Combined effect of age and severity on the risk of dementia in Parkinson's disease

Abstract

Age and severity of extrapyramidal signs have been consistently associated with incident dementia in Parkinson's disease. We evaluated the separate and combined effects of age and severity of extrapyramidal signs on the risk of incident dementia in Parkinson's disease in the setting of a population-based prospective cohort study. Age and the total Unified Parkinson's Disease Rating Scale motor score at baseline evaluation were dichotomized at the median. Four groups of Parkinson's disease patients were defined: younger age/low severity (reference), younger age/high severity, older age/low severity, and older age/high severity. Risk ratios for incident dementia were calculated with Cox proportional hazards models controlling for gender, education, ethnicity, and duration of Parkinson's disease. Of 180 patients, 52 (28.9%) became demented during a mean follow-up period of 3.6 +/- 2.2 years. The median age at baseline of the Parkinson's disease patients was 71.8 years (range, 38.5-95.9 years), and the median total Unified Parkinson's Disease Rating Scale motor score was 24 (range, 2-65). The group with older age/high severity had a significantly increased risk of incident dementia (relative risk, 9.7; 95% confidence interval, 3.9-24.4) compared with the group with younger age/low severity (reference), whereas the groups with older age/low severity (relative risk, 1.6; 95% confidence interval, 0.5-4.8) and younger age/high severity (relative risk, 1.2; 95% confidence interval, 0.5-3.2) did not. These findings suggest that the increased risk of incident dementia in Parkinson's disease associated with age and severity of extrapyramidal signs is related primarily to their combined effect rather than separate effects.

User interface design guidelines for smartphone applications for people with Parkinson’s disease

“…3 is increasingly recognized as an associated feature of PD in advanced ages and severe disease phases [27].…”

Non-motor signs in Parkinson’s disease: a review

“…On the other hand, the increased age-related dementia risk does not seem to be associated with the possible influence of age of onset of motor symptoms; in other words, patients develop dementia in a similar mean age, regardless of when the motor signs appear 54 . Other studies also showed that cognitive impairment in PD correlates with the severity of motor disabilities, male gender, low education, visual hallucinations and the presence of rigidity and axial bradykinesia 55 .…”

“…In fact, the presence of cognitive impairment or dementia in PD patients is associated with loss of independence, poor quality of life and shortening of lifespan. Moreover, individuals in advanced stages of PD who develop dementia, often present a functional decline that follows a stereotyped pattern, indicating that the beginning of this sign announces the need for a more intensive care and increased risk of mortality 54 . Thus, the onset and progression of cognitive impairment in PD have an important influence on patient management and prognosis.…”

Metabolic syndrome and dementia associated with Parkinson's disease: impact of age and hypertension

“…Population studies have shown a direct relationship between patient age and the prevalence of dementia in patients with PD, which is higher than 60% in individuals over the age of 80 years 2,19,20 .…”