Applause sign (clap test) – updated research

Here’s some new research that probably speaks to the results that Dubois got in ’05 when he and other French researchers said that the “applause sign helps to discriminate PSP from FTD and PD.”

This newly-published research looks at those with PD and “various forms of atypical parkinsonism.” (I’ll have to get the full article to know which forms were included.) These Dutch researchers found: “Although the proportion with an abnormal clapping test was significantly higher in atypical parkinsonism, the clapping test did not discriminate well between Parkinson’s disease and atypical parkinsonism.”

Journal of Neurology. 2007 Oct 15; [Epub ahead of print] Diagnostic accuracy of the clapping test in Parkinsonian disorders.

Abdo WF, van Norden AG, de Laat KF, de Leeuw FE, Borm GF, Verbeek MM, Kremer PH, Bloem BR.
Parkinson Centre Nijmegen (ParC), Institute of Neurology, Radboud University Nijmegen Medical Centre, The Netherlands.

BACKGROUND : To determine the diagnostic value of the clapping test, which has been proposed as a reliable measure to differentiate between progressive supranuclear palsy (where performance is impaired) and Parkinson’s disease (where performance should be normal).

METHODS : Our study group included a large cohort of consecutive outpatients including 44 patients with Parkinson’s disease, 48 patients with various forms of atypical parkinsonism and 149 control subjects. All subjects performed the clapping test according to a standardized protocol.

RESULTS : Clapping test performance was normal in all control subjects, and impaired in 63% of the patients with atypical parkinsonism. Unexpectedly, we also found an impaired clapping test in 29% of the patients with Parkinson’s disease.

CONCLUSION : Although the proportion with an abnormal clapping test was significantly higher in atypical parkinsonism, the clapping test did not discriminate well between Parkinson’s disease and atypical parkinsonism.

PubMed ID#: 17934886

The “applause sign” is where you ask someone who might have PSP to clap. While clapping, you tell them to stop. The person with PSP continues to clap; it takes them awhile to stop.

In a study done by Dubois, 30 out of 42 patients diagnosed with PSP could not stop applauding immediately after being told to stop. Interestingly, none of those with FTD or PD had trouble stopping.

Here’s the abstract of the Dubois article (published 6/05 in Neurology):

*Neurology. 2005 Jun 28;64(12):2132-3.

“Applause sign” helps to discriminate PSP from FTD and PD.

Dubois B, Slachevsky A, Pillon B, Beato R, Villalponda JM, Litvan I.
INSERM, Fédération de Neurologie, Hôpital de la Salpêtrière, Paris, France.

“Applause sign” helps to discriminate PSP from FTD and PD
The “applause sign” is a simple test of motor control that helps to differentiate PSP from frontal or striatofrontal degenerative diseases. It was found in 0/39 controls, 0 of 24 patients with frontotemporal dementia (FTD), 0 of 17 patients with Parkinson disease (PD), and 30/42 patients with progressive supranuclear palsy (PSP). It discriminated PSP from FTD (p < 0.001) and PD (p < 0.00). The “three clap test” correctly identified 81.8% of the patients in the comparison PSP and FTD and 75% of the patients in the comparison of PSP and PD.

PubMed ID#: 15985587 (see pubmed.gov)