Anti-glycine receptor antibody-positive progressive encephalomyelitis with rigidity and myoclonus initially presenting with one-sided stiff face: A case report

Abstract

BackgroundProgressive encephalomyelitis with rigidity and myoclonus (PERM) is a subtype of stiff-person syndrome, a rare cerebrospinal disease that causes brainstem symptoms, myoclonus, muscle rigidity, and hyperekplexia.Case presentationA 71-year-old man experienced left-sided stiff face, and was subsequently admitted to our hospital because of the appearance of left-dominant lower limb myoclonus. Muscle rigidity followed 3 days later. Magnetic resonance imaging revealed no abnormality. An electrophysiological examination showed a toughness of the antagonistic muscle following evocation of the Achilles tendon reflex, and a tonic phenomenon affecting the left facial muscles during the blink reflex. The patient's serum was positive for anti-glycine receptor (anti-GlyR) antibody, suggesting PERM. The patient was administered steroids, immunoglobulin therapy, and immunosuppressive drugs. He gradually improved after these therapies and became able to walk using a walker.ConclusionsWe conclude that this was a rare case of anti-GlyR antibody-positive PERM with unilateral brainstem symptoms, myoclonus, and muscle rigidity.

Progressive encephalomyelitis with rigidity and myoclonus (PERM) associated with anti-glycine receptor antibodies and urothelial carcinoma: a case report

“…GlyR antibodies are associated with wide variety of neurological disorders including PERM, limbic encephalitis, epileptic encephalopathy, brainstem features and demyelinating optic neuropathies [ 15 ]. The mechanism of GlyR antibody action is not clearly understood, but suppression of GlyR function is assumed to induce excessive response to sensory inputs, such as those from muscle spindles, light and sound stimuli [ 16 ]. In line with this, purified IgG from patients with GlyR antibodies were recently shown to inhibit synaptic currents in cultured motor neurons, supporting that the autoantibodies are pathogenic in PERM [ 17 ].…”