High-resolution MR imaging of cranial neuropathy in patients with anti-GQ1b antibody syndrome

A Case with Anti-ganglioside Antibodies Showing Multiple Cranial Nerve Palsies Detected on Gadolinium-enhanced Magnetic Resonance Imaging

The anti-GQ1b IgG antibody is often accompanied by other anti-ganglioside antibodies, which induces various neurological symptoms. We herein report a patient with anti-ganglioside antibodies, including anti-GQ1b IgG and anti-GT1a IgG antibodies, showing bilateral ophthalmoplegia, facial nerve palsies, dysarthria, dysphagia, dysesthesia in both hands, and enhancement of the bilateral oculomotor, abducens, and facial nerves on gadolinium (Gd)-enhanced T1-weighted brain magnetic resonance imaging (MRI). He was first treated with intravenous immunoglobulin, which improved ophthalmoplegia, bulbar palsies, and dysesthesia of hands, but the facial nerve palsies worsened, and Gd enhancement of the brain nerves persisted. High-dose methylprednisolone therapy subsequently improved the facial nerve palsies and Gd enhancement of the cranial nerves. This is the first case with anti-ganglioside antibodies presenting with multiple cranial nerve palsies that was followed to track the changes in the Gd enhancement of cranial nerves on MRI.

MR Imaging Findings in a Large Population of Autoimmune Encephalitis

BACKGROUND AND PURPOSE

Autoimmune encephalitis is a rare condition in which autoantibodies attack neuronal tissue, causing neuropsychiatric disturbances. This study sought to evaluate MR imaging findings associated with subtypes and categories of autoimmune encephalitis.

MATERIALS AND METHODS

Cases of autoimmune encephalitis with specific autoantibodies were identified from the medical record (2009-2019). Cases were excluded if no MR imaging of the brain was available, antibodies were associated with demyelinating disease, or >1 concurrent antibody was present. Demographics, CSF profile, antibody subtype and group (group 1 intracellular antigen or group 2 extracellular antigen), and MR imaging features at symptom onset were reviewed. Imaging and clinical features were compared across antibody groups using χ2 and Wilcoxon rank-sum tests.

RESULTS

Eighty-five cases of autoimmune encephalitis constituting 16 distinct antibodies were reviewed. The most common antibodies were anti-N-methyl-D-aspartate (n = 41), anti-glutamic acid decarboxylase (n = 7), and anti-voltage-gated potassium channel (n = 6). Eighteen of 85 (21%) were group 1; and 67/85 (79%) were group 2. The median time between MR imaging and antibody diagnosis was 14 days (interquartile range, 4-26 days). MR imaging had normal findings in 33/85 (39%), and 20/33 (61%) patients with normal MRIs had anti-N-methyl-D-aspartate receptor antibodies. Signal abnormality was most common in the limbic system (28/85, 33%); 1/68 (1.5%) had susceptibility artifacts. Brainstem and cerebellar involvement were more common in group 1, while leptomeningeal enhancement was more common in group 2.

CONCLUSIONS

Sixty-one percent of patients with autoimmune encephalitis had abnormal brain MR imaging findings at symptom onset, most commonly involving the limbic system. Susceptibility artifact is rare and makes autoimmune encephalitis less likely as a diagnosis. Brainstem and cerebellar involvement were more common in group 1, while leptomeningeal enhancement was more common in group 2.

Brain death-like changes: A case report of anti-GQ1b antibody syndrome

RATIONALE

Anti-GQ1b antibody syndrome originates in the peripheral nervous system or the central nervous system. Various overlapping syndromes and atypical manifestations are also seen in clinic. It is rare to see multiple sites (almost all targets) of central and peripheral damage at the same time, resulting in brain death-like changes in patient.

PATIENT CONCERNS

This is a 55-year-old female patient, with a history of prodromal upper respiratory tract infection, began with headache, quickly developed body paralysis, eye paralysis, disturbance of consciousness, apnea, and tested positive for anti-GQ1b antibody. The patient is diagnosed clearly, the disease progresses rapidly, and almost all GQ1b sites in the central nervous system and peripheral nervous system are involved, which is rare.

DIAGNOSES

Anti-GQ1b antibody syndrome.

INTERVENTIONS AND OUTCOMES

The patient was treated with tracheal intubation, ventilator assisted breathing, and immunoglobulin. The patient recovered quickly and was discharged after about 30 days in hospital.

LESSONS

The concept of anti-GQ1b antibody syndrome is not only beneficial for clinical diagnosis, but also beneficial for understanding the continuous disease spectrum with the same etiology and different clinical manifestations. The pathogenesis of each subtype has not been fully defined. There are mild patients with isolated syndromes and severe patients with multiple subtypes overlapping. Encounter severe patients but also active response, the general prognosis is good.