How did intraoperative neuromonitorization prevent tetraplegia?

PURPOSE: Patients with mucopolysaccharidosis type IVA (MPS IVA) have many risk factors for myelopathy and paresis. These are spinal cord compression, bone stenosis, and soft tissue thickening with ligament laxity, deformity, odontoid hypoplasia, and atlantoaxial instability. Although most patients with MPS IVA appear generally healthy at birth, patients often show skeletal deformities within a few years. Surgical indications are difficult to determine. Historically, many physicians have used prophylactic decompression and fusion in young, asymptomatic MPS IVA patients to prevent cord compression. Although spinal cord decompression is usually required at the craniocervical junction in patients with MPS IVA, decompression may be required at other spinal cord levels as well. There is a risk of developing neurological damage during surgery. The most common causes are ischemia secondary to cardiac output deteriorated in the prone position or due to artery damage, and local trauma due to neck movements or traction while bringing the patient to the prone position. Neurophysiological monitoring is very important during surgery to reduce the risk of neurological damage in spinal cord surgery. In this case report, a case with loss of lower extremity neuromonitorization motor evoked potential (MEP) responses in the early period of surgery without any intervention to the craniocervical junction after prone positioning will be presented.

Comparison of the Results of Suture and Resorbable Plate-Screw Fixation in Craniosynostosis.

BACKGROUND: Although many fixation methods are used alone or in combination for craniosynostosis, only few studies have compared the effectiveness and long-term results of these methods. METHOD: In this study, patients in whom suture or resorbable plate-screw system was used for fixation were evaluated in terms of postoperative results and complications. The data of patients who underwent surgery for craniosynostosis between 2002 and 2019 were retrospectively reviewed and evaluated. RESULTS: A total of 70 patients, 41 in the suture group and 29 in the resorbable plate-screw group, were included in the study. Whitaker classification was used for head shape evaluation, and anthropometric head circumference measurements were performed in all patients in the preoperative and postoperative periods. In the postoperative period, all patients were compared in terms of the operation time, transfusion requirement, discharge, follow-up period, and complications according to the chosen fixation method.The mean age, postoperative complication rates, anthropometric head circumference measurements, and Whitaker scores of both groups were found to be statistically similar. Although the resorbable plate-screw group had a longer follow-up period, the operation time was longer in the suture group. Furthermore, the suture group had lower transfusion requirement and earlier discharge from the hospital than the resorbable plate-screw group. CONCLUSIONS: If fixation with suture is chosen in suitable patients, in addition to the low patient cost, this method can be safely applied in centers with limited logistical possibilities, because of the results and complication rates being similar to fixation with resorbable plate-screws.

Sagittal spinopelvic alignment in tethered cord syndrome and split cord malformation.

PURPOSE: Sagittal imbalance is common in degenerative and congenital spinal diseases. Some studies have examined spinal deformities in the spina bifida. However, sagittal spinopelvic parameters in tethered cord syndrome (TCS) and split cord malformation (SCM) have been poorly evaluated in the literature. In this study, we investigated sagittal spinopelvic differences in TCS due to fatty filum terminale and SCM patients. MATERIAL AND METHODS: A total of 78 patients with spina bifida occulta (30 SCM and 48 TCS due to fatty filum terminale) were included in the study. Radiological images of these patients were retrospectively evaluated. We evaluated the pelvic incidence, pelvic tilt, sacral slope, sagittal vertical axis (SVA), T1 pelvic angle, lumbar lordosis (LL), thoracic kyphosis, thoracolumbar alignment, and change in those parameters with age. RESULTS: Correlation coefficients between age and LL, T1 pelvic angle, and the SVA in patients with TCS due to fatty filum terminale were statistically significant. In addition, correlation coefficients between age and LL and the SVA in patients with SCM were statistically significant. Notably, LL was increased at a statistically significant level with age in patients with TCS and SCM. CONCLUSION: Improved knowledge of spinal balance parameters in patients with TCS and SCM may be helpful in understanding the clinical course of these pathologies, and provide information regarding the success of surgery at the follow-up period.

First report of tethered cord syndrome in a patient with Sotos syndrome.

BACKGROUND: Sotos syndrome is caused by a gene deletion with an autosomal dominant pattern of inheritance. The Sotos syndrome was first described by Juan Sotos. Cole and Hughes identified the clinical characteristics of this syndrome. This syndrome is characterized by macrocephaly, frontal bossing, ocular hypertelorism, overgrowth, subdural hygroma, ventricular dilatation, agenesis of the corpus callosum. This syndrome is associated with mutations in NSD 1 (nuclear receptor SET domain-containing protein 1) gene, protein insufficiency, and a 5q35 microdeletion. Sotos syndrome is reported to occur in approximately 1/10,000-15,000 births. CASE PRESENTATION: We present a patient with Sotos syndrome who is harboring a sacral lipoma and tethered cord syndrome and she had growth retardation, frontal bossing and hypertelorism. After a standard approach for tethered cord syndrome, the patient was discharged 3 days after without any additional neurodeficits. CONCLUSION: In the literature, sacral lipoma and tethered cord syndrome with Sotos syndrome have not been published yet.

Fluorescein-guided excision of a pediatric intraparenchymal schwannoma presenting with seizure and neurogenic pulmonary edema.

Intraparenchymal schwannomas of the brain are very rare, accounting for < 1% of intracranial schwannomas. We present a case of an 11-year-old boy with a left frontotemporal lobe schwannoma presented with seizure and neurogenic pulmonary edema. To our knowledge, this is the first case of intracerebral schwannoma with neurogenic pulmonary edema published to date and is the first case of an intracerebral schwannoma operated with fluorescein guidance.

Reduced field of view under the surgical microscope due to personal protective equipment: lessons learned during the COVID-19 pandemic.

OBJECTIVE: During the coronavirus disease 2019 (COVID-19) pandemic, neurosurgeons all around the globe continue to operate in emergency cases using new self-protective measures. Personal protective equipment (PPE) use is recommended in all surgeries. The authors have experienced varying degrees of field of view (FOV) loss under the surgical microscope with different PPE. Herein, they aimed to investigate the effects of different PPE on FOV while using the surgical microscope. METHODS: Fifteen neurosurgeons and neurosurgery residents participated in this study. Three kinds of PPE (safety spectacles, blast goggles, and face shields) were tested while using a surgical microscope. FOV was measured using a 12 × 12-cm checkered sheet of paper on which every square had an area of 25 mm2 under the microscope. The surgical microscope was positioned perpendicular to the test paper, and the zoom was fixed. Each participant marked on the test sheet the peripheral borders of their FOV while using different PPE and without wearing any PPE. A one-way repeated-measures ANOVA was performed to determine if there was a significant difference in FOV values with the different PPE. RESULTS: FOV was significantly different between each PPE (F[3, 42] = 6339.845, p < 0.0005). Post hoc analysis revealed a significant decrease in the FOV from the naked eye (9305.33 ± 406.1 mm2) to blast goggles (2501.91 ± 176.5 mm2) and face shields (92.33 ± 6.4 mm2). There were no significant FOV changes with the safety spectacles (9267.45 ± 410.5 mm2). CONCLUSIONS: While operating under a surgical microscope safety spectacles provide favorable FOVs. Face shields increase the eye piece-pupil distance, which causes a severe reduction in FOV.

Iron homeostasis is altered in response to hypoxia and hypothermic preconditioning in brain glial cells

Background/aim: Altered iron metabolism is one of the pathophysiological mechanisms occurring during hypoxic injuries in the central nervous system. Proper homeostasis of cellular iron is regulated by iron import, storage, and export proteins that prevent excess iron overload or iron starvation in cells. Therapeutic hypothermia is an approved treatment for hypoxic ischemia in newborns, but the underlying molecular mechanism is still unknown. We studied the effects of hypoxia, preceded with preconditioning, on the iron homeostasis of glial cells, known as a major actor in the inflammatory process during perinatal brain injury. Materials and methods: Primary microglia and astrocytes in culture were exposed to 12 h of hypoxia with or without mild hypothermic preconditioning. The mRNA expression was assessed using qPCR. Iron accumulation was visualized via modified Perl's histochemistry. Cytokine levels in cell cultures were measured using ELISA. Results: Hypothermic preconditioning enhanced microglial viability, which previously was decreased in both cell types due to hypoxia. Hypoxia increased iron accumulation in the mixed glial cells and in ferritin expression in both microglia and astrocytes. Hypotermic preconditioning decreased the elevated ferritin-light chain expression significantly in microglia. Iron importer proteins, DMT1 and TfR1, both increased their mRNA expression after hypoxia, and hypothermic preconditioning continued to support the elevation of DMT1 in both glial cell types. Ferroportin expression increased as a survival factor of the glial cell following hypoxia. Hypothermic preconditioning supported this increase in both cell types and was especially significant in astrocytes. IL-10 levels were prominently increased in cell culture after hypothermic preconditioning. Conclusion: The data suggest that hypothermic preconditioning affects cellular iron homeostasis by regulating the storage and transfer proteins of iron. Regulation of the cellular iron traffic may prevent glial cells from experiencing the detrimental effects of hypoxia-related inflammation.

Posterior fossa horns; a new calvarial finding of mucopolysaccharidoses with well-known cranial MRI features

Background/aim: Mucopolysaccharidoses (MPS) are a group of hereditary metabolic diseases. The aim of this study was to share the previously unreported calvarial finding of internal hypertrophy of the occipitomastoid sutures (IHOMS) together with some other well-known cranial MRI findings in this patient series. Materials and methods: A retrospective evaluation was conducted of 80 cranial MRIs of patients who had been diagnosed and followed up with MPS from 2008 to 2019 in our center. Of these patients, 11 had Hurler, 14 had Hunter, 24 had Sanfilippo, 15 had Morquio, 14 had Maroteaux­Lamy, and 2 had Sly disease. The cranial MRIs were assessed in two main groups as parenchymal intradural cranial MRI findings and extradural calvarial findings. Results: The most common parenchymal intradural cranial MRI findings were white matter signal alterations (n = 51, 63%) and perivascular space enlargements (n = 39, 48%). The most common extradural calvarial findings were J-shaped sella (n = 45, 56%) and tympanic effusion (n = 44, 55%). Although IHOMS was defined in a relatively small number of the patients (n = 12, 15%), the prevalence rate was high in MPS type I (n = 6, 54%). Conclusion: The abnormal cranial MRI findings of the MPS patients, including the newly identified IHOMS, may provide diagnostic clues to differentiate the type of the disease in radiological imaging.

Unexpected Progression of Tonsillar Herniation in Two Pediatric Cases with Chiari Malformation Type I and Review of the Literature.

BACKGROUND: Chiari malformation type 1 (CM-1) is a generally congenital, rarely acquired disease characterized with 5 mm or more displacement of cerebellar tonsils through foramen magnum. METHODS: Here, we report about 2 patients with CM-1 progressed in the degree of tonsillar herniation from our clinic, whereas increasing in prolapse of tonsillar herniation after diagnosis is extremely uncommon. RESULTS: The first patient aged 17 years was diagnosed with CM-1 in 2009 and was operated due to progression of 5 mm radiologically and worsening symptoms in 2014. The second 5-month-old patient initially showed just low-settled tonsillar localization at the borderline, then it descended by 2 cm when the patient reached 3 years of age, yet could not be operated because of parents' objection. CONCLUSION: Due to lack of reports on increasing tonsillar descent in the literature, these case reports will contribute to natural history and management of CM-1.

Management of Neonatal Facial Paralysis due to Cerebellopontine Angle Arachnoid Cyst: A Case Report.

Arachnoid cysts are benign, cerebrospinal fluid-filled collections that can be located in the brain or spinal cord. Arachnoid cysts form approximately 1% of all intracranial lesions. They are accepted as arachnoid developmental anomaly and arise from membrane splitting or duplication. Generally, lesion growth causes symptoms because of mass effect or obstruction. Arachnoid cyst growing mechanisms are a largely controversial issue. We report the case of a neonatal female patient who presented with congenital facial paralysis. Magnetic resonance imaging showed a right cerebellopontine angle arachnoid cyst causing severe mass effect on the brain stem. Cyst fenestration and cystocisternal shunt was performed through retrosigmoid suboccipital craniotomy.

Hyperbaric oxygen therapy in the treatment of malign edema complication after arteriovenous malformation radiosurgery.

A 16-year-old female patient with headache was admitted to our hospital. Radiological examination showed a Spetzler-Martin Grade III arteriovenous malformation (AVM) located at the left frontal lobe. Volume-staged stereotactic radiosurgery (SRS) treatment performed in two fractions at three-month intervals and post-procedural period were uneventful. Eight months later the patient was admitted to our hospital with headache, vomiting, right-sided facial palsy and right upper extremity paresthesia. Radiological examination demonstrated severe vasogenic edema in the left centrum semiovale and temporal region. Due to severe and steroid-resistant malign edema, hyperbaric oxygen (HBO2) therapy was performed as an alternative treatment option. Neurological symptoms resolved completely after HBO2. Radiological examination demonstrated serious improvement of brain edema and mass effect.

Intracranial undifferentiated malign neuroglial tumor in Smith-Lemli-Opitz syndrome: A theory of a possible predisposing factor for primary brain tumors via a case report.

BACKGROUND: Smith-Lemli-Opitz Syndrome (SLOS) is a rare hereditary autosomal recessive disorder with broken cholesterol synthesis causing by 7-dehydrocholesterol reductase deficiency. Although the clinical features and pathogenesis is well-defined, it is unknown whether there is a relationship between SLOS and neoplastic processes, especially brain neoplasms. PURPOSE: We aimed to attract the attentions to any possibility of relation between SLOS and intracranial tumor development via a pediatric case with both intracranial high-grade neuroglial tumor and SLOS, and thus to contribute an additional data to the literature on togetherness of these two clinical conditions. METHOD: In our clinic, we experienced an interesting case of a 10-year-old child with both SLOS and huge brain tumor as rarely seen. Here, we reviewed the features and pathophysiology of SLOS and brain tumors via this case. RESULTS: The patient was operated in our clinic, after, his brain tumor had been diagnosed, and his histopathology was resulted in undifferentiated malignant neuroglial WHO grade 4 tumor. CONCLUSION: According to current literature, our case is the first report on coexisting of SLOS and intracranial undifferentiated malignant neuroglial tumor. Common pathways like impaired sonic hedgehog (Shh) signaling pathway may be considered for pathogenesis of a probable link between SLOS and brain tumors in further studies.

Clinical and surgical outcomes of upper lumbar disc herniations: a retrospective study

Background/aim: Upper lumbar disc herniation (LDH), generally involving L1?L2 and L2?L3 level herniation, is less common than lower LDH and, in this retrospective study, the clinical and radiological findings of patients who suffered from upper LDH and were operated on due to this pathology were reviewed. Materials and methods: Data regarding neurological and radiological findings of patients operated on between January 2005 and December 2013 were retrospectively collected. During this period, 3494 patients had surgery for LDH, and 129 of these patients had disc herniation at the upper levels. Seventy-eight patients with proper follow-up and data were included in the study. Results: There were 39 males and 39 females enrolled in the study. Twenty-one patients (0.6%) were operated on due to L1?L2 disc herniation and 45 (1.2%) had L2?L3 disc herniation. Twelve (0.3%) patients had disc pathologies at both levels. The mean age of the population was 59.9 years old, and this was significantly higher than lower LDH averages previously described in the literature (42 years old). Cauda equina signs and urinary disturbances were frequently seen, in addition to symptoms related to back and leg pain, neurologic claudication, and weakness in lower extremities. Conclusion: Upper LDHs requiring surgical therapy are extremely rare, more so than other LDHs. They are more frequent among older patients and are often present along with signs of cauda equina and urinary dysfunction.

Intramedullary dermoid cyst infection mimicking holocord tumor: should radical resection be mandatory?-a case report.

BACKGROUND: Dermoid cysts are benign lesions which contain epidermal and dermal elements. Dermoid cysts usually contain a dermal sinus tract but this is not mandatory. Dermoid cysts can manifest by spinal cord infection without a dermal sinus tract. An infected spinal dermoid cyst associated with a holocord spinal abscess poses diagnostic and surgical challenges. Although radical surgical drainage is considered as the main treatment modality for spinal abscess, less extensive surgery for microbiological sampling and appropriate antibiotic treatment can be another alternative modality. CASE DESCRIPTION: A 1-year-old boy patient was admitted to our hospital with progressive paraplegia, bladder dysfunction, and neck rigidity. Medical history of the patient included recurrent urinary tract infection and cephalosporin treatments several times. Initial neurological examination revealed confusion, fever, neck rigidity, paraplegia (also, the motor power of the right upper extremity was three fifths that of the upper extremities). He had urinary and gastrointestinal retention. Conservative surgery was performed to take pathological and microbiological samples. With appropriate antibiotic regimen, the nuchal rigidity and fever improved dramatically. Infectious parameters in blood biochemistry significantly decreased after the antibiotic regimen. DISCUSSION AND CONCLUSION: Holocord spinal abscesses are a rare entity. The source of the disease can be hemopoietic spread or contagious spread. The dermal sinus tract is major risk factor for contagious spread. The major hemopoietic sources are urogenital infection, endocarditis, and infective lung diseases. The hemopoietic spread is a more common source for pediatric patients. The thoracolumbar region is the most common site of involvement. Spinal infection has a tendency to extend longitudinally throughout spinal fibers. The pathogenesis of the holocord edema or syrinx is uncertain. The underlying etiology may be inflammation, infection, and associated venous congestion within the spinal canal. Also, CSF circulation alteration due to arachnoiditis may be another etiological factor. The most important entities on outcome are appropriate surgical treatment and antibiotic administration.

Effects of quercetin on chronic constriction nerve injury in an experimental rat model.

BACKGROUND: Flavonoids are popular substances in the literature, with proven effects on cardiovascular, neoplastic and neurodegenerative diseases. Antioxidant effect is the most pronounced and studied one. Among thousands of flavonoids, quercetin (QUE) is a prototype with significant antioxidant effects. This study aims to demonstrate the effects of QUE in an experimental rat model of chronic constriction injury (CCI). METHOD: A two-level study was designed with 42 adult Wistar rats that were randomly assigned to different groups. In the first part, animals in sham, control, quercetin, morphine and gabapentine groups received chronic constriction injury to their sciatic nerves and received a single dose of QUE, morphine and gabapentine. In the second part, different dose regimens of QUE were administered to different groups of animals. Pre-injury and post-injury assessments for mechanical hypersensitivity, thermal sensitivity, locomotor activity and anxiety were recorded and statistical comparisons were performed between different groups. RESULTS: Comparison of QUE with morphine and gabapentine has revealed significant effects of this agent in the current chronic constriction injury model. QUE was significantly superior to Gabapentine and morphine in terms of alleviating mechanical and thermal hypersensitivity. Additionally, pre-injury administration of QUE for 4 days demonstrated long-term effectiveness on mechanical hypersensitivity. CONCLUSIONS: This preliminary report the on effects of QUE in a chronic constriction injury model proved significant effects of the agent, which should be supplemented with different studies using different dose regimens.

Bilateral Optic Pathway Ganglioglioma: The Fifth Case in the Literature.

Gangliogliomas are mixed tumors which contain both glial and neuronal elements. The optic pathway is a very rare location for gangliogliomas, with less than 23 cases reported in the literature. Bilateral involvement of the entire optic pathway was reported in only 4 cases before. Because of similar radiological appearance of other pathological entities such as gliomas and craniopharyngiomas, histopathological diagnosis is essential. We report a ganglioglioma case that involved both optic pathways. A 12-year-old patient suffering from visual deterioration for 6 months was evaluated. After a visual field test and radiological examinations, a microsurgical biopsy procedure was performed. Pathological examination revealed dysplastic/neoplastic ganglion cells and neoplastic glial cells, and the diagnosis was a World Health Organization (WHO) grade 1 ganglioglioma. The patient is scheduled for adjuvant radiotherapy with the hope of prevention of progression.

Pathological evaluation of the filum terminale tissue after surgical excision.

PURPOSE: Tethered cord syndrome (TCS) is an important disease and can produce progressive neurological symptoms. Studies about the filum terminale (FT) have drawn attention to the importance of histopathological investigation of this structure. The most interesting of these subtypes is the FT that incorporates peripheral nerve fibers (PNF). Our study aimed to analyze the frequency of PNF in the FT of 40 cases diagnosed with TCS. METHODS: We performed a retrospective histopathological investigation of FT excised during surgery of patients with TCS who underwent de-tethering. Neurologic and other types of postoperative complications were also revised. RESULTS: Analysis of the samples showed six dominant histopathological subtypes in the FT: fibroadipose tissues including peripheral nerve bundles (n = 14, 37 %), fibroadipose tissue (n = 10, 25 %), fibrous or adipose tissue (n = 7, 17 %), glial tissues including peripheral nerve sections (n = 4, 10 %), and ependymal and glial tissues (n = 4, 10 %). None of the patients presented with neurologic postoperative complications. CONCLUSION: Embryologic studies revealed that it is common to encounter different histological subtypes of FT pathology. However, the presence of peripheral nerve cells in the FT is important for neurosurgical practice due to the risk of sectioning a functional structure during surgery. In our analysis, we demonstrated the high frequency of PNF in FT pathology. However, since none of the patients showed any symptoms of neurologic deterioration, we considered that these fibers were probably not functional. Our findings emphasize the importance of neuromonitoring in TCS surgery. Although we consider that most of the fibers are probably not functional, neuromonitoring after surgery may prevent serious complications.

Results of radiosurgery for trigeminal neuralgia: Ankara experience.

OBJECT: The purpose of this retrospective study is to demonstrate the effectiveness of Gamma Knife radiosurgery for essential trigeminal neuralgia (TGN) and assess the long-term outcome in a cohort from Turkey. METHODS: From 2004 to 2011, 93 cases of essential TGN were treated with single radiosurgery (RS). Female:male ratio was 45:48 and the mean age of the population was 57.06 years. Mean suffering time before treatment was 88.26 months. V2 + V3 was the most effected branch. 38.7% of the cases had no previous invasive procedures. Each case received doses ranging from 70 to 90 Gy in a target located at the pontine trigeminal root entry zone of the trigeminal nerve. Statistical analyses were performed to evaluate the outcome and factors leading to outcome status. RESULTS: The median follow-up period was 28 months. Of the cases 31.2% had poor outcome related to treatment failure after single RS session. The excellent and good outcomes were achieved in 29% and 39.8% of patients, respectively. The probability of maintaining pain relief was calculated as 67% at 36 months and 58% at 72 months. The only complication encountered was facial dysesthesia and was positive in 68.8% of patients. The presence of facial dysesthesia was significantly correlated with better outcomes. In this study, no other factor was determined to have significant influence on outcome. CONCLUSION: RS treatment for TGN is safe and effective. A multicenter, prospective, randomized controlled trial is needed to determine a guideline for better treatment protocols.

Gamma Knife radiosurgery for arteriovenous malformations in pediatric patients.

OBJECTIVE: The authors present the results of Gamma Knife stereotactic radiosurgery performed in a series of children with arteriovenous malformations (AVMs). METHODS: Between June 2005 and January 2014, 75 patients 18 years old or younger received Gamma Knife radiosurgery for AVMs. Of these, 58 patients were eligible for further analysis. The median age of the population was 12 years; 41% presented with hemorrhage, 34% with neurological insult, and 24% patients were diagnosed incidentally. The median AVM volume was 3.5 cm(3). The median radiosurgery-based AVM score (RSBAVMS) was 0.86. The median follow-up period was 32 months. RESULTS: Single session Gamma Knife radiosurgery resulted in complete AVM obliteration in 40 (68.9%) patients. There were 35 (60.3%) excellent outcome (complete obliteration with no new deficits) in this series. During the follow-up period, nine (15.51%) patients experienced new deficits and three (5.1%) patients experienced intracranial hemorrhage. The annual rate of developing new deficits and hemorrhage was calculated as 5.45 and 1.8%, respectively. Volume, gender, RSBAVMS, and nidus type factor were factors associated with excellent outcome. CONCLUSIONS: Radiosurgery was successful in majority of patients with minimal morbidity. Gamma Knife radiosurgery for AVMs can be a safe and successful method in pediatric patients.

Revisiting the microsurgical anatomy of the sagittal stratum and surgical implications: fiber microdissection and tractography study.

OBJECTIVE: The term "sagittal stratum" was coined by Heinrich Sachs in 1892 to define a parasagittally oriented white matter layer at the temporo-occipital cortex. Although this term has been widely used for more than 100 years, the description, classification, borders, and involved fibers of the structure vary among authors and remain imprecise. Through fiber microdissection and tractography, the authors aimed to define the sagittal stratum and resolve the uncertainty by revealing the relationship of this structure to other cerebral white matter pathways and the orientation of fibers in it. METHODS: Twenty postmortem human cerebral hemispheres were prepared according to Klingler's method. Fiber dissections were performed under a surgical microscope and with microsurgical techniques. The results of dissection at each step were photographed with 2D and 3D imaging techniques, and 3D photogrammetry techniques were used to create a 360° model. Diffusion tensor imaging and 7T high-resolution MRI were used to confirm the findings. RESULTS: This study revisited the 3D organization of white matter tracts in the sagittal stratum through fiber microdissection and tractography. The microneuroanatomical structure of the sagittal stratum and its special organization with fibers from all three fiber systems are demonstrated. The authors' findings revealed that the sagittal stratum has two layers consisting of four different fiber tracts. Its external layer consists of a long association fiber and a commissural fiber, while its internal layer consists of intertwined projection fibers, including temporo-parieto-occipitopontine fibers and the posterior thalamic peduncle. Detailed microdissection also showed the location of the posterior thalamic peduncle in the most medial site of all posterior hemispheric projection fibers. CONCLUSIONS: The structure of the sagittal stratum is distinctive in that it contains all three main fiber systems: association, commissural, and projection. Because of its expansive location in the temporal and occipital lobes, it can be damaged by most neurosurgical pathologies and procedures. The authors emphasize the significance of preserving the sagittal stratum during surgical interventions while also challenging the notion of a "silent" brain, suggesting that the current inability to fully comprehend cerebral function contributes to this misconception. Detailed knowledge of the complex white matter anatomy of the sagittal stratum can guide neurosurgeons in surgical planning and the selection of appropriate surgical approaches with intraoperative orientation for safe surgery and less comorbidity.