Paroxysmal dysarthria-ataxia syndrome: Literature review on MRI findings and report of a peculiar case with clinically isolated syndrome coexisting with anti-N-methyl-d-aspartate receptor antibodies.

Paroxysmal dysarthria and ataxia (PDA) syndrome constitutes a rare neurological disorder, and is generally reported in cases of multiple sclerosis (MS) involving the midbrain. We present an illustrative case of 32-year-old female who developed clinically isolated syndrome manifested paroxysmal dysarthria, ataxia, ptosis and diplopia, coexisting with anti-N-methyl-d-aspartate receptor antibodies. We review the literature and identify 23 other cases with brain MRI examinations to summarize the lesion locations and clinical characteristics of PDA syndrome, and ultimately provide a new framework for understanding this rare condition. The current case expands the spectrum of symptoms in PDA syndrome, which was including but not limited to dysarthria and ataxia. Caudal paramedian midbrain lesions involving decussation of the superior cerebellar peduncles appear to be critical for PDA syndrome.