Parakinesia Brachialis Oscitans in a Patient With a First Manifestation of Multiple Sclerosis.

PBO is an example of autonomic voluntary motor dissociation and reflects the interplay between loss of cortical inhibition of the cerebellum in the setting of functional spinocerebellar pathways. Clinicians should be aware of this transient phenomenon which should not be mistaken as a chronic movement disorder or focal epileptic seizures.