Lateral rectus muscle palsy, facial numbness and ataxia as the initial manifestation of multiple sclerosis.

Lateral rectus muscle (LRM) palsy due to a nuclear or fascicular sixth nerve lesion is rare as the presenting sign of multiple sclerosis (MS). It is more common to find this palsy in the company of other nearby cranial nerves deficits. Facial numbness in association with a LRM palsy or paresis may go unappreciated and therefore underreported. We report an unusual patient with a LRM palsy, facial anesthesia, ataxia and as the initial manifestation of MS. There was a demyelinating lesion in the pons seen on magnetic resonance imaging (MRI).