RT Journal Article
SR Electronic
T1 Apraxia profile differentiates behavioural variant frontotemporal from Alzheimer's dementia in mild disease stages
JF Journal of Neurology, Neurosurgery & Psychiatry
JO J Neurol Neurosurg Psychiatry
FD BMJ Publishing Group Ltd
SP 809
OP 815
DO 10.1136/jnnp-2014-308773
VO 86
IS 7
A1 Johnen, Andreas
A1 Tokaj, Amelie
A1 Kirschner, Anne
A1 Wiendl, Heinz
A1 Lueg, Gero
A1 Duning, Thomas
A1 Lohmann, Hubertus
YR 2015
UL http://jnnp.bmj.com/content/86/7/809.abstract
AB Objective Despite refined criteria for behavioural variant frontotemporal dementia (bvFTD), its differentiation from Alzheimer's dementia (AD) remains difficult at early clinical presentation. Apraxia is not considered as a supportive feature for the diagnosis of bvFTD, but for AD. However, only few studies have quantified praxis disturbances in mild disease stages and their specificity for AD compared with bvFTD remains indistinct. We explore apraxia in bvFTD and investigate the differential validity of apraxia screening tests to distinguish between AD, bvFTD and healthy controls (HC).Methods We compared composite apraxia scores assessed with standardised neuropsychological screening tests as well as performance in praxis subdomains in patients who fulfil current clinical criteria for AD (N=20), bvFTD (N=20), and in HC (N=20).Results Composite scores of apraxia screening tests provided high diagnostic accuracy for detecting mild stages of both neurodegenerative disorders compared with HC (sensitivity: 75–95%; specificity: 70–90%). Both patient groups showed pronounced impairments in limb praxis, especially in imitation of hand and finger postures (bvFTD: 71.7%; AD: 55.5%; HC: 86.7%) and pantomime of object use (bvFTD: 88.6%; AD: 81.4%; HC: 97.5%). Beyond that, patients with bvFTD displayed a unique profile of deficits for imitating face postures (bvFTD: 69%; AD: 88%; HC: 95.5%).Conclusions Praxis disturbances are important but under-represented diagnostic features in mild stages of AD and bvFTD. Apraxia screening tests are easily applicable diagnostic tools, which may support clinical diagnoses of both neurodegenerative diseases. The analysis of individual apraxia profiles can effectively facilitate differential diagnosis of AD and bvFTD.