New-Onset Right-Sided Numbness and Double Vision
A 40-year-old right-handed man sought care for right hand numbness, right-sided facial numbness, and diplopia progressing to maximal severity over 10 days. At his worst he was unable to write. His symptoms remained maximal for 4 weeks. He was hospitalized and treated with 5 days of intravenous methylprednisolone. He improved to approximately 95% of normal over 4 weeks. He had residual mild right-sided facial and right leg numbness. Antibodies to JC polyoma virus and varicella-zoster virus were positive, which indicated prior exposure to these viruses. Total 25-hydroxyvitamin D level was low at 8.2 ng/mL. Optical coherence tomography findings were normal. Magnetic resonance imaging of the brain performed 3 months after the onset of symptoms demonstrated a T2-hyperintense lesion in the left midbrain peduncle extending into the upper pons, without gadolinium enhancement. A small area of T2 hyperintensity was seen in the right frontal deep white matter. Follow-up brain magnetic resonance imaging showed almost complete resolution of the left midbrain peduncle lesion with persistence of the right frontal deep white matter lesion. Spinal fluid analysis showed 1 white blood cell/µL with 95% lymphocytes, protein 35 mg/dL, 0 unique oligoclonal bands, and normal immunoglobulin G index (0.54). A diagnosis of clinically isolated syndrome-first episode of multiple sclerosis was made. After detailed discussion with the patient, he elected to commence disease-modifying therapy with fingolimod. He underwent routine monitoring with magnetic resonance imaging of the brain and cervical and thoracic spine on an annual basis, without any further relapses at 5-year follow-up. Patients with typical demyelinating syndromes may not always fulfill the diagnostic criteria for multiple sclerosis. After careful exclusion of other mimicking conditions, most notably aquaporin-4-immunoglobulin G– and myelin oligodendrocyte glycoprotein-immunoglobulin G–associated disease, a diagnosis of clinically isolated syndrome may be made.