Paroxysmal Dysarthria and Ataxia after Treatment of Brainstem Encephalitis (P6.053)

OBJECTIVE: To highlight the phenomenon and treatment of paroxysmal dysarthria and ataxia (PDA) in a patient with brainstem encephalitis. BACKGROUND: PDA is characterized as stereotyped, transient episodes of dysarthria and ataxia that can occur multiple times per day. It was first described and recognized as a complication of multiple sclerosis in 1946 by Harry Lee Parker. Since that time, PDA has also been reported in non-demyelinating conditions, including stroke and neuro-Behcet’s disease. With the advent of MRI, lesions in the midbrain near or involving the red nucleus appear responsible for causing PDA. Attacks usually abate after weeks or months, and recurrence is unusual. Reported treatments include carbamazepine, phenytoin, lamotrigine, and acetazolamide. DESIGN/METHODS: Case report. RESULTS: A 45-year-old man with inflammatory bowel disease developed subacute bilateral intranuclear ophthalmoplegia, dysarthria, and ataxia. An MRI revealed a midbrain/superior pontine lesion. Spinal fluid analysis demonstrated a mild lymphocytic pleocytosis with no oligoclonal bands. Extensive investigations did not reveal a specific infectious or demyelinating etiology. Symptoms completely resolved after treatment with high-dose intravenous corticosteroids. A month after treatment he developed frequent, brief episodes of dysarthria and ataxia. These episodes were treated successfully with acetazolamide. He has remained symptom free for 9 years. Subsequent MRI studies have not shown any new lesions or disease recurrence. CONCLUSIONS: Paroxysmal dysarthria and ataxia is most often recognized as a complication of multiple sclerosis, but it can occur in other neurologic diseases with midbrain lesions near or involving the red nucleus. Effective treatments include carbamazepine, acetazolamide, lamotrigine, and phenytoin. Study Supported by: N/A. Disclosure: Dr. Klaas has nothing to disclose. Dr. Boes has nothing to disclose. Dr. Aksamit has nothing to disclose.