A Case of Synthetic Cannabinoid (K2)-Induced Posterior Reversible Encephalopathy Syndrome (PRES)

Background: K2 is an artificially synthesized cannabinoid (SCB), manufactured as a non-consumption herbal incense but increasingly misused as a recreational drug. Posterior reversible encephalopathy syndrome (PRES) is a rare clinical and radiological entity characterized by brain edema, often in the setting of acute hypertension. Cases of PRES caused by recreational drug use have been reported in the literature. We report an unusual case of PRES after consumption of K2 in a 24-year-old healthy woman who presented with episodic agitation and altered mental status. Magnetic resonance imaging showed nonspecific subtle high T2/FLAIR (fluid-attenuated inversion recovery) signal intensities in the region of the posterior parietal and occipital cortices. Her extensive drug screen report was positive for K2. Her mental status improved over the course of 3 weeks and she had returned to her baseline at 3-month follow-up. Our case highlights the importance of having a high clinical suspicion in patients presenting with altered mental status and a history of recreational drug use. K2 is not detected by routine urine drug testing, so a high level of clinical suspicion is required to request an extensive drug screen. It is important for the physician to counsel active synthetic cannabinoid users regarding these rare complications.