Low-frequency stimulation of a fiber tract in bilateral temporal lobe epilepsy.

OBJECTIVE: Pharmacoresistant bilateral mesial temporal lobe epilepsy often implies poor resective surgical candidacy. Low-frequency stimulation of a fiber tract connected to bilateral hippocampi, the fornicodorsocommissural tract, has been shown to be safe and efficacious in reducing seizures in a previous short-term study. Here, we report a single-blinded, within-subject control, long-term deep-brain stimulation trial of low-frequency stimulation of the fornicodorsocommissural tract in bilateral mesial temporal lobe epilepsy. Outcomes of interest included safety with respect to verbal memory scores and reduction of seizure frequency. METHODS: Our enrollment goal was 16 adult subjects to be randomized to 2-Hz or 5-Hz low-frequency stimulation of the fornicodorsocommissural tract starting at 2 mA. The study design consisted of four two-month blocks of stimulation with a 50%-duty cycle, alternating with two-month blocks of no stimulation. RESULTS: We terminated the study after enrollment of five subjects due to slow accrual. Fornicodorsocommissural tract stimulation elicited bilateral hippocampal evoked responses in all subjects. Three subjects underwent implantation of pulse generators and long-term low-frequency stimulation with mean monthly seizures of 3.14 ±â€¯2.67 (median 3.0 [IQR 1-4.0]) during stimulation-off blocks, compared with 0.96 ±â€¯1.23 (median 1.0 [IQR 0-1.0]) during stimulation-on blocks (p = 0.0005) during the blinded phase. Generalized Estimating Equations showed that low-frequency stimulation reduced monthly seizure-frequency by 0.71 per mA (p < 0.001). Verbal memory scores were stable with no psychiatric complications or other adverse events. SIGNIFICANCE: The results demonstrate feasibility of stimulating both hippocampi using a single deep-brain stimulation electrode in the fornicodorsocommissural tract, efficacy of low-frequency stimulation in reducing seizures, and safety as regards verbal memory.

Hyperventilation-induced high-amplitude rhythmic slowing: A mimicker of absence seizures in children.

PURPOSE: Hyperventilation (HV) in children can lead to HV-induced high-amplitude rhythmic slowing (HIHARS) on the EEG (electroencephalogram) which is sometimes associated with altered awareness (AA) and concomitant semiological features. Our aims were to determine the frequency of HIHARS in children, to assess if the associated semiological features were temporally related to HV, and to evaluate if specific semiological features can differentiate HIHARS with AA from absence seizures. METHODS: Consecutive children with suspected new onset seizure(s) underwent HV and awareness testing during video-EEG acquisition. Hyperventilation-induced high-amplitude rhythmic slowing was defined as 2.5- to 5-Hz generalized rhythmic slowing with amplitude ≥100 µv lasting for ≥3 s. The associated semiological features were compared between the group of children with HIHARS and AA, an age- and gender-matched control group without HIHARS, and in children who experienced absence seizures during HV. RESULTS: One hundred sixteen children with a mean age of 9.8 years were included. Hyperventilation-induced high-amplitude rhythmic slowing occurred in 39 children (33.6%) with AA documented in 30 (76.9%). The probability of developing AA during HIHARS was significantly and positively correlated with the HIHARS duration. The frequencies of HIHARS were not significantly different between children diagnosed with seizure(s) and those with nonepileptic spells. Hyperventilation cessation and staring did not occur in any child of the control group. Fidgeting and yawning were significantly more common in the group with HIHARS with AA while staring and blinking were significantly more frequent in the group of children with absence seizures. CONCLUSIONS: We ascertained that HIHARS with AA is a relatively common occurrence in children and most likely represents an age-related nonepileptic phenomenon. When associated with fidgeting or yawning, it can help differentiate this phenomenon from absence seizures. However, recording the concomitant presence of generalized spike wave discharges on the EEG remains essential to confirm the diagnosis of absence seizures.

Brivaracetam efficacy and safety in focal epilepsy.

Introduction: Brivaracetam (BRV) is an analog of levetiracetam (LEV) with 15-30 times greater affinity to SV2A and greater brain permeability than LEV. These properties have stimulated interest in its clinical trial data and post-marketing experience. Areas covered: The authors provide a background on epilepsy and its treatment, discuss the racetam family of antiepileptic drugs to which BRV belongs, and then discuss BRV properties and its efficacy and tolerability in the treatment of epilepsy. Expert opinion: While preclinical data suggest a broad spectrum of efficacy, BRV is only approved for focal epilepsy. The recommended starting dose is 100 mg per day, but in the absence of urgency, it may be prudent to start at 50 mg per day, considered the lowest effective dose. There was no added benefit when BRV was used adjunctively with LEV in clinical trials. However, post-marketing data suggest that some patients may experience improved seizure control when switching from LEV. Behavioral adverse effects seemed less common than with LEV, and most patients switched to BRV after experiencing behavioral adverse effects on LEV reported improvement. Prior or anticipated intolerability to LEV is the strongest indication for BRV in clinical practice.

Prevalence and Risk Factors for Early Seizure in Patients with Traumatic Brain Injury: Analysis from National Trauma Data Bank.

BACKGROUND: Traumatic brain injury (TBI) is a well-known risk factor for seizures. We aimed to identify the frequency and risk factors for seizure occurrence during hospitalization for TBI. METHODS: We used ICD-9-CM codes to identify patients 18 years of age or older from the National Trauma Data Bank who were admitted with TBI. We also used ICD-9-CM codes to identify the subset who had seizures during hospitalization. Patient demographics, comorbidities, Glasgow Coma Scale (GCS) score, Injury Severity Score Abbreviated Injury Scale (ISSAIS), in-hospital complications, and discharge disposition were compared in the seizure group (SG) and no-seizure group (NSG). RESULTS: A total of 1559 patients had in-hospital seizures, comprising 0.4% of all patients admitted with TBI. The mean age of SG was 3 years older than NSG [51 vs. 48; p < 0.0001]. African-American ethnicity (20 vs. 12%, p < 0.0001) and moderate TBI (8 vs. 4%, p < 0.0001) were more common in SG. History of alcohol dependence was more common in the SG (25 vs. 11%, p < 0.0001). Fall was the most common mechanism of injury in SG (56 vs. 36% in NSG; p < 0.0001). Subdural hematoma was more common in SG (31 vs. 21%, p < 0.0001). SG had higher rates of pneumonia, ARDS, acute kidney injury, and increased ICP. The average length of hospital stay was significantly higher in SG (10 vs. 6 days, p < 0.0001), and these patients had higher rate of discharge to nursing facility (32 vs. 25%, p < 0.0001). CONCLUSION: In-hospital seizures occur in 0.4% of all TBI patients. Although infrequent, seizure occurrence is associated with higher rates of hospital complications such as pneumonia and ARDS and is an independent predictor of longer hospital stay and worse hospital outcome.

Paradoxical exacerbation of myoclonic-astatic seizures by levetiracetam in myoclonic astatic epilepsy.

BACKGROUND: Levetiracetam is a broad spectrum antiepileptic drug (AED) with proven efficacy when used as adjunctive therapy against myoclonic seizures. We report two patients suffering from epilepsy with myoclonic-astatic epilepsy (MAE) who experienced a paradoxical worsening of seizures after initiation of treatment with LEV, a finding not previously described. CASE PRESENTATION: Patients included were enrolled in an ongoing large prospective study evaluating children and adults with new onset epilepsy in Lebanon conducted at the American University of Beirut Medical Center in association with the Lebanese Chapter of the International League against Epilepsy. Based on an extensive evaluation, these patients were stratified into idiopathic partial, idiopathic generalized, symptomatic partial or symptomatic generalized epilepsies. Whenever possible the electroclinical syndrome was identified according to the ILAE classification of epilepsy syndromes. Patients were subsequently followed up on regular intervals and were assessed for adverse events, and seizure recurrence. MAE was diagnosed in five (1.6%) out of 307 consecutive children enrolled in this study. LEV was used as adjunctive therapy in four of those children with two experiencing a substantial and dose related worsening in the frequency of their myoclonic and atonic seizures. CONCLUSION: LEV should be used with caution in children with MAE and an exacerbation of seizure frequency temporally related to the introduction of LEV should alert the clinician to the possibility of a paradoxical seizure exacerbation.

Valproate-induced enuresis: a prospective study.

AIM: The aim of this study was to determine the frequency and characteristics of secondary enuresis in children initiated on valproate treatment. METHOD: This was a prospective study conducted in children aged 5 to 12 years with suspected newly diagnosed epilepsy and maintained on valproate for at least 1 month. Adverse events spontaneously reported by parents were recorded at each follow-up visit. In addition, we specifically asked about enuresis and other side effects known to occur with valproate treatment. We assessed the frequency of enuresis and its association with a number of variables. RESULTS: Seventy-two children (43 males and 29 females) with a mean age of 8 years 7 months (range 5-12y) were included in this study. Secondary enuresis developed in 17 (24%) of these children after, on average, 19.8 days of exposure to valproate. The data obtained from a multivariate analysis indicate that age was the only significant factor in predicting the development of enuresis. Enuresis ceased in all children after discontinuation of valproate use, and in 10 out of 11 children still on the drug. INTERPRETATION: Secondary enuresis is a common adverse event associated with valproate use in children, which is not usually spontaneously reported and is reversible in most cases.

Levetiracetam-induced pancytopenia.

Pancytopenia is a rare side effect of levetiracetam (LEV) that is associated with severe morbidity that requires hospitalization. Here, we report a patient with a right temporoparietal tumor who underwent a temporal craniotomy with resection of the mass and was started on LEV for seizure prophylaxis per the neurosurgery local protocol. The patient developed LEV-induced pancytopenia, which was successfully managed by discontinuation of this medication. Our report aims to increase awareness of this rare cause of pancytopenia among clinicians.

Association of cardiovascular risk factors and troponin elevation after generalized tonic-clonic seizures.

PURPOSE: Troponins are very sensitive biomarkers of myocardial injury. Conflicting data regarding elevation of troponin levels following a generalized tonic-clonic (GTC) seizure have been reported. In this study we hypothesized that troponin elevation after a GTC seizure occurs more frequently in patients with cardiovascular risk factors. METHODS: Patients who presented to the ER after a single GTC seizure with troponin levels assessed by cardiac troponin T (cTnT) and drawn within 12h of the GTC seizure were included. Patients with cardiac symptoms, elevated CPK levels or renal insufficiency were excluded. The frequency and risk factors for elevated cTnT levels were analyzed. RESULTS: Fourteen patients with a mean age of 54 years (range: 19-87 years) were included. Four patients (28.6%) had elevated cTnT levels (mean=0.06µg/L; range: 0.035-0.076µg/L). Patients with elevated cTnT levels were significantly older than those with normal levels (77.5 years vs. 45.5 years; P=0.03). Of the eight patients 60 years of age and older, four (50%) had elevated cTnT levels. The coronary heart disease (CHD) score was significantly higher in patients with elevated cTnT levels compared to those with normal levels (13.5 vs. 9.75, P=0.012). CONCLUSIONS: Elevated troponin levels can occur after a GTC seizure. Patients at risk are the elderly and those with cardiovascular risk factors. Our results suggest that elevation of troponin levels after a GTC seizure reflects a minor ischemic cardiac injury related to the demand ischemia during the sympathetic overactivity that accompanies a GTC seizure.

Treatment of complex intracranial aneurysms with a telescoping stent technique.

BACKGROUND AND OBJECT: Complex intracranial aneurysms present a treatment challenge for both open and endovascular modalities of treatment. This report seeks to illustrate a series of patients with aneurysms treated with telescoping stents as a method of flow diversion for small and fusiform intracranial aneurysms. MATERIAL AND METHODS: A retrospective evaluation of six patients treated with a telescoping stent technique utilizing available stents (at that time before the pipeline era) for complex cerebral aneurysms between January 2009 and January 2010 was performed. Five patients had dissecting aneurysms and one patient had a small superior hypophyseal artery aneurysm. One of the patients was treated in the setting of a Hunt and Hess grade IV subarachnoid hemorrhage. Follow-up cerebral angiography was performed postprocedure at 6 months. RESULTS: At a mean follow-up period of 9 months, all the patients experienced complete or near-complete occlusion (>95%). No periprocedural complications were noted in this series. No episodes of hemorrhage or thromboembolic complications occurred. CONCLUSIONS: Overlapping Neuroform and Enterprise stents may induce complete thrombosis of intracranial aneurysms and facilitate parent artery remodeling. The use of self-expanding stents is still an adequate treatment modality, especially if there is a need for vessel wall stabilization rather than flow diversion. The technique is also a sufficient alternative in small intracranial aneurysms not readily amenable to open surgical treatment or traditional endovascular coil embolization.