Objective:

Background:

One-and-a-half syndrome is a rare disorder that affects horizontal eye movement. It consists of a one-side gaze palsy (one) and medial gaze palsy of the opposite side (half) with only intact contralateral abduction. It is caused by lesion in the pontine tegmentum, mostly due to lacunar infarction, demyelination, infections, or mass. In many cases, the causative lesion extends beyond the horizontal eye-gaze structures in the pons, affecting the nearby pontine structures, as the facial nerve, causing additional neurological deficits, collectively known as one and half syndrome spectrum disorder

Design/Methods:

N/A 

Results:

A 43-year-old African-American male, who presented with binocular diplopia and unsteadiness for 2 months, bilateral lateral gaze restriction, and right medial rectus palsy with right-sided left beat nystagmus on left gaze. Left medial gaze was intact. MRI brain T2/FLAIR revealed multifocal hyperintense lesions in brainstem, including pons and midbrain, and cervical spinal cord without enhancement. CSF studies were significant for positive oligoclonal bands. Hence, patient met the 2017 McDonald criteria for multiple sclerosis diagnosis. By time of presentation, ophthalmoplegia was already improving. He was started directly on Glatiramer acetate. Ophthalmoplegia completely resolved within 2 weeks of presentation. To our knowledge, this is the first reported case of similar presentation. The nystagmus of adducting eye is known as reverse internuclear ophthalmoplegia, but the associated bilateral abduction restriction has not been reported before

Conclusions:

We describe a novel syndrome “reverse one and a half syndrome”, as a presentation of multiple sclerosis. To our knowledge, no prior similar description of such a presentation. Identification of additional cases is needed to further characterize common distinctive etiological, clinical and radiological associations