GRM5 and viral encephalitis: However, in China, only 13% of patients with anti-mGluR5 encephalitis have related tumors.[8] Patients with anti-GluR5 encephalitis typically exhibited a favorable response to immunotherapy, and the majority of them had recovered completely or partially at their latest follow-ups.[8,9] Despite the fact that anti-mGluR5 encephalitis was categorized as limbic encephalitis, brain MRI scans have revealed the potential involvement of extra-limbic lesions, either independently or in conjunction with limbic lesions.