Delayed recall memory impairment in patients with Parkinson's disease

Age is one of the risk factors for dementia in patients with Parkinson's disease (PDD). Distinct cognitive syndromes of Parkinson's disease (PD) have been identified in previous studies. Questions about the role of such cognitive disorders in PD outcomes, especially memory dysfunction, in patients with PD remain unanswered.

To establish possible correlations between delayed recall memory (episodic memory), age, and other demographic variables in patients with PD.

A two-stage protocol was applied. Patients with delayed recall memory compromise, selected based on a brief battery of tests (BBRC-Edu), were classified as dementia cases and submitted to the Mattis Dementia Rating Scale (MDRS). Data from patients with memory disturbances were compared against individuals without episodic memory impairment, and correlated with age and demographic variables.

Except for identification and naming, all subtests in the screening battery showed a significant difference (p≤0.0001) between the memory-compromised group (case) and the group without memory impairment (no case). The results also correlated negatively with age (p≤0.0001) and positively with level of education (p=0.0874) in patients with PD.

The analysis showed a significant relationship between age and dementia characterized by impaired episodic memory. The findings support reports of a wide spectrum of neuropsychological performance impairment in PD with age, particularly dementia associated with memory deterioration. No correlations between disease duration and cognitive dysfunction were evident.