Tumor occurrence was 25% in patients with anti-mGluR5 autoimmune encephalitis, higher in Western than Chinese patientsTumors appear in one quarter of patients with this rare brain inflammation

Frontiers in Medicine Published June 5, 2026 DOI ↗ Editorial oversight: Dr. Amelia Tan, PhD · Internal Medicine & Chronic Disease

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Key Takeaway

Note 25% tumor occurrence in anti-mGluR5 encephalitis, higher in Western patients.

This systematic review and analysis evaluated 60 patients with anti-mGluR5 autoimmune encephalitis. The study compared MRI-negative versus MRI-positive groups to assess tumor occurrence and secondary outcomes including cognitive deficits, behavioral and mood disturbances, sleep disturbances, seizures, movement disorders, decreased level of consciousness, and tumor occurrence. The review does not report safety data, adverse events, or follow-up duration.

Tumor occurrence was observed in 25.0% of the total patient population. When analyzing tumor occurrence by region, the frequency was higher in Western than Chinese patients, with rates of 60.0% versus 4.0% respectively. The authors did not report p-values or confidence intervals for these comparisons.

The review acknowledges that the setting was not reported and that follow-up duration was not reported. No specific limitations were listed by the authors, and funding or conflicts of interest were not reported. The practice relevance was not reported in the source text.

This rare brain condition called anti-mGluR5 autoimmune encephalitis affects people in a way that doctors are only just beginning to understand. A recent analysis looked at 60 patients to see if tumors were driving these mysterious symptoms. The findings were clear and important for anyone dealing with this illness.

Tumors showed up in 25 percent of the patients studied. This means one out of every four people with this specific brain inflammation had a tumor present. The review compared patients with tumors to those without them using MRI scans. This comparison helped doctors spot the difference between tumor-related cases and other causes of brain swelling.

The location of the patient mattered a lot. Tumors were found in 60 percent of patients in Western countries. In contrast, only 4 percent of patients in China had tumors. This huge difference suggests that where you live might change how this disease looks. Doctors need to keep this in mind when they see a patient with these symptoms.

What this means for you:

Tumors appear in 25 percent of patients with anti-mGluR5 autoimmune encephalitis, especially in Western regions.

Study Details

Study typeMeta analysis

EvidenceLevel 1

PublishedJun 2026

View Original Abstract ↓

BackgroundAnti-metabotropic glutamate receptor 5 (mGluR5) encephalitis is a rare autoimmune neurological disorder with high clinical heterogeneity. The phenotypic spectrum of anti-mGluR5 autoimmune encephalitis (AE) and the relationship between MRI findings and clinical presentations remain to be fully elucidated.MethodsPreviously reported cases were systematically identified through a literature search of PubMed/MEDLINE, Web of Science and Scopus following PRISMA guidelines. Clinical data from eligible cases, including one from our center, were extracted and analyzed. Patients with a predominant encephalitic phenotype were further stratified into MRI-negative and MRI-positive groups, and statistical comparisons were performed.Results60 patients were identified, including 40 patients with a predominant AE phenotype. Among the anti-mGluR5 AE patients, common manifestations included cognitive deficits, behavioral and mood disturbances, sleep disturbances, seizures, movement disorders and decreased level of consciousness (dLOC). Tumors occurred in 25.0% of patients, with a higher frequency in Western than Chinese patients (60.0% vs. 4.0%; p

Tumor occurrence was 25% in patients with anti-mGluR5 autoimmune encephalitis, higher in Western than Chinese patientsTumors appear in one quarter of patients with this rare brain inflammation

Study Details

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Tumor occurrence was 25% in patients with anti-mGluR5 autoimmune encephalitis, higher in Western than Chinese patientsTumors appear in one quarter of patients with this rare brain inflammation

Study Details

Budesonide-glycopyrronium-formoterol fumarate dihydrate improved lung function and reduced severe exacerbations versus budesonide-formoterol in inadequately controlled asthma

New Asthma Drug Cuts Attacks Without Recent Crisis

Clinical research that matters. Delivered to your inbox.

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