GRM5 and viral encephalitis: Although some early studies reported anti‐mGluR5 encephalitis as limbic encephalitis (Abboud et al., 2021; Lancaster et al., 2011; Pruss et al., 2014), the more recent identification of a wide range of clinical symptoms (e.g., movement disorders) and extralimbic lesions by MRI indicate that this disorder is more similar to diffuse encephalitis.