Tag: Seizures

Posted on

Decoding the clinical effects of low-grade glioma–induced cortical excitability

J Neurosurg 140:18–26, 2024

Patients with low-grade glioma (LGG) in eloquent regions often present with seizures, and findings on detailed neuropsychological testing are often abnormal. This study evaluated the association between cortical excitability, seizures, and cognitive function in patients with LGG.

METHODS LGG patients who underwent transcranial magnetic stimulation (TMS) from January 2021 to December 2022 were studied. Cortical excitability was measured using the resting motor thresholds (RMTs) of the upper and lower extremities. Early postoperative seizures served as the seizure endpoint. Neuropsychological assessment was completed prior to surgery contemporaneous with the TMS studies.

RESULTS A total of 31 patients were analyzed for seizure outcome. Median (interquartile range [IQR]) upper-extremity RMT was 39% (34%–46%) of maximum stimulator output, and the median (IQR) lower-extremity RMT was 69% (51%79%). Lower-extremity RMT was higher in patients with early postoperative seizures, especially in those with motor region tumors (p = 0.02); however, RMT was not associated with seizures at presentation or long-term seizure control. A total of 26 patients completed neuropsychological assessment. There were significant negative correlations between upper-extremity RMT and psychomotor processing speed (Wechsler Adult Intelligence Scale–Fourth Edition [WAIS-IV] Processing Speed Index r = −0.42, p = 0.031; WAIS-IV Coding r = −0.41, p = 0.036; WAIS-IV Symbol Search r = −0.39, p = 0.048), executive function (Trail Making Test Part B r = −0.41, p = 0.036), and hand dexterity (Grooved Pegboard Test r = −0.50, p = 0.047).

CONCLUSIONS RMT was positively correlated with early postoperative seizure risk and negatively correlated with psychomotor processing speed, executive function, and hand dexterity. These findings support the theory of local and regional resting oscillatory network dysfunction from a glioma-brain network.

Posted on

Predictive factors for post operative seizures following meningioma resection in patients without preoperative seizures: a multicenter retrospective analysis

Acta Neurochirurgica (2023) 165:1333–1343

Meningiomas are the most common primary brain tumor and represent 35% of all intracranial neoplasms. However, in the early post-operative period approximate 3–5% of patients experience an acute symptomatic seizure. Establishing risk factors for postoperative seizures will identify those patients without preoperative seizures at greatest risk of postoperative seizures and may guide antiseizure medications (ASMs) management.

Methods Adult seizure naïve patients who underwent primary resection of a World Health Organization (WHO) Grade 1–3 meningioma at the three Mayo Clinic Campuses between 2012–2022 were retrospectively reviewed. Multivariate regression analyses were used to identify radiological, surgical, and management features with the development of new-onset seizures in patients undergoing meningioma resection.

Results Of 113 seizure naïve patients undergoing meningioma resection 11 (9.7%) experienced a new-onset post-operative seizure. Tumor volume ≥ 25 cm 3 (Odds Ratio (OR) 5.223, 95% Confidence Interval (CI) 1.546 – 17.650, p = 0.008) and cerebral convexity meningiomas (OR 4.742, 95% CI 1.255 – 14.336, p = 0.016) were most associated with new onset postoperative seizures in multivariate analysis. ASMs and corticosteroid therapies did not display a significant difference among those with and without a new onset postoperative seizure.

Conclusion In the current study, a larger tumor volume (≥ 25 cm3 ) and/or convexity meningiomas predicted the development of new onset post-operative seizures. Those who present with these factors should be counseled for their increased risk of new onset post-operative seizures and may benefit from prophylactic ASMs therapy.

Posted on

Predictors of postoperative seizure outcome in supratentorial meningioma

J Neurosurg 137:515–524, 2022

Meningiomas are the most common primary intracranial tumor. Seizures are common sequelae of meningioma development. Meningioma patients with seizures can be effectively treated with resection, with reports of seizure freedom of 60%–90%. Still, many patients manifest persistent epilepsy. Determining factors associated with worsened seizure outcomes remains critical in improving the quality of life for these patients. The authors sought to identify clinical, radiological, and histological factors associated with worse seizure outcomes in patients with supratentorial meningioma and preoperative seizures.

METHODS The authors retrospectively reviewed the charts of 384 patients who underwent meningioma resection from 2008 to 2020. The charts of patients with a documented history of preoperative seizures were further reviewed for clinical, radiological, operative, perioperative, histological, and postoperative factors associated with seizures. Engel class at last follow-up was retrospectively assigned by the authors and further grouped into favorable (class I) and worse (class II–IV) outcomes. Factors were subsequently compared by group using comparative statistics. Univariable and multivariable regression models were utilized to identify independent predictors of worse seizure outcome.

RESULTS Fifty-nine patients (15.4%) were found to have preoperative seizures, of whom 57 had sufficient postoperative data to determine Engel class outcome. Forty-two patients (74%) had Engel class I outcomes. The median follow-up was 17 months. Distinct margins on preoperative imaging (p = 0.012), Simpson grade I resection (p = 0.004), postresection ischemia (p = 0.019), WHO grade (p = 0.019), and recurrent disease (p = 0.015) were found to be the strongest predictors of Engel class outcome in univariable logistic regression. MIB-1 index (p = 0.001) and residual volume (p = 0.014) at last follow-up were found to be the strongest predictors of Engel class outcome in univariable generalized linear regression. Postresection ischemia (p = 0.012), WHO grade (p = 0.022), recurrent disease (p = 0.038), and MIB-1 index (p = 0.002) were found to be the strongest independent predictors of Engel class outcomes in multivariable analysis.

CONCLUSIONS Postresection ischemia, higher WHO grade, elevated MIB-1 index, and disease recurrence independently predict postresection seizure persistence in patients with supratentorial meningioma. Further understanding of the etiology of these markers may aid in elucidation of this complex disease process and guide management to prevent worse outcomes.

Posted on

Extent of parahippocampal ablation is associated with seizure freedom after laser amygdalohippocampotomy

J Neurosurg 135:1742–1751, 2021

The authors aimed to examine the relationship between mesial temporal subregion ablation volume and seizure outcome in a diverse cohort of patients who underwent stereotactic laser amygdalohippocampotomy (SLAH) for mesial temporal lobe epilepsy (MTLE).

METHODS Seizure outcomes and pre- and postoperative images were retrospectively reviewed in patients with MTLE who underwent SLAH at a single institution. Mesial temporal subregions and the contrast-enhancing ablation volume were manually segmented. Pre- and postoperative MR images were coregistered to assess anatomical ablation. Postoperative MRI and ablation volumes were also spatially normalized, enabling the assessment of seizure outcome with heat maps.

RESULTS Twenty-eight patients with MTLE underwent SLAH, 15 of whom had mesial temporal sclerosis (MTS). The rate of Engel class I outcome at 1 year after SLAH was 39% overall: 47% in patients with MTS and 31% in patients without MTS. The percentage of parahippocampal gyrus (PHG) ablated was higher in patients with an Engel class I outcome (40% vs 25%, p = 0.04). Subregion analysis revealed that extent of ablation in the parahippocampal cortex (35% vs 19%, p = 0.03) and angular bundle (64% vs 43%, p = 0.02) was positively associated with Engel class I outcome. The degree of amygdalohippocampal complex (AHC) ablated was not associated with seizure outcome (p = 0.30).

CONCLUSIONS Although the AHC was the described target of SLAH, seizure outcome in this cohort was associated with degree of ablation for the PHG, not the AHC. Complete coverage of both the AHC and PHG is technically challenging, and more work is needed to optimize seizure outcome after SLAH.

Posted on

Brain invasion and the risk of seizures in patients with meningioma

J Neurosurg 130:789–796, 2019

Identification of risk factors for perioperative epilepsy remains crucial in the care of patients with meningioma. Moreover, associations of brain invasion with clinical and radiological variables have been largely unexplored. The authors hypothesized that invasion of the cortex and subsequent increased edema facilitate seizures, and they compared radiological data and perioperative seizures in patients with brain-invasive or noninvasive meningioma.

METHODS Correlations of brain invasion with tumor and edema volumes and preoperative and postoperative seizures were analyzed in univariate and multivariate analyses.

RESULTS Totals of 108 (61%) females and 68 (39%) males with a median age of 60 years and harboring totals of 92 (52%) grade I, 79 (45%) grade II, and 5 (3%) grade III tumors were included. Brain invasion was found in 38 (22%) patients and was absent in 138 (78%) patients. The tumors were located at the convexity in 72 (41%) patients, at the falx cerebri in 26 (15%), at the skull base in 69 (39%), in the posterior fossa in 7 (4%), and in the ventricle in 2 (1%); the median tumor and edema volumes were 13.73 cm3 (range 0.81–162.22 cm3) and 1.38 cm3 (range 0.00–355.80 cm3), respectively. As expected, edema volume increased with rising tumor volume (p < 0.001). Brain invasion was independent of tumor volume (p = 0.176) but strongly correlated with edema volume (p < 0.001). The mean edema volume in noninvasive tumors was 33.0 cm3, but in invasive tumors, it was 130.7 cm3 (p = 0.008). The frequency of preoperative seizures was independent of the patients’ age, sex, and tumor location; however, the frequency was 32% (n = 12) in patients with invasive meningioma and 15% (n = 21) in those with noninvasive meningioma (p = 0.033). In contrast, the probability of detecting brain invasion microscopically was increased more than 2-fold in patients with a history of preoperative seizures (OR 2.57, 95% CI 1.13–5.88; p = 0.025). In univariate analyses, the rate of preoperative seizures correlated slightly with tumor volume (p = 0.049) but strongly with edema volume (p = 0.014), whereas seizure semiology was found to be independent of brain invasion (p = 0.211). In multivariate analyses adjusted for age, sex, tumor location, tumor and edema volumes, and WHO grade, rising tumor volume (OR 1.02, 95% CI 1.00–1.03; p = 0.042) and especially brain invasion (OR 5.26, 95% CI 1.52–18.15; p = 0.009) were identified as independent predictors of preoperative seizures. Nine (5%) patients developed new seizures within a median follow-up time of 15 months after surgery. Development of postoperative epilepsy was independent of all clinical variables, including Simpson grade (p = 0.133), tumor location (p = 0.936), brain invasion (p = 0.408), and preoperative edema volume (p = 0.081), but was correlated with increasing preoperative tumor volume (p = 0.004). Postoperative seizure-free rates were similar among patients with invasive and those with noninvasive meningioma (p = 0.372).

CONCLUSIONS Brain invasion was identified as a new and strong predictor for preoperative, but not postoperative, seizures. Although also associated with increased peritumoral edema, seizures in patients with invasive meningioma might be facilitated substantially by cortical invasion itself. Consideration of seizures in consultations between the neurosurgeon and neuropathologist can improve the microscopic detection of brain invasion.

 

Posted on

Predictors of aneurysmal rebleed before definitive surgical or endovascular management

A Simple and Quantitative Method to Predict Symptomatic Vasospasm After Subarachnoid Hemorrhage Based on Computed Tomography- Beyond the Fisher Scale

Acta Neurochir (2016) 158:1037–1044

Aneurysmal rebleed is the most dreaded complication following subarachnoid hemorrhage. Being a cause of devastating outcome, the stratification of risk factors can be used to prioritize patients, especially at high volume centers.

Method: A total of 99 patients with aneurysmal rebleed were analyzed in this study both prospectively and retrospectively from August 2010 to July 2014. In the control group, 100 patients were selected randomly from the patient registry. A total of 25 variables from the demographic, historical, clinical and radiological data were compared and analyzed by univariate and multivariate logistic regression analysis.

Results: Significant independent predictors of aneurysm rebleed were the presence of known hypertension (p=0.023), diastolic blood pressure of >90 mmHg on admission (p=0.008); presence of loss of consciousness (p= 0.013) or seizures (p = 0.002) at first ictus; history of warning headaches (p=0.005); higher Fisher grade (p<0.001); presence of multiple aneurysms (p= 0.021); irregular aneurysm surface (0.002).

Conclusions: Identification of high risk factors can help in stratifying patients in the high risk group. The risk stratification strategy with early intervention can prevent rebleeds. This in turn may translate into better outcomes of patients with intracranial aneurysms.

Posted on

Morbidity of Transcallosal and Transcortical Approaches to Lesions in and Around the Lateral and Third Ventricles: A Single-Institution Experience

Neurosurgery 67:1483–1496, 2010 DOI: 10.1227/NEU.0b013e3181f7eb68

Resection of an intraventricular mass can result in life-altering complications. Many advocate transcallosal rather than transcortical approaches to these lesions, citing differential postoperative seizure risk.

OBJECTIVE: To test the hypothesis that the complication rates and patient outcomes are no different between these ventricular approaches.

METHODS: The medical records of 127 patients (93 adults and 34 children) operated on for intraventricular lesions between 1996 and 2007 were retrospectively analyzed. Risk factors for specific postoperative complications and outcome were assessed by multivariate analysis.

RESULTS: The transcallosal (59%) or transcortical (41%) approach was used. Gross or nearly total resection was achieved in 87% of cases. The permanent neurological complication rate determined by a staff neurologist was 23.6%. Seizure attributable to surgery occurred after 8% of transcortical and 25% of transcallosal operations (P = .01). After controlling for a variety of factors, the transcallosal approach carried a 4.4-fold increased risk of seizure (95% confidence interval, 1.3-18.9). The operative approach was not a risk factor for any other postoperative complication. One year after surgery, 72% of patients had excellent functional outcome (Karnofsky Performance Score $ 70 and Glasgow Outcome Score = 5). High tumor grade and impaired preoperative Karnofsky Performance Score predicted poor outcome. More than 90% of patients operated on for symptomatic colloid cysts (n = 34) had an excellent outcome.

CONCLUSION: Although the 2 traditional approaches to the ventricular system had similar major complication rates, the transcallosal approach was associated with significantly increased seizure risk. Accordingly, the chosen operative corridor should optimize tumor access and the protection of vulnerable neurovascular structures.

Proudly powered by WordPress