Neonatal Seizures Amy Kao, M.D. Division of Neurology Doernbecher Children’s Hospital

Objectives Review the clinical presentation and differential diagnosis Discuss pathophysiologic implications on clinical presentation Review etiology Apply this information to evaluation and treatment Discuss prognosis

Clinical Classification Focal/Multifocal Clonic –Not generalized –Migratory –Not necessarily focal etiology Focal Tonic –Not usually generalized Generalized Myoclonic

Clinical Classification Subtle (“Hypomotor”) –Motor activity arrest –Apnea –Eye deviation –Autonomic changes Motor automatisms –Oral-buccal-lingual movements –Swimming –Bicycling

The Definition of a Seizure “paroxysmal discharge of cerebral neurons sufficient to cause clinically detectable events that are apparent either to the subject or to an observer”

Definition of a Seizure in a Neonate? Excitatory activity predominates No paroxysmal discharge on EEG? –True seizure The cortex is undeveloped Deeper origin –“Brainstem release phenomena”

Definition of a Seizure in a Neonate… Clinically detectable events? –Subtle –Truly only electrographic Iatrogenic paralysis High doses AEDs Encephalopathy or subcortical/spinal cord damage

If It Isn’t a Seizure, Then What Is It?? Possible clues –Stimulus-induced –Suppressable –No associated autonomic changes (usually not bradycardia)

Weird Baby Movements –Jitteriness Stimulus-sensitive “Tremor” Suppressable –Benign neonatal sleep myoclonus –Spinal myoclonus –Apnea of non-neurologic etiology bradycardia

Causes of Neonatal Seizures Within first 24 hours of life –Hypoxic ischemic encephalopathy –Meningitis/sepsis –Subdural/Subarachnoid/Interventricular hemorrhage –Intrauterine infection –Trauma –Pyridoxine dependency –Drug effect/withdrawal

Causes… hours –Meningitis/sepsis –In premature infants: IVH –In full-term infants: infarction, venous thrombosis –Cerebral dysgenesis

Causes…. 72 hours to 1 week –Above causes –Inborn errors of metabolism –Hypocalcemia –Familial neonatal seizures 1 week to 4 weeks –Above causes –HSV

Other Syndromes Benign idiopathic neonatal convulsions (BINC or Fifth-day fits) Benign familial neonatal convulsions (BFNC) Early myoclonic encephalopathy (EME) Early infantile epileptic encephalopathy (EIEE) Glucose transporter type I

Evaluation of Neonatal Seizures Serum lytes (gluc, Ca, Mg, Na) CSF Head ultrasound EEG (B6?) Tox screen CT or MRI of brain ?metabolic w/u, congenital infection w/u

Treatment of Electroclinical Seizures Phenobarbital 20 mg/kg –10 mg/kg boluses until microgm/ml Phenytoin 20 mg/kg Lorazepam 0.1 mg/kg Pyridoxine mg IV with EEG

Outcome 45 % controlled after either phenobarb or phosphenytoin 60 % controlled with both 30% of survivors develop epilepsy WORSE: HIE, meningitis, dysplasia WORSE: electrographic seizures BETTER: hypoCa, BINC, BIFC, stroke