Epilepsy after operative treatment of ruptured cerebral aneurysms

Long-term Risk of Epilepsy in Subarachnoid Hemorrhage Survivors With Positive Family History: A Population-Based Follow-up Study

BACKGROUND AND OBJECTIVES

Aneurysmal subarachnoid hemorrhage (aSAH) is a devastating form of stroke affecting the working-age population, where epilepsy is a common complication and major prognostic factor for increased morbidity in aSAH survivors. The objective of this analysis was to assess whether epilepsy in first-degree relatives is a risk of developing epilepsy after aSAH.

METHODS

We used a region-specific database that includes all cases of unruptured and ruptured saccular intracranial aneurysm admitted to Kuopio University Hospital from its defined Eastern Finnish catchment population. We also retrieved data from Finnish national health registries for prescription drug purchases and reimbursement, hospital discharge, and cause of death and linked them to patients with aSAH, their first-degree relatives, and population controls matched 3:1 by age, sex, and birth municipality. Cox regression modeling and Kaplan-Meier survival curves were used for analysis.

RESULTS

We examined data for 760 consecutive 12-month survivors of aSAH, born in 1950 or after, with a first aSAH from January 1, 1995, to December 31, 2018. Of the 760 patients (median age, 47 years; 53% female; median follow-up, 11 years), 111 (15%) developed epilepsy at a median of 7 months (interquartile range, 2-14 months) after admission for aSAH. Of the 2,240 population controls and 4,653 first-degree relatives of patients with aSAH, 23 (0.9%) and 80 (1.7%), respectively, developed epilepsy during the follow-up period. Among 79 patients with epilepsy in first-degree relatives, 22 (28%) developed epilepsy after aSAH; by contrast, among 683 patients with no epilepsy in first-degree relatives, 89 (13%) developed epilepsy after aSAH. Having at least 1 relative with epilepsy was an independent risk factor of epilepsy after aSAH (hazard ratio, 2.44; 95% CI 1.51-3.95). Cumulative 1-year rates by first-degree relationship were 40% with 1 or more children with epilepsy, 38% with 1 or more affected parents, 5% with 1 or more affected siblings, and 10% with no relatives with epilepsy.

DISCUSSION

Patients who developed epilepsy after aSAH were significantly more likely to have first-degree relatives with epilepsy than those who did not develop epilepsy after the aSAH.

Incidence and risk factors of epilepsy following brain arteriovenous malformation rupture in adult patients

BACKGROUND

Little is known about incidence, time of onset, clinical presentation, and risk factors of epileptic seizure following brain arteriovenous malformation (bAVM) rupture.

METHODS

We performed a monocentric retrospective cohort study from January 2003 to March 2021. The main objective of this study was to determine the incidence of seizures after spontaneous bAVM rupture in nonepileptic adult patients and describe the corresponding clinical features. The secondary objective was to identify clinical, radiological, or biological predictors for the occurrence of de novo seizures after bAVM rupture.

RESULTS

Of the 296 cases of bAVM rupture registered during the study period, 247 nonepileptic patients (male 53%, median age 40) were included in the study. Fifty-nine patients (23.9%) had at least one seizure after bAVM rupture. The use of preventive antiepileptic drugs (10.3 [1.5-74.1]; P = 0.02) and decompressive craniectomy (15.4 [2.0-125]; P < 0.009) were independently associated with the occurrence of epilepsy after the bAVM rupture. The factors independently associated with the absence of any seizure after the rupture were isolated intraventricular hemorrhage (0.3 [0.1-0.99]; P = 0.04) and infratentorial location of the bAVM (0.2 [0.1-0.5]; P = 0.09). The first seizure occurred within the first year or within 5 years in, respectively, 83.1% and 98.3% of the patients.

CONCLUSIONS

Epilepsy affects nearly a quarter of patients after bAVM rupture. Decompressive craniectomy represents an independent risk factor significantly associated with the occurrence of epilepsy after bAVM rupture. The introduction of preventive AEDs after rupture could be considered in these most severe patients who have a decompressive craniectomy.

The effect of prophylactic antiepileptic medications in aneurysmal subarachnoid hemorrhage patients: A retrospective review

OBJECTIVE

The current literary evidence suggests but does not heavily endorse the use of prophylactic antiepileptic drugs (AEDs) after aneurysmal subarachnoid hemorrhage. Literature continues to emerge suggesting not only a lack of efficacy but associated poor outcomes. This study is a retrospective review comparing seizure incidence in aneurysmal subarachnoid patients between those given prophylactic AEDs and those not.

METHODS

With IRB approval, a retrospective chart review was performed on all aneurysmal subarachnoid patients from 2012 to 2019 at the University of Mississippi Medical center. Univariate and Multivariate analysis was performed using SAS. Primary outcome was seizure incidence between groups. Factors associated with seizure and poor outcome were also investigated.

RESULTS

348 patients were identified: 120 in the AED group, and 228 patients in the non-AED group. There was no significant difference in mean age, gender, ethnicity, HH scores, treatment modality, or mean aneurysm size. The AED group had a higher history of prior aneurysmal rupture (6.7% vs. 1.3%, p = 0.01) and associated intracranial hemorrhage (22.5% vs. 10.5%, p = 0.0004). There was no significant difference in seizure incidence between the two groups (8.3% vs. 4.8%, p = 0.24). On multivariate analysis, aneurysm clipping compared to coiling (OR 3.8, p = 0.012) and delayed cerebral ischemia (OR 2.77, p = 0.023) were associated with seizures. DCI (OR 8.34), HH grade, Age (OR 1.07), Seizure (8.34), and AED use (1.7) were significantly associated with poor outcome.

CONCLUSION

This retrospective review adds to the evidence that prophylactic AED use in aneurysmal subarachnoid hemorrhage patients has not been proven to improve seizure rates and may result in worse patient outcomes.

Cardiogenic cerebral infarction in the parietal lobe predicts the development of post-stroke epilepsy

PURPOSE

Post-stroke epilepsy (PSE) is a major late complication of cardioembolic cerebral infarction. However, few studies have examined the epileptogenicity and characteristics of first-occurrence cardioembolic cerebral infarctions.

METHODS

This retrospective study included 93 consecutive patients with old cardioembolic cerebral infarctions who were classified into two groups based on their epileptic history: patients presenting with PSE or stroke without seizure (SWS). Each patient was diagnosed with an epileptic seizure subtype and treated with appropriate anti-epileptic therapy after admission. We evaluated clinical characteristics, laboratory results, and intracranial infarct areas. The sizes of these areas were measured using MRI diffusion-weighted image (DWI) of each patient after their first stroke. The volume was calculated by multiplying the total slice area with the slice thickness.

RESULTS

PSE was diagnosed in 43 (46.2 %) of 93 patients. The mean (± SD) time from infarction onset to the first seizure in the PSE group was 22.5 ± 31.6 months. The PSE group exhibited significantly more atrial fibrillation (p = 0.022) and higher glucose levels (p < 0.001) compared with the SWS group. The most common PSE seizure type was focal to bilateral tonic-clonic seizure (61.0 %). Although DWI did not reveal any significant differences in the volume of infarctions between the two groups, the involvement of the parietal lobe in infarction of the PSE group (69.8 %) upon first admission was significantly higher (p = 0.006) than that of the SWS group (40.0 %). Multiple logistic regression analysis revealed that parietal lobe involvement in infarction (OR 4.95; 95 % CI 1.25-19.60; p = 0.023) was a significant independent predictor of PSE.

CONCLUSION

The involvement of the parietal lobe in infarction was a significant independent predictor of PSE. Dysfunction of the parietal lobe might play a critical role in the epileptogenesis of PSE.

Effects of Hemosiderosis on Epilepsy Following Subarachnoid Hemorrhage

Epilepsy after aneurysmal subarachnoid hemorrhage (post-SAH epilepsy) is a critical complication that influences clinical and social prognoses. However, the underlying mechanisms remain unclear. We investigated the relationship between hemosiderosis and the incidence of post-SAH epilepsy. About 50 patients with aneurysmal SAH who were admitted to Sapporo Medical University and Oji General Hospital between April 2010 and June 2016 were enrolled in this retrospective study. Hemosiderosis detected by T2^*-weighted magnetic resonance imaging(MRI) and the incidence of post-SAH epilepsy were retrospectively analyzed. Post-SAH epilepsy was defined as an unprovoked seizures occurring more than 1 week after the onset of SAH. Six patients (12%) developed post-SAH epilepsy. In all patients, hemosiderosis in the cortex or cerebral parenchyma was detected by T2^*-weighted MRI. Statistical analyses revealed that hemosiderosis and the co-existence of intracerebral hemorrhage (ICH) related with post-SAH epilepsy (Fisher’s exact test, univariate exact logistic regression analysis: P < 0.05). Post-SAH epilepsy was predicted by hemosiderosis and the co-existence of ICH. The present results suggest that hemosiderin is the principal cause of post-SAH epilepsy and may be a predictor of this critical complication.

Seizures and Epileptiform Patterns in SAH and Their Relation to Outcomes

In subarachnoid hemorrhage (SAH), seizures are frequent and occur at different time points, likely reflecting heterogeneous pathophysiology. Young patients, those with more severe SAH (by clot burden or presence of severe mental status changes at onset or focal neurologic deficits at any time), those with associated increased cortical irritation (by infarction or presence of underlying hematoma), and patients undergoing craniotomy are at higher risk. Advanced neurophysiologic monitoring allows for seizure burden quantification, identification of subclinical seizures, and interictal patterns as well as neurovascular complications that may have an independent impact on the outcome in this population. Practice regarding seizure prophylaxis varies widely; its institution is often guided by the risk-benefit ratio of seizures and medication side effects. Newer anticonvulsants seem to be equally effective and may have a more favorable profile. However, questions regarding the association of seizures and vasospasm, the therapeutic dosing, timing, and duration of antiepileptic treatment and the impact of seizures and antiepileptics on the outcome remain unanswered. In this review, we provide a broad overview of the work in this area and offer a diagnostic and therapeutic approach based on our own expert opinion.

Post-stroke epilepsy

Post-stroke epilepsy (PSE) is a common complication after stroke, yet treatment options remain limited. While many physicians prescribe antiepileptic drugs (AED) for secondary prevention of PSE, it is unclear which treatments are most effective in the prevention of recurrence of symptoms, or whether such therapy is needed for primary prevention. This review discusses the current understanding of epidemiology, diagnoses, mechanisms, risk factors, and treatments of PSE.

Association between seizures and mortality in patients with aneurysmal subarachnoid hemorrhage: A nationwide retrospective cohort analysis

PURPOSE

The impact of seizures on outcomes in patients with subarachnoid hemorrhage (SAH) is not well understood, with conflicting results published in the literature.

METHOD

For this retrospective cohort analysis, data from the Nationwide Inpatient Samples (NIS) for 2006-2011 were utilized. All patients aged ≥18 years with a primary admitting diagnosis of subarachnoid hemorrhage were included. Patients with a diagnosis of seizure were segregated from the initial cohort. Multivariable logistic regression modeled the risk of death while adjusting for severity of SAH as well as co-morbidities. The primary outcome of this analysis was in-hospital mortality.

RESULTS

12,647 patients met inclusion criteria for the study, of which 1336 had a diagnosis of seizures. The unadjusted in-hospital mortality was higher for patients with seizures compared to those without (16.2% vs 11.6%, p<0.01). Compared to patients without seizures, patients with seizures were younger (52.4 years SD 13.9 vs 54.8 years, SD 13.6; p<0.01), more likely to be male (35.6% vs 31.0%, p<0.01) and had longer hospital stays (18.3 days, IQR 12.0-27.5 vs 14.8 days, IQR 10.0-21.9; p<0.01). After adjusting for the severity of SAH, seizures were found to be associated with increased mortality (OR 1.57, 95% CI 1.32-1.87, p<0.01).

CONCLUSION

In this large nationwide analysis, the presence of seizures in patients with SAH was associated with higher in-hospital mortality. This finding has potentially important implications for goals of care decision-making and prognostication, but further study in the area is needed.

Current Management of Aneurysmal Subarachnoid Hemorrhage Guidelines from the Canadian Neurosurgical Society

Published medical evidence pertaining to the management of aneurysmal subarachnoid hemorrhage (SAH) was critically reviewed in order to prepare practice guidelines for this condition. SAH should be considered as a possible cause of all sudden and/or unusual headaches, and every attempt should be made to recognize mild SAHs, as they are still frequently misdiagnosed. The first test for SAH is computed tomography (CT), followed by lumbar puncture when the CT is negative for intracranial bleeding (the case in only several per cent of patients within 24 hours of aneurysm bleeding). Urgent cerebral angiography is necessary to detect the underlying cerebral aneurysm. The advantage of rapid diagnosis of SAH followed by early aneurysm repair is minimizing the risk of catastrophic aneurysm rebleeding. Early surgery for aneurysm repair is often possible and is recommended, unless the aneurysm location or size renders it technically difficult to expose in clot-laden subarachnoid cisterns beneath an acutely swollen brain. Aneurysm ablation is optimally accomplished with open microsurgery and clipping of the aneurysm neck, although other options include proximal parent artery occlusion, “trapping” of the aneurysmal segment of the artery, and embolization of thrombogenic materials (e.g., platinum “microcoils”) directly into the aneurysm dome using endovascular techniques. Neurological outcome following SAH is also optimized through the prevention of secondary SAH complications, and further management specific for ruptured cerebral aneurysms can include anticonvulsants, neuroprotectants, and various agents and techniques to prevent or reverse delayed-onset cerebral vasospasm. All patients with aneurysmal SAH should be treated with the calcium antagonist nimodipine, and in certain circumstances patients should receive anticonvulsants. Induced arterial hypertension, hypervolemia and in some instances percutaneous balloon angioplasty are recommended to reverse vasospasm causing symptomatic cerebral ischemia prior to cerebral infarction.

High risk for seizures following subarachnoid hemorrhage regardless of referral bias

BACKGROUND

To investigate the frequency, predictors, and clinical impact of electrographic seizures in patients with high clinical or radiologic grade non-traumatic subarachnoid hemorrhage (SAH), independent of referral bias.

METHODS

We compared rates of electrographic seizures and associated clinical variables and outcomes in patients with high clinical or radiologic grade non-traumatic SAH. Rates of electrographic seizure detection before and after institution of a guideline which made continuous EEG monitoring routine in this population were compared.

RESULTS

Electrographic seizures occurred in 17.6 % of patients monitored expressly because of clinically suspected subclinical seizures. In unselected patients, seizures still occurred in 9.6 % of all cases, and in 8.6 % of cases in which there was no a priori suspicion of seizures. The first seizure detected occurred 5.4 (IQR 2.9-7.3) days after onset of subarachnoid hemorrhage with three of eight patients (37.5 %) having the first recorded seizure more than 48 h following EEG initiation, and 2/8 (25 %) at more than 72 h following EEG initiation. High clinical grade was associated with poor outcome at time of hospital discharge; electrographic seizures were not associated with poor outcome.

CONCLUSIONS

Electrographic seizures occur at a relatively high rate in patients with non-traumatic SAH even after accounting for referral bias. The prolonged time to the first detected seizure in this cohort may reflect dynamic clinical features unique to the SAH population.

Subarachnoid extension of hemorrhage is associated with early seizures in primary intracerebral hemorrhage

BACKGROUND

Seizures are common in patients with subarachnoid hemorrhage, potentially by inciting cortical irritability. Seizures are also commonly seen after intracerebral hemorrhage (ICH), although the mechanisms and risk factors within that population are not well understood. The objective of this study is to evaluate whether subarachnoid hemorrhage extension (SAHE) is associated with early seizures in patients with primary ICH.

METHODS

Patients with primary ICH were enrolled into a prospective registry between December 2006 and July 2012. Patients were managed per a structured protocol. SAHE was identified on imaging by expert reviewers blinded to outcomes. Electroencephalograms were routinely obtained in patients with unexplained, poor level of arousal. Seizure was determined by clinically observed convulsions or traditional electroencephalographic criteria. Early seizures were defined as occurring within 3 days of hemorrhage. A binary logistic regression model was developed to test whether the occurrence of SAHE was independently associated with seizures.

RESULTS

A total of 234 patients were studied. Of these, 93 (40%) had SAHE and 9 (4%) had early seizures. SAHE was associated with early seizures (P = .03). No additional variables were identified by regression modeling to mediate the association between SAHE and early seizures (odds ratio 5.62 [95% confidence interval 1.14-27.7], P = .034).

CONCLUSIONS

SAHE is associated with early seizures in patients with primary ICH. Further study is needed to confirm these findings and determine whether modifications to routine care based on the presence of SAHE would be of benefit.

Clinical, laboratory, and radiographic predictors of the occurrence of seizures following aneurysmal subarachnoid hemorrhage

Object

At present, the administration of prophylactic antiepileptic medication following aneurysmal subarachnoid hemorrhage (SAH) is controversial, and the practice is heterogeneous. Here, the authors sought to inform clinical decision making by identifying factors associated with the occurrence of seizures following aneurysm rupture.

Methods

Exploratory analysis was performed on 413 patients enrolled in CONSCIOUS-1 (Clazosentan to Overcome Neurological Ischemia and Infarction Occurring after Subarachnoid Hemorrhage), a prospective randomized trial of clazosentan for the prevention of angiographic vasospasm. The association among clinical, laboratory, and radiographic covariates and the occurrence of seizures following SAH were determined. Covariates with a significance level of p < 0.20 on univariate analysis were entered into a multivariate logistic regression model. Receiver operating characteristic (ROC) curve analysis was used to define optimal predictive thresholds.

Results

Of the 413 patients enrolled in the study, 57 (13.8%) had at least 1 seizure following SAH. On univariate analysis, a World Federation of Neurosurgical Societies grade of IV–V, a greater subarachnoid clot burden, and the presence of midline shift and subdural hematomas were associated with seizure activity. On multivariate analysis, only a subarachnoid clot burden (OR 2.76, 95% CI 1.39–5.49) and subdural hematoma (OR 5.67, 95% CI 1.56–20.57) were associated with seizures following SAH. Using ROC curve analysis, the optimal predictive cutoff for subarachnoid clot burden was determined to be 21 (of a possible 30) on the Hijdra scale (area under the curve 0.63).

Conclusions

A greater subarachnoid clot burden and subdural hematoma are associated with the occurrence of seizures after aneurysm rupture. These findings may help to identify patients at greatest risk for seizures and guide informed decisions regarding the prescription of prophylactic anticonvulsive therapy. Clinical trial registration no.: NCT00111085 (ClinicalTrials.gov).

Early seizures after clipping of unruptured aneurysms of the anterior circulation: analysis on consecutive 1,000 cases

Seizures occurring after clipping of unruptured cerebral aneurysms have rarely been documented in the literature. The objective of this retrospective study is to clarify whether the frequency of early seizures, i.e., seizures occurring within 14 days of surgery, is influenced by patient- or aneurysm-specific characteristics. Data on 1,000 consecutive patients who underwent clipping of unruptured anterior circulation aneurysms were reviewed. They consisted of 387 men and 613 women with mean age of 59.8 ± 9.7 years. Fifty-one patients (5.1 %) developed early seizures. Interestingly, the frequency was similar to that occurring after clipping of unruptured posterior circulation aneurysms (n = 20, 5.0 %). Multivariate regression analysis revealed that younger age was correlated with early seizures (odds ratio (OR) 0.902; 95 % confidence interval (CI) 0.891-0.989). However, other variables, including aneurysm size and operation length, were not correlated. Although patients with history of epilepsy exhibited relatively high frequency of early seizures, the difference was not statistically significant. The frequency was unaffected by location or multiplicity of aneurysms. Thirty-one patients (61 %) developed seizures within 24 h of clipping. Regarding seizure types, 34 (67 %) developed generalized seizures and the other 17 (33 %) experienced partial seizures. Patients with generalized seizures were significantly more likely to harbor an iatrogenic brain lesion than those with partial seizures (47 vs. 18 %; OR 4.148; 95 % CI 1.005-17.113). Among 40 patients with follow-up period >12 months, seizures were temporary without recurrence in 38 (95 %). Although early seizures are mostly benign, a small possibility of them becoming a permanent morbidity needs to be explained to patients undergoing elective clipping.

Guidelines for the management of aneurysmal subarachnoid hemorrhage: a guideline for healthcare professionals from the American Heart Association/american Stroke Association

PURPOSE

The aim of this guideline is to present current and comprehensive recommendations for the diagnosis and treatment of aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

A formal literature search of MEDLINE (November 1, 2006, through May 1, 2010) was performed. Data were synthesized with the use of evidence tables. Writing group members met by teleconference to discuss data-derived recommendations. The American Heart Association Stroke Council's Levels of Evidence grading algorithm was used to grade each recommendation. The guideline draft was reviewed by 7 expert peer reviewers and by the members of the Stroke Council Leadership and Manuscript Oversight Committees. It is intended that this guideline be fully updated every 3 years.

RESULTS

Evidence-based guidelines are presented for the care of patients presenting with aSAH. The focus of the guideline was subdivided into incidence, risk factors, prevention, natural history and outcome, diagnosis, prevention of rebleeding, surgical and endovascular repair of ruptured aneurysms, systems of care, anesthetic management during repair, management of vasospasm and delayed cerebral ischemia, management of hydrocephalus, management of seizures, and management of medical complications.

CONCLUSIONS

aSAH is a serious medical condition in which outcome can be dramatically impacted by early, aggressive, expert care. The guidelines offer a framework for goal-directed treatment of the patient with aSAH.

Epilepsy after subarachnoid hemorrhage: the frequency of seizures after clip occlusion or coil embolization of a ruptured cerebral aneurysm: results from the International Subarachnoid Aneurysm Trial

OBJECT

The aim of this study was to determine the probability of seizures after treatment of a ruptured cerebral aneurysm by clip occlusion and coil embolization, and to identify the risks and predictors of seizures over the short- and long-term follow-up period.

METHODS

The study population included 2143 patients with ruptured intracranial aneurysms who were enrolled in 43 centers and randomly assigned to clip application or coil placement. Those patients suffering a seizure were identified prospectively at various time points after randomization, as follows: before treatment; after treatment and before discharge; after discharge to 1 year; and annually thereafter.

RESULTS

Two hundred thirty-five (10.9%) of the 2143 patients suffered a seizure after randomization; 89 (8.3%) of 1073 and 146 (13.6%) of 1070 in the endovascular and neurosurgical allocations, respectively (p = 0.014). In 19 patients the seizure was associated with a rehemorrhage. Of those patients who underwent coil placement alone, without additional procedures, 52 suffered a seizure, and in the group with clip occlusion alone, 91 patients suffered a seizure. The risk of a seizure after discharge in the endovascular group was 3.3% at 1 year and 6.4% at 5 years. In the neurosurgical group it was 5.2% at 1 year and 9.6% at 5 years. The risk of seizure was significantly greater in the neurosurgical group at both 2 years and at up to 14 years (p = 0.005 and p = 0.013, respectively). The significant predictors of increased risk were as follows: neurosurgical treatment allocation, hazard ratio (HR) 1.64 (95% CI 1.19-2.26); younger age, HR 1.54 (95% CI 1.14-2.13); Fisher grade > 1 on CT scans, HR 1.34 (95% CI 0.62-2.87); delayed ischemic neurological deficit due to vasospasm, HR 2.10 (95% CI 1.49-2.94); and thromboembolic complication, HR 5.08 (95% CI 3.00-8.61). A middle cerebral artery (MCA) aneurysm location was also a significant predictor of increased risk in both groups; the HR was 2.23 (95% CI 1.57-3.17), with the probability of seizure at 6.1% and 11.5% at 1 year in the endovascular and neurosurgery groups, respectively.

CONCLUSIONS

The risk of seizures after coil embolization is significantly lower than that after clip occlusion. An MCA aneurysm location increased the risk of seizures in both groups.

Critical care management of subarachnoid hemorrhage

Successful critical care management of patients with aneurysmal subarachnoid hemorrhage (SAH) requires a thorough understanding of the disease and its complications and a familiarity with modern multimodality neuromonitoring technology. This article reviews the natural history of aneurysmal SAH and strategies for disease management in the acute setting, including available tools for monitoring brain function. Intensive care management of patients with SAH focuses on prevention of further neurologic injury. Aneurysmal rebleeding, hydrocephalus, seizures, and delayed ischemic injury represent major threats. There is increasing awareness of extracerebral complications, including electrolyte disturbances (eg, cerebral salt wasting) and cardiac dysfunction. Prompt recognition and treatment of these disorders maximizes the odds of a good functional outcome. Technologic advances hold the promise of improved detection and treatment of secondary neurologic insults.

Seizures and Epilepsy following Aneurysmal Subarachnoid Hemorrhage : Incidence and Risk Factors

OBJECTIVE

Although prophylactic antiepileptic drug (AED) use in patients with aneurysmal subarachnoid hemorrhage (SAH) is a common practice, lack of uniform definitions and guidelines for seizures and AEDs rendered this prescription more habitual instead of evidence-based manner. We herein evaluated the incidence and predictive factors of seizure and complications about AED use.

METHODS

From July 1999 to June 2007, data of a total of 547 patients with aneurysmal SAH who underwent operative treatments were reviewed. For these, the incidence and risk factors of seizures and epilepsy were assessed, in addition to complications of AEDs.

RESULTS

Eighty-three patients (15.2%) had at least one seizure following SAH. Forty-three patients (7.9%) had onset seizures, 34 (6.2%) had perioperative seizures, and 17 (3.1%) had late epilepsy. Younger age (< 40 years), poor clinical grade, thick hemorrhage, acute hydrocephalus, and rebleeding were related to the occurrence of onset seizures. Cortical infarction and thick hemorrhage were independent risk factors for the occurrence of late epilepsy. Onset seizures were not predictive of late epilepsy. Moreover, adverse drug effects were identified in 128 patients (23.4%) with AEDs.

CONCLUSION

Perioperative seizures are not significant predictors for late epilepsy. Instead, initial amount of SAH and surgery-induced cortical damage should be seriously considered as risk factors for late epilepsy. Because AEDs can not prevent early postoperative seizures (< 1 week) and potentially cause unexpected side effects, long-term use should be readjusted in high-risk patients.

Critical care management of subarachnoid hemorrhage

Successful critical care management of patients with aneurysmal subarachnoid hemorrhage requires a thorough understanding of the disease and its complications and a familiarity with modern multimodality neuromonitoring technology. This article reviews the natural history of aneurysmal subarachnoid hemorrhage and strategies for disease management in the acute setting. Available tools for monitoring brain function are discussed.

Generalized convulsive status epilepticus after nontraumatic subarachnoid hemorrhage: the nationwide inpatient sample

OBJECTIVE

To identify the frequency of and impact on outcome of generalized convulsive status epilepticus (GCSE) among patients with nontraumatic subarachnoid hemorrhage (SAH).

METHODS

We used the Nationwide Inpatient Sample, a database of admissions to nonfederal United States hospitals between 1994 and 2002, for this study. From this database, we identified all adult patients with nontraumatic SAH who were admitted through the emergency department. Independent predictors of GCSE and mortality were identified using multivariate logistic regression. Multivariate linear regression analysis was used to determine whether GCSE was independently associated with increased cost and/or duration of hospitalization.

RESULTS

Among the 29,998 patients hospitalized with nontraumatic SAH, GCSE was reported to occur in 0.2% of patients (N = 73 patients). GCSE occurred more frequently among those in the youngest tertiale (49 years old or younger; odds ratio, 3.2; 95% confidence interval, 2.0-5.1), those with renal disease (odds ratio, 4.8; 95% confidence interval, 2.6-8.8), and those who did not undergo a neurosurgical procedure involving a craniotomy (odds ratio, 2.2; 95% confidence interval, 1.3-3.8). GCSE was independently associated with higher in-hospital mortality (48% versus 33% of patients; odds ratio, 2.1; 95% confidence interval, 1.3-3.4; P = 0.002) and longer (9 versus 7 days; P = 0.016) and more expensive (US $39,677 versus US $26,686; P = 0.007) hospitalizations.

CONCLUSION

GCSE rarely complicates SAH; however, it is associated with increased patient mortality, length of hospital stay, and cost. GCSE occurs more frequently in young patients, those with a history of renal disease, and patients who do not undergo a craniotomy.

Postoperative seizures: epidemiology, pathology, and prophylaxis

The risk of epileptic seizures after craniotomy is extremely important but the incidence of postoperative epilepsy varies greatly, depending on the patient's conditions such as primary diseases, severity of surgical insult, and pre-existing epilepsy. Animal studies suggest that neurosurgical insults lead to seizures by two different mechanisms: One mechanism is mediated by free radical generation and the other by impaired ion balance across the cell membrane caused by ischemia or hypoxia. Conventional antiepileptic agents such as phenytoin, phenobarbital, carbamazepine, and valproic acid are promising for the prevention of early seizures, but the effect in preventing postoperative epilepsy is still controversial. Studies on the prophylactic effect of newer antiepileptic agents in craniotomized patients were very limited. Zonisamide, an antiepileptic agent with antiepileptogenic, free radical scavenging and neuroprotective actions in experimental animals, showed promising effects against postoperative epilepsy in a randomized double blind controlled trial. Prophylactic treatment for craniotomized patients significantly prevented the development of partial seizures during the follow-up period. Most recent studies have not supported the prophylactic use of antiepileptic agents in craniotomized patients, but further studies are required.

Characterization of perioperative seizures and epilepsy following aneurysmal subarachnoid hemorrhage

Object. The reported incidence, timing, and predictive factors of perioperative seizures and epilepsy after subarachnoid hemorrhage (SAH) have differed considerably because of a lack of uniform definitions and variable follow-up periods. In this study the authors evaluate the incidence, temporal course, and predictive factors of perioperative seizures and epilepsy during long-term follow up of patients with SAH who underwent surgical treatment.

Methods. Two hundred seventeen patients who survived more than 2 years after surgery for ruptured intracranial aneurysms were enrolled and retrospectively studied. Episodes were categorized into onset seizures (≤ 12 hours of initial hemorrhage), preoperative seizures, postoperative seizures, and late epilepsy, according to their timing.

The mean follow-up time was 78.7 months (range 24–157 months). Forty-six patients (21.2%) had at least one seizure post-SAH. Seventeen patients (7.8%) had onset seizures, five (2.3%) had preoperative seizures, four (1.8%) had postoperative seizures, 21 (9.7%) had at least one seizure episode after the 1st week postoperatively, and late epilepsy developed in 15 (6.9%). One (3.8%) of 26 patients with perioperative seizures (onset, preoperative, or postoperative seizure) had late epilepsy at follow up. The mean latency between the operation and the onset of late epilepsy was 8.3 months (range 0.3–19 months). Younger age (< 40 years old), loss of consciousness of more than 1 hour at ictus, and Fisher Grade 3 or greater on computerized tomography scans proved to be significantly related to onset seizures. Onset seizure was also a significant predictor of persistent neurological deficits (Glasgow Outcome Scale Scores 2–4) at follow up. Factors associated with the development of late epilepsy were loss of consciousness of more than 1 hour at ictus and persistent postoperative neurological deficit.

Conclusions. Although up to one fifth of patients experienced seizure(s) after SAH, more than half had seizure(s) during the perioperative period. The frequency of late epilepsy in patients with perioperative seizures (7.8%) was not significantly higher than those without such seizures (6.8%). Perioperative seizures did not recur frequently and were not a significant predictor for late epilepsy.

Seizures after aneurysmal subarachnoid hemorrhage treated with coil embolization

OBJECTIVE

We sought to determine the incidence of seizures among patients treated with endovascular coil embolization for ruptured intracranial aneurysms because data on which to base antiepileptic drug (AED) prescriptions and advice to patients regarding driving motor vehicles and other high-risk activities are currently lacking.

METHODS

We conducted a single-institute, single-operator observational study of 243 patients referred for endovascular treatment after aneurysmal subarachnoid hemorrhage. Prospective data collection was performed, and all successfully treated patients were followed. The incidence of seizures was compared with published surgical data, and logistic regression analysis of potential clinical associations was performed. Patients were followed for up to 7.7 years (mean follow-up period, 21.9 mo).

RESULTS

Ictal seizures occurred at the time of subarachnoid hemorrhage in 26 (11%) of 243 patients and correlated with middle cerebral artery aneurysm location, loss of consciousness at ictus, and AED prescription. No patients experienced periprocedural seizures during their hospitalization. Seven of 233 successfully treated patients (3%) experienced seizures more than 30 days after treatment: late seizures occurred de novo in four patients (1.7%) and in three patients (1.4%) were caused by preexisting epilepsy. Two patients (0.85%) who had de novo seizures developed epilepsy. Late seizures correlated with a history of previous seizures, the presence of a cerebrospinal fluid shunt, and the use of AEDs.

CONCLUSION

The low incidence of seizures does not justify the use of prophylactic AED therapy after aneurysmal subarachnoid hemorrhage in patients treated solely with coil embolization, nor does it justify subsequent restrictions on the driving of motor vehicles if the patient is otherwise fit to drive.

Risk of epilepsy in long-term survivors of surgery for aneurysmal subarachnoid hemorrhage: a population-based study in Iceland

PURPOSE

Epilepsy is known to result from aneurysmal subarachnoid hemorrhage (SAH). There are no population-based estimates of the absolute risk or the duration for which this risk is elevated. We have conducted a population-based study in Iceland of the risk of epilepsy after a ruptured cerebral aneurysm to address these questions.

METHODS

The index patients are all of the patients who presented with SAH caused by ruptured cerebral aneurysm in Iceland during an 11-year period (1958 to 1968) and survived more than 6 months. We determined the number of index patients who developed epilepsy. The observed number of cases of epilepsy was compared with that expected based on the incidence of epilepsy in Iceland.

RESULTS

There were 44 index patients; 11 (25%) developed epilepsy, all within 4 years of the insult. Seven (70%) of 10 patients with acute symptomatic seizures (defined as seizures during the first 2 weeks after the hemorrhage) developed epilepsy (relative risk, 7.0; 95% confidence interval, 2.3-21.6). Epilepsy was more frequent in patients with severe neurological residua (48%) compared with patients without (20%) (relative risk, 2.5; 95% confidence interval, 0.9-6.3).

CONCLUSIONS

The risk for epilepsy among survivors of SAH caused by ruptured cerebral aneurysm is substantially increased. Both acute symptomatic seizure and persistent neurological impairment are associated with a further increase in the risk of epilepsy.

Analysis of 561 patients with 690 middle cerebral artery aneurysms: anatomic and clinical features as correlated to management outcome

In a series of 1314 consecutive patients with cerebral aneurysms from a defined catchment area in eastern Finland (870,000 inhabitants), 561 patients (43%) had middle cerebral artery aneurysms (MCAAs). One or more associated aneurysms were common; 221 patients with MCAAs (39%) had multiple intracranial aneurysms (MIA). In other words, three-fourths (73%) of all patients with MIA had at least one MCAA. Multiple MCAAs, found in 111 patients (20%), were common in this Finnish population. One hundred of these patients had bilateral MCAAs, of whom 63 had mirror aneurysms, that is, aneurysms at the same site but on different sides. Thirty-five patients had "pure" mirror aneurysms, that is, they did not have any other aneurysms. Most MCAAs (81%) were located at the bifurcation. Three-fourths (72%) of the proximal MCAAs were associated with MIA. Giant aneurysms were significantly more common as single MCAAs than as any other single aneurysm. The frequency of intracerebral hematomas (42%) was by far higher in patients with MCAAs than in patients with ruptured aneurysms at other sites. Most of the intracerebral hematomas occurred in patients with bifurcation MCAAs that pointed laterally. Patients with MCAAs had surprisingly bad management outcomes despite good surgical results in patients with good Hunt and Hess grades. There were significantly more poor outcomes (Glasgow Outcome Scale score, 3-5) among patients with ruptured MCAAs than among those with any other anterior circulation aneurysms (32 and 25%, respectively). Also, the multiplicity of aneurysms increased the risk for poor outcome, which occurred in 39% of the patients who had MIA with one MCAA and 37% of those who had multiple MCAAs. Epilepsy, severe hemiparesis, and visual field deficits were the most common disabilities in long-term survivors, associated far more frequently with MCAAs than with aneurysm at other sites.

Short-term perioperative anticonvulsant prophylaxis for the surgical treatment of low-risk patients with intracranial aneurysms

The long-term use of anticonvulsant medication to prevent postoperative seizures in patients with aneurysms has been accepted medical practice for many years. The low incidence of seizures in more recent aneurysm series makes it appropriate to re-evaluate the use of prophylactic anticonvulsants to prevent postoperative epilepsy, especially in patients at low risk of seizure disorders. On the basis of preoperative presentation, we categorized 387 of the 420 craniotomies for aneurysms over a 4-year period to be at low risk of seizure. Postoperative anticonvulsant medication in this group was restricted to an average of 3 days. A retrospective analysis of the incidence of early postoperative seizures and late postoperative seizure disorders was performed in the populations of patients with ruptured aneurysms and with unruptured aneurysms with an average follow-up of 2.4 years. The overall seizure rate in the study group was 5.4%. Patients with ruptured aneurysms had an early postoperative seizure rate of 1.5% and a long-term seizure disorder rate of 3.0%. Early and long-term seizure rates for unruptured aneurysms were 2.6 and 4.4%, respectively. No patients who had early seizures went on to develop epilepsy, and all seizure disorders were well controlled once anticonvulsants were begun. These data support the idea that anticonvulsant medication may be safely restricted to the immediate perioperative period for most patients with aneurysms.

Management outcome for multiple intracranial aneurysms

The management outcome of 302 patients with multiple intracranial aneurysms (MIA) from a series of 1314 patients with cerebral aneurysms was assessed using the Glasgow Outcome Scale 1 year after diagnosis and/or treatment. The outcome was significantly poorer for patients with MIA than for those with single intracranial aneurysms (SIA). The difference in the frequencies of poor outcome (Glasgow Outcome Scale Grades 3-5) was most evident in patients with Hunt and Hess Grades 2 or 3 (MIA, 29%; SIA, 19%). The management mortality in all grades attributable to all causes was 24% in patients with MIA and 20% in those with SIA and 16 and 11%, respectively, after surgery. At the 1-year follow-up point, 66% of the patients with MIA were independent (SIA, 72%); after surgery, 74% (SIA, 81%); after subarachnoid hemorrhage, 65% (SIA, 71%); and after subarachnoid hemorrhage and surgery, 73% (SIA, 80%). Patients with aneurysms at the vertebrobasilar arteries fared badly; otherwise, the sites of the aneurysms and their different combinations had no effect on outcome, nor did the timing of surgery. In this study, again, only two-thirds of the detected aneurysms could be secured. The aneurysms left without treatment were mostly in patients with very poor grade (n, 55) and/or old (n, 23) patients or were intracavernous (n, 26). The results seemed to be more unsatisfactory as the number of aneurysms increased. In multivariate analysis, delayed neurological deficit had the most significant independent contribution to outcome in patients with MIA, far more than in patients with SIA. This can be explained by the increased manipulation of cerebral arteries during multiple aneurysm surgery.

Risk of epilepsy after aneurysm operations

This prospective study was undertaken to evaluate the risk of epilepsy after aneurysm operations. The patients were discharged after operation without any anticonvulsant prophylactic treatment and followed-up for 12 months. Out of 128 such patients 121 were submitted for final evaluation. Epilepsy was diagnosed if two or more seizure attacks occurred during that time. Such attacks occurred in 8 patients, so the risk of epilepsy was estimated at 7% for the 12 months after operation in patients without prophylactic treatment. In another 3 patients single seizures occurred during the follow-up, they were not treated with anticonvulsant drugs; seizures did not recur for up to two years. Detailed analysis of the patients with late epilepsy revealed that most of them were pre-operatively in the 3rd clinical group according to WFNS scale. The rationale for the use of prophylactic anticonvulsants after aneurysm surgery seems to be doubtful in view of this study and data from the literature.