Sensitivity to somatomotor conflicts links frontal subcortical dysfunction and minor hallucinations in Parkinson’s disease
Listed in
This article is not in any list yet, why not save it to one of your lists.Abstract
Background
Minor hallucinations (MH) affect 30-60% of patients with Parkinson’s disease (PD), and are considered precursors to structured visual hallucinations and cognitive decline. While the link between structured visual hallucinations and dementia is well established, the neuropsychological correlates of MH in PD remain unclear, with most studies finding no significant cognitive differences between patients with MH and those without any hallucinations.
Objectives
Presence hallucinations (PH) being among the most prevalent MH in PD, we used a technological approach to experimentally induce PH to investigate whether sensitivity to such robot-induced PH aids in detecting cognitive differences between patients with MH and without hallucinations.
Methods
Twenty-five PD patients with MH (PD-MH) and 25 without hallucinations (PD-nH) underwent a comprehensive neuropsychological assessment and a robotic somatomotor procedure that is able to induce PH. The sensitivity to report robot-induced PH was analyzed in relation to the cognitive performance in neuropsychological tests.
Results
PD-MH patients reported more robot-induced PH than PD-nH patients, supporting previous findings. While both groups showed comparable performance in the different cognitive domains, we found a significant association between increased sensitivity to the PH-induction and poorer performance in frontal subcortical functions (executive functions), in PD-MH patients.
Conclusions
These findings demonstrate that sensitivity to robot-induced PH reveals a previously undetected link between MH and frontal subcortical cognitive deficits in PD, pointing to shared underlying mechanisms between executive dysfunction and somatomotor processing. This approach offers a novel and clinically valuable means of identifying early cognitive vulnerability that standard assessments may overlook.
