title: Brain involvement in neuromyelitis optica spectrum disorders.
abstract: BACKGROUND
  Neuromyelitis optica spectrum disorders (NMOSDs) are severe inflammatory demyelinating disorders of the central nervous system. Brain involvement is increasingly recognized.
  
  
  OBJECTIVE
  To study brain involvement in NMOSDs among Hong Kong Chinese patients.
  
  
  METHODS
  Retrospective study of patients with NMOSDs.
  
  
  METHODS
  Tertiary medical center in Hong Kong. Patients  Thirty-four Hong Kong Chinese patients with NMOSDs of 2 years or longer were recruited.
  
  
  METHODS
  Brain and spinal cord magnetic resonance imaging was performed during NMOSD attacks and was repeated yearly for the first 3 years.
  
  
  METHODS
  We evaluated clinical features of NMOSDs associated with brain involvement and brain lesions on magnetic resonance imaging.
  
  
  RESULTS
  Among 34 patients with NMOSDs of 2 years or longer, 20 (59%) had brain involvement. The mean age at onset among these 20 patients was 45.6 years (age range, 19-67 years); 18 were women. Eleven patients (32% of all the patients with NMOSDs) had clinical manifestation of brain involvement, 19 patients (56%) had brain abnormalities on magnetic resonance imaging consistent with inflammatory demyelination, and 2 patients (6%) fulfilled criteria for multiple sclerosis. Clinical manifestation of brain involvement included the following: trigeminal neuralgia; vomiting, vertigo, ataxia, dysphagia, and tetraparesis from lesions around the third and fourth ventricles and aqueduct; homonymous hemianopia, aphasia, hemiparesis, and cognitive impairment from extensive hemispheric white matter lesions; and ataxia, diplopia, hiccups, facial sensory loss, internuclear ophthalmoplegia, hemisensory loss, and hemiparesis from other lesions in the midbrain, pons, cerebellar peduncles, and medulla. Eight patients (24%) developed brainstem encephalitis clinically, and brainstem encephalitis was the initial clinical manifestation in 6 patients (18%). Brain abnormalities on magnetic resonance imaging were detected in brainstem in 15 patients (44%), hemispheric periventricular white matter in 7 patients (21%), deep white matter in 7 patients (21%), corpus callosum in 4 patients (12%), subcortical white matter in 3 patients (9%), thalamus in 2 patients (6%), hypothalamus in 1 patient (3%), basal ganglia in 1 patient (3%), internal capsule in 1 patient (3%), periaqueductal gray matter in 1 patient (3%), and around the third and fourth ventricles in 1 patient (3%); large confluent lesions were detected in 2 patients (6%).
  
  
  CONCLUSIONS
  Brain involvement manifesting clinically as brainstem encephalitis is common among Hong Kong Chinese patients with NMOSDs.
authors.affiliation: Queen Mary Hospital, LKS Faculty of Medicine, University Department of Medicine, The University of Hong Kong, 4/F Professorial Block, 102 Pokfulam Rd, Hong Kong. koonho@hkucc.hku.hk
authors.forename: Koon Ho
authors.initials: KH
authors.lastname: Chan
authors.forename: C T
authors.initials: CT
authors.lastname: Tse
authors.forename: C P
authors.initials: CP
authors.lastname: Chung
authors.forename: Raymand L C
authors.initials: RL
authors.lastname: Lee
authors.forename: J S C
authors.initials: JS
authors.lastname: Kwan
authors.forename: P W L
authors.initials: PW
authors.lastname: Ho
authors.forename: J W M
authors.initials: JW
authors.lastname: Ho
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009471:Neuromyelitis Optica / Q000145:classification / Q000473:pathology*; D012189:Retrospective Studies; D013116:Spinal Cord / Q000473:pathology; D055815:Young Adult