ISNCSCI Exam Changes Following Spinal Cord Stimulation.

Objectives: To describe changes in the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) exam in sublesional motor and sensory domains following short-term epidural electrical stimulation of lumbosacral spinal segments in individuals with spinal cord injury (SCI).

Methods: Twenty individuals with SCI underwent implantation of percutaneous epidural spinal cord stimulation followed by stimulation parameter optimization and 10-12 sessions of stimulation-enabled motor training. Pre-/postintervention ISNCSCI exams were compared to determine changes in motor/sensory scores for regions within 3 levels of the neurological level of injury (NLI) and caudal to this, with subanalyses per motor/sensory complete versus incomplete baseline status.

Results: Individuals with motor complete SCI gained 6% ± 3% of available motor points within 3 levels of NLI and 1% ± 0% of motor points caudal to this (P = .08). Motor incomplete individuals gained 9% ± 22% of available motor points within 3 levels of NLI and lost 4% ± 7% of motor points caudal to this (P = .63). Following stimulation, changes in motor scores with potential high functional impact occurred in 3 individuals (5 total muscle groups with conversion from baseline <3/5 strength to ≥3/5 at completion). Individuals with sensory complete SCI had fewer sensory gains within 3 levels of NLI (6%) compared to those with sensory incomplete SCI (30%, P = .02).

Discussion: Spinal cord stimulation after SCI rapidly induces changes in both motor and sensory domains that are retained after stimulation is removed. These changes primarily occur within 3 levels of the NLI and occur to a greater degree in those with incomplete SCI.