Evaluation of Craniometric Parameters and Efficacy of Posterior Surgical Intervention Types in Basilar Invagination Patients.

OBJECTIVE: Basilar invagination is one of the most frequently observed abnormalities at the craniovertebral junction, in which the odontoid process of C2 prolapses into the foramen magnum. METHODS: The current study included 27 patients who underwent surgery for basilar invagination between October 2013 and January 2023. The study group was divided into 2 groups according to basilar invagination types; type I (the presence of type A atlantoaxial instability and instability is the main pathology) and type II (the presence of type B and C atlantoaxial instability and skull base dysgenesis is the main pathology). Craniometric parameters included in the study were atlantodental interval, posterior atlantodental interval, Chamberlain's line violation, clivus-canal angle, Welcher's basal angle, and Boogaard angle. RESULTS: The mean age of the patients was 24.30 ± 14.36 years (5-57 years). Fourteen patients (51.9%) were female, and 13 patients (48.1%) were male. Ten patients (37%) had type I basilar invagination, and 17 patients (63%) had type II basilar invagination. Preoperative and postoperative atlantodental interval and Boogaard angle were significantly higher in type I basilar invagination, as preoperative and postoperative posterior atlantodental interval and clivus-canal angle were significantly higher in type II basilar invagination. There was a positive strong correlation between Chamberlain's line violation and Boogaard angle. Postoperative Chamberlain's line violation was significantly higher in occipitocervical fixation (P = 0.035). C1 lateral mass screw fixation was found more successful in Chamberlain's line violation correction than occipital plates. Occipitocervical fixation was found to be associated with higher postoperative Nurick scores (P = 0.015) and complication rates (P = 0.020). Cages applied to the C1-C2 joint space were found to be associated with higher fusion rates (P = 0.023) and lower complication rates (P = 0.024). CONCLUSIONS: In the present study, it was found that C1-C2 fixation was more successful in correcting craniometric parameters and had lower complication rates than occipitocervical fixation. In appropriate patients, it was determined that cage application increased the success rates of the operations.

Predicting the probability of meningioma recurrence in the preoperative and early postoperative period: a multivariate analysis in the midterm follow-up.

We reviewed the clinical, radiological, surgical, and histopathological features of patients with meningiomas to identify factors that can predict tumor recurrence after "microscopic total removal," to improve preoperative surgical planning, and to help determine the need for close radiological observation at shorter intervals or the need for radiotherapy as an adjuvant treatment in the early postoperative period. Clinical data, magnetic resonance imaging studies, angiographic data, operative reports, and histopathological findings were examined retrospectively in 137 patients with a meningioma treated microsurgically and with no evidence of residual tumor on postoperative MR images. Based on univariate analysis, tumor size, a mushroom shape, proximity to major sinuses, edema, osteolysis, cortical penetration, signal intensity on T2-weighted MRIs, pial-cortical arterial supply, presence of a brain-tumor interface in surgery, Simpson's criteria, and histopathological classification were significant predictors for recurrence. However, age, gender, location of tumor, dural tail, calcification, signal intensity on T1-weighted images, and histopathologic subtypes in the benign group were not significant predictors. By Cox regression analysis the most important variables related to the time to recurrence were mushroom shape, osteolysis, dural tail, and proximity to major sinuses. Aggressive surgical therapy with wider dural removal should be considered in the presence of the preoperative predictors of a recurrence. Close radiological observation at shorter intervals or radiotherapy should be considered as adjuvant therapy in high-risk patients based on surgical findings predicting recurrence related to the brain-tumor interface, Simpson's criteria, and histopathological findings in the early postoperative period.

Chondromas of the falx cerebri and dural convexity: report of two cases and review of the literature.

Intracranial chondromas usually arise from the base of the skull. They rarely originate from the convexity dura and falx. Here we describe two cases of intracranial chondroma located at the convexity dura and falx, discuss the genesis, radiologic, histologic features and review the literature.

Risk factors for surgical site infections in neurosurgery patients with antibiotic prophylaxis.

BACKGROUND: This prospective study aimed to determine the spectrum and the main risk factors of surgical site infection (SSI) after neurosurgical procedures in our clinic. METHODS: Consecutive patients undergoing neurosurgery between November 1, 2001, and November 1, 2002, were recruited for the study. All patients were followed for a minimum of 2 weeks postoperatively and all SSIs were recorded. The complete medical records of each case were reviewed, and data on 14 possible risk factors were extracted. Statistical analyses were performed to identify the risk factors for SSIs. RESULTS: A total of 31 postoperative SSIs were identified among 503 cases included in the study, with a resulting overall infection rate of 6.2%. The risk of SSI was increased by age (odds ratio [OR], 1.1; 95% confidence interval [CI], 1.0-1.1; P = .039), operation type such as "shunt operations" (OR, 670.4; 95% CI, 2.6-171123.1; P = .021), presence of foreign body (OR, 141.0; 95% CI, 2.5-7925.9; P = .016), presence of diabetes mellitus (OR, 24.3; 95% CI, 2.1-284.9; P = .011), and intracranial pressure monitoring (OR, 4878.9; 95% CI, 23.8-1001229; P = .002). The predominantly isolated microorganisms in patients with SSIs were Staphylococcus aureus (22 [71.0%]), Acinetobacter baumanii (5 [16.1%]), and Staphylococcus epidermidis (4 [12.9%]). CONCLUSIONS: SSIs remain an important problem in neurosurgery. Identification of the risk factors for SSI will help physicians to improve patient care and may decrease mortality, morbidity, and health care costs of neurosurgery patients.

Congenital peripheral facial palsy associated with cerebellopontine angle arachnoid cyst.

OBJECTS: A rare case of cerebellopontine angle arachnoid cyst leading to congenital peripheral facial palsy was presented. CLINICAL PRESENTATION: A 1-year-old girl presented with peripheral facial paralysis since birth. Computed tomography and magnetic resonance imaging revealed left cerebellopontine angle arachnoid cyst causing moderate displacement of the brain stem. INTERVENTION: Retrosigmoid suboccipital craniotomy was performed and microsurgical resection of the cyst wall and fenestration of the cyst to the basal cisterns were achieved. CONCLUSIONS: Cerebellopontine angle arachnoid cyst should be considered as a potential cause of congenital peripheral facial palsy.

Effect of neutralization of rat IL-6 bioactivity on collateral blood supply from retrograde flow via cortical anastomoses in the rat central nervous system.

The purpose of this study was to determine whether neutralization of rat interleukin-6 (IL-6) bioactivity increases the collateral blood supply from retrograde flow via the major middle cerebral artery branches after experimental middle cerebral artery occlusion in the rat. Seventy rats were randomly allocated to four main groups: Group I (n = 10) consisted of normal controls; Group II (n = 20) underwent craniectomy only; Group III (n = 20) was subjected to middle cerebral artery occlusion; and Group IV (n = 20) underwent middle cerebral artery occlusion and treatment with anti-rat IL-6 antibody. Half of the rats from each of Groups II, III and IV were killed at 24 h and the other half at 72 h after craniectomy alone or occlusion. A single dose of antibody did not affect middle cerebral artery caliber, but administration of three doses resulted in a significant increase in the diameter of middle cerebral artery compared to the findings in the corresponding occlusion-only groups. The results suggest that neutralization of rat IL-6 bioactivity in long-term recovery increases the collateral blood supply from retrograde flow via cortical anastomoses after experimental arterial occlusion in the rat brain.

Prognosis and prognostic factors in nonaneurysmal perimesencephalic hemorrhage: a follow-up study in 29 patients.

BACKGROUND: Perimesencephalic nonaneurysmal hemorrhage is a benign form of subarachnoid hemorrhage with a low risk of rebleeding. The authors conducted a retrospective study to investigate the prognosis, possible prognostic factors, and long-term natural history in perimesencephalic nonaneurysmal subarachnoid hemorrhage (PNSH). METHODS: This report contains a retrospective analysis of 29 patients with PNSH who were followed from 1 month to 8 years with an average follow-up period of 5.4 years. We evaluated computed tomography (CT) scan features; clinical grade; loss of consciousness during hemorrhage; ventricular ratio; angiographic spasm; complications such as ischemic complications, early rebleeding, late rebleeding, epilepsy, hydrocephalus, and fixed ischemic deficit; and outcome. RESULTS: There were 7 men and 22 women, and the ages ranged from 22 to 69 years (mean 49.5 years). In the group with PNSH 93% of the patients were in grade I-II, as compared to 70.8% of patients with non-PNSH according to the Hunt and Hess system. Loss of consciousness during hemorrhage was detected in 9 patients (31%). We observed acute hydrocephalus in 4 patients (13.7%). The first cerebral four-vessel angiograms disclosed vasospasm in 3 patients (10.3%). Patients with PNSH have the best outcome according to the activities of daily living (ADL) grading system when compared with other groups of patients with negative angiogram (aneurysmal pattern and invisible blood). CONCLUSION: This study provides evidence that patients with PNSH have an uncomplicated course and a particularly favorable outcome.

The relationships among ultrastructural angiogenic features, Na+ K+, Ca+2, Mg+2 ATP-ase activities and SOD concentration in the microvasculature of intracranial meningiomas and glial tumors.

The purpose of this study was to investigate the relationship among ultrastructural angiogenic features, adenosine-5'-triphosphatase (ATP-ase) activities and superoxide dismutase (SOD) concentration in the microvasculature of intracranial meningiomas and glial tumors. We examined 20 tumor materials from 20 adult patients with intracranial meningioma or glial tumor who underwent selective surgery, dividing them into two groups based on the type of the tumors. Group I consisted of 10 meningioma-materials, and Group II of 10 glial tumor-materials. Na+-K+, Mg+2 and Ca+2 ATP-ase activities in Group I were significantly higher than those in Group II (p < 0.01). The SOD activity in Group I was significantly lower than that in Group II (p < 0.01). According to electron microscopic findings, vascular endothelial proliferation and ultrastructural cytoplasmic changes in the glial tumors were more prominent than those in the meningiomas. Our results show that there is a meaningful correlation among an increased endothelial proliferation, a decreased ATP-ase level and an increased SOD activity in the meningiomas and glial tumors.

Prognosis and prognostic factors for unexplained subarachnoid hemorrhage: review of 84 cases.

OBJECTIVE: We conducted a retrospective study to investigate the prognosis, possible prognostic factors, and long-term natural history of subarachnoid hemorrhage of unexplained cause. METHODS: This report contains a retrospective analysis of data for 84 patients with subarachnoid hemorrhage of unknown cause who were monitored for 1 month to 9.5 years, with an average follow-up period of 5.6 years. We evaluated the associations between computed tomographic (CT) scan features, clinical grade, loss of consciousness during hemorrhage, ventricular ratio, angiographic spasm, complications (such as death resulting from ischemia, early rebleeding, late rebleeding, epilepsy, hydrocephalus, and fixed ischemic deficits), and outcomes, using a nonparametric, two-sample, Kolmogorov-Smirnov test. The chi2 test was used to test the independence of two categorical variables. RESULTS: CT class exhibited a significant association with clinical grade (gamma = 0.865, P = 0.006), loss of consciousness during hemorrhage (gamma = 0.69, P = 0.001), and ventricular ratio (gamma = 0.8175, P = 0.01) but a nonsignificant association with angiographic vasospasm (gamma = 0.21, P = 0.2). Death resulting from ischemic complications and fixed ischemic deficits were strongly associated with clinical grade (P = 0.003 and P = 0.008, respectively) but weakly associated with CT class (P = 0.06 and P = 0.084, respectively). Angiographic vasospasm was strongly associated only with fixed ischemic deficits among complications (P = 0.001). Clinical outcome was strongly positively associated with CT class (gamma = 0.685, P = 0.001), clinical grade (gamma = 0.81, P = 0.001), and ventricular ratio (gamma = 0.57, P = 0.002) but weakly positively associated with loss of consciousness during hemorrhage (gamma = 0.459, P = 0.0487) and angiographic vasospasm (gamma = 0.48, P = 0.04). CONCLUSION: Our study confirms earlier studies reporting a good prognosis for survival, but it does not confirm the earlier statements regarding low morbidity rates. Although clinical grade and the presence and amount of subarachnoid blood on CT scans are the major prognostic factors related to the incidence of ischemic complications, clinical grade and CT class are also the main parameters, with ventricular ratio, indicating clinical outcomes for patients with subarachnoid hemorrhage of unknown cause.