Bilateral internal ophthalmoplegia as an initial sole manifestation of Miller Fisher syndrome

The spectrum of anti-GQ1B antibody syndrome: beyond Miller Fisher syndrome and Bickerstaff brainstem encephalitis

INTRODUCTION

Since the initial identification of Miller Fisher syndrome (MFS) and Bickerstaff brainstem encephalitis (BBE),significant milestones have been achieved in understanding these diseases.Discoveries of common serum antibodies (IgG anti-GQ1b), antecedent infections, neurophysiological data, andneuroimaging suggested a shared autoimmune pathogenetic mechanism rather than distinct pathogenesis, leadingto the hypothesis that both diseases are part of a unified syndrome, termed "Fisher-Bickerstaff syndrome". The subsequent identification of atypical anti-GQ1b-positive forms expanded the classification to a broader condition known as "Anti-GQ1b-Antibody syndrome".

METHODS

An exhaustive literature review was conducted, analyzing a substantial body of research spanning from the initialdescriptions of the syndrome's components to recent developments in diagnostic classification and researchperspectives.

RESULTS

Anti-GQ1b syndrome encompasses a continuous spectrum of conditions defined by a common serological profilewith varying degrees of peripheral (PNS) and central nervous system (CNS) involvement. MFS and BBE represent theopposite ends of this spectrum, with MFS primarily affecting the PNS and BBE predominantly involving the CNS.Recently identified atypical forms, such as acute ophthalmoparesis, acute ataxic neuropathy withoutophthalmoparesis, Guillain-Barré syndrome (GBS) with ophthalmoparesis, MFS-GBS and BBE-GBS overlap syndromes,have broadened this spectrum.

CONCLUSION

This work aims to provide an extensive, detailed, and updated overview of all aspects of the anti-GQ1b syndromewith the intention of serving as a stepping stone for further shaping thereof. Special attention was given to therecently identified atypical forms, underscoring their significance in redefining the boundaries of the syndrome.

Miller Fisher syndrome: an updated narrative review

Introduction

Miller Fisher syndrome (MFS) is considered a rare variant of Guillain-Barré syndrome (GBS), a group of acute-onset immune-mediated neuropathies characterized by the classic triad of ataxia, areflexia, and ophthalmoparesis. The present review aimed to provide a detailed and updated profile of all aspects of the syndrome through a collection of published articles on the subject, ranging from the initial description to recent developments related to COVID-19.

Methods

We searched PubMed, Scopus, EMBASE, and Web of Science databases and gray literature, including references from the identified studies, review studies, and conference abstracts on this topic. We used all MeSH terms pertaining to "Miller Fisher syndrome," "Miller Fisher," "Fisher syndrome," and "anti-GQ1b antibody."

Results

An extensive bibliography was researched and summarized in the review from an initial profile of MFS since its description to the recent accounts of diagnosis in COVID-19 patients. MFS is an immune-mediated disease with onset most frequently following infection. Anti-ganglioside GQ1b antibodies, detected in ~85% of patients, play a role in the pathogenesis of the syndrome. There are usually no abnormalities in MFS through routine neuroimaging. In rare cases, neuroimaging shows nerve root enhancement and signs of the involvement of the central nervous system. The most consistent electrophysiological findings in MFS are reduced sensory nerve action potentials and absent H reflexes. Although MFS is generally self-limited and has excellent prognosis, rare recurrent forms have been documented.

Conclusion

This article gives an updated narrative review of MFS with special emphasis on clinical characteristics, neurophysiology, treatment, and prognosis of MFS patients.

Characteristics of pupil palsy in miller-fisher syndrome: case reports and review of the literature

Pupil palsy has been a frequent finding in Miller Fisher syndrome (MFS), but its clinical characteristics have not been clearly defined. The basis for differential diagnosis with other diseases with pupil palsy has also remained vague. We report cases of four MFS patients with bilateral pupil palsy and specify pupil characteristics of light-near dissociation (LND), cholinergic super-sensitivity, vermiform movements, and prognosis. We conducted a literature review to compare with our cases and investigate common findings of pupil palsy in MFS patients. We suggest that the acute generalized pupil palsy without vermiform movements can serve as a key finding for the diagnosis of pupil palsy associated with MFS. However, the presence of LND and cholinergic super-sensitivity was not distinctive clinical findings in MFS patients who had pupil palsy and did not prove useful for differential diagnosis. The prognosis of pupil palsy in MFS patients was good in our 4 cases and the literature review.

Atypical Miller Fisher Syndrome with Anisocoria and Rapidly Fluctuating Pupillary Diameter

Miller Fisher syndrome is a variant of Guillain-Barre syndrome characterized by the classic triad of ophthalmoplegia, ataxia, and areflexia. Pupillary involvement is common in MFS and has been reported in 35–42% of MFS patients. Although case reports have discussed isolated ophthalmoplegia as a presentation of MFS, anisocoria and rapid fluctuation of pupillary diameter have not been reported in anti-GQ1b antibody positive individuals. Here we describe an individual who presented with diplopia and was found to have progressive internal and external ophthalmoplegia with frequent fluctuations in pupillary diameter and anisocoria. These exam findings are not commonly described even in atypical presentations of MFS. The onset of symptoms was preceded by an upper respiratory infection but no gastrointestinal symptoms. Imaging and CSF studies were unremarkable; however serum levels of immunoglobulin G anti-GQ1b antibody and anti-GAD antibody were elevated confirming the diagnosis of MFS. The patient was treated with IVIG and intravenous steroids with mild resolution of external ophthalmoplegia. He did not go on to develop more typical features of MFS such as ataxia or areflexia. This demonstrates that isolated external and internal ophthalmoparesis with rapidly fluctuating pupillary diameter and associated anisocoria can be the sole manifestation of atypical MFS.

Miller-Fisher Syndrome: Is the ataxia central or peripheral?

A 50-year-old man presented with a brief history of slurred speech, unsteadiness, double vision and paraesthesia. He had been unwell for 12 days with campylobacter gastroenteritis. On examination, there was ophthalmoplegia, nystagmus, areflexia and lower limb and gait ataxia. Serological testing was positive for GQ1b antibody in keeping with the diagnosis of Miller Fisher Syndrome (MFS). He was treated with two courses of intravenous immunoglobulins and made a good recovery, only displaying mild gait ataxia when reviewed in clinic 2.5 months later.

There has long been a debate as to whether the ataxia in MFS originates in the cerebellum or it is more peripheral. In this case, magnetic resonance spectroscopy (MRS) revealed a reduced NAA/Cr ratio in the cerebellar vermis and right cerebral hemisphere, suggestive of cerebellar dysfunction. The NAA/Cr normalised 2.5 months later reflecting the clinical recovery. The findings on MRS suggest that the cerebellum is involved in MFS.

Acute angle-closure glaucoma in a patient with miller fisher syndrome without pupillary dysfunction

PURPOSE

To report a case of an angle-closure glaucoma in a patient with Miller Fisher syndrome (MFS) without pupillary dysfunction.

METHODS

We present a case report of a 75-year-old male presenting with total ophthalmoplegia, complete bilateral ptosis, and gait disturbance. He was diagnosed with MFS without pupillary dysfunction, which precipitated unilateral acute angle-closure glaucoma (AACG) due to complete lid ptosis.

RESULTS

The initial ocular examination revealed hand motion in the right eye. Intraocular pressure, as assessed by Goldmann applanation tonometry, was 50 mm Hg, and gonioscopic findings revealed a closed angle on the right eye. After maximal tolerated medical therapy, laser peripheral iridotomy was performed. The unilateral AACG with MFS resolved without further incident.

CONCLUSIONS

This is the first reported case of a patient with MFS without autonomic dysfunction and AACG. We believe that pupillary dysfunction or lid ptosis due to neurological disorders may increase the possibility of AACG.

Pupillary Involvement in Miller Fisher Syndrome

Miller Fisher Syndrome is characterised by the classical triad of ophthalmoplegia, ataxia, and areflexia. Ophthalmoparesis without ataxia, without areflexia, or with neither have been attributed as atypical forms of MFS. We report two patients with MFS who had tonic pupils and raised anti-GQ1b antibody titres. Bilateral dilated pupils (either tonic or fixed) can be a manifestation of MFS and anti-GQ1b immunoglobulin G (IgG) antibodies are useful to confirm the diagnosis in unexplained cases. The site of involvement is thought to be the ciliary ganglion or short ciliary nerves.

An unusual case of Parinaud's syndrome

A 25-year-old man presented with blurred vision, headache and dizziness. On questioning, there was also a history of a preceding diarrhoeal illness. Initial investigations were normal. However, after a week, he represented with a Parinaud's syndrome. In view of the preceding diarrhoea, the transient unsteadiness and the areflexia on examination, anti-GQ1b antibodies were requested. The resulting titre was positive confirming the suspected diagnosis of Miller Fisher syndrome. He responded to intravenous immunoglobulins with full resolution of his symptoms and signs. Although various unusual neuro-ophthalmological signs have been reported localising to the brainstem, to our knowledge, this is the first case report of Parinaud's syndrome being the presenting symptom of Miller Fisher syndrome.