Session Information
Date: Wednesday, June 7, 2017
Session Title: Parkinson's Disease: Psychiatric Manifestations
Session Time: 1:15pm-2:45pm
Location: Exhibit Hall C
Objective: To study the neuropsychological and neurophysiological correlates of minor hallucinations (mH) in non-demented PD patients, by using different scales and the event-related potentials (ERP) N170 and P3a/P3b.
Background: The neuropsychological correlates of minor hallucinations in PD are unknown. Few published series including early PD patients have not found associations with specific cognitive domains1. Few studies have explored the relationship of visual hallucinations with frontal ERPs (P3a/P3b), but (i) no study has previously analyzed cognitive ERP in patients with isolated mH, or (ii) has analyzed ERPs that measure activity in other brain areas, which seems relevant since 5-HT2 agonists in temporal areas induce hallucinations that relate to changes in N170 potential2.
Methods: Prospective assessment of a representative sample of 115 non-demented PD patients (age 44-79 years, disease duration 1-16 years). Hallucinations were diagnosed by the Neuropsychiatric Inventory (NPI) and a semistructured interview for screening of presence of presence and passage hallucinations. One rater collected clinical-demographic data and administered the interview, and another rater administered the NPI and neuropsychological tests. ERP recordings were obtained by using a two-stimulus active oddball paradigm for P3a (Fz) and P3b (Pz), and by presenting objects and human faces for N170 (T5 and T6).
Results: The frequency of minor hallucinations differed if screened using the NPI (14.1%) or the interview (39.1%). In multivariate general linear model, mH were associated with worse performance in backward Corsi cubes (0.02), TMT-A and B (0.004), Buschke total recall (0.02), Rey figure’s copy (0.003), Boston Naming (0.01), and Token test (0.02).
ERP in PD with mH showed significantly longer latencies for N170 faces at T5 (0.001) and T6 (0.006), and for P3b (0.03). Longer ERP latencies significantly correlated with higher age, worse TMT-B and Rey figure scores (<0.05).
Conclusions: In this sample including patients in early and more advanced stages of the disease, mH were associated with coexistent dysfunction of executive, memory, and visuospatial tasks.
Bilateral longer N170 latency in combination with P3b longer latency were already found in patients with mild hallucinations, suggesting that cognitive ERPs could serve as a biomarker of even mild hallucinations in PD.
References: 1. Pagonabarraga J, Martinez-Horta S, Fernández de Bobadilla R, Pérez J, Ribosa-Nogué R, Marín J, Pascual-Sedano B, García C, Gironell A, Kulisevsky J. Minor hallucinations occur in drug-naive Parkinson’s disease patients, even from the premotor phase. Mov Disord. 2016; 31: 45-52.
2. Kometer M, Schmidt A, Jäncke L, Vollenweider FX. Activation of serotonin 2A receptors underlies the psilocybin-induced effects on α oscillations, N170 visual-evoked potentials, and visual hallucinations. J Neurosci. 2013; 33: 10544-51.
To cite this abstract in AMA style:
J. Pagonabarraga, J. Marin-Lahoz, A. Horta, H. Bejr-Kasem, M. Cornella, J. Pérez-Pérez, S. Martinez-Horta, J. Kulisevsky. Minor hallucinations in Parkinson’s disease: neuropshycological and neurophysiological correlates in a representative sample of non-demented patients. [abstract]. Mov Disord. 2017; 32 (suppl 2). https://www.mdsabstracts.org/abstract/minor-hallucinations-in-parkinsons-disease-neuropshycological-and-neurophysiological-correlates-in-a-representative-sample-of-non-demented-patients/. Accessed June 14, 2025.« Back to 2017 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/minor-hallucinations-in-parkinsons-disease-neuropshycological-and-neurophysiological-correlates-in-a-representative-sample-of-non-demented-patients/