The applause sign in cortical and cortical-subcortical dementia

Abstract

The "applause sign" is a motor perseveration described in focal and neurodegenerative disorders and characterized by fronto-subcortical dysfunction. Most previous formal investigations focused on Parkinson's disease or progressive supranuclear palsy. We assessed the prevalence of the applause sign in patients affected by Alzheimer's disease (AD), Lewy body dementia (LBD), corticobasal syndrome (CBS), and posterior cortical atrophy (PCA), with the aim to verify its contribution to the differential diagnosis. We enrolled 20 patients with AD, 20 with LBD, 16 with CBS, and ten with PCA, and 30 healthy controls. The three clap test (TCT) was used to elicit the applause sign, and was scored by raters blinded to the diagnosis. Correlation with motor (extrapyramidal) and cognitive measures was also performed. A maximum 40 % prevalence of a positive applause sign was found in the two parkinsonian syndromes, which could be discriminated from the two cortical groups with a positive predictive value of 82 % and a negative predictive value of 55 %. According to our findings, a diagnosis of LBD or CBS, rather than of AD or PCA, is highly probable in the presence of an abnormal TCP, but cannot be ruled out based on a negative result. No relevant correlates emerged that could clarify the origin and nature of the applause sign.

Perseveration as main symptom in dementia syndrome: case report

“…O teste do desenho do relógio permite avaliar um bom número de funções cognitivas, incluindo compreensão verbal, memória, habilidades visuo-espaciais, planejamento e concentração 14 . O sinal do aplauso refere-se a uma perseveração motora descrita em condições focais e alguns distúrbios neurogenerativos difusos e caracterizados por disfunção frontal-subcortical 15 . Investigações prévias descreveram a presença deste teste em Doença de Parkinson e na demência associada a esta condição, bem como na paralisia supranuclear progressiva, DA, demência por corpos de Lewy, síndrome corticobasal e atrofia posterior cortical 15 .…”

“…O sinal do aplauso refere-se a uma perseveração motora descrita em condições focais e alguns distúrbios neurogenerativos difusos e caracterizados por disfunção frontal-subcortical 15 . Investigações prévias descreveram a presença deste teste em Doença de Parkinson e na demência associada a esta condição, bem como na paralisia supranuclear progressiva, DA, demência por corpos de Lewy, síndrome corticobasal e atrofia posterior cortical 15 . A avaliação da função cognitiva em pacientes com sintomas sugestivos de declínio cognitivo deve preceder sempre a prescrição de inibidores da acetilcolinesterase.…”

Triple test, a diagnostic observation, can detect cognitive impairment in older adults

“…If the patient clapped three times, they were deemed negative for AS; if the patient clapped more than three times, they were considered positive for AS (PAS). Patients who clapped fewer less than three times were considered as pathologic and having PAS, as reported previously …”

Neurological signs of possible diagnostic value in the cognitive disorders clinic: Table 1

“…The applause sign was first shown in progressive supranuclear palsy,13 and later in other parkinsonian disorders such as Parkinson's disease, dementia with Lewy bodies, corticobasal degeneration and multiple system atrophy 14. It also occurs in cortical dementias, such as Alzheimer's disease and frontotemporal lobar degeneration, albeit less frequently than in progressive supranuclear palsy and dementia with Lewy bodies 15 16. The applause sign may be a motor perseveration, indicating frontal lobe dysfunction.…”