Artificial Intelligence to Detect Papilledema from Ocular Fundus Photographs.

BACKGROUND: Nonophthalmologist physicians do not confidently perform direct ophthalmoscopy. The use of artificial intelligence to detect papilledema and other optic-disk abnormalities from fundus photographs has not been well studied. METHODS: We trained, validated, and externally tested a deep-learning system to classify optic disks as being normal or having papilledema or other abnormalities from 15,846 retrospectively collected ocular fundus photographs that had been obtained with pharmacologic pupillary dilation and various digital cameras in persons from multiple ethnic populations. Of these photographs, 14,341 from 19 sites in 11 countries were used for training and validation, and 1505 photographs from 5 other sites were used for external testing. Performance at classifying the optic-disk appearance was evaluated by calculating the area under the receiver-operating-characteristic curve (AUC), sensitivity, and specificity, as compared with a reference standard of clinical diagnoses by neuro-ophthalmologists. RESULTS: The training and validation data sets from 6779 patients included 14,341 photographs: 9156 of normal disks, 2148 of disks with papilledema, and 3037 of disks with other abnormalities. The percentage classified as being normal ranged across sites from 9.8 to 100%; the percentage classified as having papilledema ranged across sites from zero to 59.5%. In the validation set, the system discriminated disks with papilledema from normal disks and disks with nonpapilledema abnormalities with an AUC of 0.99 (95% confidence interval [CI], 0.98 to 0.99) and normal from abnormal disks with an AUC of 0.99 (95% CI, 0.99 to 0.99). In the external-testing data set of 1505 photographs, the system had an AUC for the detection of papilledema of 0.96 (95% CI, 0.95 to 0.97), a sensitivity of 96.4% (95% CI, 93.9 to 98.3), and a specificity of 84.7% (95% CI, 82.3 to 87.1). CONCLUSIONS: A deep-learning system using fundus photographs with pharmacologically dilated pupils differentiated among optic disks with papilledema, normal disks, and disks with nonpapilledema abnormalities. (Funded by the Singapore National Medical Research Council and the SingHealth Duke-NUS Ophthalmology and Visual Sciences Academic Clinical Program.).

[When to look for rare causes of cerebral small vessel disease?] / Quand rechercher des causes rares de maladie des petits vaisseaux cérébraux ?

The majority of small vessel diseases is related to vascular risk factors or sporadic amyloid angiopathy, but a minority is caused by genetic, immune, or infectious diseases. In this article, we propose a pragmatic approach for the diagnosis and treatment of rare causes of cerebral small vessel disease.

La majorité des maladies des petits vaisseaux est liée à des facteurs de risque vasculaire ou à l'angiopathie amyloïde sporadique, mais une minorité est causée par des maladies génétiques, immunologiques ou infectieuses. Dans cet article, nous proposons une approche diagnostique et une prise en charge pragmatiques des maladies rares des petits vaisseaux cérébraux.

[Cerebral amyloid angiopathy-related cognitive decline: small vessels, big problems]. / Déclin cognitif vasculaire et angiopathie amyloïde cérébrale : petits vaisseaux, gros problèmes.

Cerebral amyloid angiopathy (CAA) is a common and well-defined small vessel disease characterized by the deposition of amyloid ß in the vascular wall. CAA causes devastating outcomes related to intracerebral hemorrhage and cognitive decline in older adults. The shared pathogenic pathway between CAA and Alzheimer's disease, co-occuring frequently in the same subject, has important implications for cognitive outcomes and novel anti-amyloid-ß immunotherapies. In this review, we present the epidemiology, pathophysiology, current diagnostic criteria of CAA, and future developments in the field.

L'angiopathie amyloïde cérébrale (AAC) est une maladie fréquente des petits vaisseaux, caractérisée par un dépôt de ß-amyloïde dans la paroi vasculaire entraînant des hémorragies cérébrales et un déclin cognitif. L'AAC et la maladie d'Alzheimer présentent des caractéristiques physiopathologiques communes et peuvent se retrouver chez un même individu. Cela influence le tableau cognitif et sera à prendre en compte lors de l'utilisation prochaine des nouvelles immunothérapies anti-amyloïde. Dans cet article, nous passons en revue l'épidémiologie, la pathophysiologie, les présentations cliniques ainsi que les critères diagnostiques de l'AAC et discutons des futurs développements dans le domaine.

Chordoid Glioma Infiltrating Optic Structures.

Chordoid glioma of the third ventricle (CGTV) is a rare, slow-growing, World Health Organization Grade II glial tumor, with stereotyped localization in the anterior third ventricle. Despite being considered a noninvasive tumor, CGTV is usually associated with a poor clinical outcome due to its close proximity to important cerebral structures, such as the hypothalamus and visual pathways. Our patient with CGTV experienced visual involvement, but after subtotal surgical resection showed no evidence of progression at 5-year follow-up.

Increased functional connectivity between language and visually deprived areas in late and partial blindness.

In the congenitally blind, language processing involves visual areas. In the case of normal visual development however, it remains unclear whether later visual loss induces interactions between the language and visual areas. This study compared the resting-state functional connectivity (FC) of retinotopic and language areas in two unique groups of late visually deprived subjects: (1) blind individuals suffering from retinitis pigmentosa (RP), (2) RP subjects without a visual periphery but with preserved central "tunnel vision", both of whom were contrasted with sighted controls. The results showed increased FC between Broca's area and the visually deprived areas in the peripheral V1 for individuals with tunnel vision, and both the peripheral and central V1 for blind individuals. These findings suggest that FC can develop in the adult brain between the visual and language systems in the completely and partially blind. These changes start in the deprived areas and increase in size (involving both foveal and peripheral V1) and strength (from negative to positive FC) as the disease and sensory deprivation progress. These observations support the claim that functional connectivity between remote systems that perform completely different tasks can change in the adult brain in cases of total and even partial visual deprivation.

Color synesthesia. Insight into perception, emotion, and consciousness.

PURPOSE OF REVIEW: Synesthesia is an extraordinary perceptual phenomenon, in which individuals experience unusual percepts elicited by the activation of an unrelated sensory modality or by a cognitive process. Emotional reactions are commonly associated. The condition prompted philosophical debates on the nature of perception and impacted the course of art history. It recently generated a considerable interest among neuroscientists, but its clinical significance apparently remains underevaluated. This review focuses on the recent studies regarding variants of color synesthesia, the commonest form of the condition. RECENT FINDINGS: Synesthesia is commonly classified as developmental and acquired. Developmental forms predispose to changes in primary sensory processing and cognitive functions, usually with better performances in certain aspects and worse in others, and to heightened creativity. Acquired forms of synesthesia commonly arise from drug ingestion or neurological disorders, including thalamic lesions and sensory deprivation (e.g., blindness). Cerebral exploration using structural and functional imaging has demonstrated distinct patterns in cortical activation and brain connectivity for controls and synesthetes. Artworks of affected painters are most illustrative of the nature of synesthetic experiences. SUMMARY: Results of the recent investigations on synesthesia offered a remarkable insight into the mechanisms of perception, emotion and consciousness, and deserve attention both from neuroscientists and from clinicians.

ChatGPT in glioma adjuvant therapy decision making: ready to assume the role of a doctor in the tumour board?

OBJECTIVE: To evaluate ChatGPT's performance in brain glioma adjuvant therapy decision-making. METHODS: We randomly selected 10 patients with brain gliomas discussed at our institution's central nervous system tumour board (CNS TB). Patients' clinical status, surgical outcome, textual imaging information and immuno-pathology results were provided to ChatGPT V.3.5 and seven CNS tumour experts. The chatbot was asked to give the adjuvant treatment choice, and the regimen while considering the patient's functional status. The experts rated the artificial intelligence-based recommendations from 0 (complete disagreement) to 10 (complete agreement). An intraclass correlation coefficient agreement (ICC) was used to measure the inter-rater agreement. RESULTS: Eight patients (80%) met the criteria for glioblastoma and two (20%) were low-grade gliomas. The experts rated the quality of ChatGPT recommendations as poor for diagnosis (median 3, IQR 1-7.8, ICC 0.9, 95% CI 0.7 to 1.0), good for treatment recommendation (7, IQR 6-8, ICC 0.8, 95% CI 0.4 to 0.9), good for therapy regimen (7, IQR 4-8, ICC 0.8, 95% CI 0.5 to 0.9), moderate for functional status consideration (6, IQR 1-7, ICC 0.7, 95% CI 0.3 to 0.9) and moderate for overall agreement with the recommendations (5, IQR 3-7, ICC 0.7, 95% CI 0.3 to 0.9). No differences were observed between the glioblastomas and low-grade glioma ratings. CONCLUSIONS: ChatGPT performed poorly in classifying glioma types but was good for adjuvant treatment recommendations as evaluated by CNS TB experts. Even though the ChatGPT lacks the precision to replace expert opinion, it may serve as a promising supplemental tool within a human-in-the-loop approach.

Visual hallucinosis during hypoperfusion of the right occipito-temporal cortex.

OBJECTIVES: Positive visual phenomena, although reported in lesions of visual cortex, are often overlooked in patients with acute neurological conditions. Yet, their occurrence without structural abnormalities or other underlying neurological disorders represents a unique observation. This report aims to raise awareness of these phenomena, their implications for understanding visual consciousness and to propose a practical, structured algorithm for the clinical assessment of visual hallucinations related to neurological conditions. METHODS: We describe the clinical presentation and imaging findings in two patients with isolated visual hallucinosis secondary to transitory hypoperfusion. RESULTS: One patient presented with subocclusion of the right posterior cerebral artery and the other with multifocal arterial abnormalities suggestive of reversible cerebral vasoconstriction syndrome (RCVS). Both presented isolated visual hallucinations and hypoperfusion of the right mesial occipito-temporal cortex. Hallucinated images exhibited peculiarities of certain attributes that were recognized only through guided perceptual analysis performed during their occurrence. DISCUSSION: Dysfunctions in the visual and attentional networks due to the uneven impact of hypoperfusion on the regions of the mesial occipito-temporal cortex likely contributed to the occurrence of visual hallucinations. The initial impaired awareness of certain image attributes obscured an altered, non-realistic rendering of the hallucinated images. Enhancement of awareness through clinical guidance indicates improved attentional deployment, modulation of visual information processing and hallucination-background integration. These features of the hallucinatory phenomena highlight the critical role of semiological analysis during their occurrence and question the validity of post hoc inquiries.

Colon cancer and IgG4-related disease with orbital inflammation and bilateral optic perineuritis: A case report.

RATIONALE: Immunoglobulin G4-related disease (IgG4-RD) is an inflammatory condition of unknown cause. Cancer might be related to the development of certain IgG4-RD but to date, little literature documents it. PATIENT CONCERNS: A 78-year old man presented with unilateral proptosis responsive to steroids, initially attributed to nonspecific orbital inflammation. DIAGNOSIS: Right hemicolectomy was performed because of a suspicious lesion which turned out to be tubulovillous adenoma on histological analysis. Eight months after the surgery, a mass infiltrating the mesentery was found and biopsy revealed IgG4-RD. INTERVENTIONS: Both the orbital inflammation and abdominal mass infiltrating the mesentery were responsive to steroids and rituximab administered to treat IgG4-RD. OUTCOMES: In the course of IgG4-RD, the patient developed bilateral optic perineuritis, causing bilateral visual loss. Colon cancer with synchronous multiple liver metastases was found 1 year after rituximab treatment. LESSONS: This case raises the possibility of IgG4-RD being a paraneoplastic syndrome in some patients. Cancer screening should probably be performed in some elderly patients diagnosed with IgG4-RD.

Visual brain plasticity induced by central and peripheral visual field loss.

Disorders that specifically affect central and peripheral vision constitute invaluable models to study how the human brain adapts to visual deafferentation. We explored cortical changes after the loss of central or peripheral vision. Cortical thickness (CoTks) and resting-state cortical entropy (rs-CoEn), as a surrogate for neural and synaptic complexity, were extracted in 12 Stargardt macular dystrophy, 12 retinitis pigmentosa (tunnel vision stage), and 14 normally sighted subjects. When compared to controls, both groups with visual loss exhibited decreased CoTks in dorsal area V3d. Peripheral visual field loss also showed a specific CoTks decrease in early visual cortex and ventral area V4, while central visual field loss in dorsal area V3A. Only central visual field loss exhibited increased CoEn in LO-2 area and FG1. Current results revealed biomarkers of brain plasticity within the dorsal and the ventral visual streams following central and peripheral visual field defects.

Reorganization of early visual cortex functional connectivity following selective peripheral and central visual loss.

Behavioral alterations emerging after central or peripheral vision loss suggest that cerebral reorganization occurs for both the afferented and deafferented early visual cortex (EVC). We explored the functional reorganization of the central and peripheral EVC following visual field defects specifically affecting central or peripheral vision. Compared to normally sighted, afferented central and peripheral EVC enhance their functional connectivity with areas involved in visual processing, whereas deafferented central and peripheral EVC increase their functional connectivity with more remote regions. The connectivity pattern of afferented EVC suggests adaptive changes that might enhance the visual processing capacity whereas the connectivity pattern of deafferented EVC may reflect the involvement of these regions in high-order mechanisms. Characterizing and understanding the plastic changes induced by these visual defects is essential for any attempt to develop efficient rehabilitation strategies.

Importance of eye position on spatial localization in blind subjects wearing an Argus II retinal prosthesis.

PURPOSE: With a retinal prosthesis connected to a head-mounted camera (camera-connected prosthesis [CC-P]), subjects explore the visual environment through head-scanning movements. As eye and camera misalignment might alter the spatial localization of images generated by the device, we investigated if such misalignment occurs in blind subjects wearing a CC-P and whether it impacts spatial localization, even years after the implantation. METHODS: We studied three subjects blinded by retinitis pigmentosa, fitted with a CC-P (Argus II) 4 years earlier. Eye/head movements were video recorded as subjects tried to localize a visual target. Pointing coordinates were collected as subjects were requested to orient their gaze toward predetermined directions, and to point their finger to the corresponding perceived spot locations on a touch screen. Finally, subjects were asked to give a history of their everyday behavior while performing visually controlled grasping tasks. RESULTS: Misaligned head and gaze directions occurred in all subjects during free visual search. Pointing coordinates were collected in two subjects and showed that median pointing directions shifted toward gaze direction. Reportedly all subjects were unable to accurately determine their eye position, and they developed adapted strategies to perform visually directed movements. CONCLUSIONS: Eye position affected perceptual localization of images generated by the Argus II prosthesis, and consequently visuomotor coordination, even 4 years following implantation. Affected individuals developed strategies for visually guided movements to attenuate the impact of eye and head misalignment. Our observations provide indications for rehabilitation procedures and for the design of upcoming retinal prostheses. (ClinicalTrials.gov number, NCT00407602.).