A 45-year-old female patient with stage 4 metastatic cervical cancer being treated with pembrolizumab (last dose approximately 2 weeks prior to admission) presented initially with presumed cancer related pain. After being hospitalized, her mental status became altered and she became severely agitated. There was concern for opioid overdose and flumazenil was administered; shortly afterwards, the patient had witnessed seizures. Continuous EEG identified status epilepticus. The patient was started on propofol for medically refractory status epilepticus and attempts to wean were unsuccessful due to continued seizures. Aggressive anti-convulsive treatment consisting of multiple drugs was administered including: levetiracetam, phenobarbital, valproic acid, lacosamide and topiramate. However, the regimen failed to control electrographic seizures and the patient showed no clinical improvement.

Repeat MRI brain (8 days after initial MRI brain) demonstrated some improvement in the volume of FLAIR signal abnormalities, without any new foci. However, there was no clinical improvement. Family ultimately decided to make the patient comfort care and unfortunately, the patient expired.

PRES is a rare complication associated with pembrolizumab therapy. As pembrolizumab continues to gain FDA approval to treat different cancers, more research is needed to identify what factors may place patients at a higher risk for this life-threatening therapy-related complication.