Paroxysmal dystonia as an initial presentation of multiple sclerosis posing a diagnostic challenge.

Tremor is the most common and frequently reported movement disorder in multiple sclerosis (MS). Paroxysmal dystonia (PD), also known as painful tonic spasm (PTS), is a relatively less common but well-recognized movement disorder in multiple sclerosis (MS). These are characterized by episodic attacks of involuntary flexion, extension movements of body. Such paroxysmal symptoms as an initial presenting feature raise many differential diagnoses and can often be mistaken as epileptic seizures as well as psychogenic events and may sometimes lead to delay in diagnosis as well. Diagnosis is clinical with the help of supportive investigations to rule out other paroxysmal disorders, especially epileptic seizures. We describe a case of a young lady, who was referred to us as a case of refractory seizure and diagnosed as having paroxysmal dystonia as a first manifestation of MS, with complete resolution of her symptoms after successful treatment with anti-epileptic drugs.