“Trigeminal Tract Sign” in Patients With Herpes Zoster Ophthalmicus: A Case Series of a Novel Imaging Finding

Objective Herein, we report three patients presenting with zoster ophthalmicus caused by varicella virus (VZV) unexpected and novel cervico-medullary findings on magnetic resonance imaging (MRI). Background Zoster opthalmicus involves reactivation of latent VZV in the ophthalmic division trigeminal nerve producing a dermatomal rash. In minority this leads to damage surrounding peripheral nerves through perineural/intraneural inflammation. MRI are often nondescript or normal leading misdiagnosis delays treatment. Design/Methods This was case-series describing Calgary, Alberta who presented opthalmicus, were noted incidentally have similar appearing lesions ipsilateral region brain MRI. Standard selected high-resolution images orbits globes reviewed neuroradiology (CW). Results Three patients, varying phenotypes described: 70-yo male decreased visual acuity oculomotor/abducens palsy; 75-yo female oculomotor/facial palsies; 35-yo immunocompromised blepharoconjunctivitis optic neuritis. all 3 cases, revealed profound T2 fluid-attenuated inversion recovery (FLAIR) hyperintensity along spinotrigeminal tract clinically affected side, extending from posterolateral pons medulla into cervical region. Conclusions To our knowledge, within spinal is rare finding. We coined radiologic finding “trigeminal sign” due anatomic structure affected. A thorough radiologic/laboratory workup should be considered presentations; however, high index suspicion for cases aforementioned findings. Whether radiological predicts disease severity likelihood multiple cranial involvement (as seen series) requires further study.