Farzad Moien-Afshari

Surgical outcomes in lesional and non-lesional epilepsy: A systematic review and meta-analysis

PURPOSES To provide evidence-based quantitative summary estimates of seizure outcomes in patients with non-lesional and lesional epilepsy treated with surgery, and to assess the consistency of results among published studies. METHODS An exhaustive literature search identified articles published since 1995, describing outcomes according to lesional status in patients of any age who underwent resective epilepsy surgery. Two reviewers independently assessed study eligibility and extracted the data. Disagreements were resolved through discussion. Random effects meta-analyses were used after assessing the dataset for heterogeneity. RESULTS Forty articles fulfilled eligibility criteria and described outcomes in 697 patients with non-lesional epilepsy and 2860 patients with lesional epilepsy. Overall, the odds of being seizure-free after surgery were 2.5 times higher in patients with lesions on MRI or histopathology (OR 2.5, 95%CI 2.1, 3.0, p<0.001). In patients with temporal lobe epilepsy surgery the odds were 2.7 times higher in those with lesions (OR 2.7, 95%CI 2.1, 3.5, p<0.001). In patients with extratemporal epilepsy surgery the odds were 2.9 higher in those with lesions (OR 2.9, 95%CI 1.6, 5.1, p<0.001). Outcomes were similar in children, adults, and studies that used MRI or histopathology to identify lesions. DISCUSSION Overall, the odds of seizure freedom after surgery are two to three times higher in the presence of a lesion on histopathology or MRI. The results are clinically and statistically significant, consistent across various subgroups, and quite homogeneous across studies.

Gelastic seizures associated with hypothalamic hamartomas. An update in the clinical presentation, diagnosis and treatment

Gelastic seizures are epileptic events characterized by bouts of laughter. Laughter-like vocalization is usually combined with facial contraction in the form of a smile. Autonomic features such as flushing, tachycardia, and altered respiration are widely recognized. Conscious state may not be impaired, although this is often difficult to asses particularly in young children. Gelastic seizures have been associated classically to hypothalamic hamartomas, although different extrahypothalamic localizations have been described. Hypothalamic hamartomas are rare congenital lesions presenting with the classic triad of gelastic epilepsy, precocious puberty and developmental delay. The clinical course of patients with gelastic seizures associated with hypothalamic hamartomas is progressive, commencing with gelastic seizures in infancy, deteriorating into more complex seizure disorder resulting in intractable epilepsy. Electrophysiological, radiological, and pathophysiological studies have confirmed the intrinsic epileptogenicity of the hypothalamic hamartoma. Currently the most effective surgical approach is the trancallosal anterior interforniceal approach, however newer approaches including the endoscopic and other treatment such as radiosurgery and gamma knife have been used with success. This review focuses on the syndrome of gelastic seizures associated with hypothalamic hamartomas, but it also reviews other concepts such as status gelasticus and some aspects of gelastic seizures in other locations.

Safety and Yield of Early Cessation of AEDs in Video-EEG Telemetry and Outcomes

BACKGROUND Video-electroencephalography (VEEG) telemetry is the simultaneous recording of ictal and interictal EEG pattern and paroxysmal behavior to investigate the nature of paroxysmal events. METHODS This is a prospective study performed to asses the safety and yield of early discontinuation of antiepileptic drugs (AEDs) in the telemetry unit. Over a 2.5-year period, 50 patients that met the indications for VEEG monitoring were admitted by an epileptologist to neuro-observation units with continuous monitoring, nursing coverage and EEG technicians support during working hours and on-call thereafter. In most cases AEDs (except Phenobarbital) were discontinued in 24h. We prospectively assessed the yield and safety of the telemetry investigation as well as epilepsy surgery outcomes. RESULTS Our monitoring answered the study question in 88% of the patients. The question was not answered in 12% of cases due to the lack of recorded events. Our results changed the management in 74% of cases and potentially improved quality of life by decreasing the AEDs consumption and number of seizures per month. Over all, 22% received epilepsy surgery and became either seizure free or their seizures became non-disabling. Our method significantly decreased the duration of hospital admission for monitoring and minimal complications occurred only in 8% of patients. CONCLUSIONS In conclusion, our method for short VEEG monitoring has a high yield for diagnosis, minimal complications and is cost effective. These qualities, together with good surgery results validate our method for the investigation and treatment of refractory seizure cases.

Partial anterior cervical cord infarction following vertebral artery dissection.

Infarction of the cervical spinal cord is less common than thoracolumbar cord infarction and accounts for 7-25% of cord infarcts.1,2 Causes include venous and arterial thromboses, vasculitis, fibrocartilaginous embolism, cocaine misuse, epidural anaesthesia, systemic hypotension, arteriosclerosis, Caisson disease, spinal tumor, arteriovenous malformations (AVMs) and arterial dissections.3 An increasingly recognized cause for cervical spinal cord infarction is vertebral artery dissection. Twelve reported cases of unilateral or bilateral vertebral artery dissection causing ischemia of the cervical cord were found in a review of literature from 1989-2007.4-14 While more than 80% of patients with vertebral artery dissection are reported to develop posterior circulation brain ischemia, spinal cord infarction is a rare manifestation.15 The clinical presentations and areas of involvement of the spinal cord are quite variable among these cases. Acute cord infarction may present as localized cervical pain3 which may be the cause of diagnostic confusion. In only two of these cases did unilateral vertebral artery dissection cause a clinical anterior cord syndrome.6,7 One vertebral artery frequently supplies the dominant feeder to the anterior spinal artery; therefore compromise of one vertebral artery often causes ischemic changes in the cord bilaterally.16 Laufs et al, however, described unilateral cervical cord involvement following ipsilateral vertebral artery dissection.14

How to measure fatigue in epilepsy? The validation of three scales for clinical use

Fatigue can be defined as extreme and persistent tiredness, weakness or exhaustion that could be mental, physical or both. The main objective of this study is to validate three instruments to measure fatigue (Fatigue Symptom Inventory--FSI, Fatigue Assessment Instrument--FAI, Fatigue Severity Scale--FSS) in patients with epilepsy (PWE). We used concurrent validity as a method of validation. Reliability of the fatigue scales was assessed in PWE. We applied the three selected questionnaires plus the Beck Depression Inventory (BDI) in PWE, healthy volunteers (HV) and patients with other neurological conditions. We studied 67 PWE, 34 HV and 56 patients with different neurological conditions. The mean fatigue scores in each group were as follows: (a) for the FSS, the score in HV was 2.6±1.1, in PWE 4.2±1.5, in Patients with multiple Sclerosis (PMS) 4.8±1.4, in Patients with Migraine (PWM) 4.4±1.9, in Patients with radiculopathy (PR) 4.5±0.9. (b) For the FSI, the score in HV was 2.2±1.3, in PWE 3.9±2.3, in PMS 4.1±1.9, in PWM 4.5±2.5, and in PR 5.4±1.4. (c) For the FAI in HV was 3.0±1.1, in PWE 4.2±1.3, in PMS 4.5±0.9, PWM 4.3±1.5, and in PR 4.4±1.4. The correlation between the BDI and the FSS was 0.52 (p<0.001), between the BDI and the FSI was 0.62 (p<0.001), and between the BDI and the FAI was 0.54 (p<0.001). Patients with epilepsy have consistently higher fatigue scores compared healthy controls, and scores that are comparable with other neurological conditions. The FSI, FAI and FSS display concurrent validity and high intra-observer reliability in PWE, indicating that these scales could be utilized for further study of fatigue in epilepsy.

Evaluating the single seizure clinic model: Findings from a Canadian Center

INTRODUCTION The effect of the single seizure clinic (SSC) model on patient diagnose, work-up, wait-times, and clinical care is poorly characterized and its efficacy unclear. The present study assesses patient characteristics and evaluates the impact of a single seizure clinic (SSC) model on wait-times and access to care. MATERIAL AND METHODS A prospective study of all patients (n=200) referred to our SSC for first seizure evaluation. Demographic, clinical, and paraclinicial variables were systematically collected and analyzed against a historical cohort. Binary logistic regression analysis was performed to predict impact of dichotomized variables on diagnosis of epilepsy. Diagnostic concordance between SSC nurses and epileptologists was also assessed. RESULTS Predominant referral sources were emergency department physicians and general practitioners. Mean wait-time for first assessment was significantly reduced by 70.5% employing the SSC model versus historical usual care. A diagnosis was established at first-contact in 80.5% of cases while 16.0% of patients required a second visit. Eighty-two patients (41.0%) were diagnosed with epilepsy. An abnormal EEG was found in 93.9% of patients diagnosed with epilepsy. Sixty-three patients were started on anti-epileptic drugs (63.5% lamotrigine, 7.0% levetiracetam, 5.0% phenytoin, and 5.0% topiramate). In 18% of cases driving restrictions were initiated by the SSC. The most common non-seizure diagnosis was syncope (24.0%). DISCUSSION The SSC reduced wait-times for assessment and investigations, clarified diagnoses, affected management decisions with respect to further workup, pharmacotherapy, and driving. There was moderate correlation between SSC nurses and physicians (kappa=0.54; p<0.001) as physicians were significantly more likely to diagnose epilepsy. Key factors identified as predictors of epilepsy were: presence of abnormalities on electroencephalography and imaging studies, patients stratified as high or medium-risk for seizure recurrence, semiological characteristics such as amnesia and limb stiffening, and presence of tongue trauma, or incontinence. CONCLUSIONS The SSC model reduces wait-times, streamlines assessments, and impacts clinical care decisions.

Discontinuation of antiepileptic drugs after successful surgery: who and when?

Surgery is a highly effective treatment for some specific types of refractory epilepsy and once seizure freedom is achieved many patients and clinicians have to ponder whether to taper or discontinue antiepileptic drugs (AEDs). However, there is no standard practice or guidelines and practices vary widely. The few studies that have addressed this question are retrospective and lack randomised, controlled comparisons, making it difficult to draw any solid inferences. This review examines this topic by analysing key data based on the following: controlled studies which compare outcomes in patients with either withdrawn or unmodified AEDs after epilepsy surgery, non-controlled studies, information from meta-analyses and systematic reviews, surveys of clinical practice, and other relevant reviews. Between 12 and 32% of patients had seizure relapse following tapering or discontinuation of AEDs, which was not significantly different from 7 to 45% in patients without AED modification. In the event of seizure relapse upon tapering of AEDs, 45–92.3% restarted AED treatment and regained seizure freedom. The most consistent risk factors for seizure relapsewere: age older than 30 years at the time of surgery, persistent auras, early drug tapering, seizure recurrence before a reduction of drugs, normal MRI, a longer period with epilepsy, absence of hippocampal sclerosis, and the presence of interictal discharges on EEG after surgery.

StatNet Electroencephalogram: A Fast and Reliable Option to Diagnose Nonconvulsive Status Epilepticus in Emergency Setting.

BACKGROUND The StatNet electrode set is a system that can be applied by a non-electroencephalogram (EEG) technologist after minimal training. The primary objectives of this study are to assess the quality and reliability of the StatNet recordings in comparison to the conventional EEG. METHODS Over 10 months, 19 patients with suspected nonconvulsive status epilepticus were included from university hospital emergency settings. Each patient received a StatNet EEG by a trained epilepsy fellow and a conventional EEG by registered technologists. We compared the studies in a blinded fashion, for the timeframe from EEG order to the setup time, start of acquisition, amount of artifact, and detection of abnormalities. The nonparametric Mann-Whitney two-sample t test was used for comparisons. The kappa score was used to assess reliability. RESULTS Mean age of patients was 61±16.3 (25-93) years. The inter-observer agreement for detection of abnormal findings was 0.83 for StatNet and 0.75 for conventional EEG. Nonconvulsive status epilepticus was detected in 10% (2/19) in both studies. The delay from the time of EEG requisition to acquisition was shorter in the StatNet (22.4±2.5 minutes) than the conventional EEG (217.7±44.6 minutes; p<0.0001). The setup time was also shorter in the StatNet (9.9±0.8 minutes) compared with the conventional EEG (17.8±0.8 minutes; p<0.0001). There was no difference in the percentage of artifact duration between the two studies (p=0.89). CONCLUSION This study demonstrates that StatNet EEG is a practical and reliable tool in the emergency setting, which reduces the delay of testing compared with conventional EEG, without significant compromise of study quality.

Reasons for reoperation after epilepsy surgery: a review based on a complex clinical case with three operations

The results of surgical treatment of epileptic seizures have gradually improved in the past decade, approaching 60% to 90% seizure-free outcome in temporal lobe epilepsy and 45% to 66% in extratemporal lobe epilepsy. Unfortunately some patients continue with seizures after epilepsy surgery and the studies have shown that approximately the 3% to 15% of patients with a previous failed surgical procedure are reoperated. Selected patients may be candidates for further surgery, potentially leading to a significant decrease in the frequency and severity of seizures. In patients with intractable partial epilepsy there are many possible factors, alone or in combination, that could be related to the failure of resection. Some of the factors could be genetic or acquired predisposition to epileptogenicity. In this article we report a case with intractable epilepsy that required three interventions to render seizure free. We analyzed our specific case in the light of previous reports on reoperation and enumerate the potential reasons for reoperation that could apply to all patients with failure of an initial procedure.

Update on Minimal Standards for Electroencephalography in Canada: A Review by the Canadian Society of Clinical Neurophysiologists

Surface electroencephalogram (EEG) recording remains the gold standard for noninvasive assessment of electrical brain activity. It is the most efficient way to diagnose and classify epilepsy syndromes as well as define the localization of the epileptogenic zone. The EEG is useful for management decisions and for establishing prognosis in some types of epilepsy. Electroencephalography is an evolving field in which new methods are being introduced. The Canadian Society of Clinical Neurophysiologists convened an expert panel to develop new national minimal guidelines. A comprehensive evidence review was conducted. This document is organized into 10 sections, including indications, recommendations for trained personnel, EEG yield, paediatric and neonatal EEGs, laboratory minimal standards, requisitions, reports, storage, safety measures, and quality assurance.