In Asian populations, spinal cord compression often occurs due to a different, inflammatory process affecting the posterior longitudinal ligament.
[citation needed] Clinical signs and symptoms depend on which spinal cord level (cervical,[6] thoracic, or lumbar) is affected and the extent (anterior, posterior, or lateral) of the pathology, and may include:[citation needed] Myelopathy is primarily diagnosed by clinical exam findings.
[7] In some cases the onset of myelopathy is rapid, in others, such as CSM, the course may be insidious with symptoms developing slowly over a period of months.
[citation needed] Once the clinical diagnosis myelopathy is established, the underlying cause must be investigated.
[citation needed] The presence and severity of myelopathy can also be evaluated by means of transcranial magnetic stimulation (TMS), a neurophysiological method that allows the measurement of the time required for a neural impulse to cross the pyramidal tracts, starting from the cerebral cortex and ending at the anterior horn cells of the cervical, thoracic or lumbar spinal cord.