RT Journal Article
SR Electronic
T1 Applause sign: is it really specific for Parkinsonian disorders? Evidence from cortical dementias
JF Journal of Neurology, Neurosurgery & Psychiatry
JO J Neurol Neurosurg Psychiatry
FD BMJ Publishing Group Ltd
SP 830
OP 833
DO 10.1136/jnnp.2010.224394
VO 82
IS 8
A1 S Luzzi
A1 K Fabi
A1 M Pesallaccia
A1 M Silvestrini
A1 L Provinciali
YR 2011
UL http://jnnp.bmj.com/content/82/8/830.abstract
AB Objective The applause sign, originally reported as a specific sign of progressive supranuclear palsy (PSP), has recently been found in several parkinsonian disorders. Its nature is still uncertain. It has been interpreted as a motor perseveration or a form of apraxia. The present study aims to: (a) verify the specificity of the applause sign for parkinsonian disorders, examining the presence of the applause sign in cortical dementias which should be error free and (b) clarify the nature of the applause sign (resulting or not from apraxia).Methods 77 subjects were included: 10 PSP, 15 frontotemporal dementia (FTD), 29 Alzheimer's disease (AD) and 23 normal controls. The presence of apraxia was an exclusion criterion. All patients underwent a detailed neuropsychological examination, and cognitive performance was correlated to the applause sign.Results All patient groups showed the applause sign and differed significantly from normal subjects who were error free. No difference was found when comparing PSP with FTD and FTD with AD. AD differed significantly from PSP but they were not error free (31% of patients with AD showed the applause sign). The only correlation with background neuropsychology was found for measures of executive functions.Conclusions The presence of the applause sign in cortical dementia does not confirm the specificity of the applause sign for parkinsonian disorders. The applause sign should be interpreted as a sign of frontal lobe dysfunction rather than a form of apraxia, and can likely be detected in any kind of disease which involves frontal lobe structures to some extent.