Neurophysiological assessment of the function of cortical and spinal nerve structures in cervical spinal stenosis

The complex pathogenesis of nerve damage in degenerative spinal stenosis results in a variety of clinical phenotypes and makes it difficult to determine the severity of the condition and select appropriate treatment strategies.
The aim of the article was to determine neurophysiological criteria for the analysis of the functional state of cortical and spinal nerve structures in patients with spondylotic compression of the spinal cord (SC) at follow-up after surgical treatment.
The study group included 23 patients with cervical spinal stenosis before and 6 months after surgery. Research methods: transcranial magnetic stimulation (TMS), somatosensory evoked potentials (SSEP).
In patients with neurophysiological signs of spondylotic cervical myelopathy, a statistically significant partial improvement in spinal motor conduction was observed 6 months after surgical treatment, as measured by motor evoked potentials (MEP) during TMS. A trend toward recovery was observed for the passive motor threshold (pMT) and contralateral silent period (cSP), indicating initial restoration of intracortical and spinal neural interactions. SSEP analysis revealed a statistically significant partial improvement in spinal sensory function parameters. In patients with spondylotic compression of SC, but without neurophysiological signs of motor impairment, there were no statistically significant signs of decreased spinal motor conduction 6 months after decompression, indicating preservation of spinal function without disease progression.
Changes in the temporal and amplitude parameters of MEPs, as well as SSEPs, are neurophysiological indicators of damage to the motor and sensory pathways of the cervical SC. The observed changes in the pMT and the cSP represent neurophysiological criteria for decreased excitability of cortical motor neurons, as well as disruption of intracortical inhibitory mechanisms associated with spinal stenosis.

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