To compare demyelination-related movement disorders in patients with and without spinal lesions.

Central demyelination can result in various movement disorders. We have previously shown that spinal cord lesions are the strongest predictor of demyelination-related movement disorders. The difference in movement disorder phenomenology between patients with and without cord lesions is unknown.

This was a pooled analysis of two prospective cohorts with demyelinating diseases. Each patient answered a movement-disorder survey and was clinically evaluated by a movement-disorder specialist. Patients were stratified into two groups according to the presence of spinal lesions and phenomenology was compared between both groups using chi square test. Patients with ganglionic lesions were excluded. Only movement disorders with probable spinal origin according to previously-published criteria were included in patients with spinal lesions. Movement disorders with possible mixed origin were excluded from this group to increase confidence in the spinal origin of these movements.

A total of 152 patients were included (mean age 43.9 years, 63.4% female, 95.4% with multiple sclerosis). There were 93 patients with spinal lesions and 59 without. The most common demyelination-related movement disorders in the entire cohort in a descending order were: tonic spasms, tremor, secondary restless leg syndrome (RLS), myoclonus, focal dystonia, fasciculations, spontaneous clonus, and hyperkeplexia. After excluding  movement disorders with possible mixed origin from the spinal group, the following movement disorders remained more significantly prevalent in patients with spinal lesions than those without spinal lesions: tonic spasms (P=0.013), RLS (P=0.0001), and spontaneous clonus (P=0.016). Tremor was significantly more prevalent in patients without spinal lesions (P=0.032) while dystonia, myoclonus, fasciculations, and hyperkeplexia showed no statistical difference in distribution between the two groups.