Treatment of Optic Neuritis with Elevated White Blood Cell Count

Critical First Steps

The American College of Neurology recommends initiating high-dose intravenous methylprednisolone at 1000 mg/day for 3 days immediately, followed by oral prednisone 1 mg/kg/day for 11 days with a 4-day taper, regardless of the elevated white blood cell count 1, 2
The standard treatment approach for optic neuritis does not change with the presence of leukocytosis, but it does mandate additional workup to identify the underlying cause, including lumbar puncture with comprehensive CSF analysis and MRI brain and orbits with contrast 1, 2, 3

A serology panel, including CBC with differential, ESR, CRP, ANCA, thyroid panel, AM cortisol and ACTH, autoimmune encephalopathy and paraneoplastic panels, should be performed to rule out infectious, inflammatory, or autoimmune causes 3
Neurology consultation is recommended for comprehensive evaluation and management 2, 3

Elevated WBC in CSF with normal glucose and negative cultures is common in immune-mediated optic neuritis, and may see reactive lymphocytes, neutrophils, or histiocytes on cytology 3
Lymphocytic predominance and/or elevated protein suggests autoimmune etiology 3

For patients with Systemic Lupus Erythematosus-associated optic neuritis, combination therapy with pulse IV methylprednisolone PLUS IV cyclophosphamide is recommended, with visual outcomes significantly poorer (only 30% maintain visual acuity >20/25) 1, 2
For patients with Neuromyelitis Optica Spectrum Disorder (NMOSD), initial treatment remains IV methylprednisolone 1000 mg/day for 3-5 days, and plasma exchange (PLEX) should be considered early if severe or not responding to steroids 1, 2

Plasma exchange (PLEX) is recommended for severe cases with progressive vision loss, and rituximab is recommended for refractory cases, particularly in NMOSD 1, 2

Delaying treatment beyond 2 weeks is associated with significantly poorer visual outcomes, and treatment should begin immediately while workup proceeds in parallel 1, 2, 4

Ophthalmological evaluations every 4-6 weeks, including visual acuity, visual fields, funduscopy, and contrast sensitivity, are recommended for short-term monitoring 2, 4
Visual-evoked potentials should be performed to objectively assess optic nerve recovery and detect subclinical bilateral involvement 1, 2, 4
Repeat MRI at 3-6 months to assess for new demyelinating lesions is recommended 4
Long-term surveillance is necessary, as relapses occur in 50-60% of patients during steroid taper, and any new vision loss in either eye warrants immediate repeat MRI and consideration of repeat IV methylprednisolone 1, 2, 4