Isolated sixth nerve palsy: a rare first presentation in multiple sclerosis

Abstract

True isolated sixth nerve palsy as the initial presentation of multiple sclerosis (MS) is rare. MS is a chronic inflammatory, immune-mediated disease of the central nervous system. This is the most common cause of neurological disability in young adults. Common symptoms include acute episodes of muscle weakness, altered sensation, balance and gait disturbances, visual loss and bladder dysfunction.Diagnosis of MS is supported with the incidence of symptomatic clinical episodes with subsequent cross-sectional imaging to confirm radiological lesions that are disseminated in space and time.In the following report, we discuss the case of a woman in her 30s who presented to ophthalmology with a sixth nerve palsy in the absence of ocular or systemic disease. This is the first presentation of MS, a rare clinical event.

Keywords: Cranial nerves; Multiple sclerosis; Ophthalmology; Radiology; Visual pathway.

Figure 1

Axial view of T2-weighted MRI of the brain showing bilateral pontine lesions (green arrow). Figure obtained with patient’s consent.

Figure 2

Sagittal view of T1-weighted MRI of the brain showing plaques in the splenum of the corpus callosum (red arrow), left cerebral peduncle and left pons (blue arrow). Figure obtained with patient’s consent.