To study relationships between posterior tibial (PT) nerve somatosensory evoked potentials (SEP) and recovery of ambulatory capacity in patients with incomplete spinal cord injury (SCI) participating in Lokomat training. Design: Correlation study of functional clinical outcome with quantitative electrophysiological measures of sensory processing. Setting: Queen Elizabeth National Spinal Injuries Unit, Scotland. Participants: 13 acute and 5 chronic incomplete SCI patients. Intervention: 30 hours Lokomat Training over a 6-week period. Main Outcome Measures: Outcome measures assessed at baseline after 3 and 6 weeks of Lokomat training; (1) Walking Index for Spinal Cord Injury scale (WISCI II), (2) temporal gait analysis, (3) American Spinal Injury Association (ASIA) motor and sensory scores, and (4) Posterior Tibial Nerve SEP. Results: Improvements in ambulatory capacity were seen in both acute and chronic incomplete SCI patients after 6 weeks of Lokomat training. SEP measurements in the majority of patients were abnormal with prolonged latency and reduced amplitude. Significant changes in the latency of the P1 cortical component of the PT nerve SEP were evident in acute incomplete SCI patients only (P<.01). The baseline lower-limb motor score and latency of the PT nerve SEP components are correlated with WISCI II score and temporal gait parameters after 6 weeks of Lokomat training. The double support time and cadence were significantly correlated to the N2 component latency in acute (r=.982; P<.001) and chronic (r=.949, P<.01) incomplete SCI patients. The P2 component latency was correlated to the walking speed (r=-.863, P<.01), double support time (r=.973, P<.001), stride length (r=-.863, P<.01) and cadence (r=-.973, P<.001) in the chronic group. The ASIA motor scores and PT nerve SEP are related to the ambulatory capacity of incomplete SCI patients. Accordingly, the PT nerve SEP may have some prognostic value in relation to recovery of walking and highlights the role of cortical sensorimotor processing in recovery. Conclusions: The ASIA motor scores and PT nerve SEP are related to the ambulatory capacity of incomplete SCI patients. Accordingly, the PT nerve SEP may have some prognostic value in relation to recovery of walking and highlights the role of cortical sensorimotor processing in recovery.
- somatosensory evoked potentials
- spinal cord injury