Investigators in the sections of Neurophysiology and Pediatric Neurology, Baylor College of Medicine, Houston, TX, have characterized and classified 415 clinical seizures recorded in 71 neonates and 11 with EEG seizure activity without clinical accompaniments. A cribside EEG/polygraphic/video monitoring system was employed. Seizures with a close association to EEG seizure discharges were focal clonic (58 in 14 patients), myoclonic (38 in 4 patients), focal tonic (8 in 2 patients), and apneic (4 in 1 patient). Seizures with an inconsistant or no relationship to EEG seizure discharges were motor automatisms (“subtle seizures“) involving mouth, eyes, limb pedaling and swimming (140 in 22 patients), generalized tonic (90 in 13 patients), and myoclonic (66 in 13 patients). Only 2 neonates had infantile spasms. Clonic seizures with focal EEG seizure activity correlated with focal brain lesions such as infarction or intracerebral hemorrhage and a favorable short-term outcome. Seizures with no or inconsistent relationship to the EEG were correlated with diffuse hypoxic-ischemic encephalopathy and a poor prognosis (>50% with abnormal neurologic exams at discharge, and 20% died). Those with myoclonic seizures had high morbidity (35%) and mortality (29%) compared to those with clonic seizures (71% normal at discharge). The authors question the use of potentially neurotoxic anticonvulsant drugs in neonates with nonepileptic seizures or “behaviorisms“ not accompanied by EEG seizure activity. 
COMMENT. I contacted Dr. Gerald Fenichel at Vanderbilt Univ Sch of Med, an authority on neonatal seizures, for his opinion regarding the use of anticonvulsants in the treatment of “subtle“ seizures. Unless the motor automatisms or tonic posturings can be correlated with a simultaneous recording of EEG seizure activity, he considers these subtle seizures as non-epileptic and advises against treatment with anticonvulsants. Patients with epileptiform seizures associated with acute hypoxic-ischemic encephalopathy are given IV phenobarbital in a loading dose of 20-30 mg/kg to provide a serum level of 40 ug/ml. If the patient is free from seizures on recovery from the acute illness and at the time of discharge from hospital, anticonvulsants are discontinued, (personal communication). Despite the enthusiastic promotion of newer antiepileptics, there is a growing and greater awareness of the potential toxicity of anticonvulsants in general. Any practical, less hazardous alternative or safe means of withholding medication must be considered seriously, especially in the neonate and young child. See Brent et al  re phenobarbital-induced depression and suicidal behavior in epileptic children, another area for concern in the long-term use of anticonvulsant drugs.