Left Occipital Lobe Research Articles

Anatomical features of the brain of patients with stroke (cerebrovascular accident) relative to types, sites, and shapes using computed tomography scan

Objectives: Stroke is becoming a very common disease, giving rise to an increased morbidity and mortality globally; yet, its diagnosis is shrouded in the phrase “cerebrovascular accident.” The objectives of the study were to evaluate the various types, sites, and shapes of stroke presentation using computed tomography (CT) scan. Material and Methods: A total of 500 subjects indicative of stroke referred for cranial CT scans were recruited at the Jos University Teaching Hospital, Jos and the Asi-Ukpo Hospital, Calabar. With ethical approval, a proportionate random probability sampling method was used to obtain archived cranial CT images of the different types, sites, and shapes of the lesions, viewed directly from the CT scanners. Data obtained were analyzed using Statistical Package for the Social Science and results expressed as percentages and frequencies at P < 0.05. Results: The highest occurring type of stroke was ischemic (63.2%). Others were hemorrhagic (22.8%), cerebral atrophy (4.2%), cerebral infarct with atrophy (1.6%), intracerebral (0.8%), subarachnoid (1.4%), and subdural hemorrhage (0.8%). The left parietal lobe (24.8%) was the most common site of stroke occurrence while the left occipital, left temperoccipital, and left temperoparietal lobes had 7.6%, 7.4%, and 5.6%, respectively. Furthermore, 30.8% of cases presented as either oval hyperdense or hypodense lesions. Irregular lesions were 21.8% of cases while triangular, circular, and rectangular lesions occurred in 11.6%, 8.4%, and 6.4% of cases, respectively. Meanwhile, 8.0% of cases had normal CT brain scan that presented as stroke mimics on pattern recognition. Conclusion: The study revealed a distorted gross anatomy of the brain with preponderance of left-sided intracerebral ischemic stroke mostly in the left parietal lobe that presented as oval hyperdense and hypodense lesions in the sampled Nigerian population.

BRAF mutation in overlapping form of Erdheim-Chester and Rosai Dorfman diseases: a unique case restricted to the central nervous system

A 48-year-old man with a history of pleural tuberculosis presented in 2019 with paraesthesia of the left hemiface. The clinical examination was consistent with a fifth cranial nerve involvement. A brain MRI revealed three hyper-FLAIR and contrast enhanced lesions in the left cerebellar peduncle (Fig. 1), the left temporal lobe and the left occipital lobe. Perfusion images showed no hyperperfusion, and spectroscopy revealed a tumour profile, with a pick of choline and low NAA. A whole-body CT scan, PET CT scan, spinal MRI, CSF analysis and blood tests were normal, leading to the conclusion of an isolated brain disease. Therefore, a biopsy of the left temporal lesion was performed to differentiate the three main diagnostic hypotheses: infectious (tuberculosis); inflammatory (neurosarcoidosis, neuro-Behcet); tumoral (primary CNS lymphoma) disease.

The Infratentorial Localization of Brain Metastases May Correlate with Specific Clinical Characteristics and Portend Worse Outcomes Based on Voxel-Wise Mapping.

Simple SummaryBrain metastases (BMs) are cancerous lesions that originated from cancers outside the brain. Specific types of BMs are found distributing in specific brain areas. The infratentorial regions are frequently affected, causing severe neurological symptoms. Thus, it is necessary to investigate what types of tumors tend to form infratentorial BMs and whether these lesions are more fatal. By analyzing substantial brain imaging data of BMs, we found the vulnerability of infratentorial regions to most types of BMs, and found the infratentorial localization of BMs was significantly associated with young age, male sex, lung neuroendocrine and squamous cell carcinomas, more active cell division of the tumors, and patients with poorer outcomes. Additionally, infratentorial involvement might predict worse outcomes for patients who received surgery. Our findings underlined the distinctive role of infratentorial localization of BMs and its potential relationship with specific clinical characteristics, which may assist diagnosis, treatment choice, and prognostic prediction of BMs.The infratentorial regions are vulnerable to develop brain metastases (BMs). However, the associations between the infratentorial localization of BMs and clinical characteristics remained unclear. We retrospectively studied 1102 patients with 4365 BM lesions. Voxel-wise mapping of MRI was applied to construct the tumor frequency heatmaps after normalization and segmentation. The analysis of differential involvement (ADIFFI) was further used to obtain statistically significant clusters. Kaplan-Meier method and Cox regression were used to analyze the prognosis. The parietal, insular and left occipital lobes, and cerebellum were vulnerable to BMs with high relative metastatic risks. Infratentorial areas were site-specifically affected by the lung, breast, and colorectal cancer BMs, but inversely avoided by melanoma BMs. Significant infratentorial clusters were associated with young age, male sex, lung neuroendocrine and squamous cell carcinomas, high expression of Ki-67 of primaries and BMs, and patients with poorer prognosis. Inferior OS was observed in patients with ≥3 BMs and those who received whole-brain radiotherapy alone. Infratentorial involvement of BMs was an independent risk factor of poor prognosis for patients who received surgery (p = 0.023, hazard ratio = 1.473, 95% confidence interval = 1.055–2.058). The current study may add valuable clinical recognition of BMs and provide references for BMs diagnosis, treatment evaluation, and prognostic prediction.

Changes of Brain Structure in Patients With Metastatic Non-Small Cell Lung Cancer After Long-Term Target Therapy With EGFR-TKI.

PurposeEpidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) therapy is the routine treatment for patients with metastatic non-small cell lung cancer (NSCLC) harboring positive EGFR mutations. Patients who undergo such treatment have reported cognitive decline during follow-up. This study, therefore, aimed to evaluate brain structural changes in patients receiving EGFR-TKI to increase understanding of this potential symptom.MethodThe medical records of 75 patients with metastatic NSCLC (without brain metastasis or other co-morbidities) who received EGFR-TKI therapy from 2010 to 2017 were reviewed. The modified Scheltens Visual Scale and voxel-based morphometry were used to evaluate changes in white matter lesions (WML) and gray matter volume (GMV), respectively.ResultsThe WML scores were higher at the 12-month [8.65 ± 3.86; 95% confidence interval (CI), 1.60–2.35; p < 0.001] and 24-month follow-ups (10.11 ± 3.85; 95% CI, 2.98–3.87; p < 0.001) compared to baseline (6.68 ± 3.64). At the 24-month follow-up, the visual scores were also significantly higher in younger patients (3.89 ± 2.04) than in older patients (3.00 ± 1.78; p = 0.047) and higher in female patients (3.80 ± 2.04) than in male patients (2.73 ± 1.56; p = 0.023). Additionally, significant GMV loss was observed in sub-regions of the right occipital lobe (76.71 voxels; 95% CI, 40.740–112.69 voxels), left occipital lobe (93.48 voxels; 95% CI, 37.48–149.47 voxels), and left basal ganglia (37.57 voxels; 95% CI, 21.58–53.57 voxels) (all p < 0.005; cluster-level false discovery rate < 0.05).ConclusionsAn increase in WMLs and loss of GMV were observed in patients with metastatic NSCLC undergoing long-term EGFR-TKI treatment. This might reflect an unknown side-effect of EGFR-TKI treatment. Further prospective studies are necessary to confirm our findings.

Occipital Lobe Abscess Causing Homonymous Hemianopsia After a Dental Procedure

Background: A homonymous hemianopsia visual field defect is defined as vision loss on the same side of the vertical midline in both eyes. Although the vast majority are caused by an ischemic stroke, other neurologic etiologies must be considered and ruled out. This case highlights the importance of a rapid and thorough investigation of a patient’s symptoms using both clinical examination and imaging to reduce the risk of permanent complications and potential fatality. Case Report: A 67-year-old Caucasian male presented to the eye clinic with sudden onset reduced peripheral vision to his right side in both eyes. Entering visual acuities were 20/40 OD and 20/60 OS. Humphrey visual field (HVF) testing confirmed a complete right homonymous hemianopsia. Magnetic resonance imaging (MRI) revealed a large, left occipital lobe intracranial mass. Neurosurgical intervention was necessary to confirm the diagnosis of a brain abscess, thought to be related to a prior dental procedure with tooth extraction. Conclusion: A brain abscess is a focal area of necrosis within the brain parenchyma that typically results from an infectious process. Though rare, the condition has potentially devastating neurologic complications which can be mitigated with early detection and treatment. In this case, the abscess caused a right homonymous hemianopsia field defect, which prompted his urgent request for an appointment with the eye clinic.

Effects of deafness and sign language experience on the human brain: voxel-based and surface-based morphometry

ABSTRACT We investigated how deafness and sign language experience affect the human brain by comparing neuroanatomical structures across congenitally deaf signers (n = 30), hearing native signers (n = 30), and hearing sign-naïve controls (n = 30). Both voxel-based and surface-based morphometry results revealed deafness-related structural changes in visual cortices (grey matter), right frontal lobe (gyrification), and left Heschl's gyrus (white matter). The comparisons also revealed changes associated with lifelong signing experience: expansions in the surface area within left anterior temporal and left occipital lobes, and a reduction in cortical thickness in the right occipital lobe for deaf and hearing signers. Structural changes within these brain regions may be related to adaptations in the neural networks involved in processing signed language (e.g. visual perception of face and body movements). Hearing native signers also had unique neuroanatomical changes (e.g. reduced gyrification in premotor areas), perhaps due to lifelong experience with both a spoken and a signed language.

HGG-24. HIGH-GRADE GLIOMA WITH A NOVEL FUSION GENE OF VCL-ALK

A previously healthy 2-year-old boy presented with status epilepticus following intermittent vomiting. Computed tomography scan showed a 7cm mass on the left occipital lobe with midline shift, inferior cerebellar herniation, and diffuse cerebral edema. The extensive dissemination to bilateral cerebral hemispheres, brain stem, and optic nerve was also observed. He underwent brain biopsy from the lesion on his left occipital lobe. The histopathological diagnosis determined the diffuse or epithelial proliferation of astrocytic tumor cells with high mitotic rate, positive for p53 and glial fibrillary acidic protein positive staining consistent with high-grade glioma. The progressive tumor led to communicating hydrocephalus, that was favorably controlled by cerebrospinal fluid shunting. The data from the FoundationOne CDx cancer genome profile disclosed a novel VCL- anaplastic lymphoma kinase (ALK) fusion in the tumor cells of the patient. ALK rearrangement was determined to be positive for the tumor cells assessed by fluorescence in situ hybridization. Only 4 pediatric cases of glioma with ALK-rearrangement have ever been reported. All of them received subtotal or gross total resections and then survived with or without chemotherapy. This is the first case of glioma harboring VCL as a novel partner of ALK fusion gene. After the favorable response to the first-line chemotherapy, subsequent irradiation therapy has now been scheduled. The molecular classification of high-grade glioma may help to expand the targeted therapy for unresectable advanced brain tumor.

QOL-53. GENOME ASSOCIATIONS WITH NEUROCOGNITIVE OUTCOMES, CEREBRAL MICROBLEEDS (CMBS), AND BRAIN VOLUME AND WHITE MATTER (WM) CHANGES IN PEDIATRIC BRAIN TUMOR SURVIVORS

OBJECTIVETo identify genetic predictors of neurocognition, CMBs, brain volume, and WM changes in pediatric brain tumor survivors.METHODSPatients were selected from an existing cohort (RadART) if they had: 1) at least one neurocognitive evaluation using computer-based CogState; 2) available DNA; 3) standard imaging. Candidate gene or genome-wide genotyping was performed on all patients. CMBs were identified using a semi-automated algorithm developed in MATLAB. Volume of T2/FLAIR WM signal abnormality was measured using a semi-automated method based on a convolutional neural network. Brain volume and cortical thickness were measured using FreeSurfer volumetric analysis. Logistic and linear regression were done to compare phenotypes with candidate genotypes. Genome-wide efficient mixed-model analysis was done to compare neurocognition and CMBs. Gene set analysis was done using https://fuma.ctglab.nl/.RESULTSAPOE4 was a candidate variant associated with non-lobar, larger volume CMBs (p<0.05). At the GWAS-level (n=225), specific genes trended with visual memory, psychomotor function, and CMB count (p<5x10-8). Using gene set analyses, there were gene set trends seen with CMB count and psychomotor function. Small sample size and low mutant allele frequency limited reliability of these findings. Preliminary volumetric analysis show reduced volume within the right parietal, medial occipital and inferior temporal lobes with increased cortical thickness in the left occipital and medial parietal lobe in patients carrying the ApoE4 allele. WM signal assessments are ongoing.CONCLUSIONGenetic markers may be associated with neurocognition, CMBs, brain volume and WM changes in pediatric brain tumor survivors; however, larger cohorts are needed to confirm specific gene relevance.

HGG-29. A CASE OF CIRCUMSCRIBED HIGH-GRADE ASTROCYTOMA WITH ATRX AND CDKN2A/B ALTERNATIONS WHO WAS INITIALLY DIAGNOSED AS GLIOBLASTOMA AND HAS 20 YEARS SURVIVAL

Pediatric high-grade gliomas are rare and often hard to classify, which grow locally and show longer survival than diffuse high-grade gliomas in adults. We report a case of circumscribed high-grade astrocytoma who was initially diagnosed as glioblastoma and has 20 years survival. A 7-year-old girl suffered from epileptic seizure due to a left occipital lobe tumor. The tumor was resected in another hospital and diagnosed as glioblastoma. The tumor disappeared after extended local irradiation and chemotherapy using nimustine hydrochloride (ACNU) and cisplatin (CDDP). Eighteen years after initial onset, first recurrence was confirmed as the intra-tumoral hemorrhage. The tumor was resected and diagnosed as anaplastic oligoastrocytoma. After 6 courses of temozolomide (TMZ), the tumor disappeared. Twenty years after initial onset, the second local recurrence was confirmed. Although gamma knife and TMZ was performed, the tumor did not disappear. The tumor was surgically resected. Histopathology showed localized growth with some infiltration and mitosis but lacked pseudopallisading and microvascular proliferation. The tumor was diagnosed as circumscribed high-grade astrocytoma. Immunostaining revealed ATRX nuclear loss and CDKN2A / B homozygous deletion. After 10 courses of TMZ, the third local recurrence was confirmed. The tumor was completely removed and has not occurred recurrence more than 3 months after the last operation. Circumscribed high-grade glioma is expected to survive longer than invasive glioma. Pediatric gliomas should differ from adult gliomas in the genes of tumorigenesis. Care should be taken for its diagnosis and treatments. We also need a new classification based on histology and gene profile. HGG-30, ANALYSIS OF PEDIATRIC GLIOMAS IN OUR INSTITUTE Kaoru Tamura, Mai Fujioka, Masae Kuroha, Motoki Inaji, Yoji Tanaka, Tadashi Nariai, and Taketoshi Maehara; Tokyo Medical and Dental University, Tokyo, Japan. PURPOSE: Recent advances in genetic interrogation of pediatric glioma increase the importance of molecular diagnosis using surgical specimen. However, surgical resection may be avoided to preserve quality of life, especially in brain stem glioma cases. We retrospectively examined diagnosis and treatment of pediatric gliomas in our hospital. METHODS: This study includes 14 consecutive glioma patients under the age of 18 who underwent initial treatment at our hospital from 2000 to 2019. Histopathological diagnosis, clinical course and molecular status such as IDH, H3F3A and BRAF were analyzed. RESULTS: 5 patients (1 pilocytic astrocytoma (PA), 3 diffuse astrocytomas, 1 oligodendroglioma were treated only by surgical resection (group A). 7 patients (1 PA, 1 anaplastic oligodendroglioma, 2 diffuse midline gliomas and 3 glioblastomas (GBM)) received radiation and/or chemotherapy after surgical resection (group B). 2 diffuse intrinsic pontine gliomas (DIPG) received radiation and chemotherapy without surgical resection (Group C). No IDH mutation was observed in all pathological specimen obtained cases. BRAF alteration was observed in all PA cases. 1 case of GBM had BRAF V600Emutation and the other had H3K27M mutation. During a median of 7.7 years of follow-up, group A patients have no recurrence. Group B includes various diagnosis and prognosis. 2 group C patients diagnosed DIPG by MRI showed different clinical courses. CONCLUSION: Pediatric gliomas include diverse biological subgroups and show broad range of clinical behavior. Since pediatric glioma has a low incidence and a wide variety of genetic mutations, multicenter study is important to improve the treatment of pediatric glioma.

Abstract 17204: Asymmetric Patterns of Cerebral Cortical Development in Fetuses With Complex Congenital Heart Disease

Introduction: Neurodevelopmental disabilities are common among infants with complex congenital heart disease (CHD). While hemispheric asymmetries in normal fetal brain size and shape have been reported, the effect of CHD on hemispheric development of the developing fetal brain remains unknown. Hypothesis: We hypothesized that emerging cerebral hemispheric asymmetries of the fetal CHD brain would differ compared to healthy controls using in vivo MRI tools. Methods: A total of 252 pregnant women were recruited (164 controls; 88 CHD fetuses), in which 328 fetal MRI scans were performed. Single shot fast spin echo T2-weighted images were acquired on a 1.5T GE MRI scanner. High-resolution 3D models of the fetal brain were reconstructed using slice-to-volume registration method for motion correction and Draw-EM algorithm for automatic segmentation. Volumetric analysis of brain tissues was conducted, and cortical folding measures of brain lobes were evaluated. Mixed effects regression was utilized to compare the brain features between right and left hemispheres for healthy controls and CHD fetuses. Results: The mean gestational age of all fetal MRI studies was 32.1±3.7 weeks (range: 24.0-39.4). For healthy fetuses, the volume of cortical gray matter was higher in the left hemisphere; however, this pattern was diminished in CHD fetuses. Gyrification indices were higher in the parietal and occipital lobes of the right hemisphere for controls, but not for CHD fetuses. Similarly, Gaussian curvature was higher in the right frontal lobe for controls only. Conversely, the surface area of the left occipital lobe was lower in CHD fetuses, but not in healthy fetuses. Conclusions: We report for the first time early disturbances in emerging hemispheric asymmetric patterns of the fetal brain in CHD compared to controls. The extent to which these lateralization differences reflect genetic, epigenetic and/or hemodynamic disturbances in CHD fetuses is under investigation.

Prenatal opioid exposure is associated with smaller brain volumes in multiple regions.

Background:The impact of prenatal opioid exposure on brain development remains poorly understood.Methods:We conducted a prospective study of term-born infants with and without prenatal opioid exposure. Structural brain MRI was performed between 40–48 weeks postmenstrual age. T2-weighted images were processed using the Developing Human Connectome Project structural pipeline. We compared 63 relative regional brain volumes between groups.Results:Twenty-nine infants with prenatal opioid exposure and 42 unexposed controls were included. The groups had similar demographics, except exposed infants had lower birth weights, more maternal smoking and maternal Hepatitis C, fewer mothers with a college degree, and were more likely non-Hispanic White. After controlling for sex, postmenstrual age at scan, birth weight, and maternal education, exposed infants had significantly smaller relative volumes of the deep gray matter, bilateral thalamic ventrolateral nuclei, bilateral insular white matter, bilateral subthalamic nuclei, brainstem, and cerebrospinal fluid. Exposed infants had larger relative volumes of the right cingulate gyrus white matter and left occipital lobe white matter.Conclusion:Infants with prenatal opioid exposure had smaller brain volumes in multiple regions compared to controls, with two regions larger in the opioid-exposed group. Further research should focus on the relative contributions of maternal opioids and other exposures.

NCOG-71. GENOME ASSOCIATIONS WITH NEUROCOGNITIVE OUTCOMES, CEREBRAL MICROBLEEDS (CMBS), AND BRAIN VOLUME AND WHITE MATTER (WM) CHANGES IN PEDIATRIC BRAIN TUMOR SURVIVORS

Abstract OBJECTIVE To identify genetic predictors of neurocognition, CMBs, brain volume, and WM changes in pediatric brain tumor survivors. METHODS Patients were selected from an existing cohort (RadART) if they had: 1) at least one neurocognitive evaluation using computer-based CogState; 2) available DNA; 3) standard imaging. Candidate gene or genome-wide genotyping was performed on all patients. CMBs were identified using a semi-automated algorithm developed in MATLAB. Volume of T2/FLAIR WM signal abnormality was measured using a semi-automated method based on a convolutional neural network. Brain volume and cortical thickness were measured using FreeSurfer volumetric analysis. Logistic and linear regression were done to compare phenotypes with candidate genotypes. Genome-wide efficient mixed-model analysis was done to compare neurocognition and CMBs. Gene set analysis was done using https://fuma.ctglab.nl/. RESULTS APOE4 was a candidate variant associated with non-lobar, larger volume CMBs (p&amp;lt; 0.05). At the GWAS-level (n=225), specific genes trended with visual memory, psychomotor function, and CMB count (p&amp;lt; 5x10-8). Using gene set analyses, there were gene set trends seen with CMB count and psychomotor function. Small sample size and low mutant allele frequency limited reliability of these findings. Preliminary volumetric analysis show reduced volume within the right parietal, medial occipital and inferior temporal lobes with increased cortical thickness in the left occipital and medial parietal lobe in patients carrying the ApoE4 allele. WM signal assessments are ongoing. CONCLUSION Genetic markers may be associated with neurocognition, CMBs, brain volume and WM changes in pediatric brain tumor survivors; however, larger cohorts are needed to confirm specific gene relevance.

Altered Functional Network Associated With Cognitive Performance in Early Parkinson Disease Measured by Eigenvector Centrality Mapping.

Objective: To investigate relationships between whole-brain functional changes and the performance of multiple cognitive functions in early Parkinson’s disease (PD).Methods: In the current study, we evaluated resting-state functional MRI (rsfMRI) data and neuropsychological assessments for various cognitive functions in a cohort with 84 early PD patients from the Parkinson’s Progression Markers Initiative (PPMI). Eigenvector centrality (EC) mapping based on rsfMRI was used to identify the functional connectivity of brain areas correlated with different neuropsychological scores at a whole-brain level.Results: Our study demonstrated that in the early PD patients, scores of Letter Number Sequencing (LNS) were positively correlated with EC in the left inferior occipital gyrus (IOG) and lingual gyrus. The immediate recall scores of Hopkins Verbal Learning Test-Revised (HVLT-R) were positively correlated with EC in the left superior frontal gyrus. No correlation was found between the EC and other cognitive performance scores.Conclusions: Functional alternations in the left occipital lobe (inferior occipital and lingual gyrus) and left superior frontal gyrus may account for the performance of working memory and immediate recall memory, respectively in early PD. These results may broaden the understanding of the potential mechanism of cognitive impairments in early PD.

Remarkable Clinical Improvement Following Microsurgical Resection of Left Lingual Gyrus Cerebral Cavernous Malformation: A Case Report

Abstract Introduction Cerebral cavernous malformations (CCMs) are collections of dilated and irregular capillaries in the brain. Cerebral cavernous malformations are predominantly supratentorial; occipital CCMs are rare. Surgical removal is indicated for CCMs with recurrent hemorrhage, refractory seizures, and expanding lesions. Case Description We describe a case of a 15-year-old male who presented with repeated tonic-clonic seizures and right homonymous hemianopia of 3-week duration. Magnetic resonance imaging (MRI) showed a mass located on the left medial occipital lobe, specifically in the left lingual gyrus. The T2-weighted and T2-gradient echo images confirmed the diagnosis of a CCM. Total microscopic resection was achieved. There were no surgical complications. The visual deficit improved, and the patient was seizure-free on subsequent follow-up visits. Conclusion Surgical resection of an occipital CCM resulted in a remarkable improvement in terms of seizures and visual field deficits.

Gray matter changes in chronic heavy cannabis users: a voxel-level study using multivariate pattern analysis approach.

Recent structural MRI studies on gray matter (GM) volumes using group-level mass-univariate statistical analysis suggest that chronic and heavy cannabis exposure may affect brain region-based morphology. In this prospective study, we use a multivariate pattern analysis approach to investigate the voxel-level change of GM densities in chronic heavy cannabis users. Principal component analysis and linear support vector machine are used in this study, resulting in an 88.1% separation between chronic heavy cannabis users (N = 20) and non-cannabis healthy controls (HCs, N = 22) through leave-one-out cross-validation. The model's discriminative pattern showed that GM density decreases in the part of middle frontal gyrus, inferior frontal gyrus, middle temporal gyrus, inferior temporal gyrus and left occipital lobe in heavy cannabis users with respect to HCs and increases in the part of lentiform nucleus, left cerebellum and right parietal lobe. These results suggest that GM densities alteration has taken place on chronic heavy cannabis users compared with HCs at voxel level.

Can the right hemisphere read? A behavioral and disconnectome study on implicit reading in a patient with pure alexia

ABSTRACT Patients with pure alexia have major difficulties in reading aloud. However, they often perform above chance level in reading tasks that do not require overt articulation of the target word – like lexical decision or semantic judgment – a phenomenon usually known as “implicit reading.” There is no agreement in the literature on whether implicit reading should be attributed to relative sparing of some left hemisphere (LH) reading centers or rather to signs of compensatory endeavors by the right hemisphere (RH). We report the case of an 81-year-old patient (AA) with pure alexia due to a lesion involving the left occipital lobe and the temporal infero-mesial areas, as well as the posterior callosal pathways. Although AA’s reading was severely impaired and proceeded letter by letter, she showed an above-chance-level performance for frequent concrete words in a tachistoscopic lexical decision task. A structural disconnectome analysis revealed that AA’s lesion not only affected the left occipital cortex and the splenium: it also disconnected white-matter tracts meant to connect the visual word-form system to decision-related frontal areas within the LH. We suggest that the RH, rather than the LH, may be responsible for patient AA’s implicit reading.

SLORETA Source Localisation of Visual Mismatch Negativity in Dyslexic Children During Malay Orthographical Lexicon Stimulations.

BackgroundWhile there are studies on visual lexical processing in other languages among dyslexics, no studies were done in the Malay language. The origin of visual lexical processing might be different in the Malay language. We aimed to detect the source localisation of visual mismatch negativity (vMMN) during Malay orthographic lexicon stimulations, employing an event-related potential (ERP) study.MethodsTwelve dyslexic and twelve non-dyslexic children participated in this study. They pushed button ‘1’ when they saw real (meaningful) Malay words and button ‘2’ for pseudowords (meaningless). The source localisation of vMMN was performed in the grand average waveform by applying the standardised low-resolution brain electromagnetic tomography (sLORETA) method using Net Station software.ResultsLeft occipital (BA17) and left temporal (BA37) lobes were activated during real words in the non-dyslexic and dyslexic children, respectively. During pseudowords, BA18 and BA17 areas of the left occipital lobe were activated in the non-dyslexic and dyslexic children, separately. vMMN sources were found at the left temporal (BA37) and right frontal (BA11) lobes in non-dyslexic and dyslexic children, respectively.ConclusionRight frontal lobe is the decision-making area where vMMN source was found in dyslexic children. We concluded that dyslexic children required the decision-making area to detect Malay real and pseudowords.

Neural correlates of naming errors across different neurodegenerative diseases: An FDG-PET study.

To investigate the types of errors produced in a picture naming task by patients with neurodegenerative dementia due to different etiologies and their neural correlates. The same standardized picture naming test was administered to a consecutive sample of patients (n = 148) who had been studied with [18F] FDG-PET. The errors were analyzed in 3 categories (visual, semantic, and phonologic). The PET data were analyzed using an optimized single-subject procedure, and the statistical parametric mapping multiple regression design was used to explore the correlation between each type of error and brain hypometabolism in the whole group. Metabolic connectivity analyses were run at the group level on 7 left hemisphere cortical areas corresponding to an a priori defined naming network. Semantic errors were predominant in most patients, independent of clinical diagnosis. In the whole group analysis, visual errors correlated with hypometabolism in the right inferior occipital lobe and in the left middle occipital lobe. Semantic errors correlated with hypometabolism in the left fusiform gyrus, the inferior and middle temporal gyri, and the temporal pole. Phonologic errors were associated with hypometabolism in the left superior and middle temporal gyri. Both positive (occipital-posterior fusiform) and negative (anterior fusiform gyrus and the superior anterior temporal lobe) connectivity changes were associated with semantic errors. Naming errors reflect the dysfunction of separate stages of the naming process and are specific markers for different patterns of brain involvement. These correlations are not limited to primary progressive aphasia but extend to other neurodegenerative dementias.

S2089 Massive Ischemic Stroke Due to Multiples Air Embolisms Following a Surveillance Esophagogastroduodenoscopy

INTRODUCTION: Cerebral air embolism is extremely rare, but serious complication of Esophagogastroduodenoscopy (EGD). There were only 21 reported cases in the literature by 2016. Most documented cases are iatrogenic in nature. We will present the first documented case of Cerebral air embolism following an EGD in Puerto Rico. CASE DESCRIPTION/METHODS: A 72 years old male with Chronic Liver Disease secondary to alcohol abuse, complicated with UGIB due to Esophageal Varices in the past, presented to our unit for a surveillance EGD. During procedure he developed severe retching, with distal esophageal tear accompanied by profuse bleeding, requiring endoscopic therapy with local epinephrine injection and placement of 2 clips to achieve hemostasis. After 30 minutes of standard recovery care and reversal of sedation, the patient failed to be aroused. There was only response to painful stimuli by withdrawal and the presence of Babinski reflex bilaterally. He was promptly transferred to the hospital ICU. Vital signs remained stable but with neurological deficit with GCS of 4/15. He was placed on mechanical ventilation. Initial laboratory tests were unremarkable. Head CT revealed multiple air globules within the territory of the right MCA (Figure 1) and Subsequent MRI was pertinent for extensive acute embolic hypoxic-ischemic brain injury (Figure 2). Given institution limitations, 32 hours after the precipitating event, the patient was transported and received hyperbaric oxygen therapy (HBOT) without significant neurologic improvement. Unfortunately, after prolonged hospitalization patient was discharge to hospice care in a persistent vegetative state. DISCUSSION: Cerebral air embolism is a rare, but devastating complication of endoscopic procedures. To occur it is necessary a communication between an air source and the vasculature, and the presence of a pressure gradient favoring passage of air into the circulation. Early recognition by endoscopists is essential requiring a high index of suspicion, especially since signs and symptoms may be confused as effects of persistent sedation. There are no standard treatments, but the most significant intervention appears to be HBOT, which accelerating the reabsorption and decreasing the size of the air bubbles in the vascular compartment, the maximum beneficial effects have been shown if administered during the first 4 to 6 hours after symptom onset. Unfortunately, due to severe neurological ischemic injury, our patient survived but with significant morbidity and disability.Figure 1.: MDCT axial images of the Head without Contrast: Scattered diffuse hypodense lesions throughout the right centrum semiovale and corona radiata which given the history of a recent procedure, findings are in favor of multiples cerebral air embolism within the territory of the right Middle Cerebral Artery (MCA).Figure 2.: Multiplanar multisequence MRI of the brain without Contrast: There is gyriform cortical restricted diffusion (A) with corresponding FLAIR hyperintensity (B) throughout the right cerebral hemisphere as well as to a lesser extent throughout the left frontal, parietal and occipital lobes; consistent with acute embolic (secondary to air emboli) hypoxic-ischemic brain injury and brain edema.

Individual variability of the brain occipital lobes height and their blood supply

200 hemispheres of the brain of people who died from diseases not related to brain pathology were studied. The morphometric method was used and statistical analysis was performed. It was found that men and women with dolichocranial type of skull have an asymmetry in the height of the hemispheres of the brain. In men, the height of the left hemisphere of the brain is greater than in women, but the height of the right hemisphere of the brain in men is less. The height of the left hemisphere of the brain in men with mesocranial type is greater than the right, in women the height of the right hemisphere of the brain prevails. In people with brachycranial type of skull, the height of the left hemisphere of the brain prevails in men, in women the height of the right and left hemispheres of the brain are the same. According to the dolichocranial type of skull, the height of the left occipital lobe predominates in men, and the height of the right occipital lobe predominates in women. The height of the left occipital lobe in men with mesocranial type of skull is greater than the right. In women with mesocranial type of skull, the height of the left occipital lobe predominates. In people with brachycranial type of skull, the height of the right occipital lobe of the brain prevails in both men and women. The height of the cerebral hemispheres in men and women with brachycranial type of skull is greater than in those with mesocranial and dolichocranial. The height of the occipital lobes of the brain in men and women with dolichocranial type of skull is slightly higher than in those with mesocranial and brachycranial. Sources of blood supply to the formations of the medial surface of the occipital lobe of the brain - the branches of the posterior cerebral artery, which are divided according to their areas of blood supply to the parieto-occipital, calcarine spur and cuneus. Keywords: endbrain, occipital lobe, individual anatomical variability.