Beyond nimodipine: advanced neuroprotection strategies for aneurysmal subarachnoid hemorrhage vasospasm and delayed cerebral ischemia.

The clinical management of aneurysmal subarachnoid hemorrhage (SAH)-associated vasospasm remains a challenge in neurosurgical practice, with its prevention and treatment having a major impact on neurological outcome. While considered a mainstay, nimodipine is burdened by some non-negligible limitations that make it still a suboptimal candidate of pharmacotherapy for SAH. This narrative review aims to provide an update on the pharmacodynamics, pharmacokinetics, overall evidence, and strength of recommendation of nimodipine alternative drugs for aneurysmal SAH-associated vasospasm and delayed cerebral ischemia. A PRISMA literature search was performed in the PubMed/Medline, Web of Science, ClinicalTrials.gov, and PubChem databases using a combination of the MeSH terms "medical therapy," "management," "cerebral vasospasm," "subarachnoid hemorrhage," and "delayed cerebral ischemia." Collected articles were reviewed for typology and relevance prior to final inclusion. A total of 346 articles were initially collected. The identification, screening, eligibility, and inclusion process resulted in the selection of 59 studies. Nicardipine and cilostazol, which have longer half-lives than nimodipine, had robust evidence of efficacy and safety. Eicosapentaenoic acid, dapsone and clazosentan showed a good balance between effectiveness and favorable pharmacokinetics. Combinations between different drug classes have been studied to a very limited extent. Nicardipine, cilostazol, Rho-kinase inhibitors, and clazosentan proved their better pharmacokinetic profiles compared with nimodipine without prejudice with effective and safe neuroprotective role. However, the number of trials conducted is significantly lower than for nimodipine. Aneurysmal SAH-associated vasospasm remains an area of ongoing preclinical and clinical research where the search for new drugs or associations is critical.

Exploring arterial anatomy of the internal capsule: an analysis of the deep vascular structures and related white matter pathways.

BACKGROUND AND OBJECTIVES: The internal capsule is supplied by perforators originating from the internal carotid artery, middle cerebral artery, anterior choroidal artery and anterior cerebral artery. The aim of this study is to examine the vascular anatomy of the internal capsule, along with its related white matter anatomy, in order to prevent potential risks and complications during surgical interventions. METHODS: Twenty injected hemispheres prepared according to the Klingler method were dissected. Dissections were photographed at each stage. The findings obtained from the dissections were illustrated to make them more understandable. Additionally, the origins of the arteries involved in the vascularization of the internal capsule, their distances to bifurcations, and variations in supplying territories have been thoroughly examined. RESULTS: The insular cortex and the branches of the middle cerebral artery on the insula and operculum were observed. Following decortication of the insular cortex, the extreme capsule, claustrum, external capsule, putamen and globus pallidus structures were exposed. The internal capsule is shown together with the lenticulostriate arteries running on the anterior, genu and posterior limbs. Perforators supplying the internal capsule originated from the middle cerebral artery, anterior cerebral artery, internal carotid artery and anterior choroidal artery. The internal capsule's vascular supply varied, with the medial lenticulostriate arteries (MLA) and lateral lenticulostriate arteries (LLA) being the primary arteries. The anterior limb was most often supplied by the MLA, while the LLA and anterior choroidal artery dominated the genu and posterior limb. The recurrent artery of Heubner originated mostly from the A2 segment. The distance from the ICA bifurcation to the origin of the first LLA on M1 is 9.55 ± 2.32 mm, and to the first MLA on A1 is 5.35 ± 1.84 mm. MLA branching from A1 and proximal A2 ranged from 5 to 9, while LLA originating from the MCA ranged from 7 to 12. CONCLUSION: This study provides comprehensive understanding of the arterial supply to the internal capsule by combining white matter dissection. The insights gained from this study can help surgeons plan and execute procedures including oncological, psychosurgical, and vascular more accurately and safely. The illustrations derived from the dissections serve as valuable educational material for young neurosurgeons and other medical professionals.

Medical management of chronic subdural hematoma with low-dose hydrocortisone: a case series.

Chronic subdural hematomas (cSDH) are often managed with a burr-hole craniostomy and drainage, but surgery is associated with elevated mortality, morbidity, and recurrence. Despite reports of steroid use for such patients, its efficacy and feasibility are still debated. We present our patient series treated with low-dose hydrocortisone. We retrospectively reviewed data from patients treated with hydrocortisone between 2017 and 2023. Demographics, clinical and radiological data were collected. Of 27 patients identified, nine required a burr-hole craniotomy for an average volume of 120.23 cm3, average midline shift of 9 mm, and neurological deficits. Eighteen met the criteria for inclusion. The mean age was 78.5 years; 13 were male. None had severe symptoms requiring urgent intervention. Except for one with a Karnofsky Performance Scale score of 70, all could maintain normal activity before treatment. The mean baseline volume was 52.6 cm3. Midline shift, present in six, averaged 6.8 mm. Patients underwent treatment for an average of 5.15 months. Nine had complete resolution within 3 months, while nine required longer treatment, including one who needed 9 months for a re-bleed after a fall. Paired t-tests indicated significant reductions in hematoma volumes at the second week (p = 0.01), first month (p < 0.0001), and third month (p < 0.0001) of treatment. No complications occurred and the post-treatment Karnofsky scores ranged from 90 to 100. Treatment for cSDH should be tailored to the patient. Low-dose hydrocortisone is safe and effective in asymptomatic patients, those with mild to moderate symptoms, and those who are either unsuitable for or decline surgical intervention.

Creation of a microsurgical neuroanatomy laboratory and virtual operating room: a preliminary study.

OBJECTIVE: A comprehensive understanding of microsurgical neuroanatomy, familiarity with the operating room environment, patient positioning in relation to the surgery, and knowledge of surgical approaches is crucial in neurosurgical education. However, challenges such as limited patient exposure, heightened patient safety concerns, a decreased availability of surgical cases during training, and difficulties in accessing cadavers and laboratories have adversely impacted this education. Three-dimensional (3D) models and augmented reality (AR) applications can be utilized to depict the cortical and white matter anatomy of the brain, create virtual models of patient surgical positions, and simulate the operating room and neuroanatomy laboratory environment. Herein, the authors, who used a single application, aimed to demonstrate the creation of 3D models of anatomical cadaver dissections, surgical approaches, patient surgical positions, and operating room and laboratory designs as alternative educational materials for neurosurgical training. METHODS: A 3D modeling application (Scaniverse) was employed to generate 3D models of cadaveric brain specimens and surgical approaches using photogrammetry. It was also used to create virtual representations of the operating room and laboratory environment, as well as the surgical positions of patients, by utilizing light detection and ranging (LiDAR) sensor technology for accurate spatial mapping. These virtual models were then presented in AR for educational purposes. RESULTS: Virtual representations in three dimensions were created to depict cadaver specimens, surgical approaches, patient surgical positions, and the operating room and laboratory environment. These models offer the flexibility of rotation and movement in various planes for improved visualization and understanding. The operating room and laboratory environment were rendered in three dimensions to create a simulation that could be navigated using AR and mixed reality technology. Realistic cadaveric models with intricate details were showcased on internet-based platforms and AR platforms for enhanced visualization and learning. CONCLUSIONS: The utilization of this cost-effective, straightforward, and readily available approach to generate 3D models has the potential to enhance neuroanatomical and neurosurgical education. These digital models can be easily stored and shared via the internet, making them accessible to neurosurgeons worldwide for educational purposes.

Transorbital neuroendoscopic surgery for treatment of sphenoid wing meningiomas extending to the cavernous sinus: clinical implications and a technical illustration.

OBJECTIVE: The aim of this study was to evaluate the efficacy and safety of transorbital neuroendoscopic surgery (TONES) in the management of sphenoid wing meningiomas (SWMs) with cavernous sinus and orbital invasion. METHODS: The authors conducted a retrospective review of 32 patients with SWMs treated at Gazi University using TONES from October 2019 to May 2023. The study includes clinical applications to elucidate the endoscopic transorbital approach. Surgical techniques focused on safe subtotal resection, aiming to minimize residual tumor volume for subsequent radiosurgery. Data were collected on patient demographics, tumor characteristics, surgical procedures, complications, and postoperative outcomes, including radiological imaging and ophthalmological evaluations. RESULTS: Surgical dissections delineated a three-phase endoscopic transorbital approach: extraorbital, intraorbital, and intracranial. In the clinical application, gross-total resection was not achieved in any patient because of planned postoperative Gamma Knife radiosurgery. The mean follow-up period was 16.3 months. Of 30 patients with preoperative proptosis, 25 experienced postoperative improvement. No new-onset extraocular muscle paresis or visual loss occurred postoperatively. The average hospital stay was 1.15 days, with minimal complications and no significant morbidity or mortality. CONCLUSIONS: Total resection of SWMs invading the cavernous sinus and orbit is associated with substantial risks, particularly cranial nerve deficits. TONES offers a minimally invasive alternative, reducing morbidity compared with transcranial approaches, and represents a significant advancement in the surgical management of SWMs, especially those extending into the cavernous sinus and orbit. The approach provides a safe, effective, and patient-centric approach, prioritizing subtotal resection to minimize neurological deficits while preparing patients for adjunctive radiosurgery. This study positions TONES as a transformative surgical technique, aligning therapeutic efficacy with neurovascular preservation and postoperative recovery.

The role of an open artificial intelligence platform in modern neurosurgical education: a preliminary study.

The use of artificial intelligence in neurosurgical education has been growing in recent times. ChatGPT, a free and easily accessible language model, has been gaining popularity as an alternative education method. It is necessary to explore the potential of this program in neurosurgery education and to evaluate its reliability. This study aimed to show the reliability of ChatGPT by asking various questions to the chat engine, how it can contribute to neurosurgery education by preparing case reports or questions, and its contributions when writing academic articles. The results of the study showed that while ChatGPT provided intriguing and interesting responses, it should not be considered a dependable source of information. The absence of citations for scientific queries raises doubts about the credibility of the answers provided. Therefore, it is not advisable to solely rely on ChatGPT as an educational resource. With further updates and more specific prompts, it may be possible to improve its accuracy. In conclusion, while ChatGPT has potential as an educational tool, its reliability needs to be further evaluated and improved before it can be widely adopted in neurosurgical education.

Suprafloccular transhorizontal fissure approach to the cerebellopontine angle: an anatomical study with case series.

The suprafloccular transhorizontal fissure approach is a modified variant of the classical retrosigmoid approach option to be chosen for cerebellopontine angle lesions. In this study, we aimed to demonstrate a previously described but not widely used method, the suprafloccular transhorizontal fissure approach with anatomical dissection on the cadaver, accompanied by a case presentation with the largest clinical series in the literature. Klingler's protocol was used to prepare 8 silicone injected and 8 non-silicone injected human hemispheres. A total of 210 patients who underwent surgery in the cerebellopontine angle between 2019 and 2022 were evaluated in our clinic. Of these, the suprafloccular transhorizontal fissure approach was applied in 33 patient, and it was successful in 26 patient, but this approach could not be achieved in 7 patients. The transhorizontal fissure is a fissure in the cerebellum located between the superior semilunar lobule and the inferior semilunar lobule. In the 26 patients we operated with the suprafloccular transhorizontal fissure approach, there was no need for retraction and no complications developed. However, in 7 patients, this fissure could not be dissected due to adhesions. Suprafloccular approach is an alternative to the classical retrosigmoid approach in tumours smaller than 2 cm, medially localised with little cerebellar oedema and neurovascular compression syndrome. Because in this approach, no cerebellum retraction is required, vascular structures are better preserved and the surgical time is shortened. This approach can be applied in smaller tumours than 2 cm when the sulcal anatomy is appropriate.

Cingulate sulcus morphology and paracingulate sulcus variations: Anatomical and radiological studies.

The sulci and gyri found across the cerebrum differ in morphology between individuals. The cingulate sulcus is an important landmark for deciding the surgical approach for neighboring pathological lesions. Identifying the anatomical variations of anterior cingulate cortex morphology would help to determine the safe-entry route through neighboring lesions. In this study, magnetic resonance imaging data acquired from 149 healthy volunteers were investigated retrospectively for anatomical variations of the paracingulate sulcus. Also, human cadaveric brain hemispheres were investigated for cingulate and paracingulate sulcus anatomy. All participants had cingulate sulci in both hemispheres (n = 149, 100%). Three types of paracingulate sulcus patterns were identified: "prominent," "present," and "absent." Hemispheric comparisons indicated that the paracingulate sulcus is commonly "prominent" in the left hemisphere (n = 48, 32.21%) and more commonly "absent" in the right hemisphere (n = 73, 48.99%). Ten (6.71%) people had a prominent paracingulate sulcus in both the right and left hemispheres. Seven (4.70%) of them were male, and 3 (2.01%) of them were female. Paracingulate sulci were present in both hemispheres in 19 people (12.75%), of which 9 (6.04%) were male and 10 (6.71%) were female. There were 35 (23.49%) participants without paracingulate sulci in both hemispheres. Eleven (7.38%) were male and 24 (16.11%) were female. There were 73 (48.99%) participants without right paracingulate sulcus and 57 (38.26%) participants without left paracingulate sulcus (p = 0.019). In the examinations of the cadaver hemispheres, the paracingulate sulcus was present and prominent in 25%, and the intralimbic sulcus was present in 15%. It has been observed that the paracingulate sulcus is more prominent in the normal male brain compared to females. In females, there were more participants without paracingulate sulcus. This study shows that there are both hemispheric and sex differences in the anatomy of the paracingulate sulcus. Understanding the cingulate sulcus anatomy and considering the variations in the anterior cingulate cortex morphology during surgery will help surgeons to orient this elegant and complex area.

The historical evolution of the fornix and its terminology: a review.

The historical evolution of the fornix has not been sufficiently reviewed in the literature. In this article, we follow this evolution from the first mention of the fornix in animal dissections of the second century AD, to the legalization of cadaver dissection in the 1300 s, to the introduction of neural staining techniques and the microscope in the seventeenth century, to today. We summarize the focus of fornix studies on memory to reveal its relationship with the hippocampus. We then cover the detection of the fornix and its neural connections noninvasively with the advancement of radiological imaging techniques. Finally, we discuss the prominence of the fornix as a target for deep brain stimulation in Alzheimer's disease and post-traumatic brain injury memory disorders.

The posterior interhemispheric transparieto-occipital fissure approach to the atrium of the lateral ventricle: a fiber microdissection study with case series.

The surgical approach to the atrium of the lateral ventricle remains a challenge because of its deep location and close relationship to important neurovascular structures. We present an alternative and safer approach to lesions of the atrium using a natural pathway through the parieto-occipital fissure. We demonstrate this approach through cadaveric anatomical microdissection and a case series. Five formalin-fixed brain specimens (10 hemispheres) were dissected with the Klingler technique. Transillumination was used to show the trajectory of the approach in cadaveric specimens. Clinical data from five patients who underwent this approach were reviewed. This data included intraoperative ultrasound images, operative images, pre- and postoperative magnetic resonance imaging, MR tractography, and visual field examination. The parieto-occipital fissure is a constant, uninterrupted fissure that can be easily identified in cadavers. Our anatomical dissection study revealed that the atrium of the lateral ventricle can be approached through the parieto-occipital fissure with minor damage to the short association fibers between the precuneus and cuneus, and a few fibers of the forceps major. In our series, five patients underwent total resection of their atrial lesions via the posterior interhemispheric transparieto-occipital fissure. No morbidity or mortality was observed, and the disruption of white matter was minimal, as indicated on postoperative tractography. The postoperative visual fields were normal. The posterior interhemispheric transparieto-occipital fissure approach is an alternative to remove lesions in the atrium of the lateral ventricle, causing the least damage to white matter tracts and preserving visual cortex and optic radiation.

Women in neurosurgery: perspectives from a developing country; Turkey.

Although at least half of medical students are women, neurosurgery is not often preferred by women, and the proportion of female neurosurgeons who can participate in the academic platform is very low. In this study, we aimed to show the role of female neurosurgeons in the Turkish Neurosurgical Society and to describe the number and the location of female neurosurgeons in Turkey. We examined the age, academic rank, years of work in the profession, membership rate in society subgroups, h-index parameters, and relationships of certificated female neurosurgeons registered in the Turkish Neurosurgical Society. We examined gender rate differences between society subgroups using chi-square tests. A P value < 0.05 was considered statistically significant. According to the year-end 2020 data of the Turkish Neurosurgery Society, 94 (5.5%) of the 1699 neurosurgery specialists registered in Turkey are women. There are currently 94 board-certified female neurosurgeons between the ages of 31 and 92 years; 10 are full professors (10.6%), 16 are associate professors (17%), 5 are assistant professors (5.3%), and 63 are neurosurgery specialist physicians (67%). Female neurosurgeons are present among six of the subfields categorized by the Turkish Neurosurgical Society: 7 in pediatric neurosurgery (11.47%); 8 in spinal and peripheral nerve surgery (2.4%); 3 in neurovascular surgery (2.02%); 7 in functional neurosurgery (5.8%); 11 in neuroanatomy (9.2%); and 23 in neurooncology (6.9%). The number of female neurosurgeons in Turkey continues to grow each year. To increase the proportion of women in this field, it is important to support female neurosurgeons and enable them to take on more tasks.

Is diabetes mellitus a risk factor for modic changes?: A novel model to understand the association between intervertebral disc degeneration and end-plate changes.

OBJECTIVE: Mechanical failure and inflammatory response are two mechanisms proposed for the development of Modic changes, even though they have not been clearly demonstrated, yet. Diabetes mellitus (DM) harbors micro- and macroangiopathy due to the irreversible glycation of proteins, increased oxidative stress, and inflammation. In this study, we aimed to identify whether DM was associated with Modic changes in terms of inflammatory process. METHODS: We conducted a cross-sectional study using our prospectively collected retrospective database of patients with DM who had visited the outpatient clinics at a university hospital. In 3999 patients with DM, 266 had spinal MRI due to cervical, thoracic or low back pain. We included patients, who had lumbar spine MRIs due to low back and/or leg pain and blood draw for HbA1c simultaneously. We analyzed 48 symptomatic patients with DM. We had also symptomatic patients without DM as control group. RESULTS: Severe intervertebral disc degeneration was significantly associated with Modic changes. Severe intervertebral disc degeneration had no significant association with serum HbA1c percentage and DM duration. Patients with Modic changes at any lumbar level had significantly higher HbA1c percentages, and longer duration of DM than those without Modic changes. Symptomatic patients with DM had higher rates of Modic changes compared to symptomatic ones without DM. CONCLUSIONS: Severity and duration of DM were both closely associated with Modic changes, whereas the association of severity and duration of DM with severe intervertebral disc degeneration remained unclear.

Microsurgical anatomy of the maxillary artery for extracranial-intracranial bypass in the pterygopalatine segment of the maxillary artery.

The extracranial-intracranial (EC-IC) bypass using the maxillary artery (MA) has been successfully completed using a radial artery (RA) graft but the complicated anatomy and narrow exposure make it difficult. The purpose of this article is to define the microsurgical exposure of the MA through the middle fossa and describe the branches, diameter, and length of the MA available for the EC-IC bypass in the sphenopalatine fossa and anterior part of the infratemporal fossa. 5 cadaveric specimens were dissected bilaterally (10 MA dissections) to define the microsurgical anatomy of the MA through an intracranial approach. The exposable branches of the MA at the level of the infratemporal and sphenopalatine fossae were the anterior deep temporal, posterior superior alveolar, and infraorbital arteries. The origin of each branch could be exposed. The available section of the MA for use as a donor vessel is between the origin of the anterior deep temporal artery and the infraorbital artery. The mean exposable length of the MA was 19.4 mm. The mean outer diameter of the donor MA was 3.2 mm. Tension-free EC-IC bypass was possible using a RA graft between the MA and the middle cerebral artery, the MA and the supraclinoid internal carotid artery (ICA), or the MA and the petrous ICA. Exposure of the MA at the infratemporal and sphenopalatine fossae is complicated but provides length and diameter suitable as a donor artery for the EC-IC bypass. Clin. Anat. 31:724-733, 2018. © 2017 Wiley Periodicals, Inc.

Posterior Interhemispheric Transtentorial Subsplenial Approach for Posterior Thalamic Tumors: 2-Dimensional Operative Video.

INDICATIONS CORRIDOR AND LIMITS OF EXPOSURE: The posterior interhemispheric transtentorial subsplenial approach provides a direct corridor to posterior thalamic lesions without a cortical or callosal incision. 1. ANATOMIC ESSENTIALS NEED FOR PREOPERATIVE PLANNING AND ASSESSMENT: This corridor is through the posterior interhemispheric fissure along the medial surface of the cuneus and allows the subsplenial region to be explored. Evaluating the tumor's size and extension is crucial to determining the suitability of this approach. The deep venous system may be displaced from mass effect, requiring preoperative venous examination. ESSENTIALS STEPS OF THE PROCEDURE: A 34-year-old male patient was admitted elsewhere with blurred vision and imbalance. MRI revealed a right-sided posterior thalamic tumor with heterogeneous contrast enhancement. The patient was followed-up after placement of a ventriculoperitoneal shunt. Seven months later, he was admitted to our clinic because the tumor had grown. The patient underwent surgical intervention. The patient was placed in the prone oblique position. After dural opening, the quadrigeminal cistern was opened to release cerebrospinal fluid, allowing significant gravity relaxation of the ipsilateral hemisphere. The tentorium was cut and retracted to achieve the necessary exposure. PITFALLS/AVOIDANCE OF COMPLICATIONS: The most serious complications of this approach occur from vascular injuries. Gravitational retraction of the occipital lobe protects the optic radiation, and anatomic landmarks help the surgeon maintain anatomic orientation. VARIANTS AND INDICATIONS FOR THEIR USE: The perimedian supracerebellar transtentorial approach is an alternative to the posterior interhemispheric transtentorial subsplenial approach for lesions in this area; however, the indications and limits of these approaches have some differences.The patient consented to the procedure and to the publication of his/her image.Images at 0:29 reused from Serra et al, 1 with permission from Elsevier.

Revealing the confusion of the evolution of the term sagittal stratum. Historical overview and systematic literature review.

The fiber dissection technique is one of the earliest methods used to demonstrate the internal structures of the brain, but until the development of fiber tractography, most neuroanatomy studies were related to the cerebral cortex and less attention was given to the white matter. During the historical evolution of white matter dissection, debates have arisen about tissue preservation methods, dissection methodology, nomenclature, and efforts to adopt findings from primates to the human brain. Since its first description, the sagittal stratum has been one of the white matter structures subject to controversy and has not been sufficiently considered in the literature. With recent functional studies suggesting potential functions of the sagittal stratum, the importance of attaining a precise understanding of this structure and its constituent fiber tracts is further highlighted. This study revisits the historical background of white matter dissection, unveils the early synonymous descriptions of the sagittal stratum, and provides a systematic review of the current literature. Through evaluation of the historical statements about the sagittal stratum, we provide an understanding of the divergence and explain the reasons for the ambiguity. We believe that acquiring such an understanding will lead to further investigations on this subject, which has the potential to benefit in addressing various neuropsychiatric conditions, maintaining functional connectivity, and optimizing surgical outcomes.

Selective amygdalohippocampectomy via the paramedian supracerebellar-transtentorial approach for mediobasal temporal epilepsy.

Selective amygdalohippocampectomy via the pterional transsylvian approach is a feasible option for many patients with mediobasal temporal epilepsy. However, it may be insufficient for patients when the posterior hippocampal region is involved. The paramedian supracerebellar transtentorial approach offers precise anatomical orientation when exposing the entire length of the mediobasal temporal region, including the fusiform gyrus. In addition, this approach allows selective amygdalohippocampectomy without any neocortical damage. This video presents the successful treatment of a patient with posterior hippocampal sclerosis and mediobasal temporal epilepsy through the paramedian supracerebellar transtentorial approach.

Sublabial transmaxillary approach to the inferior aspect of the orbit.

OBJECTIVE: The objective was to demonstrate the surgical steps and outcomes of the sublabial transmaxillary microsurgical approach with endoscopic assistance to treat lesions in the inferior aspect of the orbit, as well as to describe the use of patient-specific 3D models to facilitate surgical preparation and improve experience with the technique. METHODS: The authors' study evaluated data from patients who underwent an endoscope-assisted sublabial transmaxillary approach for inferior orbital lesions. For 2 patients, 3D models were created for preoperative planning and assessment of the approach. Surgical steps comprised osteotomy to access the maxillary sinus, bony resection of the orbital floor, opening of the periorbital fascia, and dissecting and removing the lesion, followed by closure. The neuroendoscope was used to inspect the surgical cavity between each step. RESULTS: The study included 5 patients with varying visual field defects and proptosis who underwent the sublabial transmaxillary microsurgical approach with endoscopic assistance. Complete resection was achieved in all, and all patients reported improvement in visual field defects and proptosis after the procedure. No complications were observed except for transient unilateral maxillary edema noted around the incision site in 3 patients during the early postoperative period, which resolved within a few days. Histopathological examination confirmed the diagnosis of cavernous malformation in all patients. CONCLUSIONS: The sublabial transmaxillary approach is a direct and safe method to resect cavernous malformations at the inferior aspect of the orbit. It reduces the risk of complications associated with lateral, transcranial, and transnasal approaches that may cross critical structures. The microsurgical approach provides the benefit of two-handed dissection for lesions embedded in orbital fat, which can be challenging because of adhesions to surrounding tissues. The use of 3D models can facilitate surgical planning and enhance familiarity with the approach.

Microsurgical Resection of a Parachiasmatic Craniopharyngioma via a Left-Sided Pterional Transsylvian Approach.

Craniopharyngiomas are histologically benign tumors that originate from squamous rests along the pituitary stalk. They make up approximately 1.2% to 4.6% of all intracranial tumors and do not show significant differences in occurrence based on sex. Adamantinomatous craniopharyngiomas have 2 peaks of incidence, commonly observed in patients from ages 5 to 15 years and again from 45 to 60 years. In contrast, papillary craniopharyngiomas mainly affect adults in their fifth and sixth decades of life.1 The "malignancy" of craniopharyngiomas is attributed to their location and the challenges associated with achieving complete removal because they can manifest in the sellar, parachiasmatic, and intraventricular regions or a combination of these.2,3 Various approaches have been used to resect these tumors.4,5 Radical resection offers the most promising option for disease control, potential cure, and the ability to transform the disease from lethal to survivable in children, allowing for a functional adult life.2,3 Meticulous evaluation is crucial to determine the appropriate approach and side, with particular emphasis on closely examining the relationship between the tumor and optic pathways (nerve, chiasm, tract), which are frequently involved. This assessment should also include the tumor's relationship with other crucial structures, such as the hypothalamus and adjacent arteries, to ensure that the strategy is adjusted accordingly to further minimize the risk of postoperative morbidity. Video 1 demonstrates a left-sided pterional transsylvian approach to remove a parachiasmatic craniopharyngioma involving the left optic chiasm and tract.

Thrombosed Posterior Inferior Cerebellar Artery Aneurysm Mimicking a Medulla Oblongata Cavernous Malformation: 2-Dimensional Operative Video.

The incidence of posterior inferior cerebellar artery (PICA) aneurysms is estimated to be between 0.5% and 3% of total aneurysm cases.1 Most patients with these aneurysms typically present with subarachnoid hemorrhage, although there are instances in which patients may present with symptoms resulting from mass effect exerted on the brain stem or lower cranial nerves.1,2 Treatment options for PICA aneurysms include endovascular procedures, surgical clipping, or bypass techniques.2 Surgical treatment is considered more effective for partially thrombosed aneurysms compared with endovascular approaches.3 In addition, endovascular coiling of these aneurysms carries the potential risk of coil migration and subsequent reopening of the aneurysm lumen.4 In certain instances, thrombosed PICA aneurysms have the potential to simulate the radiological characteristics of alternative pathologies, such as cavernous malformations or brainstem tumors.5-7 This situation can result in misdiagnosis and inappropriate management. We present the case of a patient who exhibited symptoms of imbalance and dysfunction in the lower cranial nerves. Magnetic resonance imaging findings indicated a possible cavernous malformation in the medulla oblongata. However, further investigation revealed that the underlying cause was a thrombosed PICA aneurysm. The patient was successfully treated through surgical clipping. The patient consented to the procedure and to the publication of his/her image.

Neglected tracts of the brainstem: transverse peduncular tract of Gudden and taenia pontis.

OBJECTIVE: The anatomy and function of the brainstem have fascinated scientists for centuries; however, the brainstem remains one of the least studied regions of the human brain. As the authors delved into studying this structure, they observed a growing tendency to forget or neglect previously identified structures. The aim of this study was to describe two such structures: the transverse peduncular tract, also known as the Gudden tract, and the taenia pontis. The authors analyzed the potential effects of neglecting these structures during brainstem surgery and the implications for clinical practice. METHODS: After removal of the arachnoid and vascular structures, 20 human brainstem specimens were frozen and stored at -16°C for 2 weeks, according to the method described by Klingler. The specimens were then thawed and dissected with microsurgical techniques. The results of microsurgical fiber dissection at each step were photographed. RESULTS: This study revealed two previously neglected or forgotten structures within the brainstem. The first is the transverse peduncular tract of Gudden, which arises from the brachium of the superior colliculus. This tract follows an arcuate course along the lateral and ventral surfaces of the midbrain, perpendicular to the cerebral peduncle, and terminates in the nuclei of the transverse peduncular tract within the interpeduncular fossa. The second structure is the taenia pontis, which originates contralaterally in the interpeduncular fossa. It becomes visible at the level of the pontomesencephalic sulcus and extends to the base of the lateral mesencephalic sulcus, where it divides into several thin bundles. Along the interpeduncular sulcus, between the superior and middle cerebellar peduncles, it reaches the parabrachial recess and enters the cerebellum. CONCLUSIONS: Recently, with increasing understanding and expertise in brainstem research, surgical approaches to this area have become more common, emphasizing the importance of a detailed knowledge of the brainstem. The two structures mentioned in this paper are described in history books and were widely studied in the 19th century but have not been mentioned in modern literature. The authors propose that a deeper understanding of these structures may prove valuable in neurosurgical practice and help reduce patient comorbidity.