Case Presentation: A healthy 11-year old female presented with 5 days of fever, headache, and progressive symptoms that included blurry vision, photophobia, lightheadedness, nausea, and intermittent vomiting. Family history was positive for migraine headaches.
On exam, she had pupils measuring 10 mm, blurry vision and loss of acuity, but no visual field deficits or pain with extraocular movements (EOM). There was partial improvement in lightheadedness and headache following a fluid bolus and ibuprofen, but ocular symptoms persisted. CT of the head was unremarkable. Laboratory data included normal inflammatory markers and a CBC with a mild lymphopenia.
Following admission, the patient had recrudescence of headache, and subsequently developed a left central scotoma described as a black dot and an afferent pupillary defect (APD). Dilated eye exam noted bilateral left greater than right stage 1 papilledema and vision loss (acuity, field, and color perception), consistent with papillitis or anterior optic neuritis.
Discussion: The patient’s initial signs and symptoms, and mild improvement after hydration raises suspicion for an ocular migraine in the setting of viral illness, but it is important to consider the full differential, which includes optic neuritis. Migraines can increase parasympathetic tone, leading to pre-syncopal symptoms and mydriasis, and a scintillating scotoma may be present in ocular migraines. However, an unresolving scotoma, a scotoma with an entirely degenerated visual acuity (e.g. a “black spot” as this patient describe), or an APD are all red flags for more serious involvement of the optic nerve or retina. Children with optic neuritis are more likely to present with bilateral involvement, lack of pain with EOM, and papillitis than adults. Importantly, if there is bilateral optic nerve involvement, a relative APD may be absent. The funduscopic exam offers a direct view of blood vessels and the central nervous system, and can reveal a wide variety of pathology such as optic neuritis.
Optic neuritis can be due to an isolated idiopathic event, a post-infectious/post-vaccine autoimmune response, or a systemic demyelinating disorder such as multiple sclerosis (MS). An extensive infectious, auto-inflammatory and demyelinating workup in this patient was notable for negative oligoclonal bands and anti-NMO antibody, and a normal albumin to IgG index. Pertinent positives were as follows: MRI findings of multiple non-enhancing white matter lesions within the supratentorial brain as well thoracic spinal cord, but no imaging evidence of optic neuritis; and CSF with pleocytosis and slight protein elevation. Based on current data, this patient has an acute monophasic demyelinating disease. While the ultimate diagnosis may change with time, a first-time demyelination event may be a due to a clinically isolated syndrome, acute disseminated encephalomyelitis (ADEM) or multiple sclerosis (MS).
Conclusions: Prompt recognition of optic disk edema and a subsequent diagnostic work up is important. Fundoscopic exam is a fundamental for generalists, but when clinical entities such as optic neuritis are a concern, ophthalmoscopy should be performed by an ophthalmologist. While secondary causes like infection or malignancy are more common, it may be a presenting symptom of systemic diseases like MS, ADEM, or neuromyelitis optica, for which early treatment with steroids or plasma exchange can shorten symptom duration and decrease recurrence risk.