title: The effect of 3,4-diaminopyridine on the patients with hereditary pure cerebellar ataxia.
abstract: BACKGROUND
  Downbeat nystagmus (DBN) is often seen in patients with pure cerebellar type of spinocerebellar ataxia (SCA) like spinocerebellar ataxia type 6 (SCA6). DBN frequently presents with other cerebellar symptoms such as postural imbalance or ataxia. A potassium channel blocker 3,4-diaminopyridine (3,4-DAP) has been reported to reduce DBN by increasing the excitability of Purkinje cells.
  
  
  OBJECTIVE
  The objective of this study is to determine whether 3,4-DAP has a beneficial effect on DBN along with postural imbalance and ataxic symptoms in 10 patients with SCA6 and five patients with chromosome 16q22.1-linked autosomal dominant cerebellar ataxia (16q-ADCA).
  
  
  RESULTS
  The patients took 20mg of 3,4-DAP twice a day for a week. DBN was observed in seven patients with SCA6 and two with 16q-ADCA. Although 3,4-DAP significantly reduced DBN (P<0.05), other ataxic symptoms did not improved. However, 3,4-DAP showed benefit in two patients with oscillopsia.
  
  
  CONCLUSIONS
  3,4-DAP may be effective on DBN and oscillopsia, although it was not proved to be effective on other symptoms of ataxia in SCA patients.
authors.affiliation: Department of Neurology and Neurological Science, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan. ttsunemi@ucsd.edu
authors.forename: Taiji
authors.initials: T
authors.lastname: Tsunemi
authors.forename: Kinya
authors.initials: K
authors.lastname: Ishikawa
authors.forename: Kei
authors.initials: K
authors.lastname: Tsukui
authors.forename: Takuro
authors.initials: T
authors.lastname: Sumi
authors.forename: Ken
authors.initials: K
authors.lastname: Kitamura
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Mizusawa
mesh_terms: D015761:4-Aminopyridine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D000077770:Amifampridine; D001259:Ataxia / Q000150:complications / Q000188:drug therapy / Q000235:genetics; D004334:Drug Administration Schedule; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D020417:Nystagmus, Congenital / Q000150:complications / Q000188:drug therapy* / Q000235:genetics; D011187:Posture; D026902:Potassium Channel Blockers / Q000627:therapeutic use; D020754:Spinocerebellar Ataxias / Q000150:complications / Q000188:drug therapy* / Q000235:genetics; D016896:Treatment Outcome
chemical_list: D026902:Potassium Channel Blockers; D015761:4-Aminopyridine; D000077770:Amifampridine