Epilepsy

Gregory D. Cascino, Joseph I. Sirven, William O. Tatum, Gregory D. Cascino, Joseph I. Sirven, William O. Tatum

• Publisher: Wiley-Blackwell
• Year: 2021
• Print ISBN: 9781119431824
• eBook ISBN: 9781119432005
• Edition: 2
• Topic: Medicine
• Subtopic: Neurology

Designed to provide a comprehensive but accessible introduction to epilepsy and seizure disorders, Epilepsy, 2nd edition provides state-of-the-art information in a concise format useful to a wide audience, from neurology residents to epilepsy fellows and practitioners. This illustrated guide to the assessment, diagnosis, and treatment of epilepsy is a valuable resource enabling clinicians to stay on top of the latest recommendations for best practice.

Section II
Epilepsy: Treatment of Epilepsy: Non‐Surgical Therapy

10
First Seizure

Scott Spritzer¹and Omar Danoun²

¹Department of Neurology, Division of Epilepsy, Mayo Clinic Health System, Eau Claire, WI, USA

²Department of Neurology, Henry Ford Hospital, Detroit, MI, USA

Background and Epidemiology of First‐Time Seizures

A seizure is defined by abnormal synchronized discharges of neurons, occurring within a small focus of the brain in the case of a focal onset seizure and more broadly/generalized in the case of a generalized seizure. Seizures are a relatively common phenomenon, occurring in approximately 10% of the population at some point in life. A single first‐time seizure is distinguished from epilepsy, traditionally defined by recurrent unprovoked seizures separated by an interval of 24 hours or more. Patients presenting with a first‐time seizure can generally be classified as either an acute symptomatic seizure, also referred to as provoked or reactive seizures, or an unprovoked seizure.

The risk of having a second seizure after the first unprovoked seizure in adults is estimated to range between 21–45% [1] and in children and adolescents is 14–65% [2]. The greatest risk lies in the first two years after a first‐time unprovoked seizure with 80–90% of seizures occurring within that timeframe. After two years without a second seizure, there is a significant decline in approximate risk of another seizure occurring [3].

The epidemiology of acute symptomatic seizures has been demonstrated through a number of population‐based studies. Commonly cited references include a population‐based study from Rochester, Minnesota, USA, along with a number of European studies reproducing similar data [4]. Across the lifespan, the observed incidence ranges from 29–39/100 000 person‐years. Similar to epilepsy, acute symptomatic seizures have a bimodal age distribution. The greatest incidence of first‐time seizures occurs in the first year of life. The incidence declines through childhood and early adulthood, reaching the lowest between the ages of 24–35. After the age of 35, there is a progressive increase in incidence to 123/100 000 person‐years in individuals over the age of 75. Acute symptomatic seizures occur more often in men than women [5].

Depending on the cause of the first‐time seizure, the mortality rates can be high in acute symptomatic seizures. Overall, the rate of mortality in a first acute symptomatic seizure is almost nine times higher than the first unprovoked seizure in the first 30 days post event. The mortality rates reach up to 20% in the first 30 days and even up to 40% in the elderly population. On the other hand, the risk of developing epilepsy after an acute symptomatic seizure is not significant, and the risk of a second seizure after the first provoked seizure is 80% less likely than with a first unprovoked seizure [6, 7].

Causes of Acute Symptomatic Seizures

Acute symptomatic seizures are due to many different etiologies (Table 10.1). Common considerations include metabolic and electrolyte derangements, medications, cerebral ischemia/infarct, malignancy/neoplasm, trauma, and systemic infections. In epidemiologic studies, acute symptomatic seizures are defined by proximity to the initial inciting cause, within one week in the event of stroke, trauma, or anoxic/hypoxic insult, within 24 hours of an acute toxic or metabolic disturbance, and during the course of an active central nervous system (CNS) infection [8].

Table 10.1 Selected causes of acute symptomatic seizures.

Metabolic

Hypo‐ or hyperglycemia

Hypo‐ or hypernatremia

Hypocalcemia

Uremia

Toxic

Alcohol intoxication or withdrawal

Carbon monoxide poisoning

Illicit drugs (cocaine, amphetamine...

Table of contents

• Cover
• Table of Contents
• Epilepsy
• Copyright
• Dedication
• Preface
• Foreword
• List of Contributors
• Section I: Epilepsy: Epidemiology, Diagnostic Evaluation and Co–Morbidities
• Section II: Epilepsy: Treatment of Epilepsy: Non‐Surgical Therapy
• Section III: Epilepsy: Treatment of Epilepsy: Surgical Management
• Index
• End User License Agreement