly suppress detru sor hyper-reflexia in man, It may provide a non-invasive method of ass essing patients for implantable electrical neuromodulation devices and as a therapeutic option in its own right.