[Paroxysmal focal dystonia as the initial manifestation of multiple sclerosis: case report].

Paroxysmal phenomena such as dystonia in multiple sclerosis (MS) have approximate incidence ranged between 3.8%-17%. These symptoms in MS may represent transient phenomena related to inflammation in acute plaques and probably are secondary to irritation of demyelinated axons by lymphokines. Paroxysmal dystonia can occur at any time during the course of MS, but usually is the initial manifestation of demyelinating disease. We present the case of 42-year old woman with paroxysmal dystonia as the initial symptom of MS. Further MRI studies and CSF analysis revealed findings typical for MS. Patient's neurological status improved temporary after methyloprednisolone therapy. Paroxysmal dystonia may be related to ectopic impulses, release of inflammatory soluble factors, dysfunction of ion channels and accumulation of extra-cellular potassium. Paroxysmal dystonia often causes diagnostic difficulties, especially when it is the only or the initial symptom of the disease. It requires differential diagnosis with other diseases of central nervous system such as epilepsy and neurodegenerative or inflammation pathology.