A spectrum of cognitive-behavioral-movement disorders in adrenoleukodystrophy: A case series from a tertiary care centre in the eastern part of India.

Background: Adrenoleukodystrophy (ALD) is an intriguing disease with a heterogeneous clinico-radiological profile. Behavioral and cognitive impairments are often the initial and predominant manifestations, yet their patterns are frequently overlooked. This study aims to elaborate on the patterns of cognitive dysfunction, behavioral changes, and movement disorders in ALD to facilitate its earlier diagnosis. Methods: In this case series, 12 cases of ALD were assessed and evaluated for cognitive, behavioral, and movement abnormalities to identify patterns of involvement. Results: All patients were male, with an age range of 5-46 years. 75% presented with cerebral ALD (CALD), and 25% had an adrenomyeloneuropathy phenotype. Cognitive dysfunction, behavioral changes, and seizures were observed in 75%, 66.7%, and 33.3% of ALD patients. An initial posterior to anterior pattern of progression of cognitive impairment dominated by higher-order visual dysfunction and language regression was observed in 66.7% of CALD patients, while a frontal pattern was noted in 22.2% of CALD patients. While cognitive impairment typically indicated dysfunction of occipito-parieto-temporal networks, behavioral changes predominantly suggested dysfunctional fronto-temporal-subcortical connections. A novel observation was the occurrence of tics and stereotypies in 33.3% of ALD patients. Conclusion: This study describes the patterns of cognitive, behavioral, and movement abnormalities in ALD and highlights the contributory role of dysfunctional white matter networks. Cognitive patterns predominantly reflect a posterior-to-anterior gradient of impairment of white matter connections, while behavioral markers indicate involvement of fronto-temporal-subcortical networks. Adding to this spectrum, the occurrence of tics and stereotypies is a unique observation in ALD.

Quality of life and functional vision in adolescents with surgically treated hydrocephalus in infancy.

AIM: To evaluate health- and vision-related quality of life (HR- and VR-QoL) and perceptual visual dysfunction (PVD) in adolescents with hydrocephalus surgically treated in infancy. METHODS: In total, 23 adolescents (15 males and 8 females; median age 14.9 years) with hydrocephalus and 31 controls were evaluated using validated instruments to measure HR-QoL and VR-QoL. PVDs were reported by history taking in five areas: recognition, orientation, depth, movement and simultaneous perception. RESULTS: Adolescents with hydrocephalus and the parent proxy reports showed lower mean total Paediatric Quality of Life Inventory 4.0 scores (75.8 and 63.7, respectively) compared with controls (87.6 and 91.5), p = 0.016 and p < 0.0001. Parent-reported scores were lower than self-reported scores (p = 0.001). Adolescents with myelomeningocele (n = 10) showed lower physical health scores (p = 0.001). No VR-QoL difference was found between groups. PVDs were reported in ≥1 area by 14/23 hydrocephalus participants and 2/31 controls (p < 0.0001). Associations were found in the hydrocephalus group between VR-QoL and HR-QoL (rs = 0.47, p = 0.026) and number of PVD areas (rs = -0.6, p = 0.003). CONCLUSION: Adolescents with hydrocephalus and their parents reported lower HR-QoL and more PVDs. These problems indicate the need for not only ophthalmological follow-ups but also evaluation of QoL and PVDs in individuals with infantile hydrocephalus.

Endoscopic Endonasal Approach for Optic Canal Dural Metastasis in a Patient with Progressive Visual Dysfunction: A Case Report.

To improve optic nerve function in a patient with progressive visual dysfunction, performing early decompressive and debulking surgery for a metastatic tumor located in the optic canal is essential. The endoscopic endonasal approach could be a practical and effective alternative for lesions in the inferomedial part of the optic canal. A 66-year-old man with a right visual eye field deficit had multiple lesions in the pineal gland, occipital lobe, and right inferomedial optic canal. The optic nerve was distorted by a tumor compressing against the falciform ligament. Although a systemic examination suggested the presence of primary lung cancer, the patient only complained of progressive visual impairment in the right eye. We planned surgery with endoscopic transethmoidal and transsphenoidal approaches to restore visual function and make a pathological diagnosis. During the procedure, we drilled the sella floor, tuberculum sellae, and optic canal and successfully removed the tumor underneath the dura mater. The patient's visual function improved rapidly following surgery, and no complications were observed, such as cerebrospinal fluid leakage. After confirming the pathological diagnosis, the patient subsequently received whole-brain radiotherapy. The endoscopic endonasal skull base approach to the optic canal region could be a practical alternative for treating symptomatic metastatic tumors.

Temporal trends in paediatric hydrocephalus - Rising prematurity and persistent ophthalmological challenges.

AIM: To study changes in aetiology, prematurity, comorbidity and ophthalmological outcomes in children with surgically treated hydrocephalus to provide information needed to maintain the best possible healthcare for a fragile and changing population. METHODS: Two population-based cohorts, born two decades apart in Region Västra Götaland Sweden, surgically treated for hydrocephalus at Sahlgrenska University Hospital in Gothenburg were recruited at approximately 10 years of age. The participants were examined according to an ophthalmological protocol, including history taking regarding perceptual visual dysfunction (PVD). Gestational age, aetiology and comorbidities were registered. RESULTS: The 1989-1993 group, comprised 52 children (48% girls; mean age 10, range 7.7-12.8 years), was compared with 24 children, born in 2007-2012 (29% girls; mean age 10, range 7.0-13.8 years). Extreme prematurity (gestational age ≤ 28 weeks) increased over time (p = 0.001). The vast majority of the children showed ophthalmological abnormalities, although motility defects and nystagmus decreased in the latter population. Subnormal visual acuity was associated with extreme prematurity (RR = 4.69; p = 0.030), and PVD with learning disability (RR = 2.44; p = 0.032). CONCLUSION: Paediatric hydrocephalus populations may change with improved healthcare. Since a high percentage shows ophthalmological abnormalities and more children are born extremely preterm, the entirety needs consideration both neurologically and ophthalmologically.

Prevalence of visual dysfunction and ocular motility disorders in developmentally delayed patients.

Objective: To evaluate the prevalence of reduced visual acuity (VA), refractive errors (RE), reduced contrast sensitivity and strabismus in developmentally delayed (DD) patients. Methods: This descriptive cross sectional study was carried out in Ophthalmology Departments of Mayo Hospital, Lahore, The Children's Hospital, Lahore and The Children's Hospital, Multan from June 2019 to December 2019. We recruited 257 patients of either gender, between the ages of 06-16 years having intelligence quotient (IQ) ≤ 80 by Wechsler Intelligence Scale for Children (WISC) from the out-patient departments. Detailed systemic and ophthalmic history was taken and through anterior and posterior segment examination was carried out. VA was assessed with age matched VA charts. Cycloplegic refraction with 1% cyclopentolate was carried out. Contrast sensitivity was measured with hiding Heidi charts. Strabismus was assessed with Hirschberg and covers /uncover tests. Results: The mean age of the patients was 8.88 years with standard deviation (SD) of ± 2.70. The prevalence of reduced VA, RE, strabismus and reduced contrast sensitivity in these children were 43.58%, 52.92%, 52.14% and 32.7% respectively. Out of these 52.92% RE, 56 (21.79%) were myopic, 66 (25.68%) were hyperopic and 14 (05.45%) were astigmatic. The percentage of esotropia was 72 (28.02%) and exotropia was 62 (24.12%). Conclusion: The results of our study in DD children have shown that a significant number of children have reduced VA, RE, strabismus and reduced contrast sensitivity. Apart from general management of DD children by a pediatrician, the ophthalmic management of these problems must be carried out by a pediatric ophthalmologist to improve their quality of life.

Current perspective: Cerebral visual impairment-The impending doom.

Cerebral visual impairment (CVI) has emerged as an important cause of morbidity in young children. CVI children often have a large number of visual symptoms along with motor abnormalities. It is the need of the hour to build an integrated approach towards their management. This article aimed to provide a comprehensive view of the manifestations, evaluation, and management of children with CVI.

Endoscopic Occipital Transtentorial Approach for Supracerebellar Lesions.

The occipital transtentorial approach (OTA), which is often applied for superior cerebellar lesions, has an inevitable risk of homonymous hemianopsia due to the retraction of the occipital lobe. The endoscopic approach provides increased visibility of the surgical field due to the wide-angled panoramic view and is minimally invasive in approaching deep brain lesions compared to the conventional microscopic approach. However, little is known regarding endoscopic OTA for the removal of cerebellar lesions. We experienced a case of a hemangioblastoma in the paramedian superior surface of the cerebellum that was successfully treated with endoscopic OTA combined with gravity retraction while avoiding postoperative visual dysfunction. A 48-year-old woman was diagnosed with a hemangioblastoma in the superior surface of the cerebellum. She underwent tumor removal with endoscopic OTA combined with gravity retraction of the occipital lobe instead of using brain retractors. The narrower space was sufficient for surgical manipulation with a panoramic view obtained by endoscopy. The simultaneous observation of the lesion with both an endoscope and a microscope revealed the superiority of infratentorial visualization with an endoscope. Gross total removal was achieved with no postoperative complications, including visual dysfunction. Endoscopic OTA may reduce the risk of postoperative visual dysfunction because of its minimally invasive nature, which is enhanced when combined with gravity retraction. Additionally, the panoramic view of the endoscope allows favorable visualization of an infratentorial lesion, which is otherwise hidden partly by the tentorium. The use of endoscopy is compatible with OTA, and endoscopic OTA could be an option for superior cerebellar lesions for avoiding visual dysfunction.

Predicting visual acuity with machine learning in treated ocular trauma patients.

AIM: To predict best-corrected visual acuity (BCVA) by machine learning in patients with ocular trauma who were treated for at least 6mo. METHODS: The internal dataset consisted of 850 patients with 1589 eyes and an average age of 44.29y. The initial visual acuity was 0.99 logMAR. The test dataset consisted of 60 patients with 100 eyes collected while the model was optimized. Four different machine-learning algorithms (Extreme Gradient Boosting, support vector regression, Bayesian ridge, and random forest regressor) were used to predict BCVA, and four algorithms (Extreme Gradient Boosting, support vector machine, logistic regression, and random forest classifier) were used to classify BCVA in patients with ocular trauma after treatment for 6mo or longer. Clinical features were obtained from outpatient records, and ocular parameters were extracted from optical coherence tomography images and fundus photographs. These features were put into different machine-learning models, and the obtained predicted values were compared with the actual BCVA values. The best-performing model and the best variable selected were further evaluated in the test dataset. RESULTS: There was a significant correlation between the predicted and actual values [all Pearson correlation coefficient (PCC)>0.6]. Considering only the data from the traumatic group (group A) into account, the lowest mean absolute error (MAE) and root mean square error (RMSE) were 0.30 and 0.40 logMAR, respectively. In the traumatic and healthy groups (group B), the lowest MAE and RMSE were 0.20 and 0.33 logMAR, respectively. The sensitivity was always higher than the specificity in group A, in contrast to the results in group B. The classification accuracy and precision were above 0.80 in both groups. The MAE, RMSE, and PCC of the test dataset were 0.20, 0.29, and 0.96, respectively. The sensitivity, precision, specificity, and accuracy of the test dataset were 0.83, 0.92, 0.95, and 0.90, respectively. CONCLUSION: Predicting BCVA using machine-learning models in patients with treated ocular trauma is accurate and helpful in the identification of visual dysfunction.

Inhibition of complement C3 signaling ameliorates locomotor and visual dysfunction in autoimmune inflammatory diseases.

Neuromyelitis optica (NMO) is an autoimmune inflammatory disease of the central nervous system (CNS) characterized by transverse myelitis and optic neuritis. The pathogenic serum IgG antibody against the aquaporin-4 (AQP4) on astrocytes triggers the activation of the complement cascade, causing astrocyte injury, followed by oligodendrocyte injury, demyelination, and neuronal loss. Complement C3 is positioned as a central player that relays upstream initiation signals to activate downstream effectors, potentially stimulating and amplifying host immune and inflammatory responses. However, whether targeting the inhibition of C3 signaling could ameliorate tissue injury, locomotor defects, and visual impairments in NMO remains to be investigated. In this study, using the targeted C3 inhibitor CR2-Crry led to a significant decrease in complement deposition and demyelination in both slice cultures and focal intracerebral injection models. Moreover, the treatment downregulated the expression of inflammatory cytokines and improved motor dysfunction in a systemic NMO mouse model. Similarly, employing serotype 2/9 adeno-associated virus (AAV2/9) to induce permanent expression of CR2-Crry resulted in a reduction in visual dysfunction by attenuating NMO-like lesions. Our findings reveal the therapeutic value of inhibiting the complement C3 signaling pathway in NMO.

Disrupted dynamic amplitude of low-frequency fluctuations in patients with active thyroid-associated ophthalmopathy.

Purpose: Thyroid-associated ophthalmopathy (TAO) is an autoimmune disease that affects the orbit and is the most prevalent extra-thyroidal complication of Graves' disease. Previous neuroimaging studies have focused on abnormal static regional activity and functional connectivity in patients with TAO. However, the characteristics of local brain activity over time are poorly understood. This study aimed to investigate alterations in the dynamic amplitude of low-frequency fluctuation (dALFF) in patients with active TAO and to distinguish patients with TAO from healthy controls (HCs) using a support vector machine (SVM) classifier. Methods: A total of 21 patients with TAO and 21 HCs underwent resting-state functional magnetic resonance imaging scans. dALFFs were calculated in conjunction with sliding window approaches to assess dynamic regional brain activity and to compare the groups. Then, we used SVM, a machine learning algorithm, to determine whether dALFF maps may be used as diagnostic indicators for TAO. Results: Compared with HCs, patients with active TAO showed decreased dALFF in the right calcarine, lingual gyrus, superior parietal lobule, and precuneus. The SVM model showed an accuracy of 45.24%-47.62% and area under the curve of 0.35-0.44 in distinguishing TAO from HCs. No correlation was found between clinical variables and regional dALFF. Conclusion: Patients with active TAO showed altered dALFF in the visual cortex and the ventral and dorsal visual pathways, providing further details on the pathogenesis of TAO.

Peripapillary ischemia as a potential screening biomarker for early detection of tick-borne infection.

OBJECTIVES: The objective of this study was to determine whether an observed peripapillary ischemia is a potential biomarker of tick-borne infection (TI). METHODS: An experimental design analyzing the optic nerve to demonstrate peripapillary ischemia and vessel density changes through ocular coherence tomography with angiography in subjects with TI. Glaucoma was ruled out and the study engaged subjects in the age range 8-40 years. All subjects in the experimental group experienced visual symptoms. Subjects in the control group were asymptomatic and not previously diagnosed with TI. The ocular coherence tomography with angiography scanned the vessel density of the pericapillary plexus surrounding the optic nerves; the images were rated by percentage of vessel density. A two-tail t-test analysis was used to analyze the results. RESULTS: The t-test for each measure comparing the difference-of-differences to a zero change at baseline returned statistically significant, demonstrating reduced vessel density for the subjects in the experimental group (P <0.0001; 95% confidence interval [32.37409-43.50091]). CONCLUSION: The appearance of peripapillary ischemia in persons below the age of 50 years represents a potential screening biomarker of TI. Primary care physicians, ophthalmologists, and optometrists who have patients presenting sudden onset of visual symptoms in addition to the appearance of peripapillary ischemia should be tested to rule out a TI.

[Features of visual, cognitive and neuroimaging changes in Parkinson's disease patients with freezing of gait]. / Osobennosti zritel'nykh, kognitivnykh i neirovizualizatsionnykh izmenenii pri narusheniyakh initsiatsii khod'by u patsientov s bolezn'yu Parkinsona.

OBJECTIVE: To determine visual and cognitive impairments in relation to MRI changes in patients with freezing of Gait (FOG) in Parkinson's disease (PD). MATERIAL AND METHODS: We examined 78 patients with PD without dementia, who were divided into groups according to the presence (FOG«+¼ group) or absence (FOG«-¼ group) of «freezing¼ episodes. RESULTS: A decrease in contrast sensitivity (CS) and retinal photosensitivity was determined in all subjects with PD, but in patients with FOG, the decrease in CS was more pronounced. There was a significant decrease in the volume of the cuneus, lingual gyrus, posterior cingulate gyrus, superior parietal lobe and middle frontal gyrus in the FOG«+¼ group. It was revealed that patients with FOG had cognitive impairments of both the frontal and posterior cortical subtypes, while in the FOG«-¼ group, only visuospatial deficit prevailed. A direct correlation was determined between the severity of FOG and part I of the UPDRS scale, between a decrease in CS and cortical areas related to the dorsal and ventral visual information processing systems. The presence of a negative relationship between the scores of the FOG-Q, Timed Up and Go test and the volume of cortical areas of the frontal lobe responsible for planning and programming of movements indicates their role in the development of FOG in PD. CONCLUSION: Thus, visual impairments associated with PD, along with a heterogeneous profile of cognitive impairment, make a significant contribution to the development of FOG.

The Correlation of PANSS Scores and P100 Latency in Patients with Schizophrenia and Migrene Hedache Using Visual Evoked Potentials (VEPS) According to Gender and Age.

Background: The VEPs provide an objective measure of brain function, analyzing integrity of visual processing. With patients affected with schizophrenia, the changes with the implementation of VEP are evident, such as symmetrical deceleration of the impulse and the continuance of latency, which points to a degenerative illness, suggesting the presence of optical neuritis or hemianopsia conjoined with mentioned intracranial illness. Objective: The aim of the study was to determine the correlation of positive and negative symptoms (PANSS scores) and P100 latency between patients with schizophrenia and patients with migraine headache according to gender and age. Visual evoked potentials (VEPs) were applied. Methods: The sample included 80 subjects: a) S group- 40 patients with schizophrenia (21 males; 19 females); b) H group-40 healthy subjects with migraine headache (10 males; 30 females). The study was conducted at the Department of Psychiatry and Neurology University Clinical Center Sarajevo. Results: Our research revealed positive correlation of the P100 latency and the PANSS score of negative symptoms, which means that the subjects of the observed group with a higher latency of the P100 wave of the entire visual field in both eyes have higher PANSS scores of negative symptoms. The correlation is significantly higher in female subjects (37% shared variance) than in male subjects (12% shared variance). All male subjects have a PANSS negative symptoms score of 17 or higher, while all female subjects have a PANSS negative symptoms score of less than 17 positive correlations were registered in P100 latency in left view field of both eyes and in P100 amplitude in the region of right eye (p=0.01) in comparation with left eye region (p=0.05) in patients with schizophrenia. Conclusion: Results imply that the cognitive impairment seen in schizophrenia is not just due to deficits in higher order aspects of cognition but also encompasses significant deficits in early sensory processing. Our study is useful to initiate new questions and recommendations for further studies, specifically on changes in the occipital lobe in the schizophrenic patient's brain.

Astrocyte derived TSP2 contributes to synaptic alteration and visual dysfunction in retinal ischemia/reperfusion injury.

BACKGROUND: Despite current intervention measures/therapies are able to ameliorate neuronal death following retinal injuries/diseases, the recovery of visual function remains unsatisfactory. Previous studies revealed that the retinal synapse and neurite changed during the early stage after retinopathy, which was considered to be detrimental to visual signal transmission. However, the specific profiles and the mechanisms underlying retinal neurite and synaptic alteration after retinal pathologies remain poorly understood. METHODS: Here, we revealed the spatiotemporal pattern of neurite and synaptic alteration following retinal pathologies using a rat model of acute RI/R induced by high intraocular pressure (HIOP) with Western blotting, Immunofluorescence, and electron microscopy. We further explored the potential role of activated astrocytes and their derived thrombospondin 2 (TSP2) in RI/R induced retinal neurite and synaptic alteration and visual dysfunction through viral transduction and drug injection. RESULTS: We found a defasciculation of RGC axons, a compensatory increase of presynaptic proteins (synaptophysin and synapsin 1) and synaptic vesicles between bipolar cells and ganglion cells in the inner plexiform layer (IPL), and the degenerated visual function preceded the neuronal death in rat retinae. These events were accompanied by the activation of astrocytes. Furthermore, we showed that suppressing the activation of astrocytes (intravitreal injection of fluorocitric acid, FC), TSP2 knockdown (TSP2 shRNA-AAV transduction), and competitively inhibiting the binding of TSP2 and α2δ1 (intraperitoneal injection of gabapentin, GBP) effectively alleviated the retinal synaptic and neurite alteration and the visual dysfunction following RI/R injury. CONCLUSIONS: (1) At the early stage following RI/R injury, the rat retinae develop a degeneration of ganglion cell axons and the resulting compensatory synaptic remodeling between bipolar cells and ganglion cells in IPL. These changes occur earlier than the massive loss of neurons in the ganglion cell layer (GCL). (2) Activated astrocytes may secret TSP2, which bind to α2δ1, to mediate the degeneration of rat retinal ganglion cell axons, compensatory synaptic remodeling in IPL, and visual dysfunction following RI/R injury.

Ambient particulate matter exposure causes visual dysfunction and retinal neuronal degeneration.

PM2.5 pollution is related to neurotoxic and vascular effects in eye diseases such as glaucoma. This study investigates the adverse effects of PM2.5 exposure on visual function and retinal neurons. A versatile aerosol concentration enrichment system was used to expose mice to either control air or PM2.5 polluted air. Six months after PM2.5 exposure, visual function was measured by electroretinography (ERG). Hematoxylin and eosin staining and immunofluorescence staining were used for histopathological analysis. Protein markers of apoptosis, astrocytic reactivity, inflammatory cytokines, lipid peroxidation, protein nitration and DNA damage response were quantified with ELISA, western blot or detected using immunofluorescence and immunohistochemistry. After six months of exposure, PM2.5-exposed mice responded poorly to light stimuli compared with those exposed to the control air. PM2.5 exposure caused retinal thinning and reduction in the expression of retinal ganglion cell-selective marker RNA-binding protein with multiple splicing (RBPMS). Further, positive TUNEL staining was observed in the inner nucleus and outer nuclear layers of the retinae after exposure to PM2.5, which was accompanied by the activation of apoptosis signaling molecules p53, caspase-3 and Bax. PM2.5 induced the release of inflammatory cytokines including tumor necrosis factor-α and cleaved interleukin-1ß. Furthermore, increased levels of 8-OHdG and γ-H2AX in the mouse retinea were indicative of DNA single and double strand breaks by PM2.5 exposure, which activated PARP-1 mediated DNA damage and repair. In conclusion, this study demonstrates sub-chronic systemic exposure to concentrated PM2.5 causes visual dysfunction and retinal neuronal degeneration. DATA AVAILABILITY: The datasets during and/or analyzed during the current study available from the corresponding author on reasonable request.

Body Balance Analysis in the Visually Impaired Individuals Aged 18-24 Years.

BACKGROUND: Proper body balance is maintained by both sensory, i.e., vision, hearing, vestibular, and proprioception, and motor nervous systems. Visual control facilitates balance both in a static position, as well as during movement. Visual dysfunctions can adversely affect balance and stability control. METHODS: The study comprised a group of 30 individuals visually impaired from birth aged 18-24 years. The control group consisted of 50 persons in the same age range as the study group. The trial was performed as four separate tests: two on a stable surface platform, and two on an unstable surface platform. RESULTS: No statistically significant differences were found in the posturography test on the stable platform between the study groups. When tested on an unstable ground surface, the visually impaired subjects obtained showed worse performance than the sighted persons. Statistically significant differences were observed in the majority of the analyzed results. CONCLUSIONS: Visually impaired individuals present a poorer ability to maintain balance under dynamic conditions. Tests conducted on the unstable surface platform seem to be more relevant and applicable in the diagnosis of the subjects with visual impairment, as they differentiate the subjects to a greater extent.

Ophthalmologic problems correlates with cognitive impairment in patients with Parkinson's disease.

Objective: Visual impairment is a common non-motor symptom (NMS) in patients with Parkinson's disease (PD) and its implications for cognitive impairment remain controversial. We wished to survey the prevalence of visual impairment in Chinese Parkinson's patients based on the Visual Impairment in Parkinson's Disease Questionnaire (VIPD-Q), identify the pathogens that lead to visual impairment, and develop a predictive model for cognitive impairment risk in Parkinson's based on ophthalmic parameters. Methods: A total of 205 patients with Parkinson's disease and 200 age-matched controls completed the VIPD-Q and underwent neuro-ophthalmologic examinations, including ocular fundus photography and optical coherence tomography. We conducted nomogram analysis and the predictive model was summarized using the multivariate logistic and LASSO regression and verified via bootstrap validation. Results: One or more ophthalmologic symptoms were present in 57% of patients with Parkinson's disease, compared with 14% of the controls (χ2-test; p < 0.001). The visual impairment questionnaire showed good sensitivity and specificity (area under the curve [AUC] = 0.918, p < 0.001) and a strong correlation with MoCA scores (Pearson r = -0.4652, p < 0.001). Comparing visual impairment scores between pre- and post-deep brain stimulation groups showed that DBS improved visual function (U-test, p < 0.001). The thickness of the retinal nerve fiber layer and vessel percentage area predicted cognitive impairment in PD. Interpretation: The study findings provide novel mechanistic insights into visual impairment and cognitive decline in Parkinson's disease. The results inform an effective tool for predicting cognitive deterioration in Parkinson's based on ophthalmic parameters.

Can pattern electroretinography be a relevant diagnostic aid in amblyopia? - A systematic review.

INTRODUCTION: Pattern Electroretinography (PERG) is a highly sensitive electrophysiological technique used as an indicator of changes in retinal macular area. Amblyopia seems to result from a cortical visual imbalance but changes at the retinal level may also be present. The purpose of this systematic review was to evaluate if there are any consistent changes described in the scientific literature in PERG responses of amblyopic eyes. MATERIALS AND METHODS: Searches were conducted in PubMed and Embase databases, using the keywords "Electroretinography" and "Amblyopia", combined with MeSH or Emtree terms "Pattern Electroretinography", "amblyopia", "PERG" and "amblyopia". PERG P50-N95 amplitude and P50 latency were analysed as well as the methodology used. RESULTS: A total of 234 articles were found and 6 articles were included for review. One of the articles reported results in adults and five of them in children. One of the articles in children reported no changes in either P50-N95 amplitude or P50 latency. All articles that described differences between the amblyopic eye and the normal eye found a decrease in P50-N95 amplitude and/or a delay in P50 latency. CONCLUSIONS: This review shows promising findings for the use of PERG in amblyopia as an aid in the diagnostic protocol, since this technique may be able to detect an apparent functional impairment of the amblyopic eye.

Electroencephalographic-Based Functional Connectivity Networks of Visual Hallucinations and Visuospatial Dysfunctions in Parkinson's Disease.

Visual dysfunction is an important nonmotor symptom of Parkinson's disease (PD). Visual hallucinations (VHs) and visuospatial dysfunctions (VSDs) are common visual dysfunctions in PD; however, the underlying mechanisms remain unclear. Our study aimed to evaluate neuronal synchronization between patients with PD with and without VH or VSD using electroencephalographic (EEG) coherence analysis. Twenty-four patients with sporadic PD were evaluated for the presence of VH and VSD, and were divided into VH-negative and VH-positive groups, and these groups were further subdivided by VSD status. Coherence analysis was performed on EEG data. Whole-brain and regional coherences were calculated and compared between the groups. There was a significant difference in frontal-frontal coherence between the VH+ VSD- and VH+ VSD+ groups (p = 0.026). Our findings suggest that reduced EEG coherence in frontal regions might be involved in VSD in patients with PD. Reduced neuronal synchronization between the frontal lobes may contribute to the disruption of visual processing in PD.

The clinical approach to the identification of higher-order visual dysfunction in neurodegenerative disease.

PURPOSE OF REVIEW: This review is intended to assist the reader in gaining the knowledge and skills necessary for the recognition and assessment of higher-order visual dysfunction due to neurodegenerative diseases including Alzheimer's disease, dementia with Lewy bodies, Parkinson's dementia, corticobasal degeneration, Creutzfeldt-Jakob disease, and the posterior cortical atrophy syndrome. Clinical problem-solving and pattern recognition must be developed and practiced to accurately diagnosis disturbances of higher-order visual function, and knowledge of higher-order visual brain regions and their visual syndromes forms the foundation for deciphering symptoms presented by patients and/or their care partners. Tests of higher-order visual dysfunction must be assembled by the clinician and assessment can take time and effort. The use of screening tests, follow-up visits, and formal neuropsychological referrals are critical components for accurate diagnosis and these principles are reviewed here. RECENT FINDINGS: A recent survey of neuro-ophthalmologists revealed that over half of the respondents report that 5-10% of their new patient referrals carry a diagnosis of neurodegenerative disease and many patients were referred for visual symptoms of unknown cause. Despite over a century of discovery related to higher-order visual functions of the human brain, translation of discovery to the clinical assessment of patients has been slow or absent. As with the approach to translational medicine in general, to see meaningful progress, an interdisciplinary approach is indispensable. The first step involves the application of discoveries from the field visual neuroscience by clinicians from the fields of ophthalmology, neurology, and neuropsychology, and from the disciplines of neuro-ophthalmology and behavioral neurology. The unmet need for recognition, assessment, and management of higher-order visual dysfunction in neurodegeneration is evident and clinicians can contribute to closing the gap by using the approach and the tools outlined in the review.