Study Links Cognitive Disability to Greater Disability in Moderate-to-Advanced Parkinson

Cognitive disability may be associated with greater disability in moderate-to-advanced Parkinson disease than nonambulatory status, according to a study published in Frontiers in Neurology.

The study analyzed 10,581 patients with Parkinson( PwP), with moderate-to-advanced disease according to the Hoehn and Yahr staging scale. The researchers collected the data from the Taiwan Data Bank of Persons with Disability database in order to conduct a disability evaluation and function assessment. The WHO Disability Assessment Schedule 2.0 (WHODAS 2.0)—an assessment tool developed in accordance to the conceptual framework of the International Classification of Functioning, Disability, and Health—was administered and all PwP were grouped based on their ambulatory status, which was assessed by 3-meter back and forth walk. WHODAS was modified to account for the study location (Taiwan).

WHODAS 2.0 encompasses 6 areas:

• Cognition
• Mobility
• Self-care
• Getting along with other people
• Life activities
• Participation in community activities

As disability relates to Parkinson, it is traditionally thought to be linked with motor features, but nonmotor aspects of PD, such as dementia, is oftentimes underestimated, the researchers noted. Moreover, caregivers and patients frequently report that cognitive decline is worrisome and say not treating it is an unmet need.

Of the 10,581 PwP, 4145 were categorized as having cognitive disability. The mean age was 76.4, older than the group without cognitive disability (mean age 71.1). All domains of the WHODAS 2.0 were more severely impacted in those with cognitive disability.

Taking walking status into account, the researchers grouped the patients according to the combination of 2 conditions (intact cognition/cognitive disability and ambulatory/nonambulatory status) and noted statistically significant age differences within the 4 groups:

• 44.2% fell into the ambulatory or assisted ambulatory/intact cognition category, and were the youngest group, with a mean age of 69
• 27.5% fell into the cognitive disability/non-ambulatory group, and were the oldest group, with a mean age of 77.6
• 16.7% were in the intact cognition/non-ambulatory group
• 11.6% of the patients were in the cognitive disability/ambulatory or assisted ambulatory group

Cognitive disability was linked with worse disability for both ambulatory and nonambulatory groups (P < .05).

The results indicate that efforts to preserve cognition, such as medical therapy or cognitive training, is necessary to prevent progressive disability in moderate-to-advanced PwP, the researchers said.

Reference

Wang C, Chan L, Wu D, et al. Effect of cognitive disability and ambulation status on functioning in moderate-to-advanced parkinson disease [published online January 9, 2020]. Frontiers in Neurology. doi: 10.3389/fneur.2019.01360.