The relationship between anti-seizures medications and metabolic acidosis in craniotomy operations: is topiramate or zonisamide the cause of metabolic acidosis?

BACKGROUND/AIM: The most commonly prescribed anti-seizures medications (ASMs) for the treatment of epilepsy are currently topiramate, zonisamide, lacosamide, carbamazepine and levetiracetam. The objective of this study was to examine the correlation between preoperative, intraoperative, and postoperative metabolic acidosis and the use of ASMs prior to craniotomy operations. MATERIALS AND METHODS: This retrospective cross-sectional study evaluated patients who underwent intracranial surgery with craniotomy under general anaesthesia between May 2020 and April 2023 and used ASMs. The patients were classified into four groups based on the pharmacological mechanisms of action of the ASMs administered before intracranial surgery (Group-I, zonisamide or topiramate; Group-II, lacosamide; Group-III, carbamazepine; Group-IV, levetiracetam). Metabolic acidosis severity was defined based on base excess (BE) levels: mild (-3 to -5), moderate (-5 to -10), and severe (below - 10). The study investigated the correlation between ASMs and the severity of metabolic acidosis in preoperative, intraoperative, and postoperative blood gas measurements. RESULTS: Out of 35 patients, 24 patients underwent intracranial surgery and 11 patients underwent epilepsy surgery. There were statistically significant differences in the severity of metabolic acidosis between preoperative (p < 0.001), intraoperative (p < 0.001) and postoperative (p = 0.01) groups. The preoperative mean BE of group-I was - 4.7, which was statistically lower than that of group-III (p = 0.01) and group-IV (p < 0.001). Intraoperatively and postoperatively, group-I had a mean BE of -7.5 and - 3.2, respectively, which was statistically lower than that of groups II (p = 0.007; p = 0.04), III (p = 0.002; p = 0.03), and IV (p < 0.001; p = 0.009). There was no statistically significant difference in BE between groups II, III and IV at all three time points. Group I had the lowest BE at all three time points. Intraoperative bicarbonate was administered to all patients in group I, whereas no intraoperative bicarbonate was required in the other groups. In group I, 50% of patients required postoperative intensive care. CONCLUSION: The use of ASMs in patients undergoing surgery is important in terms of mortality and morbidity. Topirimat and zonisamide are ASMs that can cause preoperative, intraoperative and postoperative metabolic acidosis. Patients receiving topirimat or zonisamide are particularly susceptible to metabolic acidosis. Special care should be taken in the management of anaesthesia in patients receiving these drugs, and monitoring of the perioperative metabolic status is essential.

The Effect of Cerebral Oxygen Saturation Changes on Early Postoperative Neuropsychological Function in Patients Undergoing Cranial Surgery.

AIM: To compare the incidence of postoperative neuropsychological dysfunction in patients managed with cerebral saturation monitoring versus traditional approaches. MATERIAL AND METHODS: A hundred patients undergoing elective intracranial surgery were divided into two groups to receive intraoperative management via cerebral saturation monitoring (Group O) or the conventional approach (Group C). The postoperative neuropsychological function was evaluated by the antisaccadic eye movement test (ASEM) and the Mini-Mental State Examination (MMSE). These tests were performed preoperatively and postoperatively on the first, second, and fifth days. The time for the modified Aldrete score to reach 9 (MAS 9), adverse effects, and pain using a Visual Analog Scale (VAS) scores were recorded. RESULTS: Patient characteristics and surgery data were not statistically different. The MAS 9 of group O was significantly lower than that of group C (p < 0.001). The MMSE at the postoperative 1, 2, and 5 days were significantly higher in Group O compared to Group C (p < 0.001). ASEM was similar between groups. Group O was subdivided according to the type of surgery applied with diagnosis, and there were no statistically significant between-group differences in terms of areas under the curve for the cerebral regional oxygen saturation. There was no between-group difference regarding the mean arterial pressure at any time perioperatively. The heart rate at 80, 90, 100, and 110 min intraoperatively was significantly higher in group C than in Group O. CONCLUSION: Intraoperative cerebral oxygenation monitoring can reduce patient mortality and morbidity by allowing early postoperative neurological evaluation to detect potential neurocognitive deficits.

The effects of the early and ultra-early intervention on the outcome in aneurysmatic subarachnoid hemorrhage.

BACKGROUND: The optimal timing of intervention for aneurysmatic subarachnoid hemorrhage is one of the historically controversial issues in neurosurgery. Although numerous studies investigated the subject, they had many limitations due to the nature of the disease. Early and ultra-early interventions have gained more and more supporters in recent decades. Nevertheless, the effects of the early and ultra-early intervention on the outcome of the disease are far from clarity. METHODS: A single-center retrospective cohort study was carried out at Trakya University Medical Faculty Training and Practice Hospital. The study includes data on all patients admitted with an aneurysmal subarachnoid hemorrhage between January 1, 2001, and December 31, 2005. Patients were divided into two groups according to their WFNS grade status: Good (I-III) or poor (IV-V) grades. Patients are also classified according to their Glasgow Outcome Scale score: Unfavorable (1-2) or favorable (3-5) outcomes. Data were analyzed statistically, and the effects of the early and ultra-early intervention on the outcome were assessed. RESULTS: A total of 580 patients were admitted in the study period. Among them, 494 were eligible for the study. The median age (interquartile range) was 55 (18) years. While 244 (49.4%) patients were women, 250 (50.6%) patients were men. Three hundred and fourteen (63.6%) patients were operated, and 25 patients (5.1%) were undergone endovascular treatment. The ultra-early intervention was achieved in 60 (12.1%) patients and 142 patients (28.7%, including the previous ultra-early intervention group) early intervention was achieved. A meaningful outcome difference was present between the poor-grade ultra-early treatment group and the rest (p=0.007). Analogously, a meaningful outcome difference was present between the poor-grade early treatment group and the rest (p<0.001). CONCLUSION: This study supports the growing trend toward early or ultra-early intervention in aneurysmatic subarachnoid hemorrhage. Our findings showed that both early and ultra-early interventions have positive effects on the outcome in poor-grade aneurysmatic subarachnoid hemorrhage patients. Future studies with more homogenized and larger samples should be realized to clarify the optimal timing of intervention for aneurysmatic subarachnoid hemorrhage.

Aromatase cytochrome P450 enzyme expression in prolactinomas and its relationship to tumor behavior.

The aim of the study was to evaluate the presence of aromatase cytochrome P450 enzyme (P450AROM) expression in normal pituitary tissues and tumor tissues of patients with prolactinoma and to examine the impact of the P450AROM expression on clinical outcome. Twenty-six consecutive human pituitary tissue samples were obtained from autopsies performed at the Institute of Forensic Medicine. Sixty-four patients who had an adenomectomy between 2000 and 2009 after prolactinoma diagnosis with histologically confirmed pituitary tumor tissues were retrospectively included in this study. The slices from the pituitary tissues were subjected to immunohistochemical staining for evaluation of P450AROM and estrogen receptor beta (ER beta) subunit. Immunohistochemistry results were compared according to age, gender, remission rate, resistance and invasion status of the patients. Higher than normal P450AROM expression was found in the pituitary tissues of the patients with prolactinoma (p < 0.001). P450AROM intensity had no relation to resistance or remission in patients with prolactinoma (p = 0.44, p = 0.45, respectively). The subgroup analysis showed that compared to males without invasive adenoma, males with invasive adenoma had higher P450AROM expression (p = 0.048). ER beta was found to have an impact on resistance (p = 0.049). This study shows that P450AROM expression is present in the pituitary tissues of patients with prolactinoma and that this presence could be important in development and tumor behavior of prolactinomas.

Reconstruction of growing skull fracture with in situ galeal graft duraplasty and porous polyethylene sheet.

OBJECTIVE: In growing skull fractures with large calvarial defects, it is difficult to use autografts for reconstruction and it requires alternative materials for cranioplasty. In this report, the authors describe their experience and introduce reconstruction of the growing skull fractures' defects with a porous polyethylene sheet (Medpor) and with a novel technique of duraplasty with in situ galeal graft, which avoid the potentially risky dissection and exposure of brain tissue. The goal of this study was to clarify effective surgical methods and to provide the rationale for these techniques. METHODS: We performed this technique on 8 patients with large calvarial defects resulting from growing skull fractures. The skin flap was retracted, leaving the galeal plane adherent to the underlying defect. After removing the bony edges and exposing the underlying retracted dural margins, duraplasty was performed by suturing the galeal tissue left in situ on the defect of the dural margins. Bone reconstruction was performed by placing porous polyethylene sheet (Medpor). CONCLUSIONS: Duraplasty with in situ galeal tissue is a simple, safe, and effective technique to reconstruct dural defects in growing skull fracture, which avoids the risky dissection of the brain tissue. Also, by using Medpor, growing skull fractures can be effectively reconstructed with good cosmetic results.

Bypass to the intracranial giant or large internal carotid artery aneurysms: superficial temporal artery to middle cerebral artery bypass re-visited.

OBJECTIVE: Hunterian ligation of the internal carotid artery is an acceptable treatment modality for inoperable intracranial carotid aneurysms. Despite the risk of thrombo-embolic complications, ligation together with superficial temporal artery-middle cerebral artery (STA-MCA) bypass surgery is vital in some patients. Our aim is to present our experience in five patients in whom STA-MCA bypass and balloon occlusion were performed due to inoperable intracranial carotid artery aneurysms. METHODS: During the last five years, five patients with inoperable internal carotid artery (ICA) aneurysms were treated by STA-MCA bypass surgery followed by permanent endovascular ICA occlusion. Patients were selected for bypass surgery on the basis of failing balloon test occlusion. Patients were managed in the intensive care unit after surgical and endovascular procedures. RESULTS: Clinical improvement was noted in all patients and no major complication during the follow-up was seen. Aneurysmal thrombosis was confirmed in all patients. CONCLUSION: Hunterian ligation associated with bypass surgery is an effective treatment method in selected patients. The following points should be considered for a good outcome: (1) experienced surgeon for bypass surgery, (2) experienced neuroradiologist for endovascular occlusion of the parent vessel as close to the aneurysm neck as possible, and (3) judicious postoperative management by means of anticoagulation, fluid replacement, and pressure control.