Multiple sclerosis therapies and pregnancy

A 24-year-old patient (see Case 16) with relapsing-remitting multiple sclerosis (RRMS) returned 6 months after diagnosis with sub-acute diplopia. She described difficulty moving her eyes to the right and horizontal, binocular diplopia, maximal in leftward gaze. There were no other neurological symptoms. Examination revealed conjugate horizontal gaze palsy to the right and limited adduction of the right eye, constituting the ‘one-and-a-half syndrome.’ A repeat MRI scan revealed a new lesion in the right pons affecting the region of the abducens nucleus and the ipsilateral medial longitudinal fasciculus. There was no enhancement. The overall burden of lesions on MRI was otherwise stable, and the enhancing right frontal lesion previously seen was less prominent.