77: Seizure Activity

I. PROBLEM

The nurse reports that an infant is having abnormal movements of the extremities consistent with seizure activity. Seizures in the neonate are common and are more prevalent during the neonatal period than any other time. Neonatal seizures may be harmful to the immature brain and may have adverse long-term neurodevelopmental outcomes. Incidence is 2.5–3.5 per 1000 in full term, and up to 22% in preterm. Neonatal seizures are rarely idiopathic and are a common manifestation of a serious central nervous system disorder: hypoxic ischemic encephalopathy (∽30–50%; most common), intracranial hemorrhage (10–17%), metabolic abnormalities (hypocalcemia [6–15%]; hypoglycemia [6–10%]), central nervous system (CNS) infections (5–14%), infarction (7%), inborn errors of metabolism (3%), CNS malformations (5%), and unknown (10%).

II. IMMEDIATE QUESTIONS

1. Is the infant really seizing? This question is very important and is often initially difficult to answer. Infants can have many unusual movements that may look like seizures but are not. It is sometimes difficult to distinguish these and an electroencephalogram (EEG) is often necessary. The following are common episodic movements that are not seizures.

   1. Jitteriness. “Jitteriness” is sometimes confused with seizures. In a jittery infant, eye movements are normal (no ocular deviation), hands stop moving if they are grasped, and movements are of a fine nature (tremor-like, not clonic-like as in seizures). In an infant who is seizing, eye movements can be abnormal (eg, staring, blinking, nystagmoid jerks, or tonic horizontal eye deviation). The hands continue to move if grasped, and movements are of a coarser nature. The EEG is normal with jitteriness and abnormal with seizure activity.

   2. Benign neonatal sleep myoclonus. Another benign condition that mimics seizures. This presents with rhythmic movements only during sleep. EEG shows no seizures.

   3. Benign myoclonus of early infancy (rare). This involves muscle spasms of the head, neck, and extremities and eye blinking that resembles seizures.

   4. Benign shuddering attacks. These events involve shuddering movements that consist of tremors and stiffening of the upper extremities.

   5. Neonatal dystonia/dyskinesia. These abnormal movements can be associated with asphyxia, metabolic diseases, or maternal drug toxicity.

   6. Rapid eye movement (REM)-associated movements. Infants can have rapid vertical and horizontal eye movements combined with twitches of the limbs to movements of the entire body.

   7. Sandifer syndrome. Infants with gastroesophageal (GE) reflux can have spells of opisthotonic posturing and stiffening with staring and jerking of extremities. This can be secondary to pain from acidic material refluxing into the esophagus. They typically occur 30 minutes after eating.

   8. Benign paroxysmal torticollis. Episodic head tilting to one side can occur with irritability and pallor.

   9. Dystonic drug reaction. This can occur with an acute drug reaction. Metoclopramide can cause this.

   10. Opisthotonos can be seen. There is prolonged arching of the back and normal eye movements. This can be secondary to meningeal irritation (Gaucher disease, kernicterus, aminoacidurias).

   11. Neonatal opsoclonus. This is characterized by rapid oscillations of the eyes. It can be normal or seen in herpes simplex encephalitis or hypoxic ...