Applause sign

Applause sign

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  Cortical surface with an overlay of the basal ganglia and thalamus

Applause Sign

The applause sign is a clinical neurological sign used to assess frontal lobe function, particularly in the context of Parkinson's disease and other neurodegenerative disorders. It is a simple test that can help differentiate between various types of dementia and movement disorders.

Description

The applause sign is elicited by asking the patient to clap their hands three times. In a normal response, the patient will clap exactly three times. However, in patients with certain frontal lobe dysfunctions, such as those seen in progressive supranuclear palsy (PSP) or corticobasal degeneration (CBD), the patient may continue clapping beyond the requested three times. This perseverative behavior is indicative of impaired executive function and motor control.

Clinical Significance

The presence of the applause sign is particularly useful in distinguishing between Parkinson's disease and atypical parkinsonian disorders such as PSP and CBD. In Parkinson's disease, the applause sign is typically absent, whereas it is often present in PSP and CBD due to the involvement of the frontal lobes.

The applause sign is also used in the assessment of frontotemporal dementia (FTD), where it may be present due to the degeneration of the frontal lobes. It is a part of a broader neurological examination that assesses cognitive function, motor skills, and behavioral changes.

Mechanism

The underlying mechanism of the applause sign involves the dysfunction of the frontal lobes, which are responsible for executive functions such as planning, inhibition, and the regulation of motor activities. In conditions where the frontal lobes are compromised, patients may exhibit perseveration, which is the repetition of a particular response despite the absence or cessation of a stimulus.

Related Pages

• Parkinson's disease
• Progressive supranuclear palsy
• Corticobasal degeneration
• Frontotemporal dementia
• Executive function
• Perseveration

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External links

• Comprehensive information from the National Institute of health.
  

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