Parkinson's disease dementia can be easily detected in routine clinical practice

Abstract

Parkinson's disease (PD) is mainly characterized by its motor manifestations, but it is also frequently associated with dementia. Early diagnosis of PD dementia (PDD) is particularly important because effective cholinesterase inhibitor treatments are available. This study aimed at validating a short procedure for screening for PDD in routine clinical practice and which adopts recently published diagnostic criteria. One hundred eighty-eight patients with PD participated in the study. The examination procedure comprised three steps: standard clinical examination, a short cognitive function assessment fulfilling the requirements of the Movement Disorders Society (Mini Mental State Examination, five-word test, word generation task, and impact on daily life, including a questionnaire on compliance with medication) and an extensive evaluation of cognitive functions and behavior. After each step, the suspected presence or absence of dementia was recorded. After the short cognitive function assessment, PDD was suspected in 18.62% of the patients [95% confidence interval (CI): 13.32-24.93%]. After the extensive assessment, 21.81% (95% CI: 16.13-28.40%) met the criteria for probable PDD. The short battery's sensitivity and specificity were 65.85% (95% CI = 49.41-79.92%) and 94.56% (95% CI = 89.56-97.62%), respectively. A stepwise logistic regression analysis showed that use of a specific cut-off considerably enhanced the short battery's sensitivity (85.37%, 95% CI = 70.83-94.43%) without decreasing its specificity (83.67%, 95% CI = 76.69-89.25%). With an easy-to-use, short battery of tests that are commonly used in routine clinical practice, it is possible to diagnose PDD in accordance with reference criteria and with the same sensitivity and specificity as in a more extensive evaluation.