title: A comparison of the efficacy of donepezil in Parkinson's disease with dementia and dementia with Lewy bodies.
abstract: BACKGROUND
  Parkinson's disease with dementia (PDD) and dementia with Lewy bodies (DLB) overlap in phenomenology and neurochemical deficits. We hypothesised they would not differ in their response to the cholinesterase inhibitor donepezil.
  
  
  METHODS
  We recruited 70 subjects, 30 DLB and 40 PDD, in an open label study to compare the efficacy of donepezil in these two patient groups. They were assessed at baseline, 4, 12 and 20 weeks. The main outcome measures were the Mini-Mental State Examination (MMSE), Neuropsychiatric Inventory (NPI) and motor sub-section of the Unified Parkinson's Disease Rating Scale (UPDRS III).
  
  
  RESULTS
  PDD patients were younger than DLB and had more severe parkinsonism at baseline. The groups were similar on all other variables of interest. By 20 weeks the mean MMSE score increased by 3.9 points in the DLB group and by 3.2 points in PDD. The mean NPI score reduced by 14.6 points for DLB and 12.0 points for PDD. These treatment effects were all significant compared to baseline (p < 0.001) but there were no significant between-group treatment differences (MMSE p = 0.56, NPI p = 0.39). UPDRS III motor scores did not change significantly from baseline values in either group. Although adverse effects were common (69%) they were usually mild and 64 patients (91%) completed the study. The four patients who did withdraw with adverse effects all had a PDD diagnosis.
  
  
  CONCLUSIONS
  Donepezil produced similar improvements in cognition and behaviour in DLB and PDD. This supports the hypothesis that the two disorders are closely related clinically and neurobiologically. Larger scale, placebo controlled clinical trials are needed to provide an evidence base to guide the clinical use of cholinesterase inhibitors in Lewy body disease.
authors.affiliation: Institute for Ageing and Health, University of Newcastle upon Tyne, Wolfson Research Centre, Newcastle General Hospital, Newcastle upon Tyne, UK.
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Thomas
authors.forename: David J
authors.initials: DJ
authors.lastname: Burn
authors.forename: Elise N
authors.initials: EN
authors.lastname: Rowan
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Littlewood
authors.forename: Jane
authors.initials: J
authors.lastname: Newby
authors.forename: David
authors.initials: D
authors.lastname: Cousins
authors.forename: Sanjeet
authors.initials: S
authors.lastname: Pakrasi
authors.forename: Jonathan
authors.initials: J
authors.lastname: Richardson
authors.forename: Jonathan
authors.initials: J
authors.lastname: Sanders
authors.forename: Ian G
authors.initials: IG
authors.lastname: McKeith
mesh_terms: D000367:Age Factors; D000368:Aged; D002800:Cholinesterase Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D003704:Dementia / Q000150:complications / Q000188:drug therapy* / Q000523:psychology; D000077265:Donepezil; D005260:Female; D006801:Humans; D007189:Indans / Q000009:adverse effects / Q000627:therapeutic use*; D020961:Lewy Body Disease / Q000188:drug therapy / Q000523:psychology; D008297:Male; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications / Q000188:drug therapy* / Q000523:psychology; D010880:Piperidines / Q000009:adverse effects / Q000627:therapeutic use*; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D002800:Cholinesterase Inhibitors; D007189:Indans; D010880:Piperidines; D000077265:Donepezil