To characterize clinical and magnetic resonance imaging (MRI) characteristics in varicella zoster virus (VZV) reactivation.

VZV persists in sensory cranial neurons or dorsal root ganglia and reactivation results in neurologic manifestations. Detailed clinical and neuroradiographic characterization of central nervous system (CNS) VZV manifestations, especially ocular disorders remain limited. 

This was a 36-patient retrospective multicenter case-series with laboratory confirmed VZV infection affecting the eye, brain or spinal cord from 2006-2020. A neuro-ophthalmologist (B.K.C.) and neuroradiologist (M.D.M.) reviewed clinical cases and MRIs

The mean age was 67 years (SD: 17 years), 25 (61%) were men, and 9 (25%) were immunocompromised. Cerebrospinal fluid (CSF) was available in 22/36 (61%) patients; median CSF white blood cell count was 11 cells/ul (range 0-154), protein 40 mg/dL (range 20-496) and glucose 65 mg/dL (range 46-103). CSF VZV PCR assays were positive in 6/21 (29%) and 8/9 vitreous or anterior chamber aqueous (90%) samples. Clinical VZV involvement included the optic nerve 23 (64%), other cranial nerves in 27 (75%), brain parenchyma in 12 (33%) and spine/nerve roots in 4 (11%) patients.  

Twenty-four of 26 immunocompetent patients (92%) had MRIs for review. Perineuritis was observed in 8 (33%) as optic nerve sheath enhancement on T1 post-contrast fat saturated sequences. All 8 experienced vision loss: 3 optic neuritis, 1 acute retinal necrosis, and 3 CNS vasculitis with 1 central and 1 branch artery occlusion and 1 uveitis.  Other findings included cavernous sinus enhancement and polycranial neuritis. Seven/8 immunosuppressed patients (88%) had greater radiographic neuroaxis involvement than immunocompetent individuals, including multiple cranial nerves, encephalitis, vasculitis and transverse myelitis; a single case had perineuritis/optic neuritis. 

Perineuritis was a common neuroradiographic finding in VZV-associated vision loss in immunocompetent patients. Optimizing MRI brain and orbits protocols to adequately assess for perineuritis in cases with vision loss and concern for VZV reactivation is warranted.