Surveys and Reviews

Bruzzone, Maria J., Chapin, Benjamin, Walker, Jessie, Santana, Marcos, Wang, Yue, Amini, Shawna, Kimmet, Faith, Perera, Estefania, Rubinos, Clio, Arias, Franchesca, Price, Catherine

Anesthesia & Analgesia 

140(5):p 1127-1139, May 2025

DOI: 10.1213/ANE.0000000000007079

Abstract

Postoperative delirium (POD) is frequent in older adults and is associated with adverse cognitive and functional outcomes. In the last several decades, there has been an increased interest in exploring tools that easily allow the early recognition of patients at risk of developing POD. The electroencephalogram (EEG) is a widely available tool used to understand delirium pathophysiology, and its use in the perioperative setting has grown exponentially, particularly to predict and detect POD. We performed a systematic review to investigate the use of EEG in the pre-, intra-, and postoperative settings. We identified 371 studies, and 56 met the inclusion criteria. A range of techniques was used to obtain EEG data, from limited 1-4 channel setups to complex 256-channel systems. Power spectra were often measured preoperatively, yet the outcomes were inconsistent. During surgery, the emphasis was primarily on burst suppression (BS) metrics and power spectra, with a link between the frequency and timing of BS, and POD. The EEG patterns observed in POD aligned with those noted in delirium in different contexts, suggesting a reduction in EEG activity. Further research is required to investigate preoperative EEG indicators that may predict susceptibility to delirium.

Subeikshanan Venkatesan, Brandon Lucke-Wold

Editorial World J Gastroenterol
2025 Feb 28;31(8):102959.

doi: 10.3748/wjg.v31.i8.102959

Abstract

Neurosurgical patients, including those with severe traumatic brain injury, spinal cord injury, stroke, or raised intracranial pressure, are at heightened risk for stress ulcers and aspiration pneumonitis, leading to significant morbidity and mortality. These patients are typically managed through both pharmacological interventions [e.g., proton pump inhibitors (PPIs), histamine 2 (H2) antagonists, sucralfate] and non-pharmacological measures (e.g., nasogastric decompression, patient positioning) to mitigate adverse outcomes. The pathogenesis of stress ulcers in neurosurgical patients is multifactorial, but the routine use of stress ulcer prophylaxis remains controversial. While gastric acid suppression with H2 receptor antagonists and PPIs is commonly employed, concerns have arisen regarding the association between elevated gastric pH, bacterial colonization, and ventilator-associated pneumonia. The lack of comprehensive data on gastroprotection in critically ill neurosurgical patients, who face a greater risk than non-neurosurgical counterparts, further complicates this issue. Recent studies, such as one by Gao et al on the efficacy of vonoprazan-amoxicillin dual therapy in elderly patients, highlight the potential of novel therapies, but the influence of pre-existing conditions like Helicobacter pylori infection remains unclear. Non-pharmacological interventions, including nasogastric decompression and early enteral nutrition, are critical in improving outcomes but require further research to refine strategies. This editorial underscores the need for tailored approaches and encourages further investigation into optimal gastroprotective strategies for neurosurgical patients.

Carolina B. Maciel, Bakhtawar Ahmad, Maria Jose Bruzzone Giraldez, Stephan Eisenschenk, Eugene Ramsay, Nicole F. Maranchick, Charles A. Peloquin, Lawrence Hirsch, Katharina M. Busl
Epilepsy & Behavior,
Volume 160
2024
110082
ISSN 1525-5050
https://doi.org/10.1016/j.yebeh.2024.110082.
(https://www.sciencedirect.com/science/article/pii/S1525505024004645)

Abstract

The outcomes of patients who experience status epilepticus during the post-cardiac arrest period, or post-anoxic status epilepticus (PASE), remain dismal despite advances in resuscitation. The combination of therapeutic nihilism and the refractoriness of seizures in a setting where pessimistic prognostic impressions prevail is likely the main driver of such poor outcomes. The resulting pervasive vicious cycle perpetuates this knowledge gap, whereby hypoxic-ischemic insults as the etiology for seizures remain a ubiquitous exclusion criterion for clinal trials in status epilepticus. Effective therapies targeting hyperexcitability resulting from hypoxic-ischemic brain injury are urgently needed. Early inhibition of gamma-aminobutyric acid (GABA) transaminase with vigabatrin holds potential as an effective adjunctive therapy for PASE. This scientific premise is based on the resulting halted GABA catabolism thereby promoting synergistic augmentation of GABAergic pathway when used in combination with positive GABAergic allosteric modulators. This paper is based on a lecture presented at the 9th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures, in London 8–10 April 2024.

Guest Editorial
Kalamangalam, Giridhar; Frauscher, Birgit
Journal of Clinical Neurophysiology 

41(5):p 397-398, July 2024. 

DOI: 10.1097/WNP.0000000000001095

Abstract

The SEEG Wave highlights the rapid rise and transformative impact of stereoelectroencephalography (SEEG) within the field of clinical neurophysiology. Once a niche technique, SEEG has expanded dramatically as advances in imaging, surgical planning, and electrode technology have reshaped how clinicians investigate complex epileptic networks. This editorial explores the scientific and cultural momentum driving the “SEEG wave,” including its advantages over traditional subdural approaches, its role in network-based models of epilepsy, and the opportunities and challenges that accompany its widespread adoption. By examining current trends, emerging evidence, and evolving clinical practice, the editorial underscores SEEG’s growing influence on surgical decision-making and charts future directions for research, innovation, and training in invasive brain mapping.

Clio Rubinos, Daniel San-Juan, Carlos Alva-Diaz, Jorge Burneo, Andres Fernandez, Luis Carlos Mayor-Romero, Jorge Vidaurre, Loreto Rio-Pohl, Marria Jose Bruzzone

Semin Neurol 2024; 44(02): 130-146
DOI: 10.1055/s-0044-1782616

Abstract

The burden of epilepsy in the Latin America and the Caribbean (LAC) region causes a profound regional impact on the health care system and significantly contributes to the global epilepsy burden. As in many other resource-limited settings worldwide, health care professionals and patients with epilepsy in LAC countries face profound challenges due to a combination of factors, including high disease prevalence, stigmatization of epilepsy, disparities in access to care, limited resources, substantial treatment gaps, insufficient training opportunities for health care providers, and a diverse patient population with varying needs. This article presents an overview of the epidemiology of epilepsy and discusses the principal obstacles to epilepsy care and key contributors to the epilepsy diagnosis and treatment gap in the LAC region. We conclude by highlighting various initiatives across different LAC countries to improve epilepsy care in marginalized communities, listing strategies to mitigate treatment gaps and facilitate better health care access for patients with epilepsy by enhancing the epilepsy workforce.

Giridhar P. Kalamangalam, R.E. Ramsay, Michael S Okun
Neurology
2024
Volume – 102, page 8
AID – 10.1212/WNL.0000000000209404 [doi]
PMID – 38513165
https://www.neurology.org/doi/full/10.1212/WNL.0000000000209404

Summary

This article is an obituary-tribute to Dr. Buna Joe “BJ” Wilder, MD, who lived from 1929 to 2023. It outlines his career, contributions to neurology, and the impact he made on clinical practice and research. It serves to acknowledge his life’s work and influences in neurology. Dr. Wilder was an accomplished neurologist and scientist whose work spanned decades in the field of neurological disorders. The piece honors his dedication to neurology both as a physician and as a researcher, emphasizing his role in advancing understanding and treatment of neurologic diseases. The article reflects on his legacy — mentoring younger neurologists, contributing to the scientific literature, and shaping the clinical landscape.

Maria Bruzzone, Benjamin Chapin, Franchesca Arias, Jessie Walker, Catherine C. Price
Alzheimer’s and Dementia

25 December 2023
https://doi.org/10.1002/alz.075376

Abstract

Background: The electroencephalogram (EEG) in the perioperative setting has been increasingly used as a tool for delirium prognostication and diagnosis. Delirium in the post-operative setting occurs in 20-25% of the patients aged 65 and older. The has been used for a long time in the intraoperative setting, with some measures being associated with the development of POD. Recently studies have been focusing on the use of the EEG preoperatively as a prediction tool, and postoperatively as a diagnostic tool for POD.

Method: We performed a systematic review to address the role of EEG in the perioperative setting as a tool for delirium prognosis and diagnosis. Twelve randomized control trials and twenty-eight observational studies were identified.

Result: Common preoperative findings associated with the development of POD include higher alpha power, increased alpha band connectivity but impaired structural connectivity, increased slow wave activity involving frontal and occipitoparietal cortex with accompanying break down in functional connectivity, lower EEG- asymmetry, lower values of pre-operative spectral edge frequencies, and polysomnography findings of longer non-REM stage 2 sleep. Common intraoperative findings associated with POD include increased magnitude and duration of EEG suppression, reduced higher frequencies, increased prevalence and duration of BSR, and low BIS values. Finally, post-operative findings associated with POD include greater delta power while awake, alterations in delta in wake versus sleep state, and disruptions in connectivity.

Conclusion: The use of EEG as a diagnostic and prognostic tool has promising utility in the perioperative setting. In the pre-and intraoperative setting, certain EEG markers may be utilized to predict delirium or triage which patients are at a higher risk of developing POD. Postoperatively, EEG use can predict and help diagnose POD. More studies are needed to further systematize and validate this data.

Fernanda J.P. Teixeira, Jacqueline Shannon, Katharina M. Busl, Christopher P. Robinson, Bakhtawar Ahmed, Jason Katz, Guanhong Miao, Jenna Seckar, Maria Bruzzone, Mackenzie C. Cervenka, Carolina B. Maciel
Epilepsy & Behavior
Volume 144,
2023
109279
ISSN 1525-5050
https://doi.org/10.1016/j.yebeh.2023.109279.
(https://www.sciencedirect.com/science/article/pii/S1525505023001981)

Abstract

Background: The ketogenic diet (KD) is a high-fat, low-carbohydrate diet with therapeutic potential in refractory seizures, both in outpatient and inpatient settings. Successful implementation of KD involves a multifaceted, interdisciplinary approach to address anticipated challenges. We sought to characterize the utilization of KD among healthcare providers caring for adults with status epilepticus (SE).

Methods: We distributed a web-based survey through professional societies, including the American Academy of Neurology (AAN), Neurocritical Care Society (NCS), American Epilepsy Society (AES), Neuro Anesthesia and Critical Care Society (NACCS), and the Academy of Nutrition and Dietetics (AND), and via research contacts. We asked respondents about practice experience and experience using KD as a treatment for SE. Descriptive statistics and Chi-square tests were used to analyze the results.

Results: Of 156 respondents, 80% of physicians and 18% of non-physicians reported experience with KD for SE. Anticipated difficulty in achieving ketosis (36.3%), lack of expertise (24.2%), and lack of resources (20.9%) were identified as the most important barriers limiting the utilization of KD. The absence of dietitians (37.1%) or pharmacists (25.7%) support was the most important missing resource. Reasons for stopping KD included perceived ineffectiveness (29.1%), difficulty achieving ketosis (24.6%), and side effects (17.3%). Academic centers had more experience with the use of KD and greater EEG monitoring availability and fewer barriers to its implementation. The need for randomized clinical trials supporting efficacy (36.5%) and better practice guidelines for implementation and maintenance of KD (29.6%) were cited most frequently as factors to increase utilization of KD.

Conclusion: This study identifies important barriers to the utilization of KD as a treatment for SE despite evidence supporting its efficacy in the appropriate clinical context, namely lack of resources and interdisciplinary support, and lack of established practice guidelines. Our results highlight the need for future research to improve understanding of the efficacy and safety of KD along with better interdisciplinary collaborations to increase its utilization.

Clio Rubinos, Maria Jose Bruzzone, Vyas Viswanathan, Lorena Figueredo, Carolina B. Maciel, Suzette LaRoche

Semin Neurol 2023; 43(05): 675-688
DOI: 10.1055/s-0043-1775816

Abstract

Electroencephalography (EEG) is a noninvasive tool that allows the monitoring of cerebral brain function in critically ill patients, aiding with diagnosis, management, and prognostication. Specific EEG features have shown utility in the prediction of outcomes in critically ill patients with status epilepticus, acute brain injury (ischemic stroke, intracranial hemorrhage, subarachnoid hemorrhage, and traumatic brain injury), anoxic brain injury, and toxic-metabolic encephalopathy. Studies have also found an association between particular EEG patterns and long-term functional and cognitive outcomes as well as prediction of recovery of consciousness following acute brain injury. This review summarizes these findings and demonstrates the value of utilizing EEG findings in the determination of prognosis.

Maria Bruzzone, Jessie Walker, Benjamin Chapin, Marcos Santana Firme, Faith Kimmet, Sabaina Ahmed, Estefania Perera, Shawna Amini, Catherine Price
Neurology, April 25, 2023
100 (17_supplement_2) 4678
https://doi.org/10.1212/WNL.0000000000204149

Abstract

Objective: To analyze common EEG findings associated with POD in the perioperative setting.

Background: The electroencephalogram (EEG) in the perioperative setting has been increasingly used as a tool for delirium prognostication and diagnosis. Delirium in the post-operative setting occurs in 20–25% of the patients aged 65 and older. The has been used for a long time in the intraoperative setting, with some measures being associated with the development of POD. Recently studies have been focusing on the use of the EEG preoperatively as a prediction tool, and postoperatively as a diagnostic tool for POD.

Design/Methods: We performed a systematic review to address the role of EEG in the perioperative setting as a tool for delirium prognosis and diagnosis. Twelve randomized control trials and twenty-eight observational studies were identified.

Results: Common preoperative findings associated with the development of POD include higher alpha power, increased alpha band connectivity but impaired structural connectivity, increased slow wave activity involving frontal and occipitoparietal cortex with accompanying break down in functional connectivity, lower EEG-asymmetry, lower values of pre-operative spectral edge frequencies, and polysomnography findings of longer non-REM stage 2 sleep. Common intraoperative findings associated with POD include increased magnitude and duration of EEG suppression, reduced higher frequencies, increased prevalence and duration of BSR, and low BIS values. Finally, post-operative findings associated with POD include greater delta power while awake, alterations in delta in wake versus sleep state, and disruptions in connectivity.

Conclusions: The use of EEG as a diagnostic and prognostic tool has promising utility in the perioperative setting. In the pre-and intraoperative setting, certain EEG markers may be utilized to predict delirium or triage which patients are at a higher risk of developing POD. Postoperatively, EEG use can predict and help diagnose POD. More studies are needed to further systematize and validate this data.

Giridhar Kalmangalam, Mircea Chelaru

A Complex Systems Approach to Epilepsy: Concept, Practice, and Therapy

Rod C Scott and J Matthew Mahoney

Cambridge University Press, March 2023

Book Summary

The epilepsies are devastating neurological disorders for which progress developing effective new therapies has slowed over recent decades, primarily due to the complexity of the brain at all scales. This reality has shifted the focus of experimental and clinical practice toward complex systems approaches to overcoming current barriers. Organized by scale from genes to whole brain, the chapters of this book survey the theoretical underpinnings and use of network and dynamical systems approaches to interpreting and modeling experimental and clinical data in epilepsy. The emphasis throughout is on the value of the non-trivial, and often counterintuitive, properties of complex systems, and how to leverage these properties to elaborate mechanisms of epilepsy and develop new therapies. In this essential book, readers will learn key concepts of complex systems theory applied across multiple scales and how each of these scales connects to epilepsy.

Gavvala, Jay, Zafar, Muhammad, Sinha, Saurabh R, Kalamangalam, Giridhar, Schuele, Stephan

Journal of Clinical Neurophysiology 

39(6):p 474-480, September 2022. 

DOI: 10.1097/WNP.0000000000000794

Abstract

Purpose: Stereotactic EEG (SEEG) is being increasingly used in the intracranial evaluation of refractory epilepsy in the United States. In this study, the authors describe current practice of SEEG among National Association of Epilepsy Centers tertiary referral (level IV) centers.

Methods: Using the Survey Monkey platform, a survey was sent to all National Association of Epilepsy Centers level IV center directors.

Results: Of 192 centers polled, 104 directors completed the survey (54% response rate). Ninety-two percent currently perform SEEG. Of these, 55% of institutions reported that greater than 75% of their invasive electrode cases used SEEG. Stereotactic EEG was commonly used over subdural electrodes in cases of suspected mesial temporal lobe epilepsy (87%), nonlesional frontal lobe epilepsy (79%), insular epilepsy (100%), and individuals with prior epilepsy surgery (74%). Most centers (72%) used single-lead electrocardiogram monitoring concurrently with SEEG, but less than half used continuous pulse oximetry (47%) and only a few used respiratory belts (3%). Other significant intercenter technical variabilities included electrode nomenclature and choice of reference electrode. Patient care protocols varied among centers in patient-to-nurse ratio and allowed patient activity. Half of all centers had personnel who had prior experience in SEEG (50.5%); 20% of centers had adopted SEEG without any formal training.

Conclusions: Stereotactic EEG has become the principal method for intracranial EEG monitoring in the majority of epilepsy surgery centers in the United States. Most report similar indications for use of SEEG, though significant variability exists in the utilization of concurrent cardiopulmonary monitoring as well as several technical and patient care practices. There is significant variability in level of background training in SEEG among practitioners. The study highlights the need for consensus statements and guidelines to benchmark SEEG practice and develop uniform standards in the United States.

Kai-Liang Wang, Joshua K. Wong, Robert S. Eisinger, Samuel Carbunaru, Christine Smith, Wei Hu, Aparna Wagle Shukla, Christopher W. Hess, Michael S. Okun, Adolfo Ramirez-Zamora
Neuromodulation: Technology at the Neural Interface
Volume 25, Issue 6
2022
Pages 796-803
ISSN 1094-7159
https://doi.org/10.1111/ner.13220.
(https://www.sciencedirect.com/science/article/pii/S1094715922000022)

Abstract

Objective: We aimed to formulate a practical clinical treatment algorithm for Holmes tremor (HT) by reviewing currently published clinical data.

Materials and Methods: We performed a systematic review of articles discussing the management of HT published between January 1990 and December 2018. We examined data from 89 patients published across 58 studies detailing the effects of pharmacological or surgical interventions on HT severity. Clinical outcomes were measured by a continuous 1-10 ranked scale. The majority of studies addressing treatment response were case series or case reports. No randomized control studies were identified.

Results: Our review included 24 studies focusing on pharmacologic treatments of 25 HT patients and 34 studies focusing on the effect of deep brain stimulation (DBS) in 64 patients. In the medical intervention group, the most commonly used drugs were levetiracetam, trihexyphenidyl, and levodopa. In the surgically treated group, the thalamic ventralis intermedius nucleus (VIM) and globus pallidus internus (GPi) were the most common brain targets for neuromodulation. The two targets accounted for 57.8% and 32.8% of total cases, respectively. Overall, compared to the medically treated group, DBS provided greater tremor suppression (p = 0.025) and was more effective for the management of postural tremor in HT. Moreover, GPi DBS displayed greater benefit in the resting tremor component (p = 0.042) and overall tremor reduction (p = 0.022).

Conclusions: There is a highly variable response to different medical treatments in HT without randomized clinical trials available to dictate treatment decisions. A variety of medical and surgical treatment options can be considered for the management of HT. Collaborative research between different institutions and researchers are warranted and needed to improve our understanding of the pathophysiology and management of this condition. In this review, we propose a practical treatment algorithm for HT based on currently available evidence.

Pais, G.M., Chang, J., Barreto, E.F. et al.

Clin Pharmacokinet 61, 929–953 (2022).

https://doi.org/10.1007/s40262-022-01137-y

Abstract

Cefepime is a broad-spectrum fourth-generation cephalosporin with activity against Gram-positive and Gram-negative pathogens. It is generally administered as an infusion over 30–60 min or as a prolonged infusion with infusion times from 3 h to continuous administration. Cefepime is widely distributed in biological fluids and tissues with an average volume of distribution of ~ 0.2 L/kg in healthy adults with normal renal function. Protein binding is relatively low (20%), and elimination is mainly renal. About 85% of the dose is excreted unchanged in the urine, with an elimination half-life of 2–2.3 h. The pharmacokinetics of cefepime is altered under certain pathophysiological conditions, resulting in high inter-individual variability in cefepime volume of distribution and clearance, which poses challenges for population dosing approaches. Consequently, therapeutic drug monitoring of cefepime may be beneficial in certain patients including those who are critically ill, have life-threatening infections, or are infected with more resistant pathogens. Cefepime is generally safe and efficacious, with a goal exposure target of 70% time of the free drug concentration over the minimum inhibitory concentration for clinical efficacy. In recent years, reports of neurotoxicity have increased, specifically in patients with impaired renal function. This review summarizes the pharmacokinetics, pharmacodynamics, and toxicodynamics of cefepime contemporarily in the setting of increasing cefepime exposures. We explore the potential benefits of extended or continuous infusions and therapeutic drug monitoring in special populations.

Maria Bruzzone, and Giridhar Kalamangalam

Journal Watch

January 2022

A Review of Josephson CB et al. JAMA Neurol 2021 Nov

Summary

Enzyme-inducing antiseizure medications are widely used in people with epilepsy, and neurologists typically discuss their well-known short-term risks (e.g., drug interactions) before issuing new prescriptions. However, there are theoretical concerns about the longer-term use of eiASM and cardiovascular risk due to, for example, augmented cholesterol production and hyperhomocysteinemia. This large, population-based cohort of PWE confirms an overall 21% higher risk for incident cardiovascular disease in PWE on eiASMs, compared to PWE on alternative ASMs. The data suggest a cumulative, chronic effect; short-term use of eiASM does not appear to confer significant cardiovascular risk. These data should be discussed with patients prior to initiating eiASMs as well as those already established on eiASMs.

Schuele, Stephan, and Kalamangalam, Giridhar

Chapter 9 in Handbook of EEG Interpretation, 3rd Edition

DOI:  10.1891/9780826147097.0009

Abstract

The placement of electrodes intracranially to record electroencephalography (EEG) directly from the surface of the brain was pioneered by Foerster in the 1930s. Invasive EEG monitoring remains an essential tool for defining the epileptogenic zone in around 30% of patients considered for epilepsy surgery. Today, both these techniques – subdural and intracerebral stereotaxic EEG (SEEG) – remain in wide use in the presurgical evaluation of potential candidates with drug-resistant focal epilepsies. Regular communication between the medical and EEG technical team and hospital clinical engineering departments can do much to assure the quality of data acquired from intracranial EEG while keeping patients safe in an often electrically complex environment. Analysis of the interictal EEG from invasive recordings is an essential prerequisite for proper interpretation of the ensuing ictal data. Electrical stimulation mapping represents an integral part of any invasive evaluation, whether subdural grid electrode or SEEG.

Felix Rosenow, Naoki Akamatsu, Thomas Bast, Sebastian Bauer, Christoph Baumgartner, Selim Benbadis, Adriana Bermeo-Ovalle, Stefan Beyenburg, Andrew Bleasel, Alireza Bozorgi, Milan Brázdil, Mar Carreño, Norman Delanty, Michael Devereaux, John Duncan, Guadalupe Fernandez-Baca Vaca, Stefano Francione, Naiara García Losarcos, Lauren Ghanma, Antonio Gil-Nagel, Hajo Hamer, Hans Holthausen, Shirin Jamal Omidi, Philippe Kahane, Giri Kalamangalam, Andrés Kanner, Susanne Knake, Stjepana Kovac, Karsten Krakow, Günter Krämer, Gerhard Kurlemann, Nuria Lacuey, Patrick Landazuri, Shi Hui Lim, Luisa V. Londoño, Giorgio LoRusso, Hans Luders, Jayanti Mani, Riki Matsumoto, Jonathan Miller, Soheyl Noachtar, Rebecca O’Dwyer, André Palmini, Jun Park, Philipp S. Reif, Jan Remi, Americo C. Sakamoto, Bettina Schmitz, Susanne Schubert-Bast, Stephan Schuele, Asim Shahid, Bernhard Steinhoff, Adam Strzelczyk, C. Akos Szabo, Nitin Tandon, Kiyohito Terada, Manuel Toledo, Walter van Emde Boas, Matthew Walker, Peter Widdess-Walsh
Seizure, Volume 78
2020
Pages 31-37
ISSN 1059-1311
https://doi.org/10.1016/j.seizure.2020.02.018.
(https://www.sciencedirect.com/science/article/pii/S1059131120300674)

Abstract

Over the last few decades, the ILAE classifications for seizures and epilepsies (ILAE-EC) have been updated repeatedly to reflect the substantial progress that has been made in diagnosis and understanding of the etiology of epilepsies and seizures and to correct some of the shortcomings of the terminology used by the original taxonomy from the 1980s. However, these proposals have not been universally accepted or used in routine clinical practice. During the same period, a separate classification known as the “Four-dimensional epilepsy classification” (4D-EC) was developed which includes a seizure classification based exclusively on ictal symptomatology, which has been tested and adapted over the years. The extensive arguments for and against these two classification systems made in the past have mainly focused on the shortcomings of each system, presuming that they are incompatible. As a furthermore detailed discussion of the differences seemed relatively unproductive, we review and assess the concordance between these two approaches that has evolved over time, to consider whether a classification incorporating the best aspects of the two approaches is feasible. To facilitate further discussion in this direction we outline a concrete proposal showing how such a compromise could be accomplished, the “Integrated Epilepsy Classification”. This consists of five categories derived to different degrees from both of the classification systems: 1) a “Headline” summarizing localization and etiology for the less specialized users, 2) “Seizure type(s)”, 3) “Epilepsy type” (focal, generalized or unknown allowing to add the epilepsy syndrome if available), 4) “Etiology”, and 5) “Comorbidities & patient preferences”.

Kalamangalam GP.

Neurosurg Clin N Am. 2020 Jul;31(3):345-371.

doi: 10.1016/j.nec.2020.03.008.

Epub 2020 Apr 25. PMID: 32475485.

Abstract

Analysis of scalp electroencephalogram (EEG) findings is indispensable to investigation of epilepsy surgery candidates. Maxima of slowing and epileptiform spiking on interictal EEG reflect gross localization of core epileptogenic regions within a network. Important negative scalp EEG findings are those associated with deep foci. Ictal EEG is important in confirming concordance with interictal EEG and other ancillary data. Generalized interictal and ictal EEG findings may occur in epilepsies that are otherwise focal. Detailed individual analyses of scalp EEG features are prelude to a more global synthesis, whose coherence in suggesting plausible network hypothesis presage a subsequently successful scalp EEG evaluation.

André Palmini, Naoki Akamatsu, Thomas Bast, Sebastian Bauer, Christoph Baumgartner, Selim Benbadis, Adriana Bermeo-Ovalle, Stefan Beyenburg, Andrew Bleasel, Giri Kalamangalam, et al. 

A commentary

Epilepsia
First published: 19 February 2020
https://doi.org/10.1111/epi.16426

Summary

Dr Fisher and colleagues have recently provided a commentary on our critique of the 2017 International League Against Epilepsy (ILAE) classification of epileptic seizures and epilepsies.1 The commentary was disappointing in that it did not depart from their original views and suggests a lack of engagement to consider an alternative framework that might improve the ILAE classifications of epileptic seizures and the epilepsies.2, 3

Epileptologists actively dealing with people with epilepsy must provide feedback and express their views on any official ILAE position, as the latter would only be valid if it succeeds in striking a balance between the perspectives of any ILAE commission and that of the practitioners. It is evident that thoughtful critiques of ILAE position papers can only be forwarded once a text is published and their directions put into use, which is what we did in our critique,4 in an effort to achieve the best synthesis of accumulated knowledge that could result in a practical, useful, and forward-looking classification of epileptic seizures and the epilepsies.

Nitish Chourasia, Atul Maheshwari, Giridhar Kalamangalam,
Epilepsy & Behavior
Volume 102
2020
106660
ISSN 1525-5050
https://doi.org/10.1016/j.yebeh.2019.106660.
(https://www.sciencedirect.com/science/article/pii/S1525505019306730)

Abstract

Lennox–Gastaut syndrome (LGS) denotes a refractory epileptic encephalopathy of childhood onset with the triad of generalized slow spike–wave (GSSW) on interictal scalp electroencephalogram (EEG), multiple seizure types, and intellectual impairment. The neurobiology of LGS is said to sustain abnormal patterns of brain activity and connectivity that ultimately impair normal cerebral developmental mechanisms. However, we describe eight patients from our combined practice who presented with electroclinical findings consistent with LGS but without significant cognitive impairment. All patients fulfilled the other criteria of LGS with multiple seizure types (three or more of generalized tonic–clonic, atonic, tonic, myoclonic, and atypical absence) and GSSW activity on EEG. Four subjects completed high school, two completed some college, two acquired college degrees, and all performed basic and instrumental activities of daily living (ADL) independently. Magnetic resonance imaging (MRI) was normal in all patients. We speculate that a variation of the classic phenotype of LGS can present with preserved cognitive and functional status, often with onset in the second decade of life, and associated with normal brain imaging.

Kutluay, Ekrem, Kalamangalam, Giridhar P.

Journal of Clinical Neurophysiology 36(5):p 330-336

September 2019. 

DOI: 10.1097/WNP.0000000000000546

Summary

Identifying the localization, distribution, and polarity of waveforms are the prime goals of clinical scalp EEG analysis. Appropriate choices of bipolar and referential montages are keys to emphasizing the diagnostic features of interest, and demand some understanding of the spatiotemporal physical behavior of the underlying neuronal generators. Several examples drawn from canonical epilepsy syndromes are used to illustrate this general message.

Hans Lüders, Naoki Akamatsu, Shahram Amina, Christoph Baumgartner, Selim Benbadis, Adriana Bermeo-Ovalle, Andrew Bleasel, Alireza Bozorgi, Mar Carreño, Michael Devereaux, Guadalupe Fernandez-Baca Vaca, Stefano Francione, Naiara García Losarcos, Hajo Hamer, Hans Holthausen, Shirin Jamal Omidi, Giridhar Kalamangalam, Andrés Kanner, Susanne Knake, Nuria Lacuey, Samden Lhatoo et al.

Epilepsia

Critical Review and Invited Commentary

28 March 2019
https://doi.org/10.1111/epi.14699

Summary

This article critiques the International League Against Epilepsy (ILAE) 2015-2017 classifications of epilepsy, epileptic seizures, and status epilepticus. It points out the following shortcomings of the ILAE classifications: (1) they mix semiological terms with epileptogenic zone terminology; (2) simple and widely accepted terminology has been replaced by complex terminology containing less information; (3) seizure evolution cannot be described in any detail; (4) in the four-level epilepsy classification, level two (epilepsy category) overlaps almost 100% with diagnostic level one (seizure type); and (5) the design of different classifications with distinct frameworks for newborns, adults, and patients in status epilepticus is confusing. The authors stress the importance of validating the new ILAE classifications and feel that the decision of Epilepsia to accept only manuscripts that use the ILAE classifications is premature and regrettable.

Hans Lüders, Guadalupe Fernandez-Baca Vaca, Naoki Akamatsu, Shahram Amina, Alexis Arzimanoglou, Christoph Baumgartner, Selim R. Benbadis, Andrew Bleasel, Adriana Bermeo-Ovalle, Alireza Bozorgi, Mar Carreño, Michael Devereaux, Stefano Francione, Naiara García Losarcos, Hajo Hamer, Hans Holthausen, Shirin Jamal-Omidi, Giri Kalamangalam, Andrés M. Kanner, Susanne Knake, Nuria Lacuey, Samden Lhatoo, Shih Hui Lim, Luisa V. Londoño, Jayanti Mani, et al.

Epileptic Disorders: 27 March 2019
https://doi.org/10.1684/epd.2019.1033

Abstract

This educational review describes the classification of paroxysmal events and a four-dimensional epilepsy classification system. Paroxysmal events are classified as epileptic and non-epileptic paroxysmal events. Non-epileptic events are, in turn, classified as psychogenic and organic paroxysmal events. The following four dimensions are used to classify epileptic paroxysmal events: ictal semiology, the epileptogenic zone, etiology, and comorbidities. Efforts are made to keep these four dimensions as independent as possible.

The review also includes 12 educational vignettes and three more detailed case reports classified using the 2017 classification of the ILAE and the four-dimensional epilepsy classification. In addition, a case is described which is classified using the four-dimensional epilepsy classification with different degrees of precision by an emergency department physician, a neurologist, and an epileptologist.

Kalamangalam, Giridhar P.; Pohlmann-Eden, Bernhard

Journal of Clinical Neurophysiology

35(4):p 274-278, July 2018. 

DOI: 10.1097/WNP.0000000000000447

Summary

The term “ictal–interictal” continuum has seen wide adoption in the critical care EEG domain, referring to the presence of abnormal periodic activity on the scalp EEG variably associated with seizures. The historical origin of the ictal–interictal continuum concept is discussed with a review of known and surmised physiological mechanisms for their origin and relationship to seizures. Therapeutic approaches to patients exhibiting ictal–interictal continuum EEG patterns are reviewed, and some open scientific questions highlighted. Further understanding of the ictal–interictal continuum is likely to significantly improve the care of the critically ill neurological patient.