Disturbance of Automatic Auditory Change Detection in Dementia Associated with Parkinson's Disease: A Mismatch Negativity Study

Objective: To investigate whether automatic auditory change detection, as measured by the mismatch negativity (MMN) event-related potential waveform, differs in dementia associated with Parkinson's disease (PDD) and dementia with Lewy-bodies (DLB) as compared to Alzheimer's disease (AD), Parkinson's disease without dementia (PD) and healthy control subjects (HC).

Method: Seventeen DLB, 15 PDD, 16 PD, 16 AD patients and 18 HC subjects participated. A passive MMN event-related potential paradigm and an oddball-distractor reaction time paradigm were presented.

Results: The PDD patients had reduced MMN area and amplitude compared to the DLB, PD, and the HC groups. The MMN area correlated significantly with number of missed target stimuli in the oddball-distractor task, and the PDD group missed targets significantly more often than the DLB group.

Conclusion: The results indicate that PDD patients to a larger degree than patients with DLB have a deficit of automatic auditory change detection that contributes to impairment in their ability to selectively attend and respond to deviant auditory stimuli.