James Barnes

Visual hallucinations in Parkinson's disease: a review and phenomenological survey

OBJECTIVES Between 8% and 40% of patients with Parkinsons disease undergoing long term treatment will have visual hallucinations during the course of their illness. There were two main objectives: firstly, to review the literature on Parkinsons disease and summarise those factors most often associated with hallucinations; secondly, to carry out a clinical comparison of ambulant patients with Parkinsons disease with and without visual hallucinations, and provide a detailed phenomenological analysis of the hallucinations. METHODS A systematic literature search using standard electronic databases of published surveys and case-control studies was undertaken. In parallel, a two stage questionnaire survey was carried out based on members of a local branch of the Parkinsons Disease Society and followed up with a clinical interview. RESULTS The review disclosed common factors associated with visual hallucinations in Parkinsons disease including greater age and duration of illness, cognitive impairment, and depression and sleep disturbances. The survey comprised 21 patients with visual hallucinations and 23 without. The hallucinators had a longer duration and a greater severity of illness, and tended to show more depressed mood and cognitive impairment. The typical visual hallucination in these patients is a complex visual image experienced while they are alert and have their eyes open. The image appears without any known trigger or voluntary effort, is somewhat blurred, and commonly moves. It stays present for a period of “seconds” or “minutes”. The content can be variable within and between hallucinators, and includes such entities as people, animals, buildings, or scenery. These features resemble those highlighted in hallucinations in the visually impaired (Charles Bonnets syndrome). CONCLUSION A consistent set of factors are associated with visual hallucinations in Parkinsons disease. The results of the phenomenological survey and those of visual hallucinations carried out in other settings suggest a common physiological substrate for visual hallucinations but with cognitive factors playing an as yet unspecified role.

Reality monitoring and visual hallucinations in Parkinson’s disease

Between 8 and 40% of Parkinson disease (PD) patients will have visual hallucinations (VHs) during the course of their illness. Although cognitive impairment has been identified as a risk factor for hallucinations, more specific neuropsychological deficits underlying such phenomena have not been established. Research in psychopathology has converged to suggest that hallucinations are associated with confusion between internal representations of events and real events (i.e. impaired-source monitoring). We evaluated three groups: 17 Parkinsons patients with visual hallucinations, 20 Parkinsons patients without hallucinations and 20 age-matched controls, using tests of visual imagery, visual perception and memory, including tests of source monitoring and recollective experience. The study revealed that Parkinsons patients with hallucinations appear to have intact visual imagery processes and spatial perception. However, there were impairments in object perception and recognition memory, and poor recollection of the encoding episode in comparison to both non-hallucinating Parkinsons patients and healthy controls. Errors were especially likely to occur when encoding and retrieval cues were in different modalities. The findings raise the possibility that visual hallucinations in Parkinsons patients could stem from a combination of faulty perceptual processing of environmental stimuli, and less detailed recollection of experience combined with intact image generation.

Executive functions are impaired in patients with Parkinson's disease with visual hallucinations

Objectives: Although cognitive impairment has been identified as a risk factor for visual hallucinations (VHs), more specific neuropsychological deficits underlying such phenomena have not been established. Here, we investigate the link between executive dysfunction and the occurrence of VHs. Methods: We evaluated three groups—17 patients with Parkinson’s disease (PD) with VHs, 20 patients with PD without VHs and 20 age-matched controls—on a battery of tests previously reported to evaluate executive functions, namely tests of inhibitory ability, short-term memory and working memory. Results: Differences were found on tests of inhibitory ability, for which the patient group with VHs showed impairment when compared with the non-hallucinating group. Conclusions: Patients with PD with VHs have substantially greater impairment of inhibitory ability than patients without VHs. These findings support interactive models of the genesis of visual hallucinations in PD.

Memory impairment in young women at increased risk of depression: influence of cortisol and 5-HTT genotype.

BACKGROUND Memory deficits are common in depressed patients and may persist after recovery. The aim of the present study was to determine whether memory impairments were present in young women at increased familial risk of depression and whether memory performance was related either to cortisol secretion or to allelic variation in the promoter region of the serotonin transporter gene (5-HTT). METHOD Young women (n=35, age range 16-21 years) with no personal history of depression but with a depressed parent (FH+) carried out the Rey Auditory Verbal Learning Test (RAVLT). They also provided samples for the measurement of waking salivary cortisol and for 5-HTT genotyping. An age-matched control group of women (n=31) with no family history of depression were similarly studied. RESULTS The FH+ participants had decreased immediate recall and recognition memory compared to controls. The impairment in recall, but not recognition, correlated negatively with increased cortisol secretion in FH+ subjects. There was no significant effect of 5-HTT allelic status on either memory or waking cortisol secretion. CONCLUSIONS Impairments in declarative memory are present in young women at increased genetic risk of depression and may be partly related to increased cortisol secretion. Further studies are needed to explore the neural mechanisms underlying the memory impairments and whether they predict the development of clinical illness.

Sleep Patterns in Parkinson's Disease Patients with Visual Hallucinations

ABSTRACT Visual hallucinations (VHs) in Parkinsons disease (PD) can be a frequent and disturbing complication of the disease with 33% of PD patients undergoing long-term treatment experiencing VHs during the course of their illness. One line of evidence that is emerging as a possible risk factor in the occurrence of VHs is the sleep–wake cycle and sleep behavior in patients with PD. This study compared sleep patterns in a group of visually hallucinating Parkinsons patients with a group of nonhallucinating PD patients and an age-matched control group. Nocturnal sleep was assessed by actigraphy and diaries, while daytime sleepiness and function were assessed by a battery of self-rating sleep questionnaires. Compared with the control group both patient groups had more sleep-related problems and significantly altered sleep patterns, as measured by both actigraphy and sleep questionnaires. Patients who hallucinated however slept less than nonhallucinating patients and also had increased awakenings after sleep onset, reduced sleep efficiency, and increased daytime sleepiness. We propose that VHs in some PD patients may be a symptom of poor sleep and prolonged daytime sleepiness, suggesting that arousal may play a role in the genesis of the hallucination phenomenon.

Altered early visual processing components in hallucination-prone individuals

Of the nonpathological general population, 0.5% experience one or more visual hallucinations on a regular basis without meeting the criteria for clinical psychosis. We investigated the relationship between a proneness to visual hallucinations in ‘normal’ individuals and early visual event-related potentials during the perception of faces, Mooney faces and scrambled Mooney faces. Findings indicated that individuals prone to visual hallucinations displayed significantly reduced early event-related potential components (P1, P2, but not N170) over parieto-temporal regions. These findings support previous suggestions that individuals who experience visual hallucinations exhibit abnormal early visual processing resulting from degraded visual input, in this case owing to disruption of low level visual processes.

‘The language is disgusting and they refer to my disability’: the cyberharassment of disabled people

Abstract Disabled people face hostility and harassment in their socio-cultural environment. The use of electronic communications creates an online context that further reshapes this discrimination. We explored the experiences of 19 disabled victims of cyberharassment. Five themes emerged from the study: disability and health consequences, family involvement, misrepresentation of self, perceived complexity, and lack of awareness and expertise. Cyberharassment incidents against disabled people were influenced by the pre-existing impairment, perceived hate-targeting, and perpetrators faking disability to get closer to victims online. Our findings highlight a growing issue requiring action and proper support.

Visual memory errors in Parkinson's disease patient with visual hallucinations

ABSTRACT The occurrences of visual hallucinations seem to be more prevalent in low light and hallucinators tend to be more prone to false positive type errors in memory tasks. Here we investigated whether the richness of stimuli does indeed affect recognition differently in hallucinating and nonhallucinating participants, and if so whether this difference extends to identifying spatial context. We compared 36 Parkinsons disease (PD) patients with visual hallucinations, 32 Parkinsons patients without hallucinations, and 36 age-matched controls, on a visual memory task where color and black and white pictures were presented at different locations. Participants had to recognize the pictures among distracters along with the location of the stimulus. Findings revealed clear differences in performance between the groups. Both PD groups had impaired recognition compared to the controls, but those with hallucinations were significantly more impaired on black and white than on color stimuli. In addition, the group with hallucinations was significantly impaired compared to the other two groups on spatial memory. We suggest that not only do PD patients have poorer recognition of pictorial stimuli than controls, those who present with visual hallucinations appear to be more heavily reliant on bottom up sensory input and impaired on spatial ability.

Cyberstalking: Investigating formal intervention and the role of Corporate Social Responsibility

Abstract Context Online harassment and stalking have been identified with growing accordance as anti-social behaviours, potentially with extreme consequences including indirect or direct physical injury, emotional distress and/or financial loss. Objective As part of our ongoing work to research and establish better understanding of cyberstalking, this study aims to investigate the role of Police, Mobile Operators, Internet Service Providers (ISPs) and owners/administrators of online platforms (e.g. websites, chatrooms) in terms of intervention in response to offences. We ask to what different authorities do people report incidents of cyberstalking? Do these authorities provide satisfactory responses or interventions? And how can this be improved? Furthermore, we discuss the role of Corporate Social Responsibility (CSR) to encourage the implementation of cyberstalking-aware schemes by service providers to support victims. In addition, CSR can be used as a means to measure the effects of externality factor in dictating the relationship between the impact of a given individuals’ privacy loss and strategic decisions on investment to security controls in an organisational context. Method A mixed method design has been used in this study. Data collection took place by means of an online survey made available for three years to record both qualitative and quantitative data. Overall, 305 participants responded from which 274 identified themselves as victims of online harassment. Result Our results suggest that most offences were communicated through private channels such as emails and/or mobile texts/calls. A significant number of victims did not report this to their service provider because they did not know they could. While Police were recognised as the first-point-of-contact in such cases, 41.6% of our sample did not contact the Police due to reasons such as fear of escalation, guilt/sympathy and self-blaming. Experiences from those who have reported offences to service providers demonstrate that no or very little support was offered. Overall, the majority of participants shared the view that third-party intervention is required on their behalf in order to mitigate risks associated with cyberstalking. An independent specialist anti-stalking organisation was a popular choice to act on their behalf followed by the Police and network providers. Conclusion Incidents are taking place on channels owned and controlled by large, cross-border international companies providing mobile services, webmail and social networking. The lack of support offered to victims in many cases of cyberstalking can be identified as Corporate Social Irresponsibility (CSI). We anticipate that awareness should be raised as regarding service providers’ liability and social responsibility towards adopting better strategies.

Behavioural coping patterns in Parkinson's patients with visual hallucinations

Visual Hallucinations are considered to affect about 20%-40% of patients with Parkinsons disease. They are generally seen as a side effect of this long-term illness and can severely affect the daily quality of life of patients. The aim of this study was to determine the coping patterns or strategies used by patients and establish whether the phenomenology and behaviours used by patients enabled control of the phenomenon. Demographic and clinical variables were recorded, including motor measures, cognitive status, and depressive symptoms. Patient with hallucinations were at a more advance stage of the disease and displayed more depressive symptoms than their non-hallucinating counterparts. Most patients used more than one constructive coping strategy, the most common were simple behavioural strategies based around motor action or cognitive approaches resulting in visual modification. In addition, humour was a common technique used by the patients to deal with the phenomenon. Emotional responses varied between patients, but it was found that the actual content of the hallucination was not directly associated with whether it caused trouble to the patient, but perceived stress was strongly correlated with the subjective disturbing nature of visual hallucinations (VHs). This study gives insight into the role of cognitive-behavioural approaches when dealing with VHs and opens up avenues for future studies in helping patient to deal with hallucinations.