Transcranial Direct Current Stimulation in the Treatment of Visual Hallucinations in Charles Bonnet Syndrome: A Randomized Placebo-Controlled Crossover Trial.

Objective: To investigate the potential therapeutic benefits and tolerability of inhibitory transcranial direct current stimulation (tDCS) on the remediation of visual hallucinations in Charles Bonnet syndrome (CBS).

Design: Randomized, double-masked, placebo-controlled crossover trial.

Participants: Sixteen individuals diagnosed with CBS secondary to visual impairment caused by eye disease experiencing recurrent visual hallucinations.

A century of prosopometamorphopsia studies.

Prosopometamorphopsia is an extremely rare disorder of visual perception characterised by facial distortions. We here review 81 cases (eight new ones and 73 cases published over the past century) to shed light on the perception of face gestalts. Our analysis indicates that the brain systems underlying the perception of face gestalts have genuine network properties, in the sense that they are widely disseminated and built such that spatially normal perception of faces can be maintained even when large parts of the network are compromised.

Resting-state EEG alpha/theta ratio related to neuropsychological test performance in Parkinson's Disease.

Objective: To determine possible associations of hemispheric-regional alpha/theta ratio (α/θ) with neuropsychological test performance in Parkinson's Disease (PD) non-demented patients.

Methods: 36 PD were matched to 36 Healthy Controls (HC). The α/θ in eight hemispheric regions was computed from the relative power spectral density of the resting-state quantitative electroencephalogram (qEEG).

Hallucinations and other psychotic experiences across diagnoses: A comparison of phenomenological features.

Although psychotic experiences are prevalent across many psychiatric, neurological, and medical disorders, investigation of these symptoms has largely been restricted to diagnostic categories. This study aims to examine phenomenological similarities and differences across a range of diagnoses. We assessed frequency, severity and phenomenology of psychotic experiences in 350 outpatients including; participants with schizophrenia spectrum disorders, hearing impairment, Parkinson's disease, Lewy Body Dementia, Alzheimer's disease, visual impairment, posttraumatic stress disorder, borderline personality disorder, and participants with recent major surgery.

Drug and Disease Effects in Parkinson's Psychosis: Revisiting the Role of Dopamine.

Background: Levodopa and dopamine agonists (dopamine replacement therapy [DRT]) are implicated in Parkinson's disease psychosis (PDP), but the relationship between DRT and neurotransmitter dysfunction inherent to PD remains unclear.

Objectives: To examine the relationship between baseline striatal dopamine transporter (DAT) binding in drug-naïve idiopathic PD, introduction of DRT, or dose change and incident early-onset PDP.

Methods: Baseline DAT binding was compared between patients with and without incident psychosis (defined here as hallucinations or delusions), controlling for age, sex, baseline cognition, and prospective DRT in the Parkinson's Progression Markers Initiative cohort.

The utility and application of electrophysiological methods in the study of visual hallucinations.

Visual hallucinations (VH) are a common symptom in multiple clinical and non-clinical populations. Although structural and functional neuroimaging has informed the understanding of VH, temporal resolution is limited. Electrophysiological techniques provide a complementary perspective on dynamic and temporal aspects of neural functioning, offering greater insight into the mechanisms underlying their formation.

Successful management of persistent distressing neuropsychiatric symptoms by clozapine in a patient suffering from dementia with Lewy bodies.

Dementia with Lewy bodies (DLB) is the second most common neurodegenerative dementia associated with poor prognosis and high carers' burden. Neuropsychiatric symptoms worsen this prognosis and are a high source of distress for service users and their carers. However, there is currently insufficient evidence to support the pharmacological and non-pharmacological management of these symptoms.

Psychosis in Parkinson's Disease.

Although illusions, hallucinations and delusions did not play a prominent role in James Parkinson's original clinical descriptions, the longitudinal view of disease progression he advocated has important lessons for the study of such symptoms today. A focus on longitudinal progression rather than individual symptoms led to the concept of PD psychosis-a spectrum of positive symptoms in Parkinson's disease. The publication of criteria for PD psychosis in 2007 helped unify the disparate set of symptoms, raising their profile and resulting in a rapid expansion of literature focussing on clinical aspects, mechanisms, and treatment.

Risk factors for early psychosis in PD: insights from the Parkinson's Progression Markers Initiative.

Background: Parkinson's Disease (PD) psychosis refers to the spectrum of illusions, formed hallucinations and delusions that occur in PD. Visual hallucinations and illusions are thought to be caused by specific cognitive and higher visual function deficits and patients who develop such symptoms early in the disease course have greater rates of cognitive decline and progression to dementia. To date, no studies have investigated whether such deficits are found prior to the onset of PD psychosis.

Cognitive decline in Parkinson disease.

Dementia is a frequent problem encountered in advanced stages of Parkinson disease (PD). In recent years, research has focused on the pre-dementia stages of cognitive impairment in PD, including mild cognitive impairment (MCI). Several longitudinal studies have shown that MCI is a harbinger of dementia in PD, although the course is variable, and stabilization of cognition - or even reversal to normal cognition - is not uncommon.

The psychosis spectrum in Parkinson disease.

In 2007, the clinical and research profile of illusions, hallucinations, delusions and related symptoms in Parkinson disease (PD) was raised with the publication of a consensus definition of PD psychosis. Symptoms that were previously deemed benign and clinically insignificant were incorporated into a continuum of severity, leading to the rapid expansion of literature focusing on clinical aspects, mechanisms and treatment. Here, we review this literature and the evolving view of PD psychosis.

Are stroke survivors with delirium at higher risk of post-stroke dementia? Current evidence and future directions.

Objectives: The idea that delirium is a risk factor for dementia, broadly defined, is derived from heterogeneous patient samples. We reviewed available evidence as to whether stroke survivors who developed delirium during the acute phase of treatment are at a higher prospective risk of incident post-stroke cognitive impairment or dementia.

Design: We searched 8721 records in the Cochrane database for reviews or protocols dealing with the study objective, Medline, EMBASE, PsycInfo and CINAHL for observational studies in the general adult population and PubMed for in-process articles.

Voxel-based magnetic resonance imaging investigation of poor and preserved clinical insight in people with schizophrenia.

Aim: To define regional grey-matter abnormalities in schizophrenia patients with poor insight (Insight(-)), relative to patients with preserved clinical insight (Insight(+)), and healthy controls.

Methods: Forty stable schizophrenia outpatients (20 Insight(-) and 20 Insight(+)) and 20 healthy controls underwent whole brain magnetic resonance imaging (MRI). Insight in all patients was assessed using the Birchwood Insight Scale (BIS; a self-report measure).

Is it me? Verbal self-monitoring neural network and clinical insight in schizophrenia.

Self-monitoring, defined as the ability to distinguish between self-generated stimuli from other-generated ones, is known to be impaired in schizophrenia. This impairment has been theorised as the basis for many of the core psychotic symptoms, in particular, poor clinical insight. This study aimed to investigate verbal self-monitoring related neural substrates of preserved and poor clinical insight in schizophrenia.

Common and distinct neural effects of risperidone and olanzapine during procedural learning in schizophrenia: a randomised longitudinal fMRI study.

Rationale: Most cognitive domains show only minimal improvement following typical or atypical antipsychotic treatments in schizophrenia, and some may even worsen. One domain that may worsen is procedural learning, an implicit memory function relying mainly on the integrity of the fronto-striatal system.

Objectives: We investigated whether switching to atypical antipsychotics would improve procedural learning and task-related neural activation in patients on typical antipsychotics.

On visual hallucinations and cortical networks: a trans-diagnostic review.

Our current clinical approach to visual hallucinations is largely derived from work carried out by Georges de Morsier in the 1930s. Now, almost a century after his influential papers, we have the research tools to further explore the ideas he put forward. In this review, we address de Morsier's proposal that visual hallucinations in all clinical conditions have a similar neurological mechanism by comparing structural imaging studies of susceptibility to visual hallucinations in Parkinson's disease, Alzheimer's disease, Dementia with Lewy bodies and schizophrenia.

From tones in tinnitus to sensed social interaction in schizophrenia: how understanding cortical organization can inform the study of hallucinations and psychosis.

The content, modality, and perceptual attributes of hallucinations and other psychotic symptoms may be related to neural representation at a single cell and population level in the cerebral cortex. A brief survey of some principles and examples of cortical representation and organization will be presented together with evidence for a correspondence between the neurobiology of brain areas activated at the time of a hallucination and the content of the corresponding hallucinatory and psychotic experiences. Contrasting the hallucinations of schizophrenia with other conditions, we highlight phenomenological aspects of hallucinations that are ignored in clinical practice but carry potentially important information about the brain regions and dysfunctions underlying them.

Visual hallucinations in the psychosis spectrum and comparative information from neurodegenerative disorders and eye disease.

Much of the research on visual hallucinations (VHs) has been conducted in the context of eye disease and neurodegenerative conditions, but little is known about these phenomena in psychiatric and nonclinical populations. The purpose of this article is to bring together current knowledge regarding VHs in the psychosis phenotype and contrast this data with the literature drawn from neurodegenerative disorders and eye disease. The evidence challenges the traditional views that VHs are atypical or uncommon in psychosis.

Negative outcome Charles Bonnet syndrome.

Background: Charles Bonnet Syndrome (CBS) is widely considered a transient condition without adverse consequence, questioning the need for treatment. Yet, while this view may be true of the majority of people with CBS, it is recognised that some have negative experiences and outcomes. Here, we attempt to better understand negative outcome CBS and the factors that influence it.

Preservation and compensation: the functional neuroanatomy of insight and working memory in schizophrenia.

Background: Poor insight in schizophrenia has been theorised to reflect a cognitive deficit that is secondary to brain abnormalities, localized in the brain regions that are implicated in higher order cognitive functions, including working memory (WM). This study investigated WM-related neural substrates of preserved and poor insight in schizophrenia.

Method: Forty stable schizophrenia outpatients, 20 with preserved and 20 with poor insight (usable data obtained from 18 preserved and 14 poor insight patients), and 20 healthy participants underwent functional magnetic resonance imaging (fMRI) during a parametric 'n-back' task.

Art and the brain: a view from dementia.

Objective: Art making encompasses a range of perceptual and cognitive functions involving widely distributed brain systems. The dementias impact on these systems in different ways, raising the possibility that each dementia has a unique artistic signature.

Design: Here we use a review of the visual art of 14 artists with dementia (five Alzheimer's disease, seven fronto-temporal dementia and two dementia with Lewy bodies) to further our understanding of the neurobiological constituents of art production and higher artistic function.

An asymmetry of translational biological motion perception in schizophrenia.

Background: Biological motion perception is served by a network of regions in the occipital, posterior temporal, and parietal lobe, overlapping areas of reduced cortical volume in schizophrenia. The atrophy in these regions is assumed to account for deficits in biological motion perception described in schizophrenia but it is unknown whether the asymmetry of atrophy found in previous studies has a perceptual correlate. Here we look for possible differences in sensitivity to leftward and rightward translation of point-light biological motion in data collected for a previous study and explore its underlying neurobiology using functional imaging.

The Dide-Botcazo syndrome: forgotten and misunderstood.

Bilateral infarcts of the posterior cerebral arteries are associated with a range of visual and memory deficits. In 1902, Dide and Botcazo presented a clinico-pathological case study linking visual field defects, topographical disorientation, retro-anterograde amnesia and alexia with bilateral medial occipito-temporal lesions. Based on the findings they suggested the occipital lobe and inferior longitudinal fasciculus played an important role in memory.

A novel method for reducing the effect of tonic muscle activity on the gamma band of the scalp EEG.

Neural oscillations in the gamma band are of increasing interest, but separating them from myogenic electrical activity has proved difficult. A novel algorithm has been developed to reduce the effect of tonic scalp and neck muscle activity on the gamma band of the EEG. This uses mathematical modelling to fit individual muscle spikes and then subtracts them from the data.