Prenatal imaging classification and potential diseases of fetal abnormal sylvian fissure / 中华超声影像学杂志

Objective:To assess the ultrasonographic features and potential diseases of fetal abnormal sylvian fissure(SF), and to explore the value of whole-genome sequencing (WGS) in prenatal detection.Methods:A total of 28 fetuses with a sonographic diagnosis of abnormal SF in Shenzhen Maternal and Child Health Hospital Affiliated to Southern Medical University between October 2018 and October 2020 were prospectively included. The fetal brain was evaluated by neuroultrasound and intrauterine MRI in detail. Amniotic fluid/cord blood obtained by amniocentesis or tissue samples from umbilical cord after birth were collected for WGS. Pregnancy outcomes and postnatal MRI were recorded, and neurodevelopment of live-born infants was followed up for more than 24 months after delivery.Results:During the study period, 28 fetuses with abnormal SF were identified, with a gestational age of 21.3-30.0 (24.8±2.0) weeks. Abnormal SF presented in MCD ( n=15, 53.6%), chromosomal anomalies ( n=3, 10.7%) or single-gene genetic syndromes ( n=3, 10.7%) with the affected fetuses showing developmental delay, hydrocephalus or leukomalacia ( n=4, 14.2%), corpus callosal agenesis with large interhemispheric cysts ( n=1, 3.6%), benign subarachnoid space enlargement with arachnoid cysts ( n=1, 3.6%), and multiple malformations ( n=1, 3.6%). Among the 15 cases with MCD, the most common pathology was lissencephaly/pachygyria, followed by schizencephaly, severe microcephaly, hemimegalencephaly with paraventricular heterotopia, and polymicrogyria. Abnormal SF presented bilaterally in 23 fetuses and unilaterally in 5. All cases were categorized into six types depending on SF morphology in the transthalamic section: no plateau-like or a small insula, linear type, irregular corrugated SF, Z-shaped, and cyst occupying type. In addition to abnormal SF, associated anomalies or mild variations were identified in all fetuses. There were 17 cases underwent intrauterine MRI, and 13 cases underwent postnatal MRI examination.And 25 pregnancies were terminated; 3 were born alive, and 2 had typical syndromic changes with poor neurodevelopmental prognosis. A related pathogenic genetic variant was detected in 57.1% (16/28) fetus, and the incidence of single nucleotide variants(SNVs) was 42.9% (12/28), among which de novo SNVs accounted for 91.7% (11/12). Conclusions:Fetal abnormal SF could be classified based on the ultrasonographic features of transthalamic section. Fetal abnormal SF may indicate MCD, some chromosomal abnormalities or single-gene genetic syndromes that may lead to poor neurodevelopmental outcomes, and may be affected by extra-cortical factors. It is suggested to carry out targeted prenatal genetic diagnosis for fetuses with abnormal SF.

Feasibility study of prenatal ultrasound in the evaluation of normal fetal sylvian fissure maturation by simplified grading / 中华超声影像学杂志

Objective:To observe the morphological changes of the sylvian fissure on the transthalamic section of fetal brain at 20-32 weeks, and grade the fetal sylvian fissure development by means of a simple scoring system and explore its clinical feasibility.Methods:From September 2018 to June 2020, 487 normal single fetuses of 20-32 weeks were examined in Shenzhen Maternal and Child Health Hospital Affiliated to Southern Medical University. The sylvian fissure maturation was analyzed on the transthalamic section of fetal brain at 20-32 weeks and was graded from 0 to 5: un-visualized (grade 0), shallow arc (grade 1), obtuse-angled platform (grade 2), right-angled platform (grade 3), acute-angled platform (grade 4), and closed operculum (grade 5). The pregnancy outcomes and gestational age were recorded.Statistical analysis was performed by SPSS 20.0 software using box plot, Mann-Whitney U test, Weighted Kappa coefficient. Results:Left sylvian fissuer grades were obtained in 280 fetuses and right sylvian fissure grades were obtained in 247 fetuses. The fetal sylvian fissure maturation at 20-32 weeks was graded from 0 to 5, which increased with advancing gestation. Grade 0 only appeared in 3 fetuses at 20 weeks, and 99.4% fetuses at 20 weeks had grade ≥1. Grade 1 appeared in 20-22 weeks, grade 2 in 20-25 weeks, grade 3 in 22-26 weeks, grade 4 in 25-32 weeks, and grade 5 in 27-32 weeks. Box-plot and Mann-Whitney U test showed that gestational week distribution of sylvian fissure at all grades was symmetric on both sides ( P>0.05). The Weighted Kappa coefficients were 0.857(95% CI=0.750-0.957) and 0.939 (95% CI=0.859-1.000), respectively, with strong consistency regarding inter- and intra-observer agreements. Conclusions:Fetal sylvian fissure maturation at 20-32 weeks can be evaluated by means of a simple scoring system with symmetrical grading of both sides.

Navegando por la fisura silviana: anatomía microquirúrgica, neuroimágenes y técnica quirúrgica / Navigating the sylvian fissure: microsurgical anatomy, neuroimaging, and surgical technique

Objetivo: Describir la anatomía quirúrgica de la fisura silviana (FS) a través de disecciones cadavéricas y neuroimágenes; desarrollar su aplicación microquirúrgica. Materiales y métodos: Se estudiaron 10 hemisferios cadavéricos humanos fijados y un cráneo humano en seco, a través de la disección de fibras blancas y de la anatomía arterial y neural, utilizando un microscopio quirúrgico. Las arterias cerebrales fueron inyectadas con silicona coloreada. La anatomía quirúrgica fue correlacionada con la anatomía neuroimagenológica. Finalmente, se recolectó la experiencia microquirúrgica adquirida y, a su vez, la anatomía del Complejo Silviano, fue revisada. Resultados: La FS se extiende desde la cara basal a la lateral del cerebro. Cada superficie tiene una parte superficial (tronco silviano y sus ramos), intermedia (compartimientos anterior y opercular lateral) y profunda (compartimiento esfenoidal, hendidura insular anterior y lateral y la región retroinsular). En 7 de los 10 hemisferios, el surco central no se intersectó con la FS en la superficie lateral del cerebro. En el 80% de los hemisferios, la principal bifurcación de la arteria cerebral media se localizó en o proximal al limen insular. Debajo de la pars triangularis se localiza el punto más ancho de la superficie lateral de la FS. Los autores comienzan la disección de la misma en o proximalmente a este punto. Conclusiones: El conocimiento anatómico profundo y su aplicación a las neuroimágenes, son herramientas esenciales para el planeamiento prequirúrgico y son requisitos mandatorios para operar con seguridad a través y alrededor de la FS

Objective: The aim of this study is to describe the microsurgical anatomy of the sylvian fissure, through cadaveric dissections and neuroimaging and to elucidate its clinical application for microsurgery. Methods: One human skull and ten cadaveric human hemispheres were studied through white matter fiber dissections and arterial and neural anatomy of the sylvian fissure and insular dissections under the microscope. The cerebral arteries were perfused with colored latex. The surgical anatomy was correlated with neuroimaging anatomy. Finally, the microsurgical experienced gained applying this anatomical knowledge was gathered, and the literature about the anatomy of the sylvian complex was revised, as well. Results: The Sylvian fissure extends from the basal to the lateral surface of the brain. Each surface has a superficial (sylvian stem and its rami), intermediate (anterior and lateral opercular compartments) and deep parts (sphenoidal compartment, anterior and lateral insular clefts and retroinsular region). In 7 out of 10 hemispheres, the central sulcus did not intersect with the sylvian fissure on the lateral surface of the brain. In 80% of the hemispheres, the middle cerebral artery main bifurcation was localized at or proximal to the limen insulae. Beneath the pars triangularis, the widest point of the lateral surface of the sylvian fissure is located. The authors start dissecting the sylvian fissure at this point. Conclusion: The thorough anatomical knowledge with its clinical application in modern neuroimaging are essential tools for preoperative planning and are mandatory requisites to safely operate through and around the sylvian fissure anatomical complex.

A Clinical Study of Anterior Sylvian Point and Use of Anterior Sylvian Point For Surface Mapping of Frontal Horn For Intraoperative Emergency Ventricular Tapping

Introduction: Anterior sylvian point (ASyP) had a constant relationship with a point in the skull just posterior to the “H”-shapedpterion over the squamous suture called the anterior squamous point (ASqP).Objectives: The objectives of this study were as follows: (1) To confirm and establish the cisternal nature of ASyP and itsrelationship to other important neural and sulcal structures along the sylvian fissure. (2) To confirm the relationship of theAntSyP (ASyP) with the external cranial landmark ASqP for surface mapping of frontal horn for emergency ventricular tapping.Materials and Methods: Forty adult human brains (20 – right side and 20 – left side), both male and female, were observedduring surgery in Government Theni Medical College. Reliability of frontal horn tapping using the apex of Paine’s trianglefrom ASyP as the entry point was analyzed using the following steps. Exposure of pterion by the standard FTP trauma flapincision. Standard FTP craniotomy opening of the skull and dura mater and observing for ASyP relation to ASqP. A catheterwas introduced through the apex of the Paine’s triangle identified using the surgical tapes to form a 2.5 cm isosceles trianglefrom the ASyP. A study of the relationship of ASyP to the external cranial surface, middle cerebral artery (MCA) bifurcation,and frontal horn of ventricles was done.Conclusion: It could be safely concluded that ASqP is a reliable external cranial landmark for ASyP. ASyP can be the referencepoint for Paine’s triangle and hence Paine’s point. Hence, Paine’s point could be used to tap the frontal horn in emergentsituations. Furthermore, MCA bifurcation can be reached by ASyP cisternal dissection.

Compaison of clinical effects of different surgical methods in patients with supratentorial hypertensive intracerebral hemorrhage / 吉林大学学报(医学版)

Objective: To explore the safeties and efficacies of temporal cortex approach, transsulcus or fissure microsurgery and drilling drainage in the treatment of the patients with supratentorial hypertensive intracerebral hemorrhage (SHICH), and to provide the references for choosing the operation methods for the SHICH patients. Methods: Th e clinical materials of 118 patients with SHICH were collected and were divided into temporal cortex approach group (cortex group, n=39), transsulcus or fissure microsurgery group (fissure group, n=31) and drilling drainage group (drilling group, n=48) according to their different operation methods. The age, hematoma volumes, Glasgow Coma Scale Score (GCS), time from onset to operation, hematoma clearance rates, improvement rates 24 h after operation, rebleeding rates after operation, intracranial infection rates, survival rates, and good prognosis rates of the patients in three groups were recorded. Results: The hematoma clearance rate, improvement rate, survival rate and good prognosis rate of the patients in fissure group were significantly higher than those in cortex group (P0. 05). There were no statistically significant differences in the prognosis indexes (hematoma, GCS, survival rate, and good prognosis rate) of the patients between 30-49 mL and 50-69 mL subgroups in fissure group and drilling group. The age of patients in 50-69 mL subgroup in drilling group was significantly higher than that in fissure group (P< 0. 05). Conclusion: The efficacies and prognosis of SHICH patients treated by transsulcus or fissure microsurgery and drilling drainage are better than those by temporal cortex approach. Drilling drainage is more suitable to the old patients with above moderate hematoma; and transsulcus or fissure microsurgery is more suitable to the patients with massive hematoma.

Interhemispheric Variation of Sylvian Fissure: A Cadaveric Brain Study.

Introduction: Language areas of brain show a beautiful anatomico-functional correlation. It has been often assumed that the interhemispheric asymmetry of Sylvian fissure and perisylvian cortex is the basis of hemispheric dominance for language.The lateral sulcus is one of the earliest-developing sulci of the human brain. Materials And Methods: 60 formalin fixed cadaveric brains irrespective of sexes were studied in the department of Anatomy. The total length of sylvian fissure on the superolateral surface till the posterior sylvian point was noted bilaterally. Among the other measurements taken were the lengths of anterior ascending, anterior horizontal and posterior limb of lateral sulcus till posterior sylvian point on the right and left cerebral hemispheres. Observation and Results: The mean of the total length of the lateral sulcus on the left side is 8.48 which is larger than the right side which is 8.39.The mean of the anterior horizontal rami on right side (1.97) is greater than left side (1.96). On the other hand the mean value of left anterior ascending ramus 2.41 is greater than the mean value of right anterior ascending ramus 2.37. The mean value of posterior limb of sylvian sulcus is also greater on the left side i.e. 6.43 than on the right side i.e.6.23.All measurements are in cms. Conclusion: The Sylvian fissure in this study is longer on the left side than the right which has been proved in previous studies.To correlate this structural asymmetry with the functional localization of speech and language calls for further studies.

Abordaje pterional / Pterional approach

Objetivo: describir, paso a paso, la realización de un abordaje pterional (AP). Descripción: Posición: El paciente es colocado en decúbito dorsal, con la cabeza rotada contralateral y deflexionada. Incisión: se extiende desde la línea media hasta el borde inferior del arco cigomático, 1 cm adelante del trago. Disección interfascial: tiene varios referentes anatómicos: la arteria temporal superficial, el reborde orbitario y al arco cigomático en su porción inferior. La incisión se inicia en la línea temporal superior, 2 cm posterior del reborde orbitario, y se extiende en dirección al sector medio del arco cigomático. Desinserción del músculo temporal: se procede a realizar un corte muscular hasta alcanzar el plano óseo, y se realiza una disección subperióstica. Craneotomía: la remoción ósea debe lograr una exposición suficiente de la fisura silviana, con mayor exposición del lóbulo frontal; así, deben exponerse los giros frontales medio e inferior y el giro temporal superior. Apertura dural: en dos colgajos, uno frontal y otro temporal. Conclusión: el AP constituye aún hoy día una técnica actual y vigente, que se resiste a ser olvidada, cuya aplicación juiciosa permite acceso a un gran numero de patologías de la base de cráneo anterior y media.

Objective: the aim of this study is to describe, step by step, the pterional approach. Description: position: the patient is placed supine, and the head rotated and also deflected. Incision: from the midline to de zygomatic arch, 1 cm in front of the tragus. Interfascial dissection: the landmarks: superficial temporal artery, orbital rim and zygomatic arch. The incision started at the level of the superior temporal line, 2 cm posterior to the orbital rim, and is pointed to the middle portion of the zygomatic arch. Temporal muscle displacement: after a transversal section of the upper portion of the muscle, it is detached in a subperiosteal fashion. Craniotomy: the osseous removal should expose the sylvian fissure and the middle and inferior frontal gyrus and also the superior temporal giri. Dural opening: in two flaps (frontal and temporal). Conclusion: the pterional approach is still, nowadays, a valid and current technique. This approach allows treating many lesions located in the anterior and middle cranial fossa.

Clipping of the Anterior Communicating Artery Aneurysm without Sylvian Fissure Dissection

OBJECTIVE: The focus of aneurysm surgery is eliminating unnecessary operative manipulations and preparing the surgeon for any crises that might arise. With this concept in mind, we have tried resection of the gyrus rectus without routine sylvian fissure dissection in selected patients with anterior communicating artery (ACom) aneurysms, and compared these results with those from the conventional transsylvian approach. METHODS: This retrospective study included 231 surgically treated patients with ACom aneurysms from March, 1997 to May, 2005. The patients were divided into two groups : Group A (96 with sylvian fissure dissection, March, 1997-December, 2000) and Group B (135 without sylvian fissure dissection, January, 2001-May, 2005). Overall surgical outcomes were compared, and operative times have been prospectively recorded since January, 04 to evaluate how this maneuver affected the length of surgical procedures. RESULTS: All aneurysms were satisfactorily clipped, and there was no evidence of increased number of procedure-related retraction injuries in group B. Overall outcome was good in 186 (80.5%); 76 (79.2%) in group A, and 110 (81.5%) in group B (x2 test, p=0.79). In good clinical grade of group A, good outcome was observed in 60 patients (89.6%) and in group B, 97 patients (94.2%) (Fisher's exact test, p=0.38) (Fig. 2). CONCLUSION: In this study, eliminating the step of sylvian fissure dissection by gentle lateral basal-frontal retraction to the side of the sylvian fissure did not increase morbidity and mortality. However, we do not intend to modify the standard approach to the ACom aneurysm that is familiar to and has been mastered by many others. Rather, we report our experience on the basis of our anatomic understanding of the technique and its results.

Direction of Middle Cerebral Artery Bifurcation Aneurysms and Surgical Approach / 대한뇌혈관외과학회지

OBJECTIVE: This study will discuss both analysis and surgical approach for the management of middle cerebral artery bifurcation aneurysms on the basis of the author's experience. METHODS: We reviewed 105 middle cerebral artery bifurcation aneurysms in 94 patients operated from May 1997 to May 2004. The clinical presentations, neurological findings, CT findings, operative approaches and outcome were analyzed. The standard pterional approach was used. The sylvian fissure can be opened in one of three ways; the medial sylvian fissure approach, distal sylvian fissure approach, transcortical approach. We favor a lateral to medial sylvian approach for most aneurysms, because it provides excellent exposure of the aneurysm and minimizes manipulation of the brain and vascular structures. RESULTS: The mean age was 55 years. 72 patients (76.6%) had subarachnoid hemorrhage (SAH), 22 patients (23.4%) had both SAH and intracranial hemorrhage (ICH). Of the 94 patients, 68 patients had single aneurysm and 26 patients had multiple aneurysm. Distal sylvian fissure approach was used in 69 operations and proximal sylvian fissure approach was used in 29 operations. The transcortical approach was used in 9 operations. 85 patients among 94 patients had good outcome after surgery. 2 patients remained disabled, and 4 patients died. CONCLUSION: We suggest that distal sylvian fissure approach can be used as routine method of operation for the management of middle cerebral artery aneurysms unless patients have either multiple aneurysms or ICH.

Pure Sylvian Fissure Arteriovenous Malformation

Pure sylvian fissure arteriovenous malformations(AVMs) are vascular malformations confined to the sylvian fissure without parenchymal involvement. Surgical removal is regarded as difficult because the nidus is located just lateral to important structures such as the basal ganglia and the internal capsule. Because most feeding arteries to the nidus are branches of the middle cerebral artery(MCA), differentiation between these feeders from en passant and normal vessels is of great importance in order to reduce morbidity and mortality from surgical intervention. We report a case of pure sylvian fissure AVM who presented with an intra-temporal lobe hematoma that was located around venous aneurysms distant from the nidus. The clinical characteristics of this AVM and the surgical methods employed to avoid complications are discussed.

Deep Sylvian Meningioma: Case Report

We report a case of deep sylvian meningioma without any dural attachment in a 36-year-old man. The patient presented with generalized tonic clonic seizure. Magnetic resonance images revealed a well enhancing round mass in the superior aspect of the left insular region. Surgical resection confirmed transitional type of meningioma. Gamma knife radiosurgery was undergone to control the tumor growth after partial resection. So far, supratentorial meningioma without any dural attachment has been rarely reported.

Dificuldades na microdissecção da fissura e da cisterna silvianas / Technical difficulties in the microsurgical dissection of the sylvian fissure and cistern

Os sulcos, as fissuras e as cisternas subaracnóideas são vias naturais de circulação do líquido cefalorraquidiano que podem ser utilizadas pelo cirurgião para alcançar regiões mais profundas do cérebro e da base do crânio. Dessas vias, as mais utilizadas na prática neurocirúrgica são afissura e a cisterna silvianas. No entanto, apesar da ampla divulgação da técnica, nem sempre a microdissecção desses espaços é simples e, por vezes, mesmo o neurocirurgião experiente e persistente encontra dificuldades técnicas em executá-la. Com a finalidade de detectar os fatores que contribuem para essas dificuldades, analisamos 10variáveis observadas em 152 pacientes submetidos ao tratamento cirúrgico de aneurismas da circulação anterior do polígono de Willis por via pterional, que foram confrontadas com o resultado da dissecção. As ocorrências cirúrgicas ? lesão pial extensa na superfície dos opérculos e tempo de dissecção da fissura e da cisterna silvianas maior que 60 minutos ? foram assumidas como evidências indiretas de dificuldade técnica na dissecção e consideradas, isoladamente ou em conjunto, como representativas de uma dissecção difícil. O percentual de casos com fissura e cisterna silvianas de difícil dissecção foi significantementemaior nos pacientes que apresentavam membrana aracnóide espessa, aderência moderada ou intensa entre os opérculos frontal e temporal, cisterna silviana virtual e veia silviana superficial com calibre maior que 3 milímetros. No entanto, quando empregada a técnica de regressãologística múltipla para estudar o efeito conjunto dessas variáveis na probabilidade da dissecção ser difícil, somente as duas primeiras apresentaram significância estatística (p = 0,005 e p = 0,015, respectivamente). A probabilidade de uma dissecção difícil da fissura e da cisterna silvianas é 2,76 vezes maior nos pacientes que têm uma membrana aracnóide espessa e 3,11 vezes maior quando a aderência entre os opérculos é moderada ou intensa. Quando o paciente não apresenta nenhuma das duas variáveis consideradas como fatores de risco, a probabilidade estimada de uma dissecção difícil é de apenas 12%. Por outro lado, quando ambos fatores estão presentes, essa probabilidade sobe para 53%. A ocorrência de uma lesão pial extensa ou a necessidade de um tempo cirúrgico maior que 60 minutos para uma dissecção completa da fissura e da cisterna silvianas não teve relação direta com qualquer tipo de repercussão clínica. Levando em consideração essa constatação e a impor tância fundamental da aber tura por microdissecção da fissura e da cisterna silvianas na via de acesso pterional, podemos concluir que a existência de dificuldades técnicas não invalida a execução dessa etapa cirúrgica.

The sulci, fissures and subarachnoid cisterns are natural pathaways of circulation of the cerebrospinal fluid that may be used by the surgeon to reach deep regions of the brain and the skull base. Among these routes, the sylvian fissure and cistern is the most commonly utilized in the neurosurgical practice. The surgical microdissection of these spaces is not always simple and even the most tenacious and experienced surgeon finds it difficult at times. With the purpose of detecting the factors that might contribute to these technical difficulties during the microsurgical dissection of the sylvian fissure and cistern we have analysed 10 variablesobserved during 152 surgical procedures carried through the pterional route for the treatment of aneurysms of the anterior circulation. These variables were confronted with the dissection results. The surgical occurrence of extensive pial lesion and extended microsurgical dissection time (over 60 minutes) were considered as indirect evidence of technical difficulty during dissection and representative of a difficult dissection.

Ependymal Cyst of the Sylvian Fissure

Cerebral ependymal cysts are very rare. About 30 cases have been reported in the literature. They mimic arachnoid cysts clinically and on imaging studies but are different from arachnoid cysts in pathological findings. They are believed to arise by the sequestration of a small segment of the primitive ependymal lining into either the cortical mantle or the perimedullary mesh. They occupy the central white matter of the frontal or temporoparietal lobes. The authors describe a case of septate ependymal cyst involving left sylvian fissure. The clinicopathological features, treatment, and results of previously reported cases are reviewed, and the etiology and pathogenesis of these cysts are discussed.

Surgical Experiences of Sylvian AVMs

An AVM located in or adjacent to the sylvian fissure is one of the most difficult to remove because it is surrounded by critical structures such as the basal ganglia and internal capsule and it involves the middle cerebral artery. We have operated on 6 cases of arteriovenous malformation(AVM) in and around the sylvian fissure. We describe the characteristic features of these AVMs from the anatomical and surgical points of view. The surgical results were satisfactory in 5 cases, and 1 patients died.

Clinical Study on Spontaneous Intracerebral Hematoma Mixed with CSF

An analysis and CT findings in 21 adult patients of spontaneous intracerebral hematoma(SICH) mixed with CSF who were admitted to the Fatima Hospital from December 1986 to May 1989. The following results were obtained; 1) We could differentiated SICH that have inhomogenous density and thought that it is composed of blood, CSF and blood-CSF mixture. 2) Previously reported pathways that intracerebral hematoma rupture into the ventricle are caudate nucleus and thalamus but intracerebral hematoma can be mixed with CSF through the subarachnoid space of Sylvian fissure as an another route. 3) Intracerebral hematoma mixed with CSF was removed easily, safely and enoughly with simple aspiration method as like resoluted hematoma in subacute or chronic phase. 4) The prognosis of patients with SICH mixed with CSF was very good unlike to that of patients with pure intracerebral hematoma and/or ventricular hemorrhage.

Spontaneous Subdural Hematoma of Arterial Origin

The occurrence of spontaneous arterial subdural hematoma is rare. We present one case of subdural hematoma caused by spontaneous rupture of cortical artery. We confirmed that the source of bleeding was rupture of a cortical artery located near the sylvian region in the operative field.