Fifty Percent Prevalence of Extracampine Hallucinations in Parkinson’s Disease Patients

Abstract

Extracampine hallucinations (EH), the sense of a presence or fleeting movement in the absence of an associated visual percept, have been reported in Parkinson’s disease (PD) patients but their prevalence, characteristics, and temporal relationship to visual hallucinations (VH) remain unclear. Given that, VH are predictive of cognitive impairment in PD, improved understanding of EH may have significant prognostic implications. The objective of this study is to evaluate the prevalence and characteristics of EH in a large unselected population with PD and to assess the temporal relationship between EH, VH, and memory decline. Cross-sectional data were collected from 414 PD patients using a questionnaire circulated via an online patient community. Data were obtained regarding the occurrence, timing, and characteristics of VH and EH and symptoms of PD, disease duration, disease severity, and medication history. About 50.4% of respondents reported EH and 15.5% reported VH. EH were typically experienced alongside, rather than behind, the individual (p < 0.001) without clear lateralization (p = 0.438) and were more likely to be of unfamiliar presences (p < 0.001). The occurrence of EH was associated with Hoehn and Yahr score (p = 0.002) but not disease duration (p = 0.158). EH onset was associated with VH onset (p = 0.046) and occurred after the onset of anosmia (p < 0.001), cognitive decline (p = 0.002), and sleep disturbance (p = 0.002). The reported prevalence of EH in PD patients was threefold greater than that of VH, with similar timings of onset, suggesting that EH are under-recognized and under-reported. Further work is needed to determine whether EH are predictive of cognitive decline.

Risk factors for minor hallucinations in Parkinson's disease

“…The authors showed that the sense of presence is a significant independent predictor of VHs (odds ratio [OR] 4.5). Similarly, Wood et al 15 revealed that patients with MHs are significantly more likely to have concomitant VHs. However, the relationship between MHs and cognitive impairment has not been demonstrated in PD patients, although formed VHs are generally considered to be linked to cognitive impairment according to a number of studies 7,8,16 .…”

The psychosis spectrum in Parkinson disease

“…An online questionnaire administered to individuals with PD suggested an overall prevalence of 50% for presence and passage hallucinations (‘extracampine hallucinations’ was used as a collective term for both experiences, although this differs from its classic usage), with individual prevalences of 25% for presence hallucinations and 46% for passage hallucinations 12 . Studies of formed hallucinations in PD have found an association between the cognitive profile and the type of hallucination experienced 13 : patients with PD whose typical hallucinations are of unfamiliar content (for example, unidentified figures) have more-profound deficits of inhibitory executive function than do patients with hallucinations that are recognized (for example, family members).…”

Neuropsychiatric Disorders in Parkinson’s Disease: What Do We Know About the Role of Dopaminergic and Non-dopaminergic Systems?

“…Passage (feeling like something is passing at the outer visual field) and presence (feeling that someone is close by) hallucinations as well as illusions (mis-or distorted perception of an actual stimulus) are the most common symptoms at early stage of the disease. Passage and presence hallucinations may concern 50% of the patients (Wood et al, 2015). As the disease progresses, visual hallucinations in PD may be complex and formed, usually vision of animals, people or objects.…”