Treatment algorithms in refractory partial epilepsy

A Review of the Prevalence, Etiology, Diagnosis, and Management of Pediatric Epilepsies in India

Pediatric seizures are one of the most common neurological manifestations seen in pediatrics. Unravelling the etiology, timely and appropriate investigations followed by suitable therapies are essential for improving quality of life. During the pandemic, focused group discussions were conducted among 50 pediatric neurologists across five cities in India to gather insights on treatment practices in pediatric epilepsy and to optimize therapeutic strategies and alternative approaches for rational use of antiepileptic medications. These discussions were mainly aimed at reviewing current literature on prevalence, etiology, diagnosis, and management of epilepsy in children and subsequently rationalizing diagnostic and treatment approaches in routine clinical practice. Epileptic encephalopathies comprise of childhood epilepsy with progressive cerebral dysfunction. Genomics plays a vital role in identifying the underlying genetic associations, empowering precision therapy. Currently, the ketogenic diet has become a well-recognized modality for reducing severity of seizures. To overcome the high incidence of adverse effects due to older antiepileptic drugs, newer drugs are being developed to improve ease of use, diminish drug interactions, decrease adverse effects, and identify drugs with unique mechanisms of action. Common lacunae in practice include information gaps, educating parents, or caregivers about rational drug use and ensuring compliance to antiepileptic medications. This article discussed the consensus clinical viewpoint of expert clinicians, as well as insights on optimized treatment of pediatric epilepsies in both infancy and childhood. It also discusses aspects, like reducing drug burden, emerging therapies in the identification of the genetic basis of epilepsies, and targeted therapy alternatives, for pediatric populations in the Indian scenario.

A modern epilepsy surgery treatment algorithm: Incorporating traditional and emerging technologies

Epilepsy surgery has seen numerous technological advances in both diagnostic and therapeutic procedures in recent years. This has increased the number of patients who may be candidates for intervention and potential improvement in quality of life. However, the expansion of the field also necessitates a broader understanding of how to incorporate both traditional and emerging technologies into the care provided at comprehensive epilepsy centers. This review summarizes both old and new surgical procedures in epilepsy using an example algorithm. While treatment algorithms are inherently oversimplified, incomplete, and reflect personal bias, they provide a general framework that can be customized to each center and each patient, incorporating differences in provider opinion, patient preference, and the institutional availability of technologies. For instance, the use of minimally invasive stereotactic electroencephalography (SEEG) has increased dramatically over the past decade, but many cases still benefit from invasive recordings using subdural grids. Furthermore, although surgical resection remains the gold-standard treatment for focal mesial temporal or neocortical epilepsy, ablative procedures such as laser interstitial thermal therapy (LITT) or stereotactic radiosurgery (SRS) may be appropriate and avoid craniotomy in many cases. Furthermore, while palliative surgical procedures were once limited to disconnection surgeries, several neurostimulation treatments are now available to treat eloquent cortical, bitemporal, and even multifocal or generalized epilepsy syndromes. An updated perspective in epilepsy surgery will help guide surgical decision making and lay the groundwork for data collection needed in future studies and trials.

Knowledge and Attitudes About Epilepsy Surgery Among Family Doctors in Ontario

BACKGROUND

Approximately 30% of patients with epilepsy have medically intractable seizures, and a proportion of them are candidates for surgical treatment. The efficacy and safety of epilepsy surgery have been supported by a large number of studies, yet only a small minority of such patients in Ontario receive surgery.

METHODS

Family physicians in Ontario were surveyed regarding demographics, referral practices and general knowledge about epilepsy surgery. Four hundred surveys were mailed to randomly selected family physicians using contact information from the College of Physicians and Surgeons of Ontario website.

RESULTS

The response rate was 50%. The majority of family physicians (81%) always refer patients with epilepsy, most often to neurologists. General knowledge of epilepsy was mixed, with 53.7% feeling that surgery should be considered in selected cases for the treatment of epilepsy, though 53.2% did not know what type of epilepsy could be surgically treated.

CONCLUSIONS

The results suggest a relatively low level of knowledge among family physicians in terms of when surgery ought to be considered, the types of epilepsy that are amenable to surgical treatment and the risks and benefits of epilepsy surgery. A lack of knowledge in these areas may partly underlie the low referral rates of epilepsy patients, though the results show that the majority of family physicians refer their patients with epilepsy to neurologists. Other factors must be considered, such as access to neurologists, epileptologists and surgical resources. Education campaigns directed at family physicians may improve knowledge and change referral practices. Future studies need to examine these possibilities.

Special requirements for electronic medical records in neurology

Electronic medical records (EMRs) are being rapidly adapted in the United States with goals of improving patient care, increasing efficiency, and reducing costs. Neurologists must become knowledgeable about the utility and effectiveness of the important parts of these systems specifically needed for care of neurology patients. The field of neurology encompasses complex disorders whose diagnosis and management heavily relies on detailed medical documentation of history and physical examination, and often on specialty-specific ancillary tests and extensive neuroimaging. Small discrepancies in documentation or absence of an in-hand ancillary test result can drastically change the current workup or treatment decision of a complex patient with neurologic disease. We describe current models and opportunities for improvements to EMRs that provide utility and efficiency in the care of neurology patients.

Critical review of palliative surgical techniques for intractable epilepsy

Approximately one third of epilepsy patients are not adequately treatable by antiepileptic medication. Curative resective epilepsy surgery can be performed in only a subgroup of these pharmacoresistent patients in whom the epileptogenic focus is localizable and does not overlap with eloquent brain areas. To the remaining patients (with bilateral or multiple epileptogenic foci, with epilepsy onset in eloquent areas, or with no identifiable epileptogenic focus) palliative epilepsy surgery can be offered if they suffer from disabling seizures. Standard palliative procedures currently comprise corpus callosotomy, multiple subpial transections, and vagus nerve stimulation. New approaches such as focus distant deep brain stimulation or direct stimulation of the hippocampus have gained the most interest. Feasibility studies, small pilot studies, and, recently, larger multicenter trials showed that direct brain stimulation shall be considered a potential helpful procedure in the field of palliative surgery. Moreover, with the increasing use of stereo-EEG in invasive video-EEG monitoring, stereo-EEG-guided thermocoagulation has the potential for a promising new treatment option in patients not amenable to resective epilepsy surgery. There is no general consensus on which palliative procedure is most effective in patients with difficult-to-treat epilepsy syndromes. The decision must be based on individual factors of a given patient. This review summarizes experience with palliative approaches collected in adult and pediatric patient series over the past decades and may help to thoroughly balance beneficial effects and risks of each procedure.

A consensus-based approach to patient safety in epilepsy monitoring units: recommendations for preferred practices

Patients in an epilepsy monitoring unit (EMU) with video-EEG telemetry have a risk for seizure emergencies, injuries and adverse events, which emphasizes the need for strategies to prevent avoidable harm. An expert consensus process was used to establish recommendations for patient safety in EMUs. Workgroups analyzed literature and expert opinion regarding seizure observation, seizure provocation, acute seizures, and activity/environment. A Delphi methodology was used to establish consensus for items submitted by these workgroups. Fifty-three items reached consensus and were organized into 30 recommendations. High levels of agreement were noted for items pertaining to orientation, training, communication, seizure precautions, individualized plans, and patient/family education. It was agreed that seizure observation should include direct observation or use of closed-circuit camera. The use of continuous observation was strongest in patients with invasive electrodes, at high risk for injury, or undergoing AED withdrawal. This process provides a first step in establishing EMU safety practices.

Lateralization of temporal lobe epilepsy using resting functional magnetic resonance imaging connectivity of hippocampal networks

PURPOSE

Early surgical intervention can be advantageous in the treatment of refractory temporal lobe epilepsy (TLE). The success of TLE surgery relies on accurate lateralization of the seizure onset. The purpose of this study was to determine whether resting functional MRI (fMRI) connectivity mapping of the hippocampus has the potential to complement conventional presurgical evaluations in distinguishing left from right TLE. In addition, we sought to determine whether this same network might separate patients with favorable from unfavorable postoperative outcomes.

METHODS

Resting fMRI acquisitions were performed on 21 patients with TLE and 15 healthy controls. The patients included seven patients with left TLE and seven patients with right TLE with seizure-free postoperative outcome, and five patients with left TLE and two patients with right TLE with recurring seizures after surgery. Functional connectivity maps to each hippocampus were determined for each subject and were compared between the controls and the seizure-free patients with left TLE and with right TLE. The one network identified was then quantified in the patients with TLE and recurring seizures.

KEY FINDINGS

The resting functional connectivity between the right hippocampus and the ventral lateral nucleus of the right thalamus was the most statistically significant network to distinguish between seizure-free patients with left TLE and with right TLE with high sensitivity and specificity. This connectivity was also significantly greater in the seizure-free patients with left TLE than the healthy controls. Finally, six of the seven patients in whom seizures recurred after surgery had connectivity values in this network unlike those who were seizure-free.

SIGNIFICANCE

This study identified a region in the ventral lateral nucleus of the right thalamus whose connectivity to the hippocampi separates left from right TLE subjects. This suggests that the quantification of resting-state functional magnetic resonance imaging (MRI) connectivity across this network may be a potential indicator of lateralization of TLE that may be added to other presurgical MRI assessments. Further validation in a larger, independent cohort is required.

Electrical stimulation in epilepsy: vagus nerve and brain stimulation

OPINION STATEMENT

Vagus nerve stimulation (VNS) for epilepsy is a well established and effective treatment for medically intractable epilepsy. VNS is indicated if resective epilepsy surgery is unsuccessful or is not an option. About 50% of patients with VNS have a seizure reduction greater than 50%, but less than 10% become seizure-free. VNS also has an alerting effect on patients and may allow a reduction in sedating medications. The major adverse event is hoarseness, but treatment is generally well tolerated. The therapeutic effect can be delayed: patients may improve several months after VNS implantation. Direct brain stimulation (DBS) is an emerging treatment for epilepsy. Scheduled stimulation is similar to brain stimulation in Parkinson's disease. Only the anterior thalamic nucleus has been studied in a larger randomized, controlled trial, in which patients with the stimulator turned on had a significantly reduced seizure frequency. Responsive stimulation applies an electrical stimulus at the site of seizure onset to terminate the seizure if one occurs. The seizure-onset zone must be well defined before implantation. Responsive stimulation requires seizure detection and application of a stimulus online. A large pivotal trial showed a significant reduction in seizure frequency. Both DBS and responsive neurostimulation are well tolerated, but there has been some concern about depression with DBS. Infection, hemorrhage, and lead breakage are adverse events possible with any type of stimulator. None of the brain stimulation devices have been approved by the US Food and Drug Administration, but final approval is expected soon. These devices are indicated for patients with bilateral seizure onset or seizure onset in eloquent areas. Although the initial trials of brain stimulation do not show overwhelming improvement in seizure frequency, the technology will improve with time as we continue to learn about the use of brain stimulation for epilepsy. Optimization of VNS has been going on for 10 years, and we need to ensure that brain stimulation is similarly developed further. In addition, sophisticated devices such as responsive neurostimulators can greatly enhance our understanding of the pathophysiology of epilepsy.