Sylvian Fissure Research Articles

Chronic subdural hematoma associated with type II and type III Galassi arachnoid cysts: illustrative cases.

Arachnoid cysts (ACs) are congenital abnormalities that can be located anywhere within the subarachnoid space along the cerebrospinal axis, although they are most often found on the left side in the temporal fossa and sylvian fissure. ACs comprise approximately 1% of all intracranial space-occupying lesions and are considered potential risk factors for subdural hematoma (SDH) in individuals of all age groups who have experienced traumatic brain injury. Although it is uncommon for an intracystic hemorrhage of an AC to occur without evidence of head trauma, it may be more common among children and young adults. Here, the authors present three cases of spontaneous AC intracystic hemorrhage with chronic SDH. Additionally, they provide a thorough review of the existing literature. All three patients with AC were adolescent males. In all cases, AC was identified using the Galassi classification (type II or III) and associated with spontaneous intracystic hemorrhage and chronic SDH as seen on imaging. Spontaneous intracystic hemorrhage is a rare complication and occurs most commonly on the left side. Surgery is the definitive treatment, requiring either craniotomy or burr hole for hematoma evacuation and microsurgical fenestration to drain the cyst into the subarachnoid cisterns.

Transorbital and supraorbital uniportal multicorridor approach to the orbit, anterior, middle and posterior cranial fossa: Anatomic study

IntroductionThe transorbital route has been proposed for addressing orbital and paramedian skull base lesions. It can be complemented by further marginotomies, as per “extended-transorbital approach” and combined with others ventro-basal approaches featuring the concept of “multiportal surgery”. Nevertheless, it cannot address some anatomical regions like the clinoid, carotid bifurcation and the Sylvian fissure. Therefore, we propose a combined transorbital and a supraorbital approach, attainable by a single infra-brow incision, and we called it “Uniportal multicorridor” approach. Research questionThe aim of our study is to verify its feasibility and deep anatomical targets through a cadaveric study. Materials and methodsAnatomic dissections were performed at the Laboratory of ICLO Teaching and Research Center (Verona, Italy) on four formalin-fixed cadaveric heads injected with colored neoprene latex (8 sides). A stepwise dissection of the supraorbital and transorbital approaches (with an infra-brow skin incision) to the anterior tentorial incisura, clinoid area, lateral wall of the cavernous sinus, middle temporal fossa, posterior fossa, and Sylvian fissure is described. ResultsWe analyzed the anatomic areas reached by the transorbital corridor dividing them as follow: lateral wall of the cavernous sinus, middle temporal fossa, posterior fossa, and Sylvian fissure; while the anatomic areas addressed by the supraorbital craniotomy were the clinoid area and the anterior tentorial incisura. ConclusionsThe described uniportal multi-corridor approach combines a transorbital corridor and a supraorbital craniotomy, providing a unique intra and extradural control over the anterior, middle, and posterior fossa, tentorial incisura and the Sylvian fissure, via an infra-brow skin incision.

Challenging Cortical Explorations in Difficult-to-Localize Seizures: The Rationale and Usefulness of Perisylvian Paralimbic Explorations With Orthogonal Stereoelectroencephalography Depth Electrodes.

Stereoelectroencephalography (SEEG) is an invasive monitoring method designed to define and localize the epileptogenic zone (EZ) and explore the putative network responsible for the electroclinical seizures using anatomo-functional-electroclinical correlations. When indicated by semiology in selected patients, exploration of both limbic and paralimbic (PL) regions is indispensable. However, the PL cortex is located in deep and highly vascularized areas in proximity to the anterior Sylvian fissure and middle cerebral artery branches. Thus, those explorations are considered surgically challenging because of the multilobar location and fear of hemorrhagic events. Here, we discuss and illustrate the rationale and SEEG methodology approach in usefulness of exploring the PL regions using standard orthogonal SEEG depth electrode trajectories with the Talariach reference system. We retrospectively studied PL exploration from a cohort of 71 consecutive SEEG procedures from Nov 2019 to Nov 2022 and identified 31 patients who underwent PL trajectories. In 31 patients, there were 32 SEEG trajectories, and no major complications were observed. PL electrodes were consistently implanted in the C10/D10 coordinates of the Talariach reference coordinates. The most common confirmed EZ in our cohort was mesio-temporal (45%), followed by temporo-perisylvian regions (16%), ventromedial frontal (13%), and mesio-lateral temporal regions (13%). The PL contacts were involved in the EZ in 10 patients (32%). Of 31 patients, 25 underwent resective surgery, and 19 obtained Engel 1 outcome with a mean follow-up of 25 months (range 12-41 months) after surgery. The orthogonal perisylvian PL trajectories are feasible and useful in sampling multiple PL regions with single-electrode trajectories. In patients with perisylvian seizures, sampling PL structures may contribute to an improved understanding of seizure propagation and the optimal anatomic demarcation of the EZs in this surgically challenging region.

P186: Longitudinal changes in the cerebrospinal-fluid volumes in patients with Alzheimer’s disease.

Objective:Although the previous studies indicated that impaired cerebrospinal fluid (CSF) dynamics might contribute to the pathophysiology of Alzheimer’s disease (AD), the longitudinal changes of CSF volumes in AD has been still unclear. In this study, using the methodology of quantitative assessment of CSF volumes in idiopathic normal pressure hydrocephalus (iNPH), we assessed longitudinal changes in CSF volumes in AD patients.Methods:The subjects were the patients with mild cognitive impairment and dementia due to AD who visited Osaka University Hospital from November 2009 to October 2018. We excluded the patients with gait disturbances and MRI findings such as Disproportionately enlarged subarachnoid-space hydrocephalus (DESH), which was the suggestive finding of iNPH. For each subject, MRI was performed in the first visit and 1 year later. We quantitatively measured CSF volumes in DESH-related regions, such as ventricle systems (VS), Sylvian fissures (SF), and sulci at high convexity and the midline (SHM)., using an automatic brain volumetric software program (AVSIS) (Ishii et al. 2006, 2013). The ratio of each regional volume to the intracranial volume was calculated and we compared these parameters between two visits.Results:We enrolled 98 patients with AD (mean (SD) age = 76.0 (5.7)). Wilcoxon signed rank test revealed that, while the ratios of CSF volumes in VS and SF significantly increased during the one-year observation (VS: 4.01 (1.05) % vs 4.14 (1.09) %, p<0.001 ;SF: 1.40 (0.21) % vs 1.42 (0.22) %, p=0.007), those in SHM significantly decreased (4.30 (0.70) % vs 4.23 (0.69) %, p<0.001). The change ratio of relative volumes in VS was correlated with those in SF and SHM (r=0.451, p<0.001; r=-0.350, p<0.001).Conclusion:In patients with AD, the CSF volumes in VS and SF increased while CSF volumes in SHM decreased. This trend of the longitudinal change was similar to the change in the patients with iNPH. The finding of this study indicates that, in the patients with AD, CSF dynamics may be impaired like the patients with iNPH.

Development and validation of a predictive model for fetal cerebral maturation using ultrasound for fetuses with normal growth and fetal growth restriction.

Investigation of fetal cerebral maturation (FCM) is necessary and important to provide crucial prognostic information for normal and high-risk fetuses. The study aimed to develop a valid and quantitative predictive model for assessing FCM using ultrasound and validate the model for fetuses with normal and restricted growth. This was a multicenter prospective observational study. Fetuses with normal growth recruited from a university teaching hospital (Center 1) and a municipal maternal unit (Center 2) were included in the training set and external validation set 1, respectively. The 124 growth-restricted fetuses enrolled in Center 1 were included in validation set 2. FCM was used to describe the gestational age (GA) in this study. The model was developed based on the sum of fetal cranial parameters (total fetal cranial parameters), including head circumference (HC) and depths of the insula (INS) and sylvian fissure (SF), parieto-occipital fissure (POF), and calcarine fissure (CF). A regression model, constructed based on total fetal cranial parameters and predicted GA, was established using the training set and validated using external validation set 1 and validation set 2. The intra- and interobserver intraclass correlation coefficients for HC, and depths of the INS and SF, POF, and CF were >0.90. An exponential regression equation was used to predict FCM: predicted GA of FCM (weeks) =11.16 × exp (0.003 × total fetal cranial parameters) (P<0.001; adjusted R2=0.973), standard error of estimate, 0.67 weeks. The standard error of the predicted GA of FCM from the model was ±4.7 days. In the validation set 1, the mean standard error of the developed prediction model for FCM was 0.97 weeks. The predictive model showed that FCM was significantly delayed in validation set 2 (2.10±1.31 weeks, P<0.001), considering the GA per the last menstrual period. The predictive performance of the FCM model developed in this study was excellent, and the novel model may be a valuable investigative tool during clinical implementation.

Sonographic demonstration of the sulci and gyri on the convex surface in normal fetuses using 3D-ICRV rendering technology.

To demonstrate morphological alteration of the sulci and gyri on the convex surface in normal fetuses using innovative three-dimensional inversion and Crystalvue and Realisticvue (3D-ICRV) rendering technology. 3D fetal brain volumes were collected from low-risk singleton pregnancies between 15+0 and 35+6 gestational weeks. Volumes were acquired from the transthalamic axial plane by transabdominal ultrasonography and were then post-processed with Crystalvue, Realisticvue rendering software and inversion mode. Volume quality was assessed. The anatomic definition of the sulci and gyri was determined according to location and orientation. The morphology alteration and sulcus display rates were recorded in sequential order of gestational weeks. Follow-up data were collected in all cases. 294 of 300 fetuses (294 brain volumes) (98%) with qualified fetal brain volumes were included (n=294, median 27 gestational weeks). 6 fetuses with unsatisfactory 3D-ICRV image quality were excluded. The morphology of the sulci and gyri on the brain convex surface could be demonstrated clearly on 3D-ICRV images. The Sylvian fissure was the first structure to be recognized. From 25 to 30 weeks, other sulci and gyri became visible. An ascending trend in the display rate of the sulci was found in this period. Follow-up showed no detectable anomalies. 3D-ICRV rendering technology is different from traditional 3D ultrasound. It can provide vivid and intuitive prenatal visualization of the sulci and gyri on the brain surface. Moreover, it may offer new ideas for neurodevelopment exploration.

Genetic variants underlying the neuro‐anatomical signatures of hypertension measured on structural MRI

AbstractBackgroundHypertension (HTN) is associated with gray matter (GM) atrophy and increased white matter hyperintensity (WMH) burden, increasing their susceptibility to Alzheimer’s disease and related dementias. We developed a machine learning based model to quantify spatial patterns of abnormality recognizing HTN‐related brain changes (SPARE‐HTN) from structural magnetic resonance images (sMRI). We performed a genome wide association study (GWAS) to identify the genetic variants and associated biological traits that underlie the “expression” of HTN‐related brain changes, i.e., the individualized SPARE‐HTN index.MethodSPARE‐HTN model was trained on the large multi‐study iSTAGING dataset, with regional GM volumes from T1‐weighted images and lobar WMH volumes from T2‐weighted FLAIR images used as imaging features. GWAS was carried out in a subset of N = 7490 (46% Female, Age = 65.5±7 years) hypertensive participants from UK‐Biobank. A GWAS of SPARE‐HTN scores was run using linear regression with Plink, correcting for the top 40 genetic principal components, age, sex, and intracranial volume. Significant SNPs were identified and mapped to functional genes using the Functional Mapping and Annotation (FUMA) platform; and candidate SNPs were mapped to the GWAS catalog.ResultSPARE‐HTN was associated with regional atrophy most prominent in perisylvian and temporal cortex and increased WMH volumes, particularly in frontal white matter. SPARE‐HTN scores showed better discriminative power between normal and stage 1 participants (Cohen’s‐d effect size, d = 0.2) and stage 2 (d = 0.71) hypertensive participants when compared to total WMH volume (d = 0.04 and 0.38, respectively). GWAS identified N = 321 independently significant SNPs, of which a subset N = 46 candidate SNPs were mapped to 6 genes (ICA1L, CARF, WDR12, NBEAL1, KRT8P15, CYP20A1) in Chromosome 2 (Figure 2). These genes were previously reported to be associated with several cardiovascular conditions including coronary artery disease and stroke, and with increased WM damage on sMRI and diffusion MRI (Figure 3).ConclusionThe individualized imaging marker, SPARE‐HTN, was associated with genes relevant to HTN with traits including cardiovascular conditions and higher prevalence of WMH, and was more sensitive to HTN than total WMH volume. SPARE‐HTN is a useful tool to characterize HTN‐related brain changes and monitor treatment effects at an individual level.

Genetic variants underlying the neuro‐anatomical signatures of hypertension measured on structural MRI

AbstractBackgroundHypertension (HTN) is associated with gray matter (GM) atrophy and increased white matter hyperintensity (WMH) burden, increasing their susceptibility to Alzheimer’s disease and related dementias. We developed a machine learning based model to quantify spatial patterns of abnormality recognizing HTN‐related brain changes (SPARE‐HTN) from structural magnetic resonance images (sMRI). We performed a genome wide association study (GWAS) to identify the genetic variants and associated biological traits that underlie the “expression” of HTN‐related brain changes, i.e., the individualized SPARE‐HTN index.MethodSPARE‐HTN model was trained on the large multi‐study iSTAGING dataset, with regional GM volumes from T1‐weighted images and lobar WMH volumes from T2‐weighted FLAIR images used as imaging features. GWAS was carried out in a subset of N = 7490 (46% Female, Age = 65.5±7 years) hypertensive participants from UK‐Biobank. A GWAS of SPARE‐HTN scores was run using linear regression with Plink, correcting for the top 40 genetic principal components, age, sex, and intracranial volume. Significant SNPs were identified and mapped to functional genes using the Functional Mapping and Annotation (FUMA) platform; and candidate SNPs were mapped to the GWAS catalog.ResultSPARE‐HTN was associated with regional atrophy most prominent in perisylvian and temporal cortex and increased WMH volumes, particularly in frontal white matter. SPARE‐HTN scores showed better discriminative power between normal and stage 1 participants (Cohen’s‐d effect size, d = 0.2) and stage 2 (d = 0.71) hypertensive participants when compared to total WMH volume (d = 0.04 and 0.38, respectively). GWAS identified N = 321 independently significant SNPs, of which a subset N = 46 candidate SNPs were mapped to 6 genes (ICA1L, CARF, WDR12, NBEAL1, KRT8P15, CYP20A1) in Chromosome 2 (Figure 2). These genes were previously reported to be associated with several cardiovascular conditions including coronary artery disease and stroke, and with increased WM damage on sMRI and diffusion MRI (Figure 3).ConclusionThe individualized imaging marker, SPARE‐HTN, was associated with genes relevant to HTN with traits including cardiovascular conditions and higher prevalence of WMH, and was more sensitive to HTN than total WMH volume. SPARE‐HTN is a useful tool to characterize HTN‐related brain changes and monitor treatment effects at an individual level.

Elmukashfi’s Protocol for Hippocampal Volumetry; 2022

There is a relation between many neuropsychiatric disorders and reduction in hippocampal volume. So, a protocol for researches in this area is highly needed. Study aimed to design and validate a protocol for hippocampal volumetry to facilitate manual segmentation of hippocampus region. It was a comparative study, carried at Diagnostic Imaging Clinic at Elmoalem Hospital; where 65 Sudanese individuals were surveyed in period (December 2021 –April 2022). Data was collected through master sheet for sociodemographic information, 3D magnetic resonance imaging for measuring hippocampus volume, and imaging acquisition. Software for measurements 3D slicer version (4.11) was used, where hippocampus is mapped by delineating its boundaries. Protocol was composed of mapping hippocampus. Mapping hippocampus: identify sagittal view, lateral fissure, temporal horn of lateral ventricle, hippocampus region, temporal and occipital horn of lateral ventricle, choroid plexus of lateral ventricle. Among these slides hippocampus has been delineated. Statistical Computing: Data was analyzed using SPSS version 23. Reliability test was performed by obtaining Cronbach’s alpha. Protocol considered reliable if value of Cronbach’s alpha is close to (+1). P-value ≤ 0.05 was considered statistically significant. Validation of Protocol: Calculation of hippocampus volume is valid as total volume correlates strongly with both right and left measurements (correlation coefficient 0.76 and 0.87 respectively and p-value &lt;0.001). Reliability test was 0.85; which was close to (+1). Conclusion and recommendation: This protocol represents a valid, reliable, and applicable method for measuring hippocampal volume. It could be a step to develop an international standard protocol for hippocampal volumetry.

Patient with AIP gene mutation presenting with pituitary adenomatosis

Abstract Introduction/Objective Familial isolated pituitary adenoma (FIAP) is frequently associated with germline mutation in the AIP gene. Clinically, it is characterized by the occurrence of isolated pituitary adenoma in 2 or more members of a family. In this case report, we describe a patient who presented with a pituitary adenoma and concurrent disseminated leptomeningeal adenomatosis. Methods/Case Report A 17-year-old female presented with amenorrhea and visual impairment. Brain MRI showed a 2.6 x 2.8 x 2.4 cm mass in the sella turcica extending to the suprasellar region. Multiple separate smaller (5-7 mm) masses in the leptomeninges of the anterior and middle cranial fossa, and small enhancing masses within the internal auditory canals bilaterally were also seen. She underwent craniotomy for resection of the pituitary tumor which was diagnosed pathologically as sparsely granulated somatotroph adenoma with co-expression of human growth hormone and prolactin. Postoperatively, she was found to have persistent hormone imbalance for which she received proton beam therapy. Genetic testing revealed mutations in the AIP gene. No mutations were detected in NF2, MEN1, and CDKN1B. At age 21, radiologic follow-up revealed recurrent pituitary adenoma, for which she underwent trans- sphenoidal resection, revealing the same histopathologic diagnosis. At age 22, MRI showed diffuse nodular enhancement throughout the subarachnoid spaces, most pronounced within the Sylvian fissures. Cytologic examination of cerebrospinal fluid (CSF) showed several loose aggregates of neuroendocrine cells, positive for synaptophysin by immunocytochemistry, consistent with the diagnosis with dissemination of pituitary adenoma cells in the leptomeninges. Results (if a Case Study enter NA) N/A Conclusion In all 136 previously reported cases, leptomeningeal dissemination of pituitary adenoma has been exclusively described in post-surgical settings or after pituitary apoplexy. To our knowledge, this is the first case of disseminated pituitary adenomatosis noted at initial clinical presentation

The Application Effect of Craniotomy through Transsylvian Rolandic Point-Insular Approach on Hypertensive Intracerebral Hemorrhage in Posterior Basal Ganglia

Objective. To evaluate the hematoma clearance and safety of small bone window craniotomy through the lateral fissure Rolandic point-insular lobe approach for patients with hypertensive intracerebral hemorrhage (HICH) in posterior basal ganglia. Methods. This retrospective study enrolled a total of 86 patients with HICH in the posterior basal ganglia region who underwent surgery between January 2020 and December 2021. These patients were divided into two groups: the conventional group and the study group. The intraoperative information, postoperative hematoma clearance rate, increasing rate of cerebral edema and rebleeding occurrence rate, postoperative complication rate, and prognoses were compared between the two groups. Additionally, we observed and compared the rate of postoperative cerebral hematoma increase, as well as the neurological function and activities of daily living (ADL) at admission, 3 months, and 6 months after surgery in both groups. Univariate and multivariate logistic regression analyses were performed to explore factors affecting the prognosis of patients with HICH in the posterior basal ganglia region after small bone window craniotomy through the lateral fissure Rolandic point-insular lobe approach. Results. The study group exhibited significantly shorter automatic eye-opening times and hospital stays compared to the conventional group ( P &lt; 0.05 ). Furthermore, the study group demonstrated better hematoma clearance rates, lower rates of cerebral hematoma at postoperative 48 h and 72 h, and lower rates of rebleeding compared to the conventional group ( P &lt; 0.05 ). At 3 and 6 months postsurgery, the study group exhibited a significantly greater improvement in neurological function and ADL compared to the conventional group ( P &lt; 0.05 ). Additionally, the incidence of postoperative complications in the study group was lower than that in the conventional group ( P &lt; 0.05 ). Furthermore, the prognosis of the study group was significantly better than that of the conventional group at the 6-month follow-up ( P &lt; 0.05 ). Conclusion. A small bone window craniotomy via transsylvian Rolandic point-insular approach has been shown to improve the hematoma clearance rate in patients with HICH in the posterior basal ganglia region while also reducing the incidence of complications. This approach is highly safe and feasible for implementation in clinical practice.

Multimodal minimally invasive surgery in the treatment of neurocysticercosis

ObjectiveNeurocysticercosis (NCC) is still a frequent cause of neurosurgical consultations in most developing countries. Conventional approaches for the resection of large cysts have been used for many years. We report here our experience in the neurosurgical management of NCC using diverse minimally invasive approaches according to the localization of lesions: minimal craniotomy for lesions in the Sylvian fissure, stereotactic surgery for lesions in the posterior fossa, and endonasal neuroendoscopy for lesions in the basal cisterns. MethodsWe reviewed the charts of 24 consecutive NCC patients who had minimally invasive surgery to resect NCC lesions in a neurological referral center in Lima, Peru. Three approaches were used: microcraneotomies through the anterior Sylvian point (n = 16), stereotactic surgery (n = 6), and endonasal endoscopy (n = 2), between January 1, 2016, and July 31, 2022. Demographic and clinical data as well as post-surgical evolution are presented using descriptive statistics. ResultsClinical improvement was observed in 23 out of 24 cases, with complete resolution of symptoms in nine and partial in 14. One patient evolved poorly and worsened his symptoms. Twenty-two patients received antiparasitic treatment after surgery. Relapse of NCC lesions was observed in three patients. There were no significant complications in any of the cases. ConclusionsMinimally invasive surgical approaches provide an excellent alternative for the management of patients with NCC, with good surgical and functional results, also markedly reducing the parasitic mass for further antiparasitic treatment.

Seizure as the first symptom of cavernous sinus dural arteriovenous fistula: A case report and literature review

Cavernous sinus dural arteriovenous fistula (CS-DAVF) is an abnormal arteriovenous communication associated with a variety of clinical manifestations. The previous literature has rarely reported the occurrence of CS-DAVF with seizures and cerebral hemorrhage, signaling the need for more case reports and literature review in this area. A 62-year-old Chinese female presented with a paroxysmal loss of consciousness, accompanied with involuntary eye movement to the left, chewing issues, salivation at the right corner of the mouth, and bit tongue. The brain computed tomography revealed that the left temporal lobe was hemorrhagic. Brain scan and contrast-enhanced magnetic resonance imaging showed diffuse meningeal enhancement and lesions in the left frontoparietal temporal lobe, insular lobe, and hippocampal head region. Electroencephalography demonstrated continuous emission of spike and slow waves in the left hemisphere. With the aid of digital subtraction angiography, the patient was confirmed with a diagnosis of CS-DAVF draining into the ipsilateral cavernous sinus, intercavernous sinus, contralateral cavernous sinus, left superior ophthalmic vein, left lateral fissure vein, and left pterygoid venous plexus. The fistula was closed with interventional embolization through the femoral vein, and immediate angiography showed complete resolution of CS-DAVF after operation. The patient did not manifest any post-operative complications. This case highlights that the prevention of epilepsy, cerebral hemorrhage, and other serious complications is extremely important for good prognosis, especially in some patients presenting with serious clinical symptoms. It also sheds light on the necessity to consider the diagnosis of CS-DAVF if seizures, although extremely rare, are present.

Continued Development and Testing of a Novel Steerable Chest Tube, Extendable Infusion Cannula, and Portable Suction-Infusion Pump for Use in Austere and Transport Environments to Prevent Retained Hemothorax.

With blunt and penetrating trauma to the chest, warfighters frequently suffer from hemothorax. Optimal management requires the placement of a chest tube to evacuate the blood. Malposition of the tube may be a causative factor of inadequate drainage (retained hemothorax). As a potential solution, we developed a previously reported steerable chest tube allowing accurate placement into a desired location to enhance effectiveness. To provide assisted aspiration, we developed a portable, battery-operated suction device capable of simultaneous or sequential infusion. This report details the ongoing progress of this project. Updated steerable tube and pump prototypes were designed and produced. The tubes were tested for feasibility in two pigs and one cadaver by fluoroscopically comparing tip positions after insertion by a number of providers. Measured drainage volumes comparing standard vs. steerable tubes after pleural infusion of 1,000 mL of saline in two pigs were compared. Testing of the pump focused on the accuracy of suction and volume functions. The steerable tube prototype consists of sequentially bonded segments of differing flexibility and an ergonomic tensioning handle. The portable suction pump accurately provides up to 80 cmH2O of suction, an infusion capability of up to 10 mL/min, and a 950 mL removable reservoir canister. After minimal training, providers easily and repeatedly placed the tip of the steerable tube in the lateral diaphragmatic sulcus in animals and cadavers. Arc was limited to the distal segment. Compared to a standard tube, the steerable tube placed along the diaphragm improved pleural fluid drainage volumes by 17%, although this did not reach statistical significance in six trials. These new prototypes represent substantial improvements and were performed according to expectations. We believe that this steerable chest tube and portable suction-infusion pump can be effectively used for warfighters with chest injuries in austere environments.

Decoding the temporal representation of facial expression in face-selective regions

The ability of humans to discern facial expressions in a timely manner typically relies on distributed face-selective regions for rapid neural computations. To study the time course in regions of interest for this process, we used magnetoencephalography (MEG) to measure neural responses participants viewed facial expressions depicting seven types of emotions (happiness, sadness, anger, disgust, fear, surprise, and neutral). Analysis of the time-resolved decoding of neural responses in face-selective sources within the inferior parietal cortex (IP-faces), lateral occipital cortex (LO-faces), fusiform gyrus (FG-faces), and posterior superior temporal sulcus (pSTS-faces) revealed that facial expressions were successfully classified starting from ∼100 to 150 ms after stimulus onset. Interestingly, the LO-faces and IP-faces showed greater accuracy than FG-faces and pSTS-faces. To examine the nature of the information processed in these face-selective regions, we entered with facial expression stimuli into a convolutional neural network (CNN) to perform similarity analyses against human neural responses. The results showed that neural responses in the LO-faces and IP-faces, starting ∼100 ms after the stimuli, were more strongly correlated with deep representations of emotional categories than with image level information from the input images. Additionally, we observed a relationship between the behavioral performance and the neural responses in the LO-faces and IP-faces, but not in the FG-faces and lpSTS-faces. Together, these results provided a comprehensive picture of the time course and nature of information involved in facial expression discrimination across multiple face-selective regions, which advances our understanding of how the human brain processes facial expressions.

Abstract 165: Subarachnoid Hemorrhage Related to Thoracic Spinal Cord Stimulator Placement

Introduction Spinal cord stimulators (SCS) offer safe and effective pain relief. Precise lead placement is critical. Indications for lead placement include chronic pain, failed back surgery syndrome and complex regional pain syndrome (1). Hardware related complications include lead fracture and lead migration into the subdural space. Complications can also include spinal cord injury, nerve root damage or lack of desired pain control (2). We present a case of subarachnoid hemorrhage (SAH) due to SCS lead migration into the subdural space. Methods An 81‐year‐old female patient with a past medical history of heart failure, atrial fibrillation and a mechanical mitral valve, presents with a severe headache and right hemiparesis. The patient was anticoagulated with a warfarin to heparin bridge. One week prior to presentation, the patient underwent SCS placement for chronic lower back pain due to post herpetic neuralgia. She was also found to have 8/10 pain on palpation of the lumbar spine and loss of sensation in the right lower extremity. An urgent CT brain revealed a SAH in the bilateral occipital lobes, right sylvian fissure and right temporal lobe. CT angiogram was also performed and did not reveal any evidence of a cerebral aneurysm. CT of the thoracic spine revealed neurostimulator lead migration into the subdural space. Neurosurgery was consulted and subsequently removed the SCS. The patient’s hemiparesis resolved, and CT brain showed no progression of the hemorrhage. MRI brain showed no infarct. Results We propose that the combined risk of anticoagulation and lead migration into the subdural space led to the development of SAH. Conclusion In cases of a SAH, where a cerebral aneurysm or arteriovenous malformation have been excluded, other sources should be considered. We report a novel case of SAH following SCS placement.

Distal femoral torsion is correlated with higher-grade trochlear dysplasia and shorter anterior condyles in patients with patellar dislocation and increased femoral torsion.

To describe the characteristics of femoral torsion in patients with different segmental torsion types and to evaluate the correlations between segmental torsion and the morphology of the femoral condyles and trochlea in patients with patellar dislocation and increased femoral torsion. Between January 2021 and March 2023, 69 patients were included and classified into two groups according to the femoral segment contributing the most to total torsion: 32 patients in Group A (femoral neck and shaft torsion) and 37 patients in Group B (distal torsion). Trochlear dysplasia was evaluated using Dejour's classification and sulcus angle. The morphology of the femoral condyles was evaluated using the lengths and ratios of the medial and lateral condyles. Correlations between femoral torsion and morphology were evaluated. Total torsion was significantly correlated with femoral neck and shaft torsion (r = 0.882, P < 0.001) and distal torsion (r = 0.262, P = 0.030). Femoral neck and shaft torsion was significantly increased with increasing total torsion. The trochlear sulcus was flatter and more dysplastic, and the anterior condyles were shorter in Group B. Distal torsion was significantly correlated with the lengths of the medial and lateral anterior condyles (r = - 0.567, P < 0.001; r = -0.701, P < 0.001), sulcus angle (r = 0.611, P < 0.001) and Dejour trochlea type (r = 0.512, P = 0.001), while femoral neck and shaft torsion showed no correlations. Femoral torsion is a complex of femoral neck and shaft torsion and distal torsion, especially femoral neck and shaft torsion. Distal torsion was significantly correlated with a flatter trochlear sulcus, higher-grade trochlear dysplasia, and shorter anterior condyles. The new findings highlighted the importance of the segmental evaluation of femoral torsion, which would facilitate understanding of the anatomical characteristics of femoral torsion in patients with patellar dislocation and increased femoral torsion and may lead to improvement in the surgical options regarding femoral torsion. Level III.

An arachnoid cyst rupture complicated with subdural hygroma in a middle-aged woman: a case report and review of the literature

BackgroundArachnoid cysts (ACs) account for about 1% of all intracranial mass lesions. The Sylvian fissure is the most common site of ACs which are usually asymptomatic. Traumatic rupture of arachnoid cysts complicated with subdural hygroma is a relatively rare entity in adults especially in females. There is no consensus on their management and each case could add to previous experiences leading to more uniform therapeutic measurements. This case encompasses a combination of watchful strategy, limited surgery and ultimately successful cyst fenestration which highlights a good outcome without complications by adopting a stepwise procedure.Case presentationHere, the case of a 51-year-old Persian woman being presented with a 2-month history of a localized headache which had begun 4 days after a minor head trauma. Early brain computed tomography (CT) obtained in another center at 4th day of post-injury which misinterpreted as an old infarct. Repeated CT in our center revealed a large AC of Sylvian fissure complicated with subdural hygroma. Initially a conservative management pursued but due to worsening of the symptoms, a burr-hole craniotomy performed for hygroma evacuation that subsequently followed by cyst fenestration about 1-month later.ConclusionPrevious awareness about radiographic characteristics of ACs as well as employing appropriate imaging modality are necessary for correct and timely diagnosis of symptomatic patients after minor head trauma because incidentally found ACs might be the underpinning causes of symptoms. Also, following a multistage therapeutic process along with the involvement of patients in decision-making are of paramount importance.

A Case Report on Cerebellar Ataxia – HIV Induced Chronic Cerebellitis

HIV-induced cerebellar complications, which are often manifested as ataxia, typically occur from cerebellar lesions resulting from opportunistic infections, vasculitis, or neoplastic processes. A 59yrs old male patient known to have HIV infection from past 15 years, presented to our hospital with weakness, ataxic gait, lower back pain and slurred speech since last 2-3 days. He had been receiving anti-retroviral therapy for over 15 years, and there was no family history of such illnesses. The results of examination were notable for dysarthria, dysmetria and dysdiadokokinesia. MRI revealed ligamentum flavum hypertrophy at multiple cervical levels, prominence of bilateral cerebral sulci and sylvian fissure and chronic lacunar infarcts. The final diagnosis was CEREBELLAR ATAXIA-HIV INDUCED CHRONIC CEREBELLITIS.

Effects of gender on fetal cortical development: a secondary analysis of a prospective cross-sectional study.

The primary objective was to evaluate the effects of fetal sex on fetal cortical development in low-risk pregnancies. Secondary objective was the evaluate the impact of gestational age. This was a secondary analysis of a prospective cross-sectional study on low-risk fetuses undergoing fetal neurosonography between 19 and 34 weeks of gestation. The depth of Sylvian Fissure (SF), Parieto Occipital Fissure (POF) and Calcarine Fissure (CF) were evaluated and related to fetal sex. Neurosonographic variables were normalized for fetal head circumference and expressed as multiple of the median (MoM). A total of 344 fetuses were considered (173 male, 171 female). The baseline characteristic of the two groups were similar except a higher birthweight present in male fetuses (p=0.044). The depth SF (p=0.023) CF (p=0.014) and POF (p=0.046) showed significantly higher values in male fetuses when all the gestational age range was considered. However, when data were controlled for gestational age, these differences resulted significant only after 28 weeks. Differences in cortical development related to gender occur after 28 weeks of gestation with an increase depth of SF, POF and CF in male fetuses.