Figure 1. Cell-Based Assays, MRI Findings, and Lesion Map of the Patient With PERM.

(A) Anti-GlyR antibodies were detected in cell-based assays in the patient's serum (1:25) and CSF (1:10) in a pattern comparable with positive controls shown (mAb2b = antibody specific for GlyR α1, dilution 1:500; positive control = other SPS patient with GlyR autoantibodies, serum dilution 1:50), but not in the negative control (= healthy person, serum dilution 1:50). (B) Brain MRI (FLAIR/T2-weighted images) of the patient performed 5 months after symptom's onset showed no significant abnormalities. (C) Follow-up MRI after 9 months showed brain atrophy, periventricular hyperintensities, edema of the basal ganglia and gliotic putamina, signal alterations within the mesencephalon involving the substantia nigra and nucleus ruber, and a degenerative olivary pseudohypertrophy in the medulla oblongata. (D) Respectively, lesion maps visualize severely (bright red), moderately (dark red), and mildly (dark red dots) affected CNS regions regarding neuronal loss, microglial activation, and inflammation in coronal sections through the right brain hemisphere at the level of the posterior basal ganglia in the coronal section (1: globus pallidus, 2: putamen, 3: nucleus caudatus, 4: thalamus), cerebellum (1: dentate nucleus, 2: cerebellar cortex), mesencephalon (1: substantia nigra, 2: reticular formation, 3: periaqueductal gray), pons (1: reticular formation, 2, 3: pontine nuclei), medulla oblongata (1: dorsal motor nucleus of the vagal nerve and solitary nuclei, reticular formation, 2: nucleus ambiguus, 3: reticular formation and trigeminal region, 4: inferior olivary nucleus), and spinal cord (1: ventral horn, 2: lateral horn, 3: dorsal horn). PERM = progressive encephalomyelitis with rigidity and myoclonus.