J. Eric Piiia-Garza Kaitlin C. James Fenichel’s Clinical Pediatric Neurology This page intentionally left blank Eighth Edition Fenichel’s Clinical Pediatric Neurology A Signs and Symptoms Approach AUTHORS J. Eric Pin˜a-Garza, MD Director, Pediatric Epilepsy The Children’s Hospital at TriStar Centennial Nashville, TN, United States Kaitlin C. James, MD Assistant Professor, Pediatric Neurology Director, Pediatric Epilepsy Monitoring Unit Departments of Pediatrics and Neurology Monroe Carell, Jr. Children’s Hospital at Vanderbilt Nashville, TN, United States Elsevier 1600 John F. Kennedy Blvd. Ste 1600 Philadelphia, PA 19103-2899 FENICHEL’S CLINICAL PEDIATRIC NEUROLOGY, A SIGNS AND SYMPTOMS APPROACH, EIGHTH EDITION ISBN: 978-0-323-48528-9 Copyright © 2019 by Elsevier, Inc. All rights reserved. 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This page intentionally left blank This page intentionally left blank 1 Paroxysmal Disorders OUTLINE Approach to Paroxysmal Disorders, 1 Paroxysmal Dyskinesias, 23 Paroxysmal Neurological Disorders of Newborns, 2 Hyperventilation Syndrome, 24 Seizure Patterns, 2 Sleep Disorders, 24 Seizure-Like Events, 3 Stiff Infant Syndrome (Hyperekplexia), 25 Differential Diagnosis of Seizures, 4 Syncope, 26 Hypoxic-Ischemic Encephalopathy, 10 Staring Spells, 26 Organic Acid Disorders, 11 Eyelid Myoclonia With or Without Absences Treatment of Neonatal Seizures, 15 (Jeavons Syndrome), 28 Paroxysmal Disorders in Children Less Than Myoclonic Seizures, 29 2 Years old, 16 Partial Seizures, 30 Apnea and Syncope, 17 Generalized Seizures, 34 Normal Self-Stimulatory Behavior, 18 Managing Seizures, 36 Febrile Seizures, 18 Antiepileptic Drug Therapy, 36 Epilepsies Exacerbated by Fever, 19 Management of Status Epilepticus, 43 Dravet Syndrome, 19 The Ketogenic Diet, 44 Generalized Epilepsy With Febrile Seizures Plus, 19 Vagal Nerve Stimulation, 44 Nonfebrile Seizures, 19 Surgical Approaches to Childhood Epilepsy, 45 Migraine, 23 References, 45 Paroxysmal Neurological Disorders (PNDs) of Childhood, 23 Paroxysmal neurological disorders are characterized by Physicians often misdiagnose syncope as a seizure, as many the sudden onset of neurological dysfunction and stereo- people stiffen and tremble at the end of a faint. The critical typed recurrence. In children, such events often clear distinction is that syncope is associated with pallor and pre- completely. Examples of paroxysmal disorders include ceded by dimming of vision, and a feeling of lightheadedness epilepsy, migraine, periodic paralysis, and paroxysmal or clamminess, whereas seizures are rarely preceded by these movement disorders. things. Also, the patient with syncope has a fast recovery of consciousness and coherence if allowed to remain supine APPROACH TO PAROXYSMAL DISORDERS postictal. Spells seldom remain unexplained when viewed. Because The diagnosing physician rarely witnesses the paroxysmal observation of the spell is critical to diagnosis, ask the family event. It is important to obtain the description of the event to record the spell. Most families either own or can borrow a from the observer or a video recording and not second hand. camera or a cell phone with video capability. Even when The information easily becomes distorted if transferred from a purchase is required, a video is often more cost effective the observer to the parent and then to you. Most “spells” are than brain imaging, and the family has something useful not seizures, and epilepsy is not a diagnosis of exclusion. to show for the expenditure. Always ask the following two 1 2 CHAPTER 1 Paroxysmal Disorders questions: Has this happened before? Does anyone else in the BOX 1.2 Seizure Patterns in Newborns family have similar episodes? Often, no one offers this important information until requested. Episodic symptoms • Apnea with tonic stiffening of body that last only seconds and cause no abnormal signs usually • Focal clonic movements of one limb or both limbs on remain unexplained and do not warrant laboratory investi- one sidea gation. The differential diagnosis of paroxysmal disorders is • Multifocal clonic limb movementsa somewhat different in the neonate, infant, child, and adoles- • Myoclonic jerking cent, and is therefore presented best by age groups. • Paroxysmal laughing • Tonic deviation of the eyes upward or to one sidea PAROXYSMAL NEUROLOGICAL DISORDERS • Tonic stiffening of the body OF NEWBORNS aDenotes the most common conditions and the ones with disease-modifying treatments Seizures are the main paroxysmal disorder of the newborn, occurring in 1.8%–3.5% of live births in the United States, and an important feature of neurological disease.1 spread beyond the contiguous cortex or to produce second- Uncontrolled seizures may contribute to further brain dam- ary bilateral synchrony. age. Brain glucose decreases during prolonged seizures and Box 1.2 lists clinical patterns that have been associated excitatory amino acid release interferes with DNA synthe- with epileptiform discharges in newborns. This classifica- sis. Therefore, seizures identified by electroencephalogra- tion is useful but does not do justice to the rich variety of phy (EEG) that occur without movement in newborns patterns actually observed, nor does the classification are important to identify and treat. The challenge for the account for the 50% of prolonged epileptiform discharges clinician is to differentiate seizure activity from normal on the EEG without visible clinical changes. Generalized neonatal movements and from pathological movements tonic-clonic seizures rarely occur. Many newborns sus- caused by other mechanisms (Box 1.1). pected of having generalized tonic-clonic seizures are actu- The long-term prognosis in children with neonatal sei- ally jittery (see Jitteriness, discussed later in this chapter). zures is better in term newborns than in premature new- Newborns paralyzed to assist mechanical ventilation pose borns.2 However, the etiology of the seizures is the an additional problem in seizure identification. In this cir- primary determinant of prognosis. cumstance, the presence of rhythmic increases in systolic arterial blood pressure, heart rate, and oxygenation desa- Seizure Patterns turation should alert physicians to the possibility of Seizures in newborns, especially in the premature, are seizures. poorly organized and difficult to distinguish from normal The term subtle seizures encompasses several different activity. Newborns with hydranencephaly or atelencephaly patterns in which tonic or clonic movements of the limbs are capable of generating the full variety of neonatal seizure are lacking, for example tonic deviation of the eyes. One patterns, which supports the notion that seizures may arise of the most common manifestations of seizures in the from the brainstem in such cases. The absence of myelin- young infant is behavioral arrest and unresponsiveness. ated pathways for seizure propagation may confine seizures Behavioral arrest is only obvious when the child is very originating in one hemisphere and make them less likely to active, which is not common in a sick neonate and therefore often goes unnoticed. The definitive diagnosis of neonatal seizures often requires EEG monitoring. A split-screen 16-channel video BOX 1.1 Movements That Resemble EEG is the ideal means for monitoring. An aEEG (ampli- Neonatal Seizures tude integrated EEG) is also a useful monitoring technique. Seizures in the newborn may be widespread and electrogra- • Benign nocturnal myoclonusa phically detectable even when the newborn is not convuls- • Jitterinessa ing clinically. • Nonconvulsive apnea • Normal movement Focal Clonic Seizures • Opisthotonos Clinical features. Repeated, irregular slow clonic • Pathological myoclonus movements (1–3 jerks/second) affecting one limb or both aDenotes the most common conditions and the ones with limbs