Visual hallucinations

Neurons in the inferotemporal (IT) cortex respond selectively to complex visual features, implying their role in object perception. However, perception is subjective and cannot be read out from neural responses; thus, bridging the causal gap between neural activity and perception demands independent characterization of perception. Historically, though, the complexity of the perceptual alterations induced by artificial stimulation of IT cortex has rendered them impossible to quantify. To address this old problem, we tasked male macaque monkeys to detect and report optical impulses delivered to their IT cortex...

This is a case report of one patient experiencing psychotic symptoms in the setting of Charles Bonnet syndrome (CBS). Case description is included, and patient has been deidentified. Patient's consent could not be obtained for the submission of the report. The case report focuses on understanding and formulating key psychological issues addressed in this case. It is important to identify that the absence of psychotic illness is classical in patients presenting with psychotic symptoms in CBS and the role of antipsychotic medication is uncertain...

Nick is a 5-year-old boy who began displaying self-stimulating behaviors and decreased social interactions shortly before turning 3 years. At the age of 3.5 years, he was diagnosed with autism spectrum disorder by a local developmental-behavioral pediatrician. His parents recall that the physician described Nick to be "high functioning" and encouraged them to expect that he would attend college and live independently as an adult. Upon receiving the diagnosis, intervention was initiated using an applied behavioral analysis (ABA) approach...

Parkinson's disease (PD) has been linked to a vast array of vitamins among which vitamin B12 (Vit B12) is the most relevant and often investigated specially in the context of intrajejunal levodopa infusion therapy. Vit B12 deficiency, itself, has been reported to cause acute parkinsonism. Nevertheless, concrete mechanisms through which B12 deficiency interacts with PD in terms of pathophysiology, clinical manifestation and progression remains unclear. Recent studies have suggested that Vit B12 deficiency along with the induced hyperhomocysteinemia are correlated with specific PD phenotypes characterized with early postural instability and falls and more rapid motor progression, cognitive impairment, visual hallucinations and autonomic dysfunction...

As global aging becomes more prominent, neurocognitive disorders (NCD) incidence has increased. Patients with NCD usually have an impairment in one or more cognitive domains, such as attention, planning, inhibition, learning, memory, language, visual perception, and spatial or social skills. Studies indicate that 50-80% of these adults will develop neuropsychiatric symptoms (NPS), such as apathy, depression, anxiety, disinhibition, delusions, hallucinations, and aberrant motor behavior. The progression of NCD and subsequent NPS requires tremendous care from trained medical professionals and family members...

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is an autoimmune disorder with diverse clinical manifestations including myelitis, meningitis, encephalitis, and optic neuritis. MOGAD rarely presents with unilateral cerebral cortical encephalitis (CCE), rendering the diagnosis difficult in these cases. Furthermore, MOGAD is frequently accompanied by other autoimmune diseases such as thyroid disease or inflammatory bowel disease. Herein, we report a case of unilateral CCE with positive anti-myelin oligodendrocyte glycoprotein (MOG) antibodies...

The relationship between sensory stimuli and perceptions is brain-state dependent: in wakefulness, suprathreshold stimuli evoke perceptions; under anesthesia, perceptions are abolished; and during dreaming and in dissociated states, percepts are internally generated. Here, we exploit this state dependence to identify brain activity associated with internally generated or stimulus-evoked perceptions. In awake mice, visual stimuli phase reset spontaneous cortical waves to elicit 3-6 Hz feedback traveling waves...

INTRODUCTION: Pareidolias, or visual misperceptions, are a non-motor symptom of Parkinson's disease (PD) with unclear pathophysiology. The noise pareidolia test (NPT) is a tool for screening pareidolias. The usefulness of the NPT in differentiating PD from atypical parkinsonian syndromes (APS) is also unknown. METHODS: We retrospectively investigated 74 patients with PD and 18 patients with APS who took the NPT. Correlations between the number of pareidolic responses, gray matter volume, and cerebral blood flow were also examined in the patients with PD...

BACKGROUND: Visual hallucinations (VH) are associated with visual prediction error in patients with dementia with Lewy bodies (DLB). Given this relationship, environmental adjustments have been suggested, but detailed contents for implementing such environmental adjustments and assessments are poorly documented. This case report preliminarily demonstrates methods for improving VH through our experience with two patients with DLB. We conducted familial interviews to assess the phenomenological features of VH and reviewed photographs of patients' homes to identify the environmental triggers of VH, known as photo assessment of the living environment (PA-LE)...

BACKGROUND: Charles Bonnet syndrome (CBS) is characterized by visual hallucinations occurring in people with visual impairment. CBS can negatively impact psychological well-being, and the COVID-19 pandemic period was associated with an exacerbation of symptoms. OBJECTIVES: To compare clinical practice patterns and reporting of CBS at a tertiary eye care center between an interval prior to the COVID-19 pandemic and an interval during the pandemic. DESIGN: Retrospective chart review...

First developed in the 1960s in Europe and approved briefly for use in the United States, fenethylline (sold as Captagon, one of its early trade names) is now a prominent drug of abuse in the Eastern Mediterranean Region. The drug was withdrawn from the United States market because of side effects that included hallucinations, visual distortions, and psychosis; it has also been linked to rare cases of myocardial infarction, seizures, and delusions. The chemical synthesis of fenethylline is straightforward and inexpensive...

Dementia is characterized by cognitive impairment and difficulties in executive functioning. It is an umbrella term for different subtypes that should be differentiated using a meticulous review of the patient's history, physical exam, and work-up. Posing difficulties in diagnosis, findings at times may be inconclusive. We report a case of a depressed patient on hemodialysis for end-stage renal disease (ESRD) who presents with an acute agitated episode following a visual hallucination that he has been experiencing intermittently for six months, along with a three- to four-year history of cognitive impairments...

INTRODUCTION: Although the reported frequency of diplopia is between 10 to 40% of patients with Parkinson's disease (PD) and other movement disorders, it remains one of the most undiagnosed non-motor symptoms. Furthermore, it has a major impact on the quality of life of these patients. The aim of this study is to systematically review the literature regarding the frequency, causes, and implications of diplopia in movement disorders. METHODOLOGY: An electronic search was conducted in March and June 2023 using the PubMed database in order to identify appropriate studies...

Illusory neuropsychiatric symptoms such as hallucinations or the feeling of a presence (FOP) can occur in diffuse brain lesion or dysfunction, in psychiatric diseases as well as in healthy individuals. Their occurrence due to focal brain lesions is rare, most probably due to underreporting, which limits progress in understanding their underlying mechanisms and anatomical determinants. In this single case study, an 86-year-old patient experienced, in the context of an acute right central opercular ischemic stroke, visual hallucinatory symptoms (including palinopsia), differently lateralized auditory hallucinations and FOP...

No abstract text is available yet for this article.

BACKGROUND: Depression is a prevalent mood disorder during the perioperative period, with both preoperative concurrent depression and new-onset postoperative depression impacting postoperative recovery. Recent studies have indicated that the dissociative anesthetic esketamine may alleviate perioperative depressive symptoms. OBJECTIVE: This meta-analysis aimed to assess the efficacy and safety of esketamine in treating perioperative depression. METHODS: We selected randomized controlled trials comparing esketamine to placebo in terms of postoperative depressive symptoms...

The Riddoch syndrome is thought to be caused by damage to the primary visual cortex (V1), usually following a vascular event. This study shows that damage to the anatomical input to V1, i.e., the optic radiations, can result in selective visual deficits that mimic the Riddoch syndrome. The results also highlight the differential susceptibility of the magnocellular and parvocellular visual systems to injury. Overall, this study offers new insights that will improve our understanding of the impact of brain injury and neurosurgery on the visual pathways...

Felt presence is a widely occurring experience, but remains under-recognised in clinical and research practice. To contribute to a wider recognition of the phenomenon, we aimed to assess the presentation of felt presence in a large population sample ( n = 10 447) and explore its relation to key risk factors for psychosis. In our sample 1.6% reported experiencing felt presence in the past month. Felt presence was associated with visual and tactile hallucinations and delusion-like thinking; it was also associated with past occurrence of adverse events, loneliness and poor sleep...

A 77-year-old male attended the stroke clinic as a delayed presentation of a stroke and was initially managed as an occipital stroke. He presented with a gradual decline in visual acuity with an initial suspicion of field deficit over a period of three to four months. He underwent extensive tests including imaging for a confirmatory diagnosis. He had a rapid deterioration of his vision, function, and cognition over a few weeks resulting eventually in death. The case highlights a rare variant of sporadic Creutzfeld-Jakob disease (sCJD), the Heidenhain Variant (HV-CJD)...

PURPOSE: Complex visual hallucinations are rarely seen in neurooncology. They are commonly observed alongside psychotic symptoms in schizophrenia or dementia, in Parkinson's or Lewy-body disease, after opioid medications or anesthesia, and, in particular, they appear with visual impairments. METHODS: Here we report two normal-sighted and mentally healthy patients with unusual visual hallucinations after the resection and irradiation of brain metastases, the main features of which were persistent colorful and meaningful images with hallucinatory perseveration...