Clinical features of minor hallucinations in different phenotypes of Parkinson’s disease: A cross-sectional study

Abstract

BackgroundMinor hallucinations (MHs) are the most common psychiatric symptom associated with Parkinson’s disease (PDPsy), but little is known about their characteristics in different motor phenotypes, especially postural instability gait difficulty (PIGD). The aim of this study was to explore the clinical features of MHs in different subtypes of PD.MethodsIn this cross-sectional study, 213 patients with Parkinson’s disease (PD) were recruited, and the data obtained included comprehensive demographics, motor subtypes, clinical scale scores, and MH contents. Motor subtypes were classified as tremor-dominant (TD), PIGD or indeterminate according to Stebbins’ method.ResultsA total of 213 PD patients were included: 90 (42.3%) TD patients, 98 (46.0%) PIGD patients and 25 (11.7%) indeterminate. In total, 70 (32.9%) patients experienced MHs. Compared to patients with the TD phenotype, we found that patients with the PIGD phenotype had more severe motor and nonmotor symptoms. They also had a higher incidence of visual illusions (VIs) and a shorter MH latency.ConclusionOur study demonstrated that compared to patients with the TD phenotype, patients with the PIGD phenotype had a higher incidence of MHs, especially VIs, which may lead to a higher incidence of visual hallucinations (VHs). They also had a shorter latency of MHs than patients with the TD phenotype, suggesting an earlier onset of MHs and a worse prognosis.

Exploring the Spectrum of Visual Illusions and Other Minor Hallucinations in Patients with Parkinson’s Disease in Lithuania

“…Other minor hallucinations, i.e., passage and presence hallucinations, could be linked to dysfunctional motion perception and eye movement control in PD [16]. Furthermore, it has been suggested that certain phenotypic subtypes of PD may have a higher occurrence of minor hallucinations, as supported by a study that found a greater incidence of minor hallucinations, particularly visual illusions, in patients with the postural instability gait difficulty phenotype compared with the tremor-dominant phenotype; however, it is important to note that this finding could have been influenced by confounding factors, since the postural instability gait difficulty phenotype was also associated with more severe motor and other non-motor symptoms, as well as higher LEDD [19]. Regarding the clinical course, insufficient data are available to state that minor hallucinations independently increase the risk of developing visual hallucinations; while some studies suggest a close association between these phenomena, showing that minor hallucinations (including visual illusions) usually precede visual hallucinations and may even represent their milder form, others have shown that only a small proportion of PD patients with visual illusions evolve towards visual hallucinations over 2 years [20,21].…”