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.

Posterior median surgical approach to anterior sacral meningocele complicated by rectothecal fistula.

In this case report, we aimed to describe the clinical presentation, surgical approach, and follow-up of a patient with rare anterior meningocele associated with rectothecal fistula. An 17-year-old female patient was admitted to the emergency department with meningitis. On further examinations, an anterior sacral meningocele accompanied by rectothecal fistula was detected. Appropriate antibiotic treatment was arranged and surgical plan was made with the pediatric surgery clinic. The patient underwent meningocele repair via posterior approach and colostomy operation. The patient did not experience any neurological issues after the surgery. The colostomy was reversed 3 months later, and third-month follow-up MRI showed complete regression of the meningocele sac with no neurological complications. Anterior meningocele accompanied by a rectothecal fistula is a rare and complicated case. Only seven cases of coexisting ASM and RTF have been reported in literature. Although both anterior and posterior approaches have been used for the treatment of ASM, the choice of treatment is essentially based on the patient's clinical and imaging findings.

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.

Single-institution comparative analysis for odontoid resection: posterior transaxis versus anterior transnasal approach.

OBJECTIVE: The resection of an upwardly migrated odontoid is most widely performed via an anterior endoscopic endonasal approach after the addition of posterior occipitocervical instrumentation. In patients with craniovertebral junction (CVJ) anomalies like basilar invagination (BI), surgery is usually achieved in two separate stages. However, the authors have recently introduced a novel posterior transaxis approach in which all the therapeutic goals of the surgery can be safely and effectively accomplished in a single-stage procedure. The aim of the current study was to compare the widely used anterior and the recently introduced posterior approaches on the basis of objective clinical results in patients who underwent odontoid resection for BI. METHODS: Patients with BI who had undergone odontoid resection were retrospectively reviewed in two groups. The first group (n = 7) consisted of patients who underwent anterior odontoidectomy via the standard anterior transnasal route, and the second group (n = 6) included patients in whom the novel transaxis approach was performed. Patient characteristics, neurological conditions, and modified Rankin Scale (mRS) scores at admission were evaluated. Operative time, changes in intraoperative neurophysiological monitoring, blood loss during surgery, odontoid resection rate, postoperative complications, and mortality were compared between the patient groups. RESULTS: Data were retrospectively reviewed for 13 patients who underwent odontoid resection, posterior CVJ decompression, and occipitocervical instrumentation at the Ankara University School of Medicine Department of Neurosurgery between 2009 and 2022. In the first group (n = 7), patients who underwent anterior odontoidectomy via the standard endonasal route, two serious complications were observed, pneumocephaly and basilar artery injury. In the second group (n = 6), patients in whom the novel transaxis approach was performed, only one complication was observed, occipital plate malposition. CONCLUSIONS: This study represents the results of what is to the authors' knowledge the first comparison of a novel approach with a widely used surgical approach to odontoid resection in patients with BI. The preliminary data support the successful utility of the transaxis approach for odontoid resection that meets all the operative therapeutic demands in a single-stage operation. Considering the diminished surgical risks and operative time, the transaxis approach may be regarded as a primary approach for the treatment of BI.

Changes in Callosal Angle and Evans' Index After Placing a Lumboperitoneal Shunt in Patients with Idiopathic-Normal- Pressure Hydrocephalus.

AIM: To evaluate changes in the Evans? index (EI) and callosal angle (CA) in patients who underwent lumboperitoneal (LP) shunting for idiopathic normal pressure hydrocephalus (INPH) and whose symptoms improved post-operatively. MATERIAL AND METHODS: We retrospectively analysed patients who were clinically and radiologically diagnosed with INPH and treated with an LP shunt between 2010 and 2020. In all patients, we performed radiological imaging with EI and CA measurements and completed clinical assessments, including Mini-Mental State Examination (MMSE) and cognitive, urinary continence, balance and 10-m walking tests, preoperatively and post-operatively (less than 1 year later). Results were compared by statistical analyses. RESULTS: We evaluated 42 patients who received an LP shunt for INPH and had cranial magnetic resonance imaging (MRI) performed within the first 2 months after surgery. When the pre-operative and post-operative MRIs of the patients were compared, a statistically significant decrease was found in EI and CA measurements (p < .001, for each). A statistically significant improvement was found in clinical tests. Post-op early radiological images predicted recovery of the gait-balance function and urinary incontinence (p < .001) but did not predict recovery of dementia (p=.06). CONCLUSION: Radiological and clinical improvements are expected after the placement of ventriculoperitoneal (VP) or LP shunts in patients with INPH. Radiological measurements after an LP shunt in patients with INPH have not been reported in the literature. In the current study, radiological measurements after LP shunt placement were evaluated for the first time in patients with INPH. Significant changes in EI and CA after LP shunt placement may indicate whether patients will benefit clinically from an LP shunt during follow-up. A significant decrease in CA and EI measurements in the early period may be a marker for whether patients with INPH will show signs of clinical improvement and benefit from an LP shunt.