title: Apraxia in mild cognitive impairment and Alzheimer's disease: validity and reliability of the Van Heugten test for apraxia.
abstract: OBJECTIVE
  To assess the reliability and validity of the Van Heugten test for apraxia (VHA), developed for and used in stroke patients, in a memory clinic population. Furthermore, we assess the presence and severity of apraxia in mild cognitive impairment (MCI) and Alzheimer's disease (AD) and investigate which AD patients are likely to develop apraxia.
  
  
  METHODS
  We included 90 controls (age: 60 ± 9 years, MMSE: 28 ± 2), 90 MCI patients (age: 65 ± 7 years, MMSE: 26 ± 2) and 158 AD patients (age: 66 ± 8 years, MMSE: 20 ± 5). Apraxia was evaluated by the VHA assessing ideational and ideomotor praxis. We retested 20 patients to assess reliability.
  
  
  RESULTS
  Intrarater reliability was 0.88 and interrater reliability was 0.73. AD patients performed worse on the VHA (median: 88; range: 51-90) than controls (median: 90; range: 88-90) and MCI patients (median: 89; range: 84-90) (both p < 0.001). Apraxia was prevalent in 35% of AD patients, in 10% of MCI and it was not observed in controls (0%; p < 0.001). In AD, dementia severity was the main risk for apraxia; 15% of mildly versus 52% of moderately demented patients had apraxia (OR = 6.7, 95% CI 2.9-15.6). The second risk factor was APOE genotype. APOE ε4 noncarriers (47%) were at increased risk compared to carriers (30%) (OR = 2.1, 95% CI 1-4.7).
  
  
  CONCLUSIONS
  Apraxia can be reliably measured with the VHA and is present in a proportion of patients with MCI and AD. The presence of apraxia in AD is related to dementia severity and APOE ε4.
authors.affiliation: Department of Neurology, Alzheimer Center, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Lieke L
authors.initials: LL
authors.lastname: Smits
authors.forename: Marinke
authors.initials: M
authors.lastname: Flapper
authors.forename: Nicole
authors.initials: N
authors.lastname: Sistermans
authors.forename: Yolande A L
authors.initials: YA
authors.lastname: Pijnenburg
authors.forename: Philip
authors.initials: P
authors.lastname: Scheltens
authors.forename: Wiesje M
authors.initials: WM
authors.lastname: van der Flier
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000150:complications / Q000175:diagnosis / Q000235:genetics / Q000503:physiopathology; D053327:Apolipoprotein E4 / Q000235:genetics*; D001072:Apraxias / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology / Q000235:genetics / Q000523:psychology; D060825:Cognitive Dysfunction / Q000175:diagnosis / Q000523:psychology; D003704:Dementia / Q000175:diagnosis / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D009483:Neuropsychological Tests; D015995:Prevalence; D011569:Psychiatric Status Rating Scales; D015203:Reproducibility of Results; D012307:Risk Factors; D012720:Severity of Illness Index
chemical_list: D053327:Apolipoprotein E4