Evolution of tibial SSEP after traumatic spinal cord injury: baseline for clinical trials.

OBJECTIVE: To describe the spontaneous evolution of tibial somatosensory evoked potentials (tSSEPs) after spinal cord injury (SCI) and its relation to neurological and functional parameters.

METHODS: tSSEPs were assessed in 297 patients within five standardized time intervals throughout the first year after injury, along with neurological and functional parameters.

RESULTS: Roughly 60% of the patients did not show any recordable tSSEP throughout the first year after injury. Approximately 20% had recordable potentials at every assessment stage and showed an improvement of tSSEP parameters over time. In about 10% of the patients, a potential recovered during the first year. In the remaining cases, potentials were inconsistently recordable. All groups showed a similar amount of neurological and functional improvement.

CONCLUSIONS: Recordability, latencies and amplitudes of tSSEPs can change over time after SCI. The early recordability of a tSSEP is associated with a favorable functional and neurological status and outcome. In contrast, an initially absent tSSEP is not always associated with a poorer status and outcome but only in those 75% of the patients in whom the potential remains absent.

SIGNIFICANCE: This exact description of the spontaneous improvements of neurophysiological, neurological and functional parameters after SCI is an important prerequisite in appraising the efficacy of new interventional therapies.