A Bayesian predictive processing account of Othello syndrome in Parkinson's disease.

Introduction: Although delusions in Parkinson's disease (PD) are rare, when they occur they frequently take the form of "Othello syndrome": the irrational belief that a spouse or partner is being unfaithful. Hitherto dismissed as either a by-product of dopamine therapy or cognitive impairment, there are still no convincing theoretical accounts to explain why only some patients fall prey to this delusion, or why it persists despite clear disconfirmatory evidence.Methods: We discuss the limitations of existing explanations of this delusion, namely hyperdopaminergia-induced anomalous perceptual experiences and cognitive impairment, before describing how Bayesian predictive processing accounts can provide a more comprehensive explanation by foregrounding the importance of prior experience and its impact upon computation of probability. We illustrate this new conceptualisation with three case vignettes.Results: We suggest that in those with prior experience of romantic betrayal, hyperdominergic-induced aberrant prediction errors enable anomalous perceptual experiences to accrue greater prominence, which is then maintained through Bayes-optimal inferencing to confirm cognitive distortions, eliciting and shaping this dangerous delusion.Conclusions: We propose the first comprehensive mechanistic account of Othello syndrome in PD and discuss implications for clinical interventions.

Presence phenomena in parkinsonian disorders: Phenomenology and neuropsychological correlates.

INTRODUCTION: The feeling of a presence that occurs in the absence of objectively identifiable stimuli is common in parkinsonian disorders. Although previously considered benign and insignificant, recent evidence suggests that presence phenomena may act as the gateway to more severe hallucinations and dementia. Despite this, we still know relatively little about these phenomena. OBJECTIVE: To examine parkinsonian disorder patients' subjective experience of presence phenomena, and retrospectively analyse their cognitive correlates, in order to elucidate the emergence of information processing deficits in parkinsonian disorders. METHODS/DESIGN: 25 patients who endorsed presence phenomena were asked to complete a semi-structured interview about their experiences. The cognitive profiles of these patients were then compared to those of age- and education-matched patients who denied presence phenomena. RESULTS: Patients described the presence as mostly that of an unknown human with neutral valence. Patients who described it as unpleasant were noted to also demonstrate elevated anxiety. Patients who identified the presence as a known person, described it as touching them, or interacted with the presence emotionally or physically demonstrated reduced insight. Patients with presence phenomena demonstrated more frequent impairments in visual processing, executive function and speed of processing. CONCLUSIONS: Presence phenomena occur in the company of advancing cognitive impairment and involvement of the posterior cortical functions. Initially encountered as a neutral spatial skeleton, the experience is then shaped by the patient's affective state and level of insight.

Relationship of Cognitive Function to Motor Symptoms and Mood Disorders in Patients With Isolated Dystonia.

OBJECTIVE: To investigate the relationship of dystonia symptoms to cognitive function by comparing cognitive performance in patients with focal (cervical) and generalized dystonia subtypes and examining the differential contributions of severity of symptoms and mood disorders to cognition. BACKGROUND: Studies of the nonmotor syndrome in isolated dystonia have reported evidence of cognitive dysfunction, but the cause of this impairment remains unclear. Several studies have suggested that poor cognitive performance reflects the distracting effects of the motor symptoms and/or a mood disorder. METHODS: In this retrospective study, we used an extensive battery of cognitive and mood assessments to compare 25 patients with cervical dystonia, 13 patients with generalized dystonia, and 50 healthy controls. RESULTS: We found cognitive performance to be independent of all clinical and mood variables. We found no significant differences in cognition between the two dystonia groups. The combined dystonia groups had significant impairment on only one measure of cognitive function, the Trail Making Test. Two patients were also impaired on the Stroop test, and six on the Hayling Sentence Completion Test. CONCLUSIONS: The nonmotor features of dystonia include subtle cognitive symptoms and high rates of mood disorders, both of which occur independent of motor symptom severity and level of disability. Thus, we would argue that isolated dystonia is a tripartite disorder, with motor, affective, and subtle cognitive features.

No dual-task practice effect in Alzheimer's disease.

Diagnosis of Alzheimer's disease (AD) requires evidence of progressive decline in cognitive function. However, many tests used to assess cognitive function suffer from considerable practice effects, reducing their reliability. Several studies have reported that the ability to do two things at once, or dual tasking, is impaired in AD, but unaffected by healthy ageing. The apparent specificity of this impairment suggests that this assessment may be particularly useful in the early diagnosis of AD, but the reliability of this assessment remains unknown. Therefore, this study investigated simultaneous performance of digit recall and tracking tasks across six testing sessions in eight people with AD, eight healthy older adults and eight healthy younger adults. The results found that dual-task performance was unaffected by healthy ageing, but significantly impaired in AD, with no effect of repeated exposure. The absence of any improvements in performance despite increased familiarity with the task's demands suggests that not only is the dual-task assessment well suited for monitoring progression over time, but also that dual tasking involves a specific cognitive function which is impaired in the AD brain.

The influence of working memory and processing speed on other aspects of cognitive functioning in de novo Parkinson's disease: Initial findings from network modelling and graph theory.

Deficits in working memory (WM) and processing speed (PS) are thought to undermine other cognitive functions in de novo Parkinson's disease (dnPD). However, these interrelationships are only partially understood. This study investigated whether there are stronger relationships between verbal WM and verbal episodic memory encoding and retrieval, whether verbal WM and PS have a greater influence on other aspects of cognitive functioning, and whether the overall strength of interrelationships among several cognitive functions differs in dnPD compared to health. Data for 198 healthy controls (HCs) and 293 dnPD patients were analysed. Participants completed a neuropsychological battery probing verbal WM, PS, verbal episodic memory, semantic memory, language and visuospatial functioning. Deficit analysis, network modelling and graph theory were combined to compare the groups. Results suggested that verbal WM performance, while slightly impaired, was more strongly associated with measures of verbal episodic memory encoding and retrieval, as well as other measured cognitive functions in the dnPD network model compared to the HC network model. PS task performance was impaired and more strongly associated with other neuropsychological task scores in the dnPD model. Associations among task scores were stronger overall in the dnPD model. Together, these results provide further evidence that WM and PS are important influences on the other aspects of cognitive functioning measured in this study in dnPD. Moreover, they provide novel evidence that verbal WM and PS might bear greater influence on the other measured cognitive functions and that these functions are more strongly intertwined in dnPD compared to health.

Improving Conversations about Parkinson's Dementia.

BACKGROUND: People with Parkinson's disease (PD) have an increased risk of dementia, yet patients and clinicians frequently avoid talking about it due to associated stigma, and the perception that "nothing can be done about it". However, open conversations about PD dementia may allow people with the condition to access treatment and support, and may increase participation in research aimed at understanding PD dementia. OBJECTIVES: To co-produce information resources for patients and healthcare professionals to improve conversations about PD dementia. METHODS: We worked with people with PD, engagement experts, artists, and a PD charity to open up these conversations. 34 participants (16 PD; 6 PD dementia; 1 Parkinsonism, 11 caregivers) attended creative workshops to examine fears about PD dementia and develop information resources. 25 PD experts contributed to the resources. RESULTS: While most people with PD (70%) and caregivers (81%) shared worries about cognitive changes prior to the workshops, only 38% and 30%, respectively, had raised these concerns with a healthcare professional. 91% of people with PD and 73% of caregivers agreed that PD clinicians should ask about cognitive changes routinely through direct questions and perform cognitive tests at clinic appointments. We used insights from the creative workshops, and input from a network of PD experts to co-develop two open-access resources: one for people with PD and their families, and one for healthcare professionals. CONCLUSION: Using artistic and creative workshops, co-learning and striving for diverse voices, we co-produced relevant resources for a wider audience to improve conversations about PD dementia.

Apathy in Parkinson's Disease: A Retrospective Study of Its Prevalence and Relationship With Mood, Anxiety, and Cognitive Function.

Apathy is thought to be an important clinical feature of Parkinson's disease (PD). However, its prevalence ranges greatly across studies because of differing definitions, assessment tools, and patient inclusion criteria. Furthermore, it remains unclear how the presentation of apathy in PD is related to mood disorder and/or cognitive impairment. This study sought to examine the prevalence of a pure apathy syndrome in PD, distinct from both depression and anxiety, and reveal its associated cognitive profile. A retrospective study was performed on 177 PD patients who had completed measures of apathy [Apathy Evaluation Scale (AES)] and mood functioning [Hospital Anxiety and Depression Scale (HADS)] and had undergone extensive neuropsychological assessment, using measures of intellectual functioning, memory, executive function, attention, language, visual processing, and cognitive speed; 14.7% of the sample indicated clinically significant levels of apathy, but this nearly always co-presented with depression and/or anxiety, with cases of "pure" apathy very rare (2.8%). On extensive cognitive assessment, patients with mood disorder performed worse on a measure of non-verbal intellectual functioning, but patients with additional apathy or apathy only demonstrated no further losses. The syndrome of apathy in PD greatly overlaps with that of depression and anxiety, suggesting that apathy in PD may be in large an epiphenomenon of mood disorder, with no specific neuropsychological features.

Phonemic fluency quantity and quality: Comparing patients with PSP, Parkinson's disease and focal frontal and subcortical lesions.

Progressive supranuclear palsy (PSP) can be difficult to distinguish from Parkinson's disease (PD), but has a much graver prognosis. PSP is characterised severely reduced output on measures of phonemic fluency, suggesting that it may be a specific marker of PSP. However, reduced phonemic fluency has also been noted in PD, and very few studies have actually compared phonemic fluency in PSP and PD. Although anecdotal reports suggest that phonemic fluency output in PSP may have specific characteristics, with more low-frequency words and perseverative errors, no study to date has formally explored this. Further investigation into phonemic fluency output and its cognitive and neuroanatomical correlates is now critical for improving our understanding of the verbal fluency in PSP. In this study, we compared phonemic fluency characteristics (including quantity, frequency and error rates) in patients with PSP, PD and focal frontal or subcortical lesions, and age- and education-matched healthy controls. We then compared these characteristics with performance on extensive neuropsychological testing. We found that PSP patients generated significantly fewer words than patients with PD and patients with right frontal focal lesions, and healthy controls. Phonemic fluency was also significantly reduced in patients with left frontal and subcortical focal lesions. However, there were no significant group differences in word frequency or error rates. Phonemic fluency was best predicted by performance on the Vocabulary and Hayling neuropsychological tests. We argue that these findings provide important evidence that reduced phonemic fluency is a hallmark of PSP and argue that the specificity of this impairment betrays an underlying impairment in energization, reflecting dysfunction of left frontal and subcortical networks.

A case study investigating the role of the anterior temporal lobes in general semantics and semantics specific to persons, emotions and social conceptual knowledge.

The role of the anterior temporal lobes (ATLs) in semantic representation remains still much debated. Long thought to support domain-general semantic processing, recent accounts have alternatively suggested that they may be preferentially involved in the processing of person-related semantic knowledge. Several studies have supported such a distinction, but few have either examined both types of semantic processing together, or considered the role of potentially important confounding variables. Here, we address these issues by investigating both domain-general and person-specific semantic processing in a patient with focal ATL damage. The patient presents with dense anterograde and retrograde amnesia. Performance was impaired on tests of general semantic knowledge, but most striking deficits were for person-related semantics, including recognition and identification, knowledge of emotions and social conceptual knowledge. This unique case provides compelling evidence that, in addition to the role in general semantic knowledge, the ATLs are critical for person-related semantics.

Factors contributing to the distress, concerns, and needs of UK Neuroscience health care workers during the COVID-19 pandemic.

COVID-19 research from China suggests health care workers are at risk of distress, have specific concerns, and need support. It remains unknown whether findings are applicable to UK health care staff and whether psychological support based on generic approaches is effective. We administered an online survey at a leading neuroscience hospital in the UK to examine how individual staff characteristics contribute to distress, concerns, and interventions most valued during the COVID-19 pandemic. We found a high incidence of distress, particularly in females and staff with previous mental health history. Concerns fell into three factors: 'risk of infection', 'work challenges', and 'social change', and were affected by professional role and contact with COVID-19 patients. These three factors predicted distress. Psychological support and clear updates were deemed most useful, with specific needs affected by age, professional role, and contact with COVID-19 patients. This is the first documentation of a high incidence of psychological distress predicted by three types of concerns in health care workers of a neuroscience hospital. Distress, concerns, and interventions most valued were all affected by individual staff characteristics. These findings highlight the importance of providing stratified, one to one support interventions, tailored to professional group, and background, rather than more generic approaches. PRACTITIONER POINTS: The COVID-19 pandemic has resulted in a high incidence of psychological distress in UK health care staff. Distress, concerns, and interventions most valued are influenced by individual staff characteristics. Stratified, one-to-one support interventions, tailored to professional group, and background, rather than more generic approaches for stress reduction and resilience, are crucial.

Psychological interventions for people with Parkinson's disease in the early 2020s: Where do we stand?

PURPOSE: To explore the heterogeneity of the literature on psychological interventions for psychological difficulties in people with Parkinson's disease (PD). METHODS: A scoping review was performed across five major databases (MEDLINE Complete, PsycINFO, CINAHL, Academic Search Ultimate, and Cochrane Library) up to June 2020. RESULTS: From an initial return of 4911 citations, 56 studies were included, of which 21 were RCTs. A relatively wide range of therapeutic models have been adopted with people with PD, from common therapies such as cognitive behavioural therapy (CBT) and mindfulness, to less frequent approaches, for example, acceptance and commitment therapy (ACT) and psychodrama. The clinical implications of the findings are discussed, and suggestions are provided for future research on intervention studies and key psychological outcomes. CONCLUSIONS: CBT appears to be effective in treating depression and sleep disorders in people with PD, while psychoeducation programmes alone should be avoided. The use of CBT to improve anxiety, quality of life, and impulse control, as well mindfulness-based interventions, should be undertaken with some caution because of insufficient research and inconsistent results. As we enter the new decade, more high-quality evidence is required for psychological interventions in people with PD in general and to corroborate preliminary positive findings on the adoption of less frequent approaches such as ACT. PRACTITIONER POINTS: Parkinson's disease is a progressive neurodegenerative condition associated with several psychological difficulties which be targeted by psychological interventions. Currently, cognitive behavioural therapy (CBT) can be recommended to treat depression and sleep disorders in people with Parkinson's, while psychoeducation alone should be avoided. Caution is advised regarding the use of CBT and mindfulness-based interventions to improve anxiety, quality of life, and impulse control. Further evidence is required for less common approaches, such as acceptance and commitment therapy, psychodrama, and EMDR.

Dual task performance and post traumatic brain injury.

PRIMARY OBJECTIVE: To determine if people with traumatic brain injury (TBI) display deficits in dual tasking ability. RESEARCH DESIGN: Observational and correlational research design used, to identify and describe the nature of dual task impairment in people with TBI. METHODS AND PROCEDURES: Eighty-six people with TBI were assessed using a new standardized paper-and-pencil assessment of dual tasking ability and a number of other neuropsychological tests assessing attention, executive functioning and memory. MAIN OUTCOME AND RESULTS: Twenty-three out of the 86 people with TBI (26.74%) performed below the cut-off for normal performance, suggesting that only one quarter of the TBI sample assessed had deficits in attentional control. CONCLUSIONS: Deficits in task co-ordination are not a necessary consequence of TBI.

Comfort Always: The Importance of Providing Psychological Support to Neurology Staff, Patients, and Families During COVID-19.

BACKGROUND: Although the impact of COVID-19 disruption on healthcare staff is increasingly understood, there has been no discussion of how it affects neurological patients and their families. This study sought to understand the impact of COVID-19 on staff, patients and families. METHODS: The Department of Neuropsychology at the National Hospital for Neurology and Neurosurgery established three new support services for staff, patients and families. Semi-structured interviews elicited concerns and if these were affected by COVID-19. Staff members were asked to complete the General Health Questionnaire-12. RESULTS: Few staff members presented for support, but nearly all indicated significant distress, reflecting increased anxiety and reduced social support. Patients described exacerbated emotional, cognitive and physical concerns, and greater vulnerability to isolation and economic hardship. Families and carers reported increased distress arising from hospital lockdown. CONCLUSION: COVID-19 disruption affects staff, patients and families. Patients and families described additional challenges, which emphasize the importance of providing psychological support during these extraordinary times.

Impaired spatial processing in visual perception, imagery and art-making following parieto-occipital infarcts.

Visual imagery, like vision as such, is widely thought to be supported by two distinct and dissociable processing streams, dedicated to object representation and spatial analysis respectively. However, this simple dichotomy has been contested, with recent studies suggesting that impairments in perception-for-action and visuo-spatial imagery may reflect a more general deficit in space-based attention. Although previous studies have revealed the impact of brain damage on artistic expression, few have examined the impact on artistic expression in terms of the perceptual and spatial components of either visual processing or visual imagery. Here we present the case of an artist whose artistic expression was dramatically affected following devastating posterior brain damage. Of particular interest, we demonstrate how these changes relate to impairments in integrating and aligning different spatial features in both visual processing and visual imagery, suggestive of a general simultanagnosia not previously described.

Evaluation of START (STrAtegies for RelaTives) adapted for carers of people with Lewy body dementia.

Family carers of people with Lewy body dementia (LBD) have a particularly high burden of care, as LBD has a faster rate of decline, greater physical dependence and additional neuropsychiatric disturbances compared with other dementias. Despite this, there are no evidence-based support services designed specifically for LBD carers. STrAtegies for RelaTives (START) is an eight-session, individually delivered coping therapy that has been shown in a randomised controlled trial to reduce depression and anxiety symptoms and increase quality of life in carers of people with dementia, with effects lasting several years. We adapted START for LBD, and piloted its use both face-to-face and on the phone with 10 carers to test acceptability and indications of similar effects in this group. Our findings suggest that the therapy was acceptable and feasible using either delivery mode, providing much appreciated and needed strategies, education and support for carers of people with LBD. Trials of effectiveness are now needed.

Impairment in Theory of Mind in Parkinson's Disease Is Explained by Deficits in Inhibition.

OBJECTIVE: Several studies have reported that people with Parkinson's disease (PD) perform poorly on tests of 'Theory of Mind' (ToM), suggesting impairment in the ability to understand and infer other people's thoughts and feelings. However, few studies have sought to separate the processes involved in social reasoning from those involved in managing the inhibitory demands on these tests. In this study, we investigated the contribution of inhibition to ToM performance in PD. METHODS: 18 PD patients and 22 age-matched healthy controls performed a ToM test that separates the ability to infer someone else's perspective from the ability to inhibit one's own. Participants also completed a battery of standard measures of social and executive functioning, including measures of inhibition. RESULTS: The PD patients performed worse on the ToM test only when the inhibitory demands were high. When the level of inhibition required was reduced, there were no significant group differences. Furthermore, executive impairments in PD patients were limited to measures of inhibition, with disadvantages associated with poorer ToM performance in this group. CONCLUSIONS: This study provides convincing evidence that the apparent impairment observed on ToM tests in PD is explained by deficits in inhibition.

Standardised Neuropsychological Assessment for the Selection of Patients Undergoing DBS for Parkinson's Disease.

DBS is an increasingly offered advanced treatment for Parkinson's disease (PD). Neuropsychological assessment is considered to be an important part of the screening for selection of candidates for this treatment. However, no standardised screening procedure currently exists. In this study, we examined the use of our standardised neuropsychological assessment for the evaluation of surgical candidates and to identify risk factors for subsequent decline in cognition and mood. A total of 40 patients were assessed before and after DBS. Evaluation of mood and case notes review was also undertaken. Before DBS, patients with PD demonstrated frequent impairments in intellectual functioning, memory, attention, and executive function, as well as high rates of mood disorder. Post-DBS, there was a general decline in verbal fluency only, and in one patient, we documented an immediate and irreversible global cognitive decline, which was associated with older age and more encompassing cognitive deficits at baseline. Case note review revealed that a high proportion of patients developed mood disorder, which was associated with higher levels of depression at baseline and greater reduction in levodopa medication. We conclude that our neuropsychological assessment is suitable for the screening of candidates and can identify baseline risk factors, which requires careful consideration before and after surgery.

Sensitivity and Specificity of the ECAS in Parkinson's Disease and Progressive Supranuclear Palsy.

Disentangling Parkinson's disease (PD) and progressive supranuclear palsy (PSP) may be a diagnostic challenge. Cognitive signs may be useful, but existing screens are often insufficiently sensitive or unsuitable for assessing people with motor disorders. We investigated whether the newly developed ECAS, designed to be used with people with even severe motor disability, was sensitive to the cognitive impairment seen in PD and PSP and able to distinguish between these two disorders. Thirty patients with PD, 11 patients with PSP, and 40 healthy controls were assessed using the ECAS, as well as an extensive neuropsychological assessment. The ECAS detected cognitive impairment in 30% of the PD patients, all of whom fulfilled the diagnostic criteria for mild cognitive impairment. The ECAS was also able to detect cognitive impairment in PSP patients, with 81.8% of patients performing in the impaired range. The ECAS total score distinguished between the patients with PSP and healthy controls with high sensitivity (91.0) and specificity (86.8). Importantly, the ECAS was also able to distinguish between the two syndromes, with the measures of verbal fluency offering high sensitivity (82.0) and specificity (80.0). In sum, the ECAS is a quick, simple, and inexpensive test that can be used to support the differential diagnosis of PSP.