Posterior clinoid process in children: morphometric analysis, pneumatization ratio, and surgical implications.

PURPOSE: To describe pneumatization and topographic position of the posterior clinoid process (PCP) in healthy children when approaching the anterior and middle fossae. METHODS: The study consisted of computed tomography images of 180 pediatric patients (90 males / 90 females), aged 1-18 years. The presence or absence of PCP pneumatization was noted, and the distances of certain landmarks to PCP were measured. RESULTS: The distances of the foramen ovale, foramen rotundum, superior orbital fissure, anterior clinoid process (ACP), foramen magnum and crista galli to PCP were measured as 18.59 ± 3.36 mm, 15.37 ± 3.45 mm, 14.60 ± 3.05 mm, 5.27 ± 3.24 mm, 32.03 ± 3.27 mm, and 30.45 ± 3.93 mm, respectively. These parameters increased with growth (between 1-18 years), but the distance between PCP and ACP decreased with an irregular pattern. In 11 sides (3.10%), a fusion between PCP and ACP was determined. PCP pneumatization was identified in 32 sides (8.9%). Its pneumatization correlated with pediatric ages (p < 0.001), but not gender (p = 0.459) or side (p = 0.711). Most of PCP pneumatization appeared after late childhood period (i.e., between 10-18 years). CONCLUSION: Our study provides beneficial data for neurosurgeons to use PCP as a reference point for creating a skull base map in children, because of the incomparable position of PCP in the skull base center.

Effect of endoscopic endonasal skull base approaches on olfactory function and facial development in children.

INTRODUCTION: Endoscopic approaches for skull base pathologies are increasingly being performed, and the subsequent complications, especially in the long term, have also been partially clarified. However, there is no information on the effects of endoscopic endonasal skull base surgeries (EESBS) in children on odor and facial development in parallel with long-term development. We conducted this study to investigate postoperative olfactory function and facial development in pediatric patients who underwent skull base surgery using the endoscopic endonasal method. METHODS: We evaluated the smell test, sinonasal symptoms, and facial development of pediatric patients who underwent endoscopic endonasal skull base surgery after long-term follow-up. Odor was evaluated using the "Sniffin' Sticks" test kit, which assessed the T (odor threshold), D (odor discrimination), and I (odor identification) parameters. Sinonasal symptoms were evaluated using the SNOT-22 (sinus-nose outcome test) questionnaire. SNA (sella-nasion-A point), SNB (sella-nasion-B point), and ANB (A point-nasion-B point) angles were calculated from maxillofacial tomography and magnetic resonance imaging) to evaluate facial development. Data were compared with those of the healthy control group. RESULTS: We included 30 patients comprising 19 (63.3%) boys and 11 (36.7%) girls, with no age difference between case and control groups. The mean follow-up period was 7 years. Odor test data, cephalometric measurements, and SNOT-22 analysis results showed no statistically significant differences between the two groups. CONCLUSION: To our knowledge, this is a comprehensive study with the longest follow-up period in terms of evaluation of facial development after EESBS in children to analyze odor using the Sniffin' Sticks test kit and the quality of life using SNOT-22. Olfactory function, facial development, and quality of life remained unaffected after long-term follow-up after EESBS  in children. Although this surgical approach is minimally invasive, we recommend considering the possibility of complications, and the procedure should be performed by an experienced surgical team with adequate equipment.

Polymorphous low-grade neuroepithelial tumor of the young (PLNTY): A case report with surgical and neuropathological differential diagnosis.

BACKGROUND: Polymorphous low-grade neuroepithelial tumor of the young (PLNTY) is a rare entity of low-grade neuroepithelial tumors that primarily affects children and young adults. This distinct type of tumor presents unique challenges in diagnosis and management. With its relatively recent identification, researchers and clinicians are striving to understand the characteristics, behavior, and optimal treatment strategies. The symptoms are primarily related to seizures. However, PLNTY can be asymptomatic in some cases. MATERIALS AND METHODS: This is a single-center case report study and a literature review paper. We reviewed a case treated and diagnosed at the Ankara University Faculty of Medicine, Department of Neurosurgery. The demographic data, clinical follow-ups, laboratory, and radiological data of the patients were assessed. RESULTS: We present a 32-year-old male patient who has undergone gross total surgical excision with strict clinical follow-up. Clinical course as well as surgical data of the patient were observed and analyzed. CONCLUSION: On imaging, morphologic resembling and indistinctive clinical course can be nonspecific, contributing to diagnostic uncertainties. This case report was written with the notion that rare diagnoses present an opportunity to understand the progression and patho-oncological factors that can pave the way for better treatment.

Prediction of Meningioma Grade Using Hematological Parameters.

OBJECTIVE: Predicting the aggressiveness of meningiomas may influence the surgical strategy timing. Because of the paucity of robust markers, the systemic immune-inflammation (SII) index is a novel biomarker to be an independent predictor of poor prognosis in various cancers including gliomas. We aimed to investigate the value of SII as well as neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) indices in predicting prognosis. METHODS: Records including demographic, clinical, and laboratory data of patients operated on due to intracranial meningioma in 2017-2023 were retrospectively reviewed. RESULTS: A total of 234 patients were included in this study. All of SII index, NLR, and PLR values at presentation were significantly higher in grade ≥2 meningiomas. A positive correlation was observed between SII index and Ki67 index (r=0.313; P<0.001); between NLR and Ki67 index (r=0.330; P<0.001); and between PLR and Ki67 index (r=0.223; P<0.01). SII index (optimal cutoff level >618), NLR (optimal cutoff level >3.53), and PLR (optimal cutoff level >121.2) showed significant predictive values. CONCLUSIONS: This is the first study to assess the prognostic value of the SII index in patients with intracranial meningiomas. Increased SII index, NLR and PLR were correlated with higher grade and higher Ki-67 index. They also harbor the potential to screen patients that may need more aggressive treatments or more frequent follow-up examinations.

A Novel Foley Catheter-Based Brain Retraction Method for the Interhemispheric Approach: Technical Considerations and an Illustrative Video.

BACKGROUND: Management of interhemispheric pathologies requires surgical intervention through a restricted anatomical corridor ensconced within critical cerebral structures. The use of retractors to facilitate operative access may cause damage to cerebral tissue. The development of an innovative retraction technique designed to alleviate cerebral damage in such cases is imperative. In this study, we present a novel and gentle retraction method to facilitate the interhemisferic approach. METHODS: We retrospectively examined data of 9 right-handed patients who underwent surgical resection of interhemispheric lesions between 2021 and 2022. All patients underwent surgery for the first time because of this pathology. All operative specimens were histologically confirmed. Clinical characteristics, operative details, and follow-up data were retrospectively analyzed. RESULTS: The new retraction technique was successfully applied to 8 tumor patients and 1 patient with an aneurysm. Eight patients had an anterior interhemispheric approach, and 1 patient had a posterior interhemispheric approach. Complete surgical excision was achieved in all patients with no postoperative complications. Postoperative Gadolinium (Gd)-enhanced magnetic resonance imaging (MRI) showed no signs of ischemia or contusion. All patients exhibited significant improvements in their symptoms. An illustrative video that elucidates the removal of an interhemispheric epidermoid tumor, employing the anterior ipsilateral interhemispheric approach, featuring the novel retraction method. CONCLUSIONS: The ideal retraction technique during the interhemispheric approach is still a challenge. Our novel retraction technique may help minimize brain parenchymal damage during surgical resection of interhemispheric lesions.

Topographic Anatomy and Pneumatization of the Posterior Clinoid Process in Chiari Type I Malformation.

OBJECTIVE: This study aimed to examine pneumatization and topographic location of the posterior clinoid process (PCP) in Chiari type I malformation (CIM) for skull base approaches. METHODS: Computed tomography images of 52 (23 males/29 females) CIM subjects aged 23.87 ± 16.09 years and 71 (26 males/45 females) healthy subjects aged 42.48 ± 21.48 years constituted the study universe. RESULTS: The distances of PCP to the foramen magnum (P = 0.037), superior orbital fissure (P < 0.001), foramen rotundum (P < 0.001), and foramen ovale (P < 0.001) were smaller, but the distance of PCP to the crista galli (P = 0.038) was greater in CIM patients, compared with normal subjects. In CIM, the fusion between PCP and the anterior clinoid process was observed in 9 sides (8.70%), while in controls it was observed in 12 sides (8.50%). PCP pneumatization was observed in 40 sides (38.50%) in CIM patients, while it was observed in 28 sides (19.70%) in normal subjects. These data displayed that PCP pneumatization was affected by CIM (P < 0.001). CONCLUSIONS: The distances of PCP to the crista galli and foramen magnum indicate the anterior fossa length and the posterior fossa depth, respectively; thus CIM patients have a longer anterior fossa and a shallow posterior fossa. In addition, the distances of PCP to the superior orbital fissure, foramen rotundum, and foramen ovale indicate the middle fossa width; hence CIM patients have less middle fossa width than normal individuals. CIM patients have an approximately 50% higher PCP pneumatization rate, and this may increase the risk of complications such as cerebrospinal fluid fistula during the application of posterior clinoidectomy.

Navigating the calvaria with mobile mixed reality-based neurosurgical planning: how feasible are smartphone applications as a craniotomy guide?

OBJECTIVE: Virtual simulation and imaging systems have evolved as advanced products of computing technology over the years. With advancements in mobile technology, smartphones, and tablets, the quality of display and processing speed have gradually improved, thanks to faster central processing units with higher capacity. Integrating these two technologies into the fields of healthcare and medical education has had a positive impact on surgical training. However, contemporary neurosurgical planning units are expensive and integrated neuronavigation systems in operating rooms require additional accessories. The aim of this study was to investigate the compatibility of smartphone applications in augmented reality (AR)-based craniotomy planning, which can be available even in disadvantaged workplaces with insufficient facilities. METHODS: Thirty patients diagnosed with supratentorial glial tumor and who underwent operations between January 2022 and March 2023 were included in the study. The entire stages of the surgical procedures and the surgical plans were executed with neuronavigation systems. The patient CT scans were reconstructed using software and exported as a 3D figure to an AR-enhanced smartphone application. The evaluation of the application's success was based on the spatial relationship of the AR-based artificial craniotomy to the neuronavigation-based craniotomy, with each AR-based craniotomy scaled from 0 to 3. RESULTS: In the comparison between neuronavigation-based and AR fusion-based craniotomies, 8 of 30 (26.6%) patients scored 0 and were considered failed, 6 (20%) scored 1 and were considered ineffective, 7 (23.3%) scored 2 and were considered acceptable, and 9 (30%) scored 3 and were considered favorable. CONCLUSIONS: AR technology has great potential to be a revolutionary milestone of neurosurgical planning, training, and education in the near future. In the authors' opinion, with the necessary legal permissions, there is no obstacle to the integration of surgical technological systems with mobile technology devices such as smartphones and tablets that benefit from their low-budget requirements, wide-range availability, and built-in operating systems.

Defining the Temporal and Occipital Lobes: Cadaveric Study with Application to Neurosurgery of the Inferior Brain.

BACKGROUND: For surgical interventions, a precise understanding of the anatomical variations of the brain and defined anatomical landmarks to demarcate the regions of the temporal lobe is essential. Many anatomical studies have facilitated important surgical approaches to the temporobasal region. Because there is considerable sulcal variability, morphological analysis of the brain is imperative. The aim of this study was to define the boundaries of the temporal and occipital lobes and to define the variations in sulci and gyri in the inferior aspect. METHODS: In 110 cerebral hemispheres variations were identified and the major landmarks of the gyral-sulcal pattern at the inferior aspect of the brain were defined. RESULTS: The anatomy of the inferior aspect of the brain is defined in detail by morphological analysis of formalin-fixed hemispheres with a view to informing important surgical approaches. CONCLUSIONS: Since the literature defines no clear separation between the temporal and occipital lobes, certain landmarks such as the preoccipital notch and a basal temporo-occipital line were suggested as ways of making the distinction. The parahippocampal ramus is a constant structure that can be used as a reliable landmark for the posterior end of the hippocampus.

Massa intermedia in adults: incidence, dimension, location and clinical importance.

PURPOSE: This retrospective magnetic resonance imaging investigation aimed to obtain information related to the anatomy of the massa intermedia (MI) in an adult population. METHODS: The work conducted on MRI views of 1058 (539 males and 519 females) healthy adult samples aged with 48.93 ± 17.63 years. Initially, the presence or absence of MI was noted, and then if present, its numbers and location in the third ventricle were recorded. Its horizontal (HDMI) and vertical (VDMI) diameters were measured on MRI views, while the cross-sectional area (CSAMI) was calculated using its diameters. RESULTS: MI was missing in 2.6% (27 cases) of 1058 adult samples. Six subjects (0.6%) had a double MI. HDMI, VDMI and CSAMI were measured as 4.83 ± 1.01 mm, 4.86 ± 0.98 mm, and 19.11 ± 7.23 mm2, respectively. MI size did not show a significant alteration from 19 up to 49 years, but then its size distinctly decreased between 50 and 60 years. After age 60, MI dimension did not display an important change. MI was settled in the antero-superior quadrant in 929 cases (90.63% of 1025 subjects), in the postero-superior quadrant in 22 cases (2.15%), in the antero-inferior quadrant in 32 cases (3.12%), in the postero-inferior quadrant in 8 cases (0.78%), and in the central part in 34 cases (3.32%). CONCLUSIONS: The size, position and incidence of MI were not affected by sex, and its position and incidence were not affected by adult age periods. In adults, MI size demonstrated a significant decrease in the middle age.

Mixed Reality Assisted Navigation Guided Microsurgical Removal of Cranial Lesions.

AIM: To demonstrate the possible use of mixed reality (MR) technology in neurosurgery for multiple purposes, including preoperative planning, training, and three-dimensional (3D) navigation. MATERIAL AND METHODS: Using magnetic resonance imaging (MRI) and computed tomography (CT), 3D holographic images of three patients were created and inspected using a remote control. Preoperative planning was performed in a conference room using holographic images. Intraoperatively, the 3D images were matched and the adjacent structures were examined. RESULTS: The MR System (MRS) was a useful tool for preoperative planning and intraoperative navigation during the cranial intervention. It reduces operative time, decreases the incidence of complications, increases surgical success, and enhances surgical outcomes. Eventually, MRS may be more economical. CONCLUSION: The MRS can be used for intraoperative navigation by displaying a 3D hologram at the surgeon's fingertips and for preoperative 3D examination of the lesions and its surrounding structures. The MRS enhances surgical efficacy, reduces healthcare costs, and has a shorter learning curve than the conventional methods. It also enables customized patient-specific surgery.