Article

Neurophysiological investigation has shown that patients with
clinically complete spinal cord injury can have residual motor sparing ("motor discomplete"). In the current study somatosensory conduction was assessed in a
patient with clinically complete spinal cord injury and a novel methodology for
assessing such preservation is described, in this case indicating "sensory
discomplete" spinal cord injury. METHODS: Blood oxygenation level-dependent
functional magnetic resonance imaging (BOLD fMRI) was used to examine the
somatosensory system in a healthy subject and in a subject with a clinically
complete cervical spinal cord injury, by applying tactile stimulation above and
below the level of spinal cord injury, with and without visual feedback. RESULTS: In the participant with spinal cord injury, somatosensory stimulation below the
neurological level of the lesion gave rise to BOLD signal changes in the
corresponding areas of the somatosensory cortex. Visual feedback of the
stimulation strongly modulated the somatosensory BOLD signal, implying that
cortico-cortical rather than spino-cortical connections can drive activity in the
somatosensory cortex. Critically, BOLD signal change was also evident when the
visual feedback of the stimulation was removed, thus demonstrating sensory
discomplete spinal cord injury. CONCLUSION: Given the existence of sensory
discomplete spinal cord injury, preserved but hitherto undetected somatosensory
conduction might contribute to the unexplained variability related to, for
example, the propensity to develop decubitus ulcers and neuropathic pain among
patients with clinically complete spinal cord injury.

Langue : ANGLAIS