16 Pediatric Epilepsy NEONATAL SEIZURES 153 LENNOX-GASTAUT SYNDROME 161 INFANTILE SPASMS AND TUBEROUS SCLEROSIS 155 BENIGN CHILDHOOD EPILEPSY WITH CENTROTEMPORAL ABSENCE SEIZURES 157 SPIKES 163 FEBRILE SEIZURES 159 STATUS EPILEPTICUS 164 JUVENILE MYOCLONIC EPILEPSY 160 Neonatal Seizures Volpe classified neonatal seizures into subtle, clonic, tonic, and myoclonic, further classified as focal, multi- focal, or generalized. Clonic seizures can be classified as focal or multifocal. Focal clonic seizures are character- Vignette ized by rhythmic unilateral jerking movements involving the face or one limb that can spread to involve other body A 2-day-old baby girl, while being changed by her parts on the same side without affecting consciousness. mother, became less responsive and started expe- Focal clonic seizures can be associated with an underly- riencing jerking movements of the left arm, fol- ing structural abnormality such as a focal cerebrovascular lowed by right leg jerking. When the nurse was lesion (ischemic or hemorrhagic) but may also accom- called to the bedside she noticed that the right arm pany diffuse encephalopathies such as hypoxic-ischemic instead was jerking. The baby was the product of a or metabolic (Rust and Volpe in Dodson and Pellock). full-term pregnancy of a 38-year-old mother. Labor The EEG findings may be consistent with focal ictal sharp lasted 48 hours and the baby was delivered by mid- wave discharges and interictal focal slowing or back- forceps. There was no family history of neurologi- ground attenuation. cal disorders. Multifocal clonic seizures are manifested by jerking movements that shift randomly from one body part to Localization another, ipsilaterally and contralaterally in a non- jacksonian pattern, and are often associated with meta- Cortical: Is this episode a seizure? bolic causes of brain dysfunction such as hypocalcemia or with hypoxic-ischemic encephalopathy. Multifocal Differential Diagnosis and Diagnosis rhythmic discharges and interictal slowing can be ob- served on the EEG study. Seizures represent the most important manifestation of Subtle seizures are described by Rust and Volpe as par- neurological dysfunction in the newborn. Neonatal con- oxysmal abnormal manifestations more often observed in vulsions usually present with a focal or multifocal pattern premature babies that involve the motor or autonomic particularly compared to seizures of older children and function or the behavior and that cannot be categorized adults (Rust and Volpe in Dodson and Pellock). Seizures as tonic, clonic, or myoclonic seizures. They are char- in the newborn are less organized, therefore generalized acterized by repetitive facial movements, such as sucking, tonic-clonic and absence seizures are not commonly en- chewing, drooling, eye blinking, fixation of gaze, eye de- countered. The age-dependent clinical and EEG features viation, and so on, or other motions of the extremities in neonates are due to the immaturity of cortical organi- such as pedaling and boxing-like movements, and so on. zation and myelination (Holmes). It is not always an easy These manifestations have not been consistently associ- task to distinguish a possible seizure activity from other ated with EEG abnormalities, according to Mizrahi and phenomena that can represent normal movements or be- Kellaway. Only tonic deviation of the eye has been con- havior or from abnormal movements of different etiology. sistently associated with seizure activity. Abnormal paroxysmal recurrent behavior, motor or au- Tonic seizures can be classified as focal or generalized. tonomic manifestations, should be considered a possible Focal tonic seizures, often observed in hypoxic-ischemic seizure. encephalopathy, manifest with protracted flexion or ex- 153 154 16. Pediatric Epilepsy tension of an extremity or of axial muscle groups and are ground, focal monorhythmic periodic patterns of different usually associated with epileptiform discharge. frequencies, and multifocal ictal pattern. Neuroimaging Generalized tonic seizures can simulate decerebrate or (CT, MRI) studies are important for the detection of struc- decorticate posturing with sustained hyperextension of tural abnormalities, and lumbar puncture should be con- the limbs or tonic flexion of the upper extremities with sidered highly in order to rule out infections. extension of the lower extremities (Rust and Volpe).They Further investigations may be needed in selected cases can be observed in premature neonates often in associa- if the possibility of an inborn error of metabolism or a tion with structural brain lesions such as intraventricular disorder of mitochondria or peroxisomes is suspected. hemorrhage. Mizrahi and Kellaway proposed the possi- These tests include serum amino acids, lactate, ammonia, bility that they may consist of a brainstem release phe- very-long-chain fatty acids, and urine test for organic acid nomenon partly because of the poor response to anticon- screen. vulsant medications. It is not an easy task to differentiate between epileptic Myoclonic seizures present with sudden brief rapid and nonepileptic phenomena. Rust and Volpe mention jerks of muscle groups. They can be distinguished into several observations that can be made to facilitate the focal, multifocal, or generalized, and are associated with distinction, such as stimulus sensitivity of the nonepilep- metabolic abnormalities, hypoxia, or structural brain tic behavior, its suppression or elimination by gentle pas- lesions. sive restraint, and the absence of associated autonomic Apneic spells rarely represent seizure activity in the phenomena. Some of the neonatal movements and be- absence of other abnormal phenomena. haviors that need to be distinguished from seizures include Etiology • Jitteriness or tremulousness characterized by rhythmic movements of flexion and extension may simulate Rust and Volpe differentiated between early- and late- clonic activity but the flexion-extension phases have onset convulsions based on the time of presentation dur- the same amplitude and duration and can be precipi- ing the first three days of life or after that period. tated by tactile, proprioceptive, or auditory stimuli. Jit- In terms of etiology, they considered the most common teriness can be a benign phenomenon but can also be cause of early seizures that occur during the first 3 days associated with hypoxic and metabolic encephalopa- being hypoxic-ischemic encephalopathy. Prenatal indi- thies, drug intoxication and withdrawal, and intracra- cators may be represented by intrauterine growth retar- nial hemorrhage. dation and decreased fetal movements. Postnatal signs • Benign neonatal sleep myoclonus manifests with bi- consist of low Apgar scores, jitteriness, lethargy, obtun- lateral asymmetrical myoclonic jerks that occur during dation, increased intracranial pressure, and so on. Meta- sleep and are not stimulus sensitive. Such movements bolic causes such as hypoglycemia, hypocalcemia, hy- stop when the infant is awakened. EEG shows normal ponatremia, and hypernatremia can also be responsible activity. for early neonatal seizures as well as drug withdrawal, • Other nonepileptic phenomena include nonspecific and particularly heroin, methadone, sedative-hypnotics, and random movements of the extremities, spontaneous alcohol. sucking movements, head rolling, body rocking, and Cerebrovascular lesions, such as infarction or hemor- so on. Hyperreflexia has been defined as an exagger- rhage (subarachnoid, subdural, intracerebral), congenital ated startle response to a sudden stimulus in otherwise and postnatal brain infections, and so on, can also rep- healthy infants. resent the pathology underlying early neonatal seizures. After 72 hours, inborn errors of metabolism, especially Treatment aminoaciduria represent an important consideration (Fenichel). The correction of a possible metabolic abnormality is an Evaluating a neonate with seizures requires attentive important part of the management. Phenobarbital and documentation of the family and prenatal history, and a phenytoin are the first line treatment in neonatal seizure. careful examination of the infant. The half-life of these drugs is prolonged in the neonate Laboratory investigations, particularly serum electro- compared with the adult. Phenobarbital is recommended lytes, glucose, calcium, magnesium, and phosphorus, are in an initial loading dose of 20 mg/kg, and a maintenance important in order to rule out a metabolic dysfunction. dose of 3 to 4 mg/kg/day. Serum levels between 16 and EEG is valuable as a diagnostic instrument and also in 40 mcg/ml are required to obtain a good therapeutic re- term of prognosis. Holmes divides the ictal patterns into sponse. Phenytoin can be administered at a loading dose four basic types: focal ictal pattern with normal back- of 15 to 20 mg/kg. The duration of therapy is based on ground activity, focal ictal pattern with abnormal back- the risk of developing recurrent seizures (Volpe). Infantile Spasms and Tuberous Sclerosis 155 Infantile Spasms and year of life. Later on, most patients will experience other types of generalized convulsion or focal seizures. Tuberous Sclerosis Infantile Spasms Vignette Spasms are characterized by clusters of sudden, briefly sustained movements (Dulac et al.). They can involve the A 2-year-old girl was brought to your attention be- flexor or the extensor muscles and affect the axial and/or cause of aggressive behavior, emotional lability, appendicular musculature. poor social interaction,