Cutaneomuscular reflexes following stroke: a 2-year longitudinal study.
Cutaneomuscular reflex responses (CMRs) have been studied in nine stroke patients (55-84 years) starting from the first 1-7 weeks after stroke and continuing at intervals of 6-8 weeks for up to 2 years. Multi-unit surface EMG signals were recorded from the stroke and non-stroke first dorsal interosseous (1DI) hand muscle while subjects gripped a dowel, and concomitant stimulation of the digital nerves of the index finger was delivered at 2.5 x threshold for perception. Motor function was measured using the Motor Assessment Scale (MAS) and patients were classified as having a good or a poor recovery according to their final functional outcome. None of the patients showed a change in the sizes of the E1, I1 and E2 reflex components over time. At initial testing, the size of the E1 component for all patients who showed good recovery fell within the 95% reference range (0-16.5% modulation of background EMG) found for normal age matched controls. In contrast, when first tested, 5/5 patients who showed no significant recovery over the 2-year period, had exaggerated spinal E1 components greater than 16.5%. We conclude that exaggerated E1 components could be predictive of a poor functional outcome at 2 years.
Nadler
Martine A
MA
Department of Physiology, University College London, Gower Street, WC1E 6BT, London, UK.
Harrison
Linda M
LM
Stephens
John A
JA
D000344:Afferent Pathways / Q000503:physiopathology*; D000368:Aged; D000369:Aged, 80 and over; D004558:Electric Stimulation; D004576:Electromyography; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology; D018482:Muscle, Skeletal / Q000294:innervation / Q000503:physiopathology*; D010812:Physical Stimulation; D011237:Predictive Value of Tests; D011379:Prognosis; D020127:Recovery of Function / Q000502:physiology; D012021:Reflex, Abnormal / Q000502:physiology*; D012867:Skin / Q000294:innervation; D020521:Stroke / Q000503:physiopathology*