# A Case of Miller−Fisher Overlap Syndrome With Positive Anti‐GM4 Antibody and Atypical Symptoms

## TL;DR

A patient with Miller−Fisher overlap syndrome showed atypical symptoms and positive anti-GM4 antibodies, suggesting a possible link to chlamydial pneumonia and the importance of timely treatment.

## Contribution

This case highlights atypical symptoms and the potential role of chlamydial pneumonia in triggering MFS overlap syndrome.

## Key findings

- The patient exhibited atypical symptoms like persistent headache and delayed facial palsy in MFS overlap syndrome.
- Positive anti-GM4 antibodies were found, possibly indicating a key immunological factor in the condition.
- The patient's improvement after IV immunoglobulin treatment supports early intervention in similar cases.

## Abstract

Miller−Fisher syndrome (MFS) is a recognized clinical variant of Guillain−Barré syndrome (GBS), characterized by the classic triad of ophthalmoplegia, ataxia, and areflexia. When accompanied by additional symptoms such as bulbar palsy, limb weakness, or lethargy, it is termed MFS overlap syndrome.

This report describes a male patient diagnosed with MFS overlap syndrome, presenting with ophthalmoplegia, ataxia, bulbar palsy, numbness in both arms, positive GM4 IgG antibodies, a persistent, intractable headache, and a delayed onset of left‐sided peripheral facial palsy. The patient had a preceding suspected case of chlamydial pneumonia before symptom onset, and his condition improved significantly following treatment with intravenous immunoglobulin.

This case suggests that chlamydial pneumonia might predispose individuals to GBS. Patients with MFS/pharyngeal‐cervical‐brachial (PCB) overlap syndrome may exhibit atypical symptoms, including persistent, intractable headaches, and delayed peripheral facial paralysis. Atypical symptoms should not delay the diagnosis and treatment of GBS once other conditions have been adequately excluded. The presence of anti‐GM4 antibodies, often found alongside other anti‐ganglioside antibodies, may serve as a critical immunological factor in MFS/PCB overlap syndrome.