A Rare Association Between Herpes Simplex Virus Type 1 and Miller-Fisher Syndrome.

The etiopathogenesis for Guillain-Barré syndrome (GBS) and Miller-Fisher syndrome (MFS), a variant of GBS, is well-documented in the literature. However, the association between MFS and an underlying herpes simplex virus type 1 (HSV-1) infection is very limited. We present a unique case of a 48-year-old man who developed diplopia, bilateral ptosis, and gait instability following an acute diarrheal illness and recurring cold sores. The patient was diagnosed with MFS precipitated by recurrent HSV-1 infection following a Campylobacter jejuni acute infection. The diagnosis of MFS was supported by a positive anti-GQ1b ganglioside immunoglobulin (Ig)G and abnormal MRI-enhancing lesions of the bilateral cranial nerves III and VI. Intravenous immunoglobulin and acyclovir produced a significant clinical response in the patient within the first 72 hours. Our case highlights the rare association between two pathogens and MFS and the importance of recognizing risk factors, symptomatology, and appropriate workup accompanying an atypical MFS case.