Risk factors for a first epileptic seizure symptomatic of brain tumour or brain vascular malformation. A case control study

Prevalence and risk factors of early postoperative seizures in patients with glioma: a systematic review and meta-analysis

Objective

This study aimed to explore the prevalence and risk factors of early postoperative seizures in patients with glioma through meta-analysis.

Methods

Case-control studies and cohort studies on the prevalence and risk factors of early postoperative seizures in glioma patients were retrieved from various databases including CNKI, Wanfang, VIP, PubMed, Embase, Cochrane Library, and Web of Science, and the retrieval deadline for the data was 1 April 2023. Stata15.0 was used to analyze the data.

Results

This review included 11 studies consisting of 488 patients with early postoperative seizures and 2,051 patients without early postoperative seizures. The research findings suggest that the prevalence of glioma is complicated by seizures (ES = 19%, 95% confidence interval [CI] [14%-25%]). The results also indicated a history of seizures (RR = 1.94, 95% CI [1.76, 2.14], P = 0.001), preoperative dyskinesia (RR = 3.13, 95% CI [1.20, 8.15], P = 0.02), frontal lobe tumor (RR = 1.45, 95% CI [1.16, 1.83], P = 0.001), pathological grade ≤2 (RR = 1.74, 95% CI [1.13, 2.67], P = 0.012), tumor≥ 3 cm (RR = 1.70, 95% CI [1.18, 2.45], P = 0.005), tumor resection (RR = 1.60, 95% CI [1.36, 1.88], P = 0.001), tumor edema ≥ 2 cm (RR = 1.77, 95% CI [1.40, 2.25], P = 0.001), and glioma cavity hemorrhage (RR=3.15, 95% CI [1.85, 5.37], P = 0.001). The multivariate analysis results showed that a history of seizures, dyskinesia, tumor ≥3 cm, peritumoral edema ≥2 cm, and glioma cavity hemorrhage were indicated as risk factors for glioma complicated with early postoperative seizures.

Significance

Based on the existing evidence, seizure history, dyskinesia, frontal lobe tumor, pathological grade ≤2, tumor ≥3 cm, partial tumor resection, edema around tumor ≥2 cm, and glioma cavity hemorrhage are indicated as risk factors for glioma complicated with early postoperative seizures.

Awake craniotomy for gliomas involving motor-related areas: classification and function recovery

PURPOSE

Motor mapping with direct cortical stimulation (DCS) is useful for motor function preservation. Nevertheless, many patients still experience postoperative motor dysfunction after motor mapping. This study aimed to provide a classification of gliomas involved in motor-related areas to help understand which types of gliomas are prone to induce postoperative motor impairments.

METHODS

Sixty-four patients were retrospectively recruited. Based on tumor location, four types of gliomas were identified: (I) precentral gyrus; (II) premotor and/or supplementary motor areas but not invading pre-central gyrus; (III) adjacent to the posterior limb of the internal capsule; and (IV) other supra-tentorial area. The recovery of motor function was evaluated by muscle strength testing before surgery and 3 days, 7 days, 14 days, and 3 months after surgery.

RESULTS

Half of the patients experienced postoperative transient motor impairment within a week. Six patients suffered from permanent motor dysfunction, and four of them had type III glioma. Compared with types I and IV, patients with type III gliomas took more than three times as long to recover. Furthermore, patients with types I and II gliomas were more susceptible to preoperative epilepsy than those with types III and IV. There was no difference in postoperative seizure control between the four types.

CONCLUSIONS

Our classification of gliomas involving motor-related eloquent areas was useful for predicting postoperative motor functional prognosis in patients who underwent motor mapping with DCS. Even if no positive sites were detected, a conservative strategy of tumor resection is recommended in cases that gliomas located close to the posterior limb of the internal capsule.

Vascular Abnormalities and the Role of Vascular Endothelial Growth Factor in the Epileptic Brain

Epilepsy is a chronic neurological disorder generally defined to be caused by excessive neuronal activity. Thus, excessive neuronal activity is the main target of the currently used antiepileptic drugs (AEDs). However, as many as 30% of epileptic patients show drug resistance to currently available AEDs, which suggests that epilepsy should be attributed not only to neuronal cells but also to other brain cells, such as glial cells and vascular cells. Astrocytes, pericytes, and endothelial cells in particular comprise the blood–brain barrier (BBB), which tightly regulates the exchange of substances between the brain parenchyma and the circulating blood. It has been proposed that BBB dysfunction, especially barrier leakage, exacerbates epileptic progression, and conversely, that epileptic seizures induce barrier leakage. Furthermore, several studies have shown that BBB dysfunction is one of the main causes of drug resistance in epilepsy. To better understand the mechanisms that link BBB dysfunction and intractable epilepsy to gain insights for the future development of treatments, we review and discuss the relationships between epilepsy and brain vascular abnormalities, mainly by focusing on vascular malformation, BBB dysfunction, and excessive angiogenesis. Because these abnormalities have been reported to be caused by vascular endothelial growth factor (VEGF) in the ischemic brain, we discuss the possible role of VEGF in vascular abnormalities in the epileptic brain, in which the upregulation of VEGF levels has been reported. Both glial cells and endothelial cells express VEGF receptors (VEGFRs); thus, these cells are likely affected by increases in VEGF during seizures, which in turn could cause vascular abnormalities. In this review, we review the possible role of VEGF in epilepsy and discuss the mechanisms that link vascular abnormalities and intractable epilepsy.

Correlation between glioma location and preoperative seizures: a systematic review and meta-analysis

Epilepsy is a common manifestation of glioma patients and negatively impacts on quality of life and neurocognitive function. The risk of preoperative seizures in patients with glioma is currently under discussion. We aimed to evaluate the relationship between tumor locations in the cerebrum and preoperative seizures in patients with glioma. PubMed, EMBASE, Web of Science, China Biology Medicine, and the Cochrane Library were systematically searched from inception to July 15, 2017, for original studies including reports of preoperative seizures in patients with gliomas in different brain regions. The pooled odds ratio (OR) and 95% confidence interval (CI) of the meta-analysis for preoperative seizure risk stratified by cerebrum regions were calculated. The quality of evidence was assessed per outcome, using the approach of the Grades of Recommendation, Assessment, Development and Evaluation. Overall, 4323 participants in 16 population-based studies were included in this meta-analysis. The meta-analysis indicated that gliomas in the frontal lobe (OR = 1.51, 95% CI = 1.09-2.09, P = 0.013) were associated with a higher risk for preoperative seizure compared to occipital lobe involved (OR = 0.53, 95% CI = 0.32-0.88, P = 0.014). Regarding the other three lobe involved gliomas, no difference was found between the incidence of preoperative seizures and tumor location. Current limited data suggest that frontal gliomas were associated with a higher risk of preoperative seizures, while gliomas in the occipital lobe were associated with a lower seizure risk. Further RCT studies recruiting larger sample sizes are required to validate these results and guide clinical practice.

Factors associated with epileptic seizure of cavernous malformations in the central nervous system in West China

OBJECTIVE

To explore the factors associated with preoperative and postoperative epileptic seizure in patients with cavernous malformations (CMs).

METHODS

A total of 52 consecutive patients from January 2009 to June 2011 who underwent surgical treatment in West China Hospital of Sichuan University due to CMs and confirmed by histopathology were retrospectively reviewed.Patients were divided into two groups (epilepsy-group and non-epilepsy group) according to clinical presentation. Other clinical data, treatment procedure, and follow-up information were collected. Engel classification was used to evaluate seizure outcome.

RESULTS

Low birth weight, temporal lobe involvement and cortical lesion showed significant difference between two groups (p=0.017, 0.003 and 0.025 respectively). Cortical lesion highly increased risk for preoperative epileptic seizure (OR=10.48; 95% CI 1.61-68.23). After a mean follow-up of 2.1 years, 77.8% of epileptic patients achieved Engel class I. Temporal lobe involvement, lesion size < 2.5cm and surgery within one year of symptom onset were found associated with better seizure outcome (p=0.016, 0.012 and 0.050). Temporal lobe involvement significantly decreased the risk for postoperative epileptic seizure (OR=0.038; 95% CI 0.002-0.833). Application of ECoG made no significant difference to seizure outcome (p=0.430). Most patients need continuing medication therapy after surgery.

CONCLUSION

Surgical treatment of patient with CMs is satisfactory in most cases and temporal lobe involvement usually predict favourable postoperative seizure outcome whether under the monitoring of ECoG or not. Thus, epileptic patients with CMs should be considered for surgical treatment especially when cortical brain layer or temporal lobe was involved.