title: Progressive encephalomyelitis with rigidity and myoclonus: the first pediatric case with glycine receptor antibodies.
abstract: OBJECTIVE
  Progressive encephalomyelitis with rigidity and myoclonus is characterized by rigidity, painful muscle spasms, hyperekplexia, and brainstem signs. Recently, glycine receptor alpha 1 antibodies have been described in adult patients with progressive encephalomyelitis with rigidity and myoclonus. We describe a pediatric case.
  
  
  METHODS
  A 14-month-old child developed startle-induced episodes of generalized rigidity and myoclonus, axial hyperextension, and trismus, without impairment of consciousness. Episodes occurred during wakefulness and sleep, lasted seconds, and were accompanied by moaning, tachypnea, and oxygen desaturation. Imaging, cerebrospinal fluid, endocrine, metabolic, and genetic screening findings were normal or negative. She was treated with intravenous steroids and immunoglobulins with resolution of symptoms, but she relapsed weeks later. At this time, episodes were more severe. Glycine receptor alpha 1 antibodies were found in serum (titer of 1:200, later 1:320) and cerebrospinal fluid (titer of 1:2). Treatment was restarted with intravenous steroids and immunoglobulins, with major improvement, and she began treatment with oral steroids. She had 4 milder relapses, with improvement after treatment adjustments.
  
  
  CONCLUSIONS
  To our knowledge, this is the first pediatric case of progressive encephalomyelitis with rigidity and myoclonus associated with glycine receptor alpha 1 antibodies, a potentially severe but treatable antibody-mediated neurological disorder.
authors: Departments of Neurology, Centro Hospitalar do Porto, Porto, Portugal.
authors: Joana
authors: J
authors: Damásio
authors: M Isabel
authors: MI
authors: Leite
authors: Ester
authors: E
authors: Coutinho
authors: Patrick
authors: P
authors: Waters
authors: Mark
authors: M
authors: Woodhall
authors: Manuela A
authors: MA
authors: Santos
authors: Inês
authors: I
authors: Carrilho
authors: Angela
authors: A
authors: Vincent
mesh_terms: D004679:Encephalomyelitis / Q000097:blood / Q000134:cerebrospinal fluid / Q000150:complications / Q000188:drug therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007136:Immunoglobulins / Q000097:blood / Q000134:cerebrospinal fluid; D016756:Immunoglobulins, Intravenous / Q000627:therapeutic use; D007155:Immunologic Factors / Q000627:therapeutic use; D007223:Infant; D009127:Muscle Rigidity / Q000097:blood / Q000134:cerebrospinal fluid / Q000150:complications / Q000188:drug therapy; D009207:Myoclonus / Q000097:blood / Q000134:cerebrospinal fluid / Q000150:complications* / Q000188:drug therapy; D018009:Receptors, Glycine / Q000276:immunology*; D012720:Severity of Illness Index; D013256:Steroids / Q000627:therapeutic use; D016896:Treatment Outcome
chemical_list: D007136:Immunoglobulins; D016756:Immunoglobulins, Intravenous; D007155:Immunologic Factors; D018009:Receptors, Glycine; D013256:Steroids