title: The outcome of the movement disorder in methcathinone abusers: clinical, MRI and manganesemia changes, and neuropathology.
abstract: OBJECTIVE
  There is limited knowledge regarding the long-term outcome of the methcathinone/manganese-induced movement disorder. Our purpose was to define prognosis in intravenous methcathinone abusers affected by this distinctive disorder attributed to manganese (Mn) toxicity. Also, neuropathology from a globus pallidus region biopsy from a former user is reported.
  
  
  METHODS
  Eighteen methcathinone abusers were categorized as active (five), discontinued (four) or former (nine) users. They were reassessed after a median of 32.5 months (range 3.4-59.6) clinically, on rating scales, and with MRI and blood Mn levels. The biopsy was examined ultrastructurally.
  
  
  RESULTS
  Overall the group showed a slight tendency to deterioration at follow-up on clinical assessment of motor functioning, especially the active users. No significant change occurred on parkinsonian rating scale reassessment. Significant reduction in Mn levels occurred in former users, and decreased T1-weighted hyperintensity on basal ganglia MRI occurred in 3 of 4 former and 2 of 3 discontinued users, despite lack of clinical improvement. The biopsy consisted of white matter showing decompacted myelin sheaths and frequent abnormalities of mitochondria.
  
  
  CONCLUSIONS
  No improvement in this Mn-induced movement disorder occurs after cessation of methcathinone abuse despite improvement of Mn blood levels and/or MRI abnormalities. Ultrastructural abnormalities in a former user confirm structural damage to white matter is associated with the disorder. Methcathinone/Mn toxicity is an important, disabling and permanent medical sequel of intravenous drug abuse in the former Soviet Union.
authors.affiliation: Laboratory for Research in Rehabilitation, Riga Stradins University, Riga, Latvia.
authors.forename: A
authors.initials: A
authors.lastname: Stepens
authors.forename: V
authors.initials: V
authors.lastname: Groma
authors.forename: S
authors.initials: S
authors.lastname: Skuja
authors.forename: A
authors.initials: A
authors.lastname: Platkājis
authors.forename: P
authors.initials: P
authors.lastname: Aldiņš
authors.forename: I
authors.initials: I
authors.lastname: Ekšteina
authors.forename: I
authors.initials: I
authors.lastname: Mārtiņsone
authors.forename: R
authors.initials: R
authors.lastname: Bricis
authors.forename: M
authors.initials: M
authors.lastname: Donaghy
mesh_terms: D000328:Adult; D004409:Dyskinesia, Drug-Induced / Q000097:blood / Q000473:pathology*; D005260:Female; D005917:Globus Pallidus / Q000473:pathology*; D006801:Humans; D008297:Male; D008345:Manganese / Q000097:blood*; D020149:Manganese Poisoning / Q000097:blood / Q000473:pathology*; D008875:Middle Aged; D011427:Propiophenones / Q000009:adverse effects*; D055815:Young Adult
chemical_list: D011427:Propiophenones; C047806:monomethylpropion; D008345:Manganese
keywords: extrapyramidal; manganese toxicity; methcathinone; movement disorder; parkinsonism