Increased V/D-ratio in lumbosacral SEP's as a new electrophysiological measure of spasticity.
METHODS
Open-label, prospective study.


OBJECTIVE
To establish the amplitude-ratio of V-response and D-response (V/D-ratio) as a new measure of spasticity, comparing the motor effect of the H-reflex to the sensoric input.


METHODS
In 13 legs of seven patients with spasticity and in four legs of patients without central nervous system disease, maximal M-response and maximal H-reflex were recorded. Lumbosacral SEP's were recorded with the same stimulus parameters as the maximal H-reflex. H/M-ratio and V/D-ratio were compared to the increased muscle tone.


RESULTS
The H/M-ratio and the V/D-ratio in legs with spasticity differed significantly from the H/M-ratio and the V/D-ratio in normal legs. But only the V/D-ratio was higher in legs with moderately or highly increased muscle tone than in legs with slightly increased muscle tone.


CONCLUSIONS
The V/D-ratio increases in spasticity and shows an even closer relationship to increased muscle tone than the H/M-ratio.
Rösche
J
J
Department of Neurology and Epileptology (Department of Psychiatry I, University of Ulm), Ravensburg-Weissenau, Germany.
Mauch
E
E
D004558:Electric Stimulation; D005073:Evoked Potentials, Somatosensory; D006181:H-Reflex / Q000502:physiology; D006801:Humans; D007866:Leg; D008161:Lumbosacral Region; D009128:Muscle Spasticity / Q000503:physiopathology*; D009129:Muscle Tonus; D011930:Reaction Time; D013126:Spinal Nerve Roots / Q000503:physiopathology*; D013979:Tibial Nerve / Q000503:physiopathology