Cystic degeneration of the fibrous dysplasia presenting with loss of vision.

Cystic degeneration of the fibrous dysplasia is a very rare clinical condition and may present with loss of vision when it involved the skull base. A 12-year-old female child presented with an enlargement of the skull. She was diagnosed as large skull base and skull vault tumor. She underwent partial removal of the tumor, and custom-made titanium implant was inserted. The diagnosis was fibrous dysplasia. Two years after the initial diagnosis, she presented with total loss of vision at her right eye. Radiological imaging confirmed the cystic degeneration within the tumor. She re-operated and the cyst fluid was evacuated in association with the removal of cyst wall. The diagnosis was the cystic degeneration of the fibrous dysplasia. Her vision was improved a few days after the surgery. Fibrous dysplasia of the skull base should be closely followed-up in order to prevent severe visual complications.

Unveiling the etiological impact of GST-M1, GST-T1, and P53 genotypic variations on brain carcinogenesis.

BACKGROUND: Functional variants of glutathione-S-transferase (GST)-M1, GST-T1, p53 might modulate brain cancer risk by altering the rate of metabolism and clearance of carcinogens from the brain tissue. In this study, the role of GST-M1, GST-T1, p53 polymorphisms on brain tumor was investigated. METHODS AND RESULTS: Brain tumor tissues of 143 patients were obtained from the Gulhane Training and Research Hospital, Department of Neurosurgery between 2019 and 2020. In the xenobiotic mechanism, the null allele frequency in the GST-T1, GST-M1 gene regions of Phase II enzymes by qPCR method were investigated. Single nucleotide polymorphism encoding Arg/Pro conversion in the p53 gene region was analyzed in 120 cases by sequence analysis method. The data were analyzed statistically with patient's demographic and clinical data. GST-M1, GST-T1, p53 genotypes of the patient group were determined. The most frequent genotype was null genotype (0/0) for GST-M1 (χ2 = 39.756, p < 0.001). GST-M1 genotype frequencies were 30.8%, 23.1%, 44.3% for 1/1, 1/0, 0/0, respectively. The most frequent genotype was GST-T1 1/1 following by GST-T1 1/0 (χ2 = 0.335, p = 0.846). GST-T1 genotype frequencies were 64.3%, 30.8%, 4.9% for 1/1, 1/0, 0/0, respectively. GST-M1 null genotype might be associated with the development of brain tumors. Genotype distribution obtained in p53 exon 4 codon 72; Arg/Arg was determined as 31 (25.8%), Arg/Pro 70 (58.3%), and Pro/Pro 19 (15.8%) in the case group, while there were 18 (38.3%), 23 (48.9%), and 6 (12.8%) respectively in the control group. However, the genotype distribution of p53 exon 4 codon 72 among tumorous tissue did not significantly vary from healthy control tissues (χ²=2.536, p = 0.281). CONCLUSION: The null allele frequency encountered in the GST-M1, GST-T1 gene regions is consistent with the rates in the gene pool called Caucasian in the literature. GST-M1 gene polymorphism may play a crucial role in brain carcinogenesis in Turkish patients. This study based on clinical data is thought to help to understand the important epidemiological features of brain tumors.

Endoscopic endonasal approach to the cavernous sinus Epstein-Barr virus-positive B cell non-Hodgkin lymphoma in a child: case report.

Cavernous sinus (CS) lymphoma without paranasal sinuses involvement is extremely rare in pediatric population and remains a diagnostic challenge due to its similarity to other tumors located in this area. An 8-year-old boy presented with a 6-day history of gradually developing ptosis in the right eyelid. After admission, his symptoms progressed within 24 h to include right-sided ophthalmoplegia consisting of oculomotor and abducens nerve palsies. Endoscopic endonasal approach (EEA) was performed urgently to decompress the CS and to obtain a diagnosis. The postoperative course was uneventful, and there was no complication related to the surgical approach. No immunodeficiency was identified. The histopathological diagnosis was an Epstein-Barr virus (EBV)-positive high-grade mature B cell non-Hodgkin lymphoma. He was initiated chemotherapy according to COG ANHL01P1 protocol. Two months after surgery, the third and sixth nerve palsies had resolved completely. Currently, he is well and has no clinical or radiological recurrence. This is the first pediatric case with EBV-positive CS lymphoma that underwent EEA for the diagnosis and decompression. In the pediatric population, EEA enables minimally invasive access to the CS and can play an alternative role in the management of CS lesions, either through biopsy or debulking.

Direct Stimulation of Neural Placode and Nerve Roots in Open Myelomeningocele: The Efficacy of Neural Tube Reconstruction.

INTRODUCTION: Intraoperative electrophysiological studies are increasingly used in spinal surgery. However, its use in myelomeningocele (MMC) surgery is still not widespread. The aim of this study was to present our experience in neural placode (NP) and nerve root stimulations in newborns with open MMC. METHODS: Eight newborns underwent surgical treatment for thoracolumbar and lumbosacral MMCs. Intraoperative neuromonitoring including free-running electromyography and stimulation of NP, nerve roots, and spinal cord were performed in all cases. Stimulation sites and intensities and distal response's amplitudes and latencies were recorded. RESULTS: Five patients had thoracolumbar and 3 patients had lumbosacral MMC. Two patients had no movements at the lower extremities while the other had some movements. No response on the lower extremities was obtained in only 1 patient. Responses from the nerve root stimulations were more robust and significant than the placode stimulations. CONCLUSIONS: It is clear that the NP and nerve roots originating from the placode are mostly functional and should be preserved during the surgery. Intraoperative neuromonitoring and direct stimulation should be performed during the MMC repair in order to obtain a better neurological outcome.

Port-a-cath and ventriculoatrial shunt at the same atrium: technical note.

Hydrocephalus is a rare complication of brain involving acute lymphoblastic leukemia (ALL). The standard treatment is ventriculoperitoneal (VP) shunting, while ventriculoatrial (VA) shunting is the second option in a case of VP shunt failure in young children. But the presence of port catheter at the right atrium restricts and makes a VA shunt difficult to place in the same atrium. We presented a 4-year-old boy who had the diagnoses of ALL and underwent chemotherapy through a port-a-cath. He also had hydrocephalus due to the brain invasion of the ALL. He firstly underwent VP shunting for the treatment of hydrocephalus, but it failed due to an intraabdominal cyst. Then, he underwent VA shunting through the left internal jugular vein. This is the first case in the literature showing both catheters in the right atrium.

Intracranial infections: lessons learned from 52 surgically treated cases.

OBJECTIVE: Intracranial infections are serious and life-threatening health problems. They may present as subdural empyemas or intracerebral abscesses. Surgical drainage and subsequent antibiotic treatment is the main technique for a satisfactory clinical outcome. The aims of this study were to present a 10-year intracranial infection series and discuss the surgical characteristics in the light of literature. METHODS: Fifty-two patients with intracranial infection underwent surgical treatment between 2008 and 2018. Eleven patients were female and 41 patients were male. The mean age was 40.46 years (range 10-75 years). Eighteen patients had intracerebral abscesses, and 34 had subdural empyemas. All patients underwent surgical treatment as well as an antibiotic regimen. RESULTS: No etiological agent was isolated in 29 (56%) cases. Bacterial agents were detected in 20 cases, while fungi were observed in 3 cases. Staphylococci species were the most common agents and were isolated in 8 (15%) cases. Endoscopic aspiration was performed in 3 cases, while surgical drainage and capsule resection via craniotomy was performed in 49 cases. An associated intracranial tumor was diagnosed in 2 patients with brain abscesses. Four (8%) patients died despite surgical and medical treatments. CONCLUSIONS: Surgical treatment via craniotomy is an older method, but it is still the best to treat the intracranial infections not only for decompression of the brain but also to attain an accurate diagnosis. The abscess wall should always be histologically examined after surgery to rule out any intracranial tumor.

Glutathione S-Transferases and Cytochrome P450 Enzyme Expression in Patients with Intracranial Tumors: Preliminary Report of 55 Patients.

OBJECTIVE: Intracranial tumors are one of the most frightening and difficult-to-treat tumor types. In addition to surgery, protocols such as chemotherapy and radiotherapy also take place in the treatment. Glutathione S-transferase (GST) and cytochrome P450 (CYP) enzymes are prominent drug-metabolizing enzymes in the human body. The aim of this study is to show the expression of GSTP1, GSTM1, CYP1A1, and CYP1B1 in different types of brain tumors and compare our results with those in the literature. SUBJECTS AND METHODS: The expression of GSTP1, GSTM1, CYP1A1, and CYP1B1 was analyzed using immunostaining in 55 patients with intracranial tumors in 2016-2017. For GST and CYP expression in normal brain tissue, samples of a portion of surrounding normal brain tissue as well as a matched far neighbor of tumor tissue were used. The demographic features of the patients were documented and the expression results compared. RESULTS: The mean age of the patients was 46.72 years; 29 patients were female and 26 were male. Fifty-seven specimens were obtained from 55 patients. Among them, meningioma was diagnosed in 12, metastases in 12, glioblastoma in 9, and pituitary adenoma in 5. The highest GSTP1, GSTM1, and CYP-1A1 expressions were observed in pituitary adenomas. The lowest GSTP1 expression was detected in glioblastomas and the lowest CYP1B1 expression in pituitary adenomas. CONCLUSION: GSTP1 and CYP expression is increased in intracranial tumors. These results should be confirmed with a larger series and different enzyme subtypes.

Limited Dorsal Myeloschisis with and without Type I Split Cord Malformation: Report of 3 Cases and Surgical Nuances.

Limited dorsal myeloschisis (LDM) is a rare form of spina bifida which is characterized by a fibroneural stalk between the inner part of the skin and the spinal cord. It may be associated with split cord malformation (SCM). Diagnosis and management of this complex malformation is challenging. We presented 3 different cases of LDM. Two of them were associated with Type I SCM and the other had no associated malformation. All of them were evaluated radiologically just after the birth and underwent surgical treatment under intraoperative neuromonitoring. They discharged without any complication. Newborns with spinal cystic lesions should be carefully evaluated for spinal malformations after the birth and treated surgically as soon as possible in order to prevent neurological and urological complications secondary to tethered cord syndrome. Surgical technique in LDM-SCM patients is quite different than the patients with solitary LDM.

Expression of Sigma-Class Glutathione-S-Transferase in Fetal and Pediatric Filum Terminale Samples: A Comparative Study.

Background and objectives: The pathophysiology of tethered cord syndrome (TCS) in children is not well elucidated. An inelastic filum terminale (FT) is the main factor underlying the stretching of the spinal cord in TCS. Our study aimed to investigate the expression of glutathione-S-transferase (GST) in children and fetal FT samples in order to understand the relationship between this enzyme expression and the development of TCS. Materials and Methods: FT samples were obtained from ten children with TCS (Group 1) and histological and immunohistochemical examinations were performed. For comparison, FT samples from fifteen normal human fetuses (Group 2) were also analyzed using the same techniques. Statistical comparison was made using a Chi-square test. Results: Positive GST-sigma expression was detected in eight (80%) of 10 samples in Group 1. The positive GST-sigma expression was less frequent in nine (60%) of 15 samples from Group 2. No statistically significant difference was detected between the two groups (p = 0.197). Conclusions: Decreased FT elasticity in TCS may be associated with increased GST expression in FT. More prospective studies are needed to clarify the mechanism of the GST-TCS relationship in children.

Relationship between individual payload weight and spondylolysis incidence in Turkish land forces.

OBJECTIVEThe aim of this study was to investigate the relationship between lumbar spondylolysis and payload weight between different combat units of Turkish land forces (TLF).METHODThe authors reviewed clinical and radiological data of the military personnel with low-back pain (LBP) admitted to their clinic between July 2017 and July 2018. Age, BMI, average payload weight, and military service unit were recorded. CT scans were evaluated for pars interarticularis fractures and spondylolisthesis, whereas MRI studies were evaluated for spondylolisthesis, Modic-type endplate changes, or signal loss on T2-weighted images compatible with disc degeneration.RESULTFollowing exclusion, a total of 642 all-male military personnel were included. Of these personnel, 122 were commandos, 435 were infantry, and 85 were serving in the artillery units. Bilateral pars interarticularis fracture was noted in 42 commandos (34.42%) and 2 infantrymen (0.45%). There was no spondylolysis in the artillery units. There was no multiple-level spondylolysis and the most common level of spondylolysis was L5. Commandos had a significantly higher incidence of spondylolysis and more average payload weight (p < 0.001). Twelve patients (27.2%) with spondylolysis had accompanying MRI pathologies at the same level, whereas 32 patients (72.7%) had no accompanying MRI pathologies.CONCLUSIONSIncreased payload weight in military personnel is associated with spondylolysis, and commandos in the TLF have significantly heavier payloads, which causes an increased rate of spondylolysis compared to other units. Additionally, spondylolysis without adjacent-level changes on MRI could be undiagnosed. LBP in active military personnel who have a history of carrying heavy payloads should be evaluated extensively with both MRI and CT scans.

Lhermitte-Duclos Disease in a Six-Year Old Child: A Rare Presentation.

Lhermitte-Duclos disease (LDD) is a rare, slow-growing, benign lesion of the cerebellum. It is often seen in the second and fourth decades. This disease is extremely rare in childhood. A 6-year-old girl presented with loss of balance. A mass lesion in the right cerebellum was detected by magnetic resonance imaging. The patient underwent surgical removal of the lesion, and the histological diagnosis was dysplastic gangliocytoma (LDD). The patient was discharged without complication, and her balance improved in the follow-up period. In this report, we present this rare occurrence in childhood and discuss the clinical course and management. LDD is very rare in early childhood and should be considered in the differential diagnosis of posterior fossa lesions.

The evaluation of the effects of steroid treatment on the tumor and peritumoral edema by DWI and MR spectroscopy in brain tumors.

OBJECTIVE: To investigate the effects of dexamethasone on brain tumor and peritumoral edema by different sequences of magnetic resonance imaging (MRI). MATERIALS AND METHODS: MRI was performed in 28 patients with brain tumor. Patients were divided into the 3 groups based on the histological diagnosis; Group I: high-grade glial tumor, Group II: low-grade glial tumor, and Group III: brain metastasis. The measurements of peritumoral edema volume and apparent diffusion coefficient (ADC) values were performed while the peak areas of cerebral metabolites were measured by spectroscopy in groups I and II. The changes in edema volumes, ADC values and cholin/creatine peak areas were compared. RESULTS: The volume of peritumoral edema was decreased in groups I and II, but increased in group III after dexamethasone treatment. These changes were not statistically significant for 3 groups. ADC value was decreased in group I and increased in groups II and III. Changes in ADC values were statistically significant. Cholin/creatine peak areas were decreased after dexamethasone in groups I and II, but these changes were also not significant. CONCLUSION: Dexamethasone has no significant effect on the volume of peritumoral edema in glial tumor and metastasis. Moreover, dexamethasone increases the fluid movements in low grade gliomas and metastases, decreases in high grade gliomas. However, more comprehensive clinical studies are needed to show the effects of dexamethasone on brain tumors and peritumoral edema.

Hemimyeloschisis associated with hydrocephalus.

Hemimyeloschisis is a very rare congenital malformation of the spine which is characterized by a split cord malformation associated with complete exposureof the one hemicord to the exterior. We report a case of hemimyeloschisis on the right hemicord in a patient with hydrocephalus. The patient was a female neonate with myeloschisis, skin defect, and hypertrichosis visible at birth in the upper lumbar region. There was also skin defect around the myeloschisis. Computed tomography (CT) revealed a bony septum at the L2 level as well as the myeloschisis on the right hemicord, which enabled us to make a precise preoperative diagnosis of this rare malformation. There was also mild hydrocephalus in cranial CT scan. Closure of the myeloschisis and removal of the septum were successfully performed associated with the closure of the skin in one stage surgery to prevent subsequent infection and neurological deterioration. Ventriculoperitoneal shunt insertion was performed for hydrocephalus. The presence of combined split cord malformation and myeloschisis is consistent with the hypothesis of an ontogenic basis of development. This combination also emphasizes the importance of early imaging for diagnosis in this complex malformation.

Histological structure of the medial and lateral walls of cavernous sinus in human fetuses.

PURPOSE: The aim of this study is to elucidate the architecture of these fine structures in human fetuses. METHODS: The histological examination of medial wall (MW) and lateral wall (LW) was performed in 15 normal human fetuses. Eleven fetuses were female and four were male. The gestational age ranged between 14 and 35 weeks. The weight ranged between 180 and 1750 g. The wall samples (two MW and two LW from each fetus) were obtained by microsurgical technique and underwent histological examination. Each wall was examined for the structure and composition of collagen and elastic fibers, ganglions, peripheral nerves, and vessels. RESULTS: A total of 60 wall samples (30 MW and 30 LW) were examined in 15 fetuses. Loose connective tissue composed of type III collagen was observed in both of the walls. Elastic fibers were observed only in three wall samples (two MW and one LW). Ganglion was detected in 11 samples (nine in LW and two in MW), and peripheral nerve was found in 28 walls (18 LW and 10 MW). Vessels were observed in 51 samples (26 LW and 25 MW). None of the walls was stained with type I collagen. CONCLUSIONS: The structure of LW and MW of the cavernous sinus (CS) in fetuses is mainly composed of collagen tissue while some elastic fibers are supported by this tissue. Type III collagen is the main component of fetal CS walls. Because of the weak histological structure, CS may be more prone to tumor invasion in infants.

Morphological structure and variations of lumbar plexus in human fetuses.

The objective of this study is to study the anatomy of lumbar plexus on human fetuses and to establish its morphometric characteristics and differences compared with adults. Twenty lumbar plexus of 10 human fetal cadavers in different gestational ages and genders were dissected. Lumbar spinal nerves, ganglions, and peripheral nerves were exposed. Normal anatomical structure and variations of lumbar plexus were investigated and morphometric analyses were performed. The diameters of lumbar spinal nerves increased from L1 to L4. The thickest nerve forming the plexus was femoral nerve, the thinnest was ilioinguinal nerve, the longest nerve through posterior abdominal wall was iliohypogastric nerve, and the shortest nerve was femoral nerve. Each plexus had a single furcal nerve and this arose from L4 nerve in all fetuses. No prefix or postfix plexus variation was observed. In two plexuses, L1 nerve was in the form of a single branch. Also, in two plexuses, genitofemoral nerve arose only from L2 nerve. Accessory obturator nerve was observed in four plexuses. According to these findings, the morphological pattern of the lumbar plexus in the fetus was found to be very similar to the lumbar plexus in adults.

Anatomical relationship and positions of the lumbar and sacral segments of the spinal cord according to the vertebral bodies and the spinal roots.

Segments of the spinal cord generally do not correspond to the respective vertebral level and there are many anatomical variations in terms of the segment and the level of vertebra. The aim of this study is to investigate the variations and levels of lumbar and sacral spinal cord segments with reference to the axilla of the T11, T12, and L1 spinal nerve roots and adjacent vertebrae. Morphometric measurements were made on 16 formalin fixed adult cadaveric spinal cords. We observed termination of the spinal cord between the axilla of the L1 and L2 spinal nerve roots in 15 specimens (93.8%). In all cadavers the emergence of the T11, T12, and the L1 spinal nerve roots was at the level of the lower one-third of the same vertebral body. In 15 specimens (93.8%), the beginning of the lumbar spinal cord segment was found to be above the T11 spinal nerve root axilla and corresponded to the upper one-third of the T11 vertebral body. The beginning of the sacral spinal cord segment occurred above the L1 spinal nerve root axilla and corresponded to the upper one-third of the L1 vertebral body. The results of this study showed that when the conus medullaris is located at the L1-L2 level, the beginning of the lumbar spinal cord segment always corresponds to the body of T11 vertebra. This study provides detailed information about the correspondence of the spinal cord segments with reference to the axilla of the spinal nerve roots.

Simultaneous Closure of Bilateral Cranial Defects Using Custom-Made 3D Titanium Implants: A Single Institution Series.

AIM: To investigate the outcomes of the simultaneous closure of bilateral cranial defects using custom-made three-dimensional (3D) titanium implants. MATERIAL AND METHODS: Demographic data of 26 patients with bilateral cranial defects who underwent cranioplasty using the 3D custom-made titanium implants in our clinic between 2017 and 2022 were retrospectively reviewed. Data on the area of cranium defect, the time interval between last cranial surgery and cranioplasty, postoperative complications, etiology of the cranium defect, and hospitalization of the patient were statistically evaluated. RESULTS: The incidence of bilateral cranioplasty was 19.11%. The gender distribution of patients was 4 (15.4%) female and 22 (84.6%) male, with a mean age of 29.08 ± 14.65 years. The mean defect area was 35.0 ± 19.03 and 29.24 ± 22.51 cm2 on the right and left sides, respectively. The etiology of the cranium defect was gunshot wounds in 12 patients, and 14 patients had a history of trauma-related injuries such as falls and vehicle accidents. Eight patients had a history of failed cranioplasty with autologous bone. Postoperative complications were wound dehiscence in two patients and diffuse cerebral edema in one patient. No mortality was recorded. CONCLUSION: The custom-made cranioplasty is feasible for simultaneous closure of bilateral cranial defects. Many complications can be prevented by careful preoperative evaluation before surgery and an appropriate implant selection for the patient.

Comparison of intrathecal dotarizine and nimodipine treatments in cerebral vasospasm after subarachnoid hemorrhage: an experimental study in rabbits.

BACKGROUND: cerebral vasospasm (CVS) is one of the most considerable complications of subarachnoid hemorrhage (SAH). The aim of this study was to assess and to compare the ability of intrathecal dotarizine and nimodipine to prevent and treat vasospasm in a rabbit model of subarachnoid hemorrhage. METHOD: thirty male New Zealand white rabbits weighing 2,500-3,000 g were allocated into five groups randomly. The treatment groups were as follows: Control, only SAH, SAH/Dotarizine, SAH/Nimodipine, SAH/Vehicle. Forty-eight hours after SAH injection, all animals underwent femoral artery catheterization procedure by open surgery under anesthesia and angiography performed for each animal in the fifth day just before sacrifice. FINDINGS: basilar artery vessel diameters are measured by angiography. Basilar artery vessel diameters and luminal sectional areas are measured in pathology slides. There was a statistically significant difference between the mean basilar artery cross-sectional areas and the mean arterial wall thickness measurements of the control and SAH-only groups (p < 0.05). CONCLUSIONS: these findings demonstrate that calcium channel blocker dotarizine has marked vasodilatory effect in an experimental model of SAH in rabbits. Nimodipine is an effect-proven agent in CVS, but dotarizine may take place of it.

Comparison of intrathecal flunarizine and nimodipine treatments in cerebral vasospasm after experimental subarachnoid hemorrhage in rabbits.

BACKGROUND: the aim of this study was to assess and to compare the ability of intrathecal flunarizine and nimodipine to prevent vasospasm in a rabbit model of subarachnoid hemorrhage (SAH). METHOD: forty male New Zealand white rabbits were allocated into 5 groups randomly. The treatment groups were as follows: (1) control (no SAH [n = 8]), (2) SAH only (n = 8), (3) SAH plus vehicle (n = 8), (4) SAH plus nimodipine (n = 8), and (5) SAH plus flunarizine (n = 8). Before sacrifice, all animals underwent femoral artery catheterization procedure by open surgery under anesthesia and angiography performed for each animal. FINDINGS: there was a statistically significant difference between the mean basilar artery cross-sectional areas and the mean arterial wall thickness measurements of the control and SAH-only groups (p < 0.05). Basilar artery vessel diameter and luminal section areas in group 4 were significantly higher than in group 2 (p < 0.05). Basilar artery vessel diameter and basilar artery luminal section areas in group 5 were significantly higher than in group 2 (p < 0.05).Basilar artery vessel diameter and basilar artery luminal section areas in group 5 were significantly higher than in group 4 (p < 0.05). CONCLUSIONS: these findings demonstrate that flunarizine has marked vasodilatatory effect in an experimental model of SAH in rabbits.

Level I to III craniofacial approaches based on Barrow classification for treatment of skull base meningiomas: surgical technique, microsurgical anatomy, and case illustrations.

OBJECT: Although craniofacial approaches to the midline skull base have been defined and surgical results have been published, clear descriptions of these complex approaches in a step-wise manner are lacking. The objective of this study is to demonstrate the surgical technique of craniofacial approaches based on Barrow classification (Levels I-III) and to study the microsurgical anatomy pertinent to these complex craniofacial approaches. METHODS: Ten adult cadaveric heads perfused with colored silicone and 24 dry human skulls were used to study the microsurgical anatomy and to demonstrate craniofacial approaches in a step-wise manner. In addition to cadaveric studies, case illustrations of anterior skull base meningiomas were presented to demonstrate the clinical application of the first 3 (Levels I-III) approaches. RESULTS: Cadaveric head dissection was performed in 10 heads using craniofacial approaches. Ethmoid and sphenoid sinuses, cribriform plate, orbit, planum sphenoidale, clivus, sellar, and parasellar regions were shown at Levels I, II, and III. In 24 human dry skulls (48 sides), a supraorbital notch (85.4%) was observed more frequently than the supraorbital foramen (14.6%). The mean distance between the supraorbital foramen notch to the midline was 21.9 mm on the right side and 21.8 mm on the left. By accepting the middle point of the nasofrontal suture as a landmark, the mean distances to the anterior ethmoidal foramen from the middle point of this suture were 32 mm on the right side and 34 mm on the left. The mean distance between the anterior and posterior ethmoidal foramina was 12.3 mm on both sides; the mean distance between the posterior ethmoidal foramen and distal opening of the optic canal was 7.1 mm on the right side and 7.3 mm on the left. CONCLUSIONS: Barrow classification is a simple and stepwise system to better understand the surgical anatomy and refine the techniques in performing these complex craniofacial approaches. On the other hand, thorough anatomical knowledge of the midline skull base and variations of the neurovascular structures is crucial to perform successful craniofacial approaches.