Article

Dermatomal somatosensory evoked potentials (dSSEPs) not only provide
a neurophysiological readout comparable with conventional SSEPs but also provide
an opportunity to track changes in sensory function corresponding to individual
dermatomes (ie, a single spinal segment) above, at, and below the level of spinal
cord injury (SCI). OBJECTIVES: This study aimed to determine the reliability and
responsiveness of dSSEPs and electrical perception thresholds (EPTs) to monitor
changes in sensory function after cervical SCI. METHODS: Initial and follow-up
dSSEPs and EPTs were recorded from cervical dermatomes (C4-C8) of patients with
traumatic tetraplegia (C3-C8; ASIA Impairment Scale A-D) during recovery after
SCI (n = 18). RESULTS: Follow-up examination of 74 initial dSSEPs unaffected by
SCI (n = 18) revealed no significant change in latency (Delta = 0.0 +/- 1.4 ms; P
= .9) or EPT sensitivity (Delta = 0.1 +/- 0.8 mA; P = .3). In 41 dSSEPs initially
delayed after SCI (n = 14), latencies significantly decreased on follow-up
examination (Delta = -3.1 +/- 2.9 ms; P < .01) without a corresponding increase
in sensitivity of the EPT (Delta = 0.2 +/- 3.4 mA; P = .7). dSSEPs that were not
measurable initially were subsequently recorded in 11 dermatomes (n = 5) on
follow-up examination. This conversion of abolished-to-recordable dSSEPs was
often preceded by the perception of an initial EPT and associated with a
concomitant recovery of EPT at follow-up. CONCLUSION: SSEPs and EPT can be
reliably recorded to monitor changes in sensory function for each individual
spinal segment after cervical SCI. dSSEPs may be potentially useful to monitor
the safety of a therapeutic drug or cell transplant in early-phase (I/II)
clinical trials as well as document the potential efficacy of interventions where
the standard neurological assessment might not detect subtle therapeutic effects.

Langue : ANGLAIS