P66-S Corticospinal function in poliomyelitis survivors

Abstract

Background Poliomyelitis survivors (PS) become candidates to post-polio syndrome (PPS) in their later lives. The mechanism of PPS has been suggested to be multifactorial involving cortical, spinal and peripheral mechanisThe aim of this study was to evaluate TMS parameters in PS and to compare them with those of amyotrophic lateral sclerosis (ALS) patients and controls. Material and methods Single and paired TMS, contralateral and ipsilateral silent period (SP) and triple stimulation technique (TST) were performed by recording from abductor digiti minimi (ADM) and abductor pollicis brevis (APB) muscles of 18 PS, 31 ALS patients and 21 controls. The results were compared with mixed ANOVA and nonparametric independent tests. Results No significant difference was present for within and between subject factors except those for the different interstimuli intervals. Resting motor threshold and MEP/M% in ADM, MEP amplitudes and latencies and TST% in both ADM and APB were significantly different. In posthoc analyses, MEP latencies were higher and TST% were lower in both ADM and APB in ALS group (20.7 ± 4.2 ms, 22.4 ± 5.0 ms, 83.1 ± 42.2, 72.3 ± 29.9) as compared to PS (18.3 ± 1.0 ms, 19.2 ± 2.0 ms, 101.6 ± 15.9, 98.1 ± 14.9), MEP/M% in ADM were lower in PS group (56.0 ± 13.4) as compared to controls (85.2 ± 23.9). SPs, TST, MEP amplitudes and latencies and MEP/M amplitudes did not show any significant difference between ADM and APB in both patient groups. Conclusions Our results revealed upper motor neuron dysfunction in ALS compared to PS and may provide limited evidence about presence of an abnormal cortical drive to mostly uninvolved upper extremity muscles in PS.