Turkish neurosurgery最新文献

Aim: To propose a patient-specific interbody cage with graded stiffness distributions analogous to the Young's modulus of the cervical spinal bone interface in order to improve mechanical compatibility, promote physiological load sharing, and enhance osseointegration.

Material and methods: A synthetic database of spinal bone Young modulus values was used, incorporating anatomical regions (cervical, thoracic, lumbar) and patient-specific factors (age, bone density, health status). A parametric generative design approach allowed dynamic modification of lattice unit cell geometry to achieve target stiffness values (200-3000 MPa) while preserving structural integrity.

Results: Finite element endplate analysis demonstrated a 30%-50% reduction in stress shielding compared with conventional solid or homogeneous mesh lattices. Additively manufactured prototypes showed tunable stiffness-porosity trade-offs, achieving yield strength ≥150 MPa while supporting osseointegration.

Conclusion: This study demonstrates improved load distribution and reduced risk of cage collapse compared with cadaveric spine data. Integrating computational design, biomechanical compatibility, and additive manufacturing may facilitate the development of patient-specific spinal implants with superior mechanical and biological performance.

Aim: To evaluate the potential genetic differences between systemic lupus erythematosus (SLE) and cerebrovascular disorders (CVDs) patients.

Material and methods: This genetic association study conducted Mendelian randomization (MR) analyses on the derived exposures and outcomes from summary statistics of genome-wide association studies (GWAS). This study employed univariate MR (UVMR) analysis, multivariable MR (MVMR) analysis, and meta-analysis, using data from large genomic databases such as the UK Biobank, FinnGen, and OpenGWAS. These methods aim to overcome confounding factors by using genetic variants as instrumental variables to infer causal relationships.

Results: UVMR analysis revealed a genetic causal relationship between SLE and ischemic stroke, with a positive correlation (odds ratio [OR] 1.000367; 95% confidence interval [CI] 1.000074--1.00066; p=0.014). No evidence of a genetic causal relationship was found between SLE and other types of CVDs, including cerebral aneurysm, intracerebral hemorrhage, subarachnoid hemorrhage, stroke, and transient ischemic attack. MVMR analysis, after adjusting for confounders such as smoking and type 2 diabetes, confirmed the robustness of the association between SLE and ischemic stroke. Furthermore, a meta-analysis of multiple MR outcomes was conducted to verify the stability of the results (OR, 1.00037; 95% CI, 1.00008-1.00067).

Conclusion: Our study enhances the understanding of the genetic basis between SLE and various CVDs, particularly suggesting a positive causal association between SLE and ischemic stroke, and we emphasize the need for further research.

Aim: To investigate the anatomical characteristics, procedural constraints, and technical details of anterior endoscopic transcervical approach (AETCA) through cadaveric dissection.

Material and methods: Nine human cadaver heads, transected at the C6-C7 level and preserved in 10% formalin for no less than 4 weeks, were utilized. A 0° endoscope and surgical drills were used for odontoid removal. The resection extent was determined through volumetric analysis using CT scans performed before and after the procedure. Fluoroscopy was employed for orientation, and volumetric measurements were used to assess the resection outcomes.

Results: Across the specimens, the average resection rate of the dens was 54%. Complete removal was achieved in two cases, subtotal in another two, and partial in five. The use of angled drills yielded significantly greater resection compared to flat-ended variants. No significant vascular or neurological injuries were noted. In seven cases, the resection extended to the odontoid's posterior wall. Challenges included the narrow and elongated operative corridor and difficulty maintaining midline orientation; however, these were addressed with the assistance of a custom-designed tubular trocar.

Conclusion: AETCA offers notable benefits, such as reduced risk of postoperative infections, shorter hospitalization, and decreased morbidity and healthcare expenditure. The study underscores the importance of technical expertise and enhanced instrumentation in achieving successful outcomes, particularly for complete odontoid removal while preserving adjacent anatomy. AETCA emerges as a viable and safer alternative for odontoidectomy, enhancing procedural efficiency. These findings contribute to the understanding of anatomical and technical factors relevant to the approach, supporting its clinical adoption and potentially shortening the learning curve.

Bi-thalamic stroke is rarely reported in the literature as a complication of an endonasal endoscopic procedure. It has been associated with presence of a Percheron artery variant, as well as with top of the basilar syndrome, both of which significantly increase patient surgical morbidity. Infundibulo-neurohypophysitis in turn, is an unusual inflammatory disorder affecting the infundibulum, the pituitary stalk, and the neurohypophysis. We present the case of a patient with visual impairment and an abnormal hormone profile compatible with infundibulo-neurohypophysitis, in whom tumor resection was conducted through an endoscopic endonasal approach (EEA). Patient developed postoperative bi-thalamic stroke due to Percheron artery infarct. A review of both conditions is included. This is the fourth case reported in the literature of a Percheron artery infarct, and to the best of our knowledge, the first linking it to endoscopic treatment of neurohypophysitis, itself an infrequent condition.

Aim: To evaluate the efficacy of diffusion tensor imaging (DTI) and diffusion tensor tractography (DTT) in establishing the relationship between cervical extramedullary tumors and the spinal cord with reference to, especially treatment planning, clinical outcome prediction and diagnostic accuracy.

Material and methods: This was a retrospective study conducted on 15 patients diagnosed with cervical extramedullary tumors, wherein each patient underwent standard 3.0-T magnetic resonance imaging, DTI, and DTT to evaluate microstructural changes and neural tract displacement. Fractional anisotropy (FA) values were examined, and the relationship of tractography results with clinical presentation and outcomes was evaluated.

Results: FA values revealed disturbances in the microstructure, which exhibited marked changes in lesion areas compared with that of normal tissue and displaced spinal cord (DSC). The DTT of each patient revealed neural tract anomalies or deformities related to the degree of their clinical symptoms. Receiver operating characteristic curve analysis demonstrated the excellent diagnostic accuracy of FA in separating lesions from normal tissue (AUC = 0.880) and DSC (AUC = 0.840).

Conclusion: FA values could help particularly in detecting early myelopathic changes due to cervical cord displacement, which might be a critical indication for surgical decisions. This study supports the usage of DTI and DTT in evaluating cervical extramedullary lesions, surgical planning, and outcome prediction by exposing microstructural changes and lesion-tract relationships.

Back pain is a widespread and debilitating condition that significantly impairs quality of life, often eroding patients' sense of autonomy and independence, and contributes to global disability rates. The initial management of back pain generally follows a conservative approach, encompassing physical therapy, pharmacological interventions, and lifestyle modifications aimed at alleviating symptoms and restoring functionality. Spine surgery, while frequently beneficial in addressing underlying structural issues, carries certain inherent risks. Among the most challenging outcomes of spine surgery is the persistence or recurrence of pain, a condition commonly referred to as failed back surgery syndrome (FBSS). The effective management of FBSS requires a comprehensive and meticulous approach. When conservative measures for FBSS fail to yield satisfactory results, revision surgery can be considered. The role of advanced imaging techniques is critical in these cases. Standard imaging modalities each involve unique advantages and limitations, and a multimodal approach is therefore important to achieve a comprehensive and accurate evaluation of the patient's condition. In recent years, single-photon emission computed tomography combined with computed tomography (SPECT/CT) has gained recognition as a valuable tool in the postoperative assessment of spine surgery patients. SPECT/CT has demonstrated superior efficacy in detecting specific complications, such as pseudoarthrosis, hardware failure, and screw loosening. By integrating metabolic activity data from the spine and surrounding bony structures with the three-dimensional reconstruction capabilities of CT, SPECT/CT enhances diagnostic accuracy and informs more precise treatment decisions. This review aims to synthesize the current body of literature on the application of SPECT/CT in the postoperative evaluation of spine surgery patients, while also providing a comparative overview of other imaging modalities within this context. Our objective is to underscore the pivotal role that advanced imaging techniques play in improving patient outcomes after spine surgery, reducing the incidence of FBSS, and shortening its duration.

Aim: To evaluate the incidence and identify the risk factors of stereotactic radiosurgery (SRS)-induced peritumoral edema (PTE) in the asymptomatic convexity, parasagittal, and parafalcine meningiomas without pre-existing PTE.

Material and methods: We retrospectively analyzed 52 patients with asymptomatic convexity, parasagittal, or parafalcine meningiomas without pre-existing PTE who underwent single-fraction Gamma Knife radiosurgery between 2019 and 2024. The median tumor volume and the maximum tumor diameter were 3.3 cc (range: 0.31–10.2 cc) and 2.0 cm (range: 0.98–3.1 cm), respectively. The median margin dose was 12 Gy (range: 11 Gy–13 Gy). The median radiological and clinical follow-up durations were 21 months (range: 6–65 months) and 26 months (range: 12–66 months), respectively.

Results: SRS-induced PTE occurred in 5.8% of patients (n=3), exclusively in elderly individuals (≥65 years) with parasagittal or parafalcine meningiomas. No cases were observed in convexity meningiomas (0/24). Multivariable analysis revealed a trend toward statistical significance for the association between age and SRS-induced PTE (p=0.074). In the overall cohort, the incidence of SRS-induced PTE was significantly higher in elderly patients compared to younger patients (< 65 years) (3/14 vs. 0/38, p=0.016), and this difference remained significant within the parasagittal/parafalcine subgroup (3/7 vs. 0/21, p=0.011).

Conclusion: SRS appears to be a safe treatment modality in terms of PTE risk in patients aged below 65 years with asymptomatic convexity, parasagittal, or parafalcine meningiomas without pre-existing PTE. In contrast, elderly patients with parasagittal or parafalcine meningiomas may be more susceptible to SRS-induced PTE, thereby warranting a more cautious approach to SRS in this subgroup. Additional studies involving larger cohorts are warranted to validate these findings.

Aim: To evaluate the diagnostic and prognostic significance of miRNA signatures by identifying differences in miRNA expression between ruptured and unruptured intracranial aneurysm (IA) cases, as well as to pinpoint miRNAs that correlate with clinical severity in patients with aneurysmal subarachnoid hemorrhage (aSAH).

Material and methods: Peripheral blood samples were collected from 50 IA patients (25 without rupture and 25 with rupture) and 25 healthy controls. In the ruptured group, analyses were performed on samples collected on Days 3 and 5 after SAH. The clinical severity and outcomes of the disease were assessed using Fisher grades, WFNS grades, Hunt-Hess grades, and the Modified Rankin Scale.

Results: We found that the expression levels of miR-21-5p and miR-15a were significantly altered in unruptured aneurysms (UA) patients compared to controls. The expression levels of 10 miRNAs were significantly decreased in ruptured aneurysms (RA) patients compared to controls. The ruptured group also exhibited an upregulation of 16 miRNAs relative to the unruptured group. Furthermore, we noted a significant increase in miR-24 expression in RA patients between Days 3 and 5, suggesting its potential role in the progression of aSAH. miR-9p-3p and miR-497 were found to be associated with aSAH severity. Moreover, the levels of miR-451a, miR-146a-5p, miR-502-5p, and miR-497 were significantly lower in patients with poor outcomes compared to those with favorable outcomes.

Conclusion: These findings suggest that specific miRNAs may serve as potential diagnostic and prognostic biomarkers for IA and subsequent SAH, particularly on Day 3 following aSAH.