Pediatric Phencyclidine (PCP) Intoxication: First Reported Human MRI and EEG Findings (3054)

Objective: Current understanding of MRI and EEG findings associated with phencyclidine (PCP) intoxication is based solely on in vitro pharmacology and animal models. This case report documents the clinical effects, and MRI and EEG findings of PCP intoxication in a pediatric patient. Background: Not Applicable Design/Methods: Not Applicable Results: A 12-month old, ex-full-term boy was found unresponsive by his mother and was brought to the emergency department (ED). He regained consciousness after midazolam administration. Initial labs identified PCP on urine toxicology (confirmed on history), hypoglycemia and elevated creatine kinase. He was hemodynamically stable and did not require oxygen supplementation. The initial video EEG showed multifocal epileptiform discharges during sleep with rare to occasional clusters of fronto-centrally predominant spike and slow wave discharges. Frontally predominant rhythmic delta (similar in appearance to FIRDA but prolonged) was observed with sleep into awake states, eventually resolving with sustained wakefulness. Despite initiation of levetiracetam, status epilepticus occurred on day 2 of presentation requiring lorazepam and phenobarbital rescues. Standing phenobarbital was added. Status epilepticus recurred on day 4, prompting a third standing antiepileptic, lacosamide. Seizures were independently multifocal with bilateral onset and clear fronto-centro-temporal predominance. A brain MRI with and without contrast on day 4 showed reduced diffusivity and confluent T2 hyperintensity throughout the subcortical white matter. A repeat MRI with and without contrast on day 15 was notable for slight cerebral volume loss, persistence of juxtacortical T2 hyperintensity, and near resolution of white matter diffusion restriction. Conclusions: This is the first human case report to describe radiologic and electrographic findings in PCP intoxication. The patient’s EEG and late MRI findings are analogous to animal models of PCP intoxication, including high voltage frontally predominant delta waves, and global volume loss. Early diffusion restriction and T2 hyperintensity in white matter seen in our patient are unique findings not previously described. Disclosure: Dr. Stainman has nothing to disclose. Dr. Nelson has nothing to disclose. Dr. Lau has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Prevail Therapeutics. Dr. Lau has received personal compensation in the range of $500-$4,999 for serving as a Consultant for ASPA Therapeutics. Dr. Lau has received personal compensation in the range of $10,000-$49,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Genzyme. Dr. Lau has received personal compensation in the range of $10,000-$49,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Takeda. Dr. Lau has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Ultragenyx. Dr. Lau has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Chiesi. Dr. Lau has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Orphazyme. Dr. Lau has received personal compensation in the range of $10,000-$49,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Biomarin. Dr. Lau has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Enzyvant. Dr. Lau has received personal compensation in the range of $10,000-$49,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Amicus. Dr. Lau has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Audentes. Dr. Lau has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Pfizer. Dr. Lau has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Prevail. The institution of Dr. Lau has received research support from Amicus. The institution of Dr. Lau has received research support from Biomarin. The institution of Dr. Lau has received research support from Genzyme/Sanofi. The institution of Dr. Lau has received research support from Shire/Takeda. The institution of Dr. Lau has received research support from Ultragenyx. The institution of Dr. Lau has received research support from Mallinckrodt. The institution of Dr. Lau has received research support from Orphazyme. The institution of Dr. Lau has received research support from Prevail Therapeutics. The institution of Dr. Lau has received research support from ASPA Therapeutics. The institution of Dr. Lau has received research support from Denail.