Imaging characteristics and treatment strategies for carotid artery occlusion caused by skull base fracture:Three case reports

BACKGROUND Traumatic internal carotid artery(ICA)occlusion is a rare complication of skull base fractures,characterized by high mortality and disability rates,and poor prognosis.Therefore,timely discovery and correct management are crucial for saving the lives of such patients and improving their prognosis.This article retrospectively analyzed the imaging and clinical data of three patients,to explore the imaging characteristics and treatment strategies for carotid artery occlusion,combined with severe skull base fractures.CASE SUMMARY This case included three patients,all male,aged 21,63,and 16 years.They underwent plain film skull computed tomography(CT)examination at the onset of their illnesses,which revealed fractures at the bases of their skulls.Ultimately,these cases were definitively diagnosed through CT angiography(CTA)examinations.The first patient did not receive surgical treatment,only anticoagulation therapy,and recovered smoothly with no residual limb dysfunction(Case 1).The other two patients both developed intracranial hypertension and underwent decompressive craniectomy.One of these patients had high intracranial pressure and significant brain swelling postoperatively,leading the family to choose to take him home(Case 2).The other patient also underwent decompressive craniectomy and recovered well postoperatively with only mild limb motor dysfunction(Case 3).We retrieved literature from PubMed on skull base fractures causing ICA occlusion to determine the imaging characteristics and treatment strategies for this type of disease.CONCLUSION For patients with cranial trauma combined with skull base fractures,it is essential to complete a CTA examination as soon as possible,to screen for blunt cerebrovascular injury.

Interobserver and intraobserver reliability of skull base angles measured on magnetic resonance images

BACKGROUND Determination of platybasia and basilar kyphosis are significant parts of routine cranial magnetic resonance(MR)interpretations.These situations may explain a patient’s symptoms or may be associated with other anomalies.AIM To indicate the interobserver and intraobserver reliability of the skull base angles(SBA)(Koenigsberg standard)and modified SBA(mSBA)measurement techniques.METHODS In total,391 patients who had undergone cranial MR imaging were re-assessed regarding the SBA measurements.The SBA and mSBA techniques were used on MR images.Two reviewers independently measured the same angles twice within a 15-day interval,using different monitors.Intraclass correlation coefficient(ICC)was calculated to reveal the intraobserver and interobserver agreements.RESULTS There was an excellent agreement between reviewers regarding both angle measurements(ICC was 0.998 for SBA and mSBA).Excellent agreement levels were also observed for intraobserver measurements.ICC was 0.998 for SBA and 0.999 for mSBA for reviewer 1.ICC was 0.997 for SBA and 0.999 for mSBA according to the measurement results of reviewer 2.Higher SBA and mSBA values were observed for females compared to males.There was no correlation between SBA and age for SBA.However,a negative and low-level correlation was observed between mSBA values and age for both reviewers.CONCLUSION SBA and mSBA measurements indicated excellent agreement regarding interobserver and intraobserver differences.The study results showed that SBA angles were reliable measurement techniques to be used on MR images.

Imaging characteristics and treatment strategies for carotid artery occlusion caused by skull base fracture

The internal carotid artery occlusion caused by head and neck trauma,also known as traumatic intracranial artery occlusion,is relatively rare clinically.Traumatic skull base fracture is a common complication of traumatic brain injury.Traumatic skull base fracture is one of the causes of traumatic internal carotid artery occlusion.If not detected early and treated in time,the prognosis of patients is poor.This editorial makes a relevant analysis of this disease.

“In situ bone flap” combined with vascular pedicled mucous flap to reconstruction of skull base defect

BACKGROUND At present,neuroendoscopy technology has made rapid development,and great progress has been made in the operation of lesions in the saddle area of the skull base.However,the complications of cerebrospinal fluid and intracranial infection after the operation are still important and life-threatening complications,which may lead to poor prognosis.AIM To investigate the method of in situ bone flap combined with nasal septum mucosal flap for reconstruction of enlarged skull base defect by endonasal sphenoidal approach and to discuss its application effect.METHODS Clinical data of 24 patients undergoing transnasal sphenoidal endoscopic approach in the Department of Neurosurgery,Affiliated 2 Hospital of Nantong University from January 2019 to December 2022 were retrospectively analyzed.All patients underwent multi-layer reconstruction of skull base using in situ bone flap combined with nasal septum mucosa flap.The incidence of intraoperative and postoperative cerebrospinal fluid leakage and intracranial infection were analyzed,and the application effect and technical key points of in situ bone flap combined with nasal septum mucosa flap for skull base bone reconstruction were analyzed.RESULTS There were 5 cases of high flow cerebrospinal fluid(CSF)leakage and 7 cases of low flow CSF leakage.Postoperative cerebrospinal fluid leakage occurred in 2 patients(8.3%)and intracranial infection in 2 patients(8.3%),which were cured after strict bed rest,continuous drainage of lumbar cistern combined with antibiotic treatment,and no secondary surgical repair was required.The patients were followed up for 8 to 36 months after the operation,and no delayed cerebrospinal fluid leakage or intracranial infection occurred during the follow-up.Computed tomography reconstruction of skull base showed satisfactory reconstruction after surgery.CONCLUSION The use of in situ bone flap combined with vascular pedicled mucous flap to reconstruction of skull base defect after endonasal sphenoidal approach under neuroendoscopy has a lower incidence of cerebrospinal fluid leakage and lower complications,which has certain advantages and is worthy of clinical promotion.

Clinical observation of endoscopic skull base reconstruction with an anterolateral thigh free fascia flap

Objective:Radiation osteonecrosis of the skull base after radiotherapy for nasopharyngeal carcinoma is one of the most serious complications,affecting patient survival and quality of life.To date,surgical resection is the main treatment for radiation osteonecrosis.The repair after the operation is very important.Inappropriate repair or lack of repair can easily cause local infection that can even spread to the brain,aggravating osteonecrosis.This study aimed to verify the feasibility and safety of the ante-rolateral thigh free fascia flap in repairing large skull base defects.Methods:From June 2021 to July 2022,a total of 12 patients with a history of radiotherapy for naso-pharyngeal carcinoma received surgical treatment at the Department of Otolaryngology Head&Neck Surgery,Sir Run Run Shaw Hospital,Zhejiang University School of Medicine.All patients were diagnosed with radiation osteonecrosis of the skull base with large skull base defects.During the endoscopic operation,a free anterolateral thigh fascia flap was used to repair the skull base and complete vascular anastomosis reconstruction.The preoperative and postoperative pain scores were retrospectively analyzed,and the dynamic changes in endoscopic surgery sites were observed.Results:The 12 patients had a median age of 58 y,with 8(66.7%)males and 4(33.3%)females.The median headache score for the patients was 5(4-7)before surgery.The patient's headache was significantly relieved postoperatively,with 11 patients having a score of 0 and one patient having a score of 1.The stench was completely resolved after the operation.There were no serious complications during the perioperative period or 12 months after the operation.Conclusion:The application of anterolateral thigh free fascia flap in skull base reconstruction is a safe and reliable reconstruction technique suitable for endoscopic surgical repair of large-scale skull base necrosis.

Skull Base Osteomyelitis: A Rare Cause of Multiple Cranial Nerve Palsies—A Case Report from Ghana

Introduction: Skull Base Osteomyelitis (SBO) is an infectious inflammation of the skull bones that is often caused by malignant otitis externa (MOE) and affects the temporal bone. This condition commonly affects immunocompromised individuals and the elderly, particularly those with a history of diabetes mellitus. Diagnosis is challenging because of non-specific symptoms that lead to late detection and complications. This report discusses a case of SBO with multiple bilateral cranial nerve abnormalities and highlights the diagnostic and management challenges in high-risk individuals with subtle clinical signs. Case presentation: This report describes a 63-year-old patient with hypertension and diabetes who underwent surgical debridement of the left ear due to malignant otitis externa 4 months prior to presentation. The patient presented with significant dysarthria, dysphagia, ptosis of the left eye with double vision, and hearing impairment in the left ear. Examination revealed bilateral CN VI palsy, right CN VII palsy, left CN VIII palsy, and a right CN XII deficit. Initial tests were unremarkable, but a high Fungitell assay and a second review of the CT scan and MRI revealed a pathological process in the base of the skull involving bony structures and cranial nerves bilaterally, which helped diagnose SBO. The patient was subsequently discharged with oral voriconazole and continued his usual medications. The patient requested further management abroad, because he did not notice resolution of his symptoms. Surgical treatment was employed abroad to relieve his symptoms, as he recovered slowly. Conclusion: This case report underscores the importance of a multidisciplinary approach to address SBO. Collaboration between specialists in infectious diseases, otolaryngology, radiology, and neurology plays a pivotal role in achieving an accurate diagnosis and developing a tailored treatment plan. Although SBO may be infrequent, this case report highlights the need to maintain heightened clinical suspicion in high-risk individuals.

3D printing of calcium phosphate bioceramic with tailored biodegradation rate for skull bone tissue reconstruction

The bone regenerative scaffold with the tailored degradation rate matching with the growth rate of the new bone is essential for adolescent bone repair.To satisfy these requirement,we proposed bone tissue scaffolds with controlled degradation rate using osteoinductive materials(Ca-P bioceramics),which is expected to present a controllable biodegradation rate for patients who need bone regeneration.Physicochemical properties,porosity,compressive strength and degradation properties of the scaffolds were studied.3D printed Ca-P scaffold(3DS),gas foaming Ca-P scaffold(FS)and autogenous bone(AB)were used in vivo for personalized beagle skull defect repair.Histological results indicated that the 3DS was highly vascularized and well combined with surrounding tissues.FS showed obvious newly formed bone tissues.AB showed the best repair effect,but it was found that AB scaffolds were partially absorbed and degraded.This study indicated that the 3D printed Ca-P bioceramics with tailored biodegradation rate is a promising candidate for personalized skull bone tissue reconstruction.

Skull metastasis in papillary carcinoma of thyroid:A case report

Papillary thyroid carcinoma with metastasis to the skull is extremely rare.We report a case of unsuspected papillary thyroid carcinoma with skull metastasis.A 48-year-old female patient presenting with painless,pulsatile,progressively increasing swelling in the occipitoparietal region of the scalp approached for an X-ray of the skull.Ultrasound of palpable swelling in the neck revealed a heteroechoic lesion with increased vascularity.Foci of calcification were seen involving both lobes of the thyroid.Ultrasound of scalp showed a destructive mass in the skull with increased vascularity.Biopsy of thyroid lesions revealed branching papillae having a dense fibrovascular core covered by cuboidal epithelial cells with nuclei having a clear ground glass appearance.This case illustrates how isolated extensive skull metastasis can be found in papillary carcinoma patients without causing significant morbidity.Therefore,in the clinical course of thyroid papillary carcinoma,skull metastasis should be considered,and the patients should be meticulously investigated and followed up.

Industrial growth of yttria-stabilized cubic zirconia crystals by skull melting process

We reported the development of a Ф100 cm growth apparatus for skull melting growth of yttria-stabilized cubic zirconia(YSZ) crystals and more than 1000 kg crystals have been grown in the furnace each time.The growth conditions were optimized and the structure of the as-grown crystals was characterized by X-ray diffraction.The transmittance of 15 mol.% yttria-stabilized cubic zirconia crystal was nearly 80% in the range of 400–1600 nm.The refractive indices were measured and fitted the Sellmeier equation whi...

Amendment on the strain measurement of thin-walled human skull shell as intracranial pressure changes

The human skull, composed of tabula extema, tabula intema, and a porous diploe sandwiched in between, is deformed with changing intracranial pressure （ICP）. Because the human skull＇s thickness is only 6 mm, it is simplified as a thin-walled shell. The objective of this article is to analyze the strain of the thin-wailed shell by the stress-strain calculation of a human skull with changing ICP. Under the same loading conditions, using finite element analysis （FEA）, the strains of the human skull were calculated and the results were compared with the measurements of the simulative experiment in vitro. It is demonstrated that the strain of the thin-walled shell is totally measured by pasting the one-way strain foils on the exterior surface of the shell with suitable amendment for data. The amendment scope of the measured strain values of the thin-walled shell is from 13.04% to 22.22%.

Skull metastasis from hepatocellular carcinoma with chronic hepatitis B

A 56-year-old male visited our hospital for evaluation of an occipital mass.Contrast computed tomography showed hypervascular enhancement with osteolytic change in the skull and a huge enhanced mass in the liver.Magnetic resonance imaging showed bone metastasis in the thoracic vertebrae.Assays for hepatitis B surface antigen and hepatitis B core antibody were positive and his liver condition was Child-Pugh grade A.Our diagnosis was hepatocellular carcinoma(HCC) with skull and vertebrae metastases on chronic hepatitis B.He was treated with radiation therapy for bone metastases and transcatheter arterial chemoembolization for HCC.But he developed acute respiratory failure because of aspiration pneumonia,congestion and oedema with haemorrhage of the lungs and died.Dissection showed HCC with multiple bone metastases.The liver tumor was categorized as well-differentiated HCC,Edmondson classification Ⅰ,trabecular type and pseudoglandular type.In the liver mild infiltration of lymphocytes was seen in Glisson's capsules which were signif icantly enlarged with well preserved limiting plates.Piecemeal necrosis was not obvious.No fibrosis was noted.An 8 cm × 7 cm × 3 cm metastatic lesion had formed in the left occipitotemporal part of the cranial bone.The lesion was osteolytic and showed invasion into the dura mater.Neither the subdural cavity nor the brain showed involvement from the metastatic tumor.However,skull metastasis from HCC is very rare and it affects the patient's prognosis and the quality of life.Therefore,it is very important to make an early diagnosis and carry out proper management of skull metastasis from HCC.

Skull metastasis revealing a papillary thyroid carcinoma

Although thyroid carcinoma is a relatively common form of malignancy,metastatic spread to the skull is rare.Here,we report a case of papillary thyroid carcinoma with frontal and parietal metastasis.A 61-year-old Chinese woman presented with a one year history of a growing mass on the center of the frontal and parietal bone,initially thought to be meningioma.Biopsy of the skull base mass after intracalvarium excision,indicated a tumor of thyroid origin.One month later the patient underwent a total thyroidectomy.Pathological examination confirmed a diagnosis of papillary thyroid carcinoma with frontal and parietal bone metastasis.Based on this experience,the key to successful management of the skull metastasis of thyroid carcinoma is prompt diagnosis and appropriate treatment.Skull metastasis should be considered at the outset of the clinical course of papillary thyroid cancer.To facilitate this,patients should be meticulously investigated by a multidisciplinary team to improve quality of life.

Improvement of Mechanical Stability for Single Unit Recording Based on Skull Cap in Living Chinchilla

Three-point head fixation was constructed to provide mechanical stability for single unit recording(SUR)on vestibular sensory system in living chinchilla previously.However,it is no more qualified to this work when the stimulation intensity becomes large because of frequent unit losing and neuron damage,which strongly implies that the mechanical stability has been broken during the stimulation.Here,we constructed a novel hea0 fixation(skull cap assistant head fixation)provided by skull cap on the basis of three-point head fixation in order to improve the mechanical stability for SUR under the stimulation with large magnitude.The large area bone connection is the feature and advantage of this improved method,which directly fixes the tested local nervous tissue and microelectrode in an intact stable system through skull cap except two ear bars and a tube face mask.Our data exhibited that skull cap assistant head fixation could significantly improve the success rate of neural response activity recording in the population of semicircular canal neurons under the stimulation with large intensity(amplitudd 00 deg/s).Based on the analysis of neural response activity and noise base-line during stimulation,our data further indicated that this method could significantly improve the mechanical stability for SUR during high-speed motion stimulation on vestibular system in living chinchilla.Skull cap assistant head fixation extends the application of SUR on vestibular neuron in linear response range and provides a solid foundation for electrophysiological research on vestibular sensory system in fhrther studies.

Trifocal distraction osteogenesis for reconstruction of skull defect

Objective: To apply trifocal distraction osteogenesis in canine model of skull segmental defects and to provide reference for clinical treatment. Methods: Six labrador dogs were selected in this study and divided into observation group and control group randomly. Each group contained 3 dogs. Skull segmental defects models were established by surgery, and dogs in bservation group received trifocal distraction osteogenesis treatment. Bone density was observed and compared between two groups during treatment. Results: There were no significant difference in bone density between two groups on th 1st day ( P>0.05). The bone density of observation group on the 30th day, and 60th day were higher than that of control group ( P<0.01). Conclusions: Trifocal distraction osteogenesis has significant clinical effect, and it would be widely used in clinical treatment.

Comparison of diagnostic value of PET using 18- fluoro-2-deoxyglucose, CT and MR1 in detecting skull base invasion of nasopharyngeal carcinomas

Objective： We compared positron emission tomography （PET） using 18-fluoro-2-deoxyglucose （FDG）, enhanced computed tomography （CT） and magnetic resonance imaging （MRI） in detecting skull base invasion of nasopharyngeal carcinomas （NPC） and to evaluate the value of these three methods in determining the existence of skull base invasion of nasopharyngeal carcinomas. Methods： The images of enhanced CT, MRI and PET-CT scans, performed at intervals -〈 20 days on 57 NPC patients from July 2004 to February 2007, were selected and reviewed. The endpoints of the comparison were sensitivity, specificity, accuracy, positive predictive value （PPV） and negative predictive value （NPV） of Enhanced CT, MRI and PET-CT, based on histopathologic findings or clinical imaging follow-up for at least 6 months. Results： For detecting skull base invasion of NPC, the sensitivity of enhanced CT, MRI and PET-CT were 68.18%, 84.09%, 97.67% respectively; speci- ficity were 76.92%, 69.23%, 57.14% respectively; accuracy were 70.18%, 80.7%, 87.72% respectively; PPV were 90.9%, 90.24%, 87.5% respectively; NPV were 41.67%, 56.25%, 88.89% respectively. Conclusion： PET-CT has obvious advantages in sensitivity over CT （P 〈 0.05） and MRI, better than the two methods in accuracy and NPV and may be more valuable for new patients in detecting skull base invasion of NPC patients.

Application of CUSA Excel ultrasonic aspiration system in resection of skull base meningiomas

Background： Effective methods for managing patients with solitary pulmonary nodules（SPNs） depend critically on the predictive probability of malignancy.Methods： Between July 2009 and June 2011, data on gender, age, cancer history, tumor familial history, smoking status, tumor location, nodule size, spiculation, calcification, the tumor border, and the final pathological diagnosis were collected retrospectively from 154 surgical patients with an SPN measuring 3-30 mm. Each final diagnosis was compared with the probability calculated by three predicted models—the Mayo, VA, and Peking University（PU） models. The accuracy of each model was assessed using area under the receiver operating characteristics（ROC） and calibration curves.Results： The area under the ROC curve of the PU model [0.800; 95% confidence interval（CI）： 0.708-0.891] was higher than that of the Mayo model（0.753; 95% CI： 0.650-0.857） or VA model（0.728; 95% CI： 0.623-0.833）; however, this finding was not statistically significant. To varying degrees, calibration curves showed that all three models overestimated malignancy.Conclusions： The three predicted models have similar accuracy for prediction of SPN malignancy, although the accuracy is not sufficient. For Chinese patients, the PU model may has greater predictive power.Background： Here, we introduced our short experience on the application of a new CUSA Excel ultrasonic aspiration system, which was provided by Integra Lifesciences corporation, in skull base meningiomas resection.Methods： Ten patients with anterior, middle skull base and sphenoid ridge meningioma were operated using the CUSA Excel ultrasonic aspiration system at the Neurosurgery Department of Shanghai Huashan Hospital from August 2014 to October 2014. There were six male and four female patients, aged from 38 to 61 years old（the mean age was 48.5 years old）. Five cases with tumor located at anterior skull base, three cases with tumor on middle skull base, and two cases with tumor on sphenoid ridge.Results： All the patents received total resection of meningiomas with the help of this new tool, and the critical brain vessels and nerves were preserved during operations. All the patients recovered well after operation.Conclusions： This new CUSA Excel ultrasonic aspiration system has the advantage of preserving vital brain arteries and cranial nerves during skull base meningioma resection, which is very important for skull base tumor operations. This key step would ensure a well prognosis for patients. We hope the neurosurgeons would benefit from this kind of technique.Background： The purposes of this study were to explore the effects of high mobility group protein box 1（HMGB1） gene on the growth, proliferation, apoptosis, invasion, and metastasis of glioma cells, with an attempt to provide potential therapeutic targets for the treatment of glioma. Methods： The expressions of HMGB1 in glioma cells（U251, U-87 MG and LN-18） and one control cell line（SVG p12） were detected by real time PCR and Western blotting, respectively. Then, the effects of HMGB1 on the biological behaviors of glioma cells were detected： the expression of HMGB1 in human glioma cell lines U251 and U-87 MG were suppressed using RNAi technique, then the influences of HMGB1 on the viability, cycle, apoptosis, and invasion abilities of U251 and U-87 MG cells were analyzed using in a Transwell invasion chamber. Also, the effects of HMGB1 on the expressions of cyclin D1, Bax, Bcl-2, and MMP 9 were detected. Results： As shown by real-time PCR and Western blotting, the expression of HMGB1 significantly increased in glioma cells（U251, U-87 MG, and LN-18） in comparison with the control cell line（SVG p12）; the vitality, proliferation and invasive capabilities of U251 and U-87 MG cells in the HMGB1 siR NA-transfected group were significantly lower than those in the blank control group and negative control（NC） siR NA group（P〈0.05） but showed no significant difference between the blank control group and NC siR NA group. The percentage of apoptotic U251 and U-87 MG cells was significantly higher in the HMGB1 siR NA-transfected group than in the blank control group and NC siR NA group（P〈0.05） but was similar between the latter two groups. The HMGB1 siR NA-transfected group had significantly lower expression levels of Cyclin D1, Bcl-2, and MMP-9 protein in U251 and U-87 MG cells and significantly higher expression of Bax protein than in the blank control group and NC siR NA group（P〈0.05）; the expression profiles of cyclin D1, Bax, Bcl-2, and MMP 9 showed no significant change in both blank control group and NC siR NA group. Conclusions： HMGB1 gene may promote the proliferation and migration of glioma cells and suppress its effects of apoptosis. Inhibition of the expression of HMGB1 gene can suppress the proliferation and migration of glioma cells and promote their apoptosis. Our observations provided a new target for intervention and treatment of glioma.

Transcanal endoscopic assisted skull base endolymphatic sac tumor resection: A rare disease with advanced technology

Endolymphatic sac tumors(ELSTs) are rare, papillary adenomatous tumors that arise from the endothelium of the endolymphatic sac. We demonstrate a difficult case of endolymphatic sac tumor and how it is managed via transcanal endoscopic assisted technique, with discussion of feasibility of transcanal approach to lateral skull base tumor.

Hepatocellular carcinoma metastasizing to the skull base involving multiple cranial nerves

We describe a rare case of HCV-related recurrent multiple hepatocellular carcinoma （HCC） metastasizing to the skull base involving multiple cranial nerves in a 50-year-old woman. The patient presented with symptoms of ptosis, fixation of the right eyeball, and left abducens palsy, indicating disturbances of the right oculomotor and trochlear nerves and bilateral abducens nerves. Brain contrast-enhanced computed tomography （CT） revealed an ill-defined mass with abnormal enhancement around the sella turcica. Brain magnetic resonance imaging （HR/） disclosed that the mass involved the clivus, cavernous sinus, and petrous apex. On contrast-enhanced HRI with gadolinium-chelated contrast medium, the mass showed inhomogeneous intermediate enhancement. The diagnosis of metastatic HCC to the skull base was made on the basis of neurological findings and imaging studies including CT and MRI, without histological examinations, Further studies may provide insights into various methods for diagnosing HCC metastasizing to the craniospinal area.

Geographic Variation in the Skull Morphometry of Four Populations of Batrachuperus karlschmidti(Urodela:Hynobiidae)

Geographic variation of morphology is an important topic of evolutionary biology,and research on geographic variation can provide insights on the formation,evolution,and adaptation of species and subspecies.The vertebrate skull is a developmentally and functionally complex morphological structure with multiple functions,that is susceptible to vary according to selection pressure.In this study,geographic variations in skull morphology of Batrachuperus karlschmidti from four different geographic populations(Shade,Gexi,Shangluokema,and Xinduqiao)were examined via geometric morphometrics.No significant differences were found among these populations with regard to skull size;however,significant variation was found in skull shape.The most notable shape changes are the relative sizes and positions of the frontal,maxilla,pterygoid,and vomer.Skull shape changes were not related to allometry.However,due to limitation of sample populations and size,the results of this study need to be further verified by more sample populations and individuals in the future.The results of this study contribute to our knowledge about these aspects of morphological variability in this species as well as in hynobiid salamanders.

THIRTY YEARS IN SKULL BASE SURGERY

The skull base generally refers to the anterior, middle and posterior cranial fossa and structures on the outside side of these skull areas. The cranial roof and skull base are separated by a line connecting the external occipital protuberance, parietal notch and supraorbital ridge[1].The skull base supports the brain above, is connected to