Case studyFocal status epilepticus and progressive dyskinesia: A novel phenotype for glycine receptor antibody-mediated neurological disease in children

- Glycine receptor antibodies are associated with focal status epilepticus, encephalopathy and progressive focal dyskinesias.
- Glycine receptor antibody titres correlate clinically to dyskinetic movements in this immunotherapy-responsive patient.
- Testing for autoimmune encephalitis should include glycine receptor antibodies, other anti-neuronal antibodies and CSF.

BackgroundAntibody-associated disorders of the central nervous system are increasingly recognised in adults and children. Some are known to be paraneoplastic, whereas in others an infective trigger is postulated. They include disorders associated with antibodies to N-methyl-d-aspartate receptor (NMDAR), voltage-gated potassium channel-complexes (VGKC-complex), GABAB receptor or glycine receptor (GlyR). With antibodies to NMDAR or VGKC-complexes, distinct clinical patterns are well characterised, but as more antibodies are discovered, the spectra of associated disorders are evolving. GlyR antibodies have been detected in patients with progressive encephalopathy with rigidity and myoclonus (PERM), or stiff man syndrome, both rare but disabling conditions.Case ReportWe report a case of a young child with focal seizures and progressive dyskinesia in whom GlyR antibodies were detected. Anticonvulsants and immunotherapy were effective in treating both the seizures and movement disorder with good neurological outcome and with a decline in the patient's serum GlyR-Ab titres.ConclusionGlycine receptor antibodies are associated with focal status epilepticus and seizures, encephalopathy and progressive dyskinesia and should be evaluated in autoimmune encephalitis.