Background/Purpose: Glycine-receptor antibody (GlyR-Ab) encephalitis is a rare, reversible autoimmune
disease that typically manifests in adults as PERM or stiff-person syndrome. Paediatric
cases are few, and early symptoms often mimic peripheral neuropathy or psychiatric
illness, delaying diagnosis.
Methods/Case Presentation: We report a 16-year-old boy who experienced a 12-month diagnostic odyssey that began
with episodic hypertension and panic attacks and progressed to bilateral ptosis, cerebellar
ataxia, pyramidal hyperreflexia, bulbar dysarthria, startle-like myoclonus, and urinary
dysfunction. Seven months after onset, an antibody panel revealed low-titre acetylcholine-receptor
antibodies, prompting high-dose corticosteroids, IVIG, azathioprine, and pyridostigmine
with partial facial improvement. An additional laboratory screen subsequently identified
pathogenic high levels of GlyR-IgG in serum and CSF.
Results: The patient was transferred for five plasma-exchange sessions followed by rituximab
and a tapering oral prednisolone course. Maintenance therapy comprised six monthly
IVIG cycles and a second rituximab dose 3 months later. Neurological signs improved
rapidly after plasma exchange and rituximab and resolved completely within 2 months.
At 1-year follow-up (month 12 after onset), he was able to return to school and sports
without deficits.
Conclusion: This case highlights the protean presentation of paediatric GlyR-Ab encephalitis
and emphasizes three aspects: (1) early mixed autonomic, brainstem and pyramidal signs
should prompt consideration of central autoimmunity even with normal imaging; (2)
low-titre acetylcholine-receptor seropositivity may coexist and obscure the underlying
diagnosis; and (3) plasma-exchange plus B-cell depletion can achieve sustained remission.
Clinicians should include GlyR-Ab testing in serum and CSF with a live-cell-based
assay in seronegative or atypical autoimmune-encephalitis panels to facilitate timely,
life-altering treatment.
