Sign Up for a Free Account
  • Updated 09.29.2021
  • Released 12.03.2010
  • Expires For CME 09.29.2024

Anti-GQ1b antibody syndrome

Introduction

Overview

Prior to the discovery of IgG antibodies against GQ1b, there were clinical variants that were considered linked to Guillain-Barré syndrome due to common clinical features shared with Guillain-Barré syndrome. The most notable are Miller Fisher syndrome, which is characterized by acute ophthalmoplegia, ataxia, areflexia, and Bickerstaff brainstem encephalitis, in which consciousness is also affected. Following the discovery of an association of anti-GQ1b antibodies with Miller Fisher syndrome in 1992, other neurologic presentations with similar serological profiles emerged in the literature, including Bickerstaff brainstem encephalitis, acute ophthalmoplegia, acute ataxic neuropathy, pharyngeal-cervical-brachial weakness, and acute vestibular syndrome. In this article, the author discusses the current understanding behind the anti-GQ1b antibody syndrome.

Key points

• Anti-GQ1b antibody syndrome represents a group of disorders that share a common serological profile with links also to Guillain-Barré syndrome.

• GQ1b antibodies are a serological marker of Miller Fisher syndrome and Bickerstaff brainstem encephalitis but can been detected in other neurologic syndromes as a continuous spectrum.

• The overall prognosis is good even without immunotherapy in those patients who have typical Miller Fisher syndrome or acute ophthalmoplegia, but intravenous immunoglobulin (IVIg) or plasma exchange is recommended when there is altered consciousness, limb weakness, or bulbar palsy.

• Important mimics to be excluded include brainstem syndromes of other etiologies and neuromuscular junction disorders. The presence of GQ1b antibodies would make the latter disorders unlikely.

• Miller Fisher syndrome and Bickerstaff brainstem encephalitis can occur in association with a COVID-19 infection, but no patients have tested positive for GQ1b antibodies, indicating that a novel antigen might be implicated in the mechanism.

Historical note and terminology

The most recognizable variant of Guillain-Barré syndrome is Miller Fisher syndrome, which was first described in 1956 by Charles Miller Fisher. He reported three patients who presented with a triad of total external ophthalmoplegia, ataxia, and areflexia subsequent to upper respiratory tract infection (12). The presence of cerebrospinal fluid albuminocytological dissociation and antecedent infection likened Miller Fisher syndrome to Guillain-Barré syndrome.

Prior to this, in 1951, Bickerstaff and Cloake described three patients who presented with prominent drowsiness followed by brainstem signs causing ophthalmoplegia, facial palsy, bulbar palsy, and ataxia following a prodrome of infective illness. The etiology of this condition was speculated to be similar to that of Guillain-Barré syndrome based on the presence of prodromal symptoms in all 3 patients, areflexia with CSF albuminocytological dissociation in one patient, and subsequent recovery of neurologic symptoms in all three patients (04). Six years later, Bickerstaff extended his observations including an additional five patients with similar patterns of brainstem signs, emphasizing the benign outcomes in all but one patient, who died following a seizure (03). This condition has since been referred to as Bickerstaff brainstem encephalitis.

In 1992, Chiba and colleagues identified IgG antibodies against ganglioside GQ1b in six patients with typical Miller Fisher syndrome (07). The GQ1b IgG antibodies were initially considered as a serological marker of Miller Fisher syndrome. However, the antibodies were also detected in patients with acute postinfectious ophthalmoplegia without ataxia (05), Guillain-Barré syndrome with ophthalmoplegia (05), and Bickerstaff brainstem encephalitis (70; 23). The latter findings supported the continuity between the two syndromes, with Miller Fisher syndrome representing one end of the spectrum and Bickerstaff brainstem encephalitis the other, with involvement of the central nervous system. Patients with milder clinical features, such as ophthalmoparesis without ataxia (68), or more extensive involvement with limb weakness (42), were also found to have GQ1b IgG antibodies on serological testing. In view of the common serological profile shared by this group of patients, it has been referred to as "anti-GQ1b antibody syndrome" (55).

This is an article preview.
Start a Free Account
to access the full version.

  • Nearly 3,000 illustrations, including video clips of neurologic disorders.

  • Every article is reviewed by our esteemed Editorial Board for accuracy and currency.

  • Full spectrum of neurology in 1,200 comprehensive articles.

Questions or Comment?

MedLink®, LLC

3525 Del Mar Heights Rd, Ste 304
San Diego, CA 92130-2122

Toll Free (U.S. + Canada): 800-452-2400

US Number: +1-619-640-4660

Support: service@medlink.com

Editor: editor@medlink.com

ISSN: 2831-9125