B48-22 Not So Reversible After All: A Severe Presentation of Posterior Reversible Encephalopathy Syndrome

Abstract Introduction Posterior reversible encephalopathy syndrome (PRES) is a neurological condition associated with impaired cerebral autoregulation in maintaining adequate cerebral blood flow across a range of systemic blood pressures through vasoconstriction and vasodilation of cerebral vessels. Cerebral vasoconstriction reaches its maximum capacity when blood pressure exceeds the autoregulatory threshold. This elevated hydrostatic pressure can disrupt the blood-brain barrier, resulting in the extravasation of intravascular fluid into the surrounding brain parenchyma, ultimately causing vasogenic edema. Case Presentation A 72-year-old male patient with past medical history of hypertension presented with complaints of severe headache and altered mental status. On arrival to the ER, his blood pressure was 193/101 mmHg. CT of the head and neck showed abnormal gyriform enhancement in the left occipital lobe with moderate 80% focal stenosis of the left internal carotid artery (ICA). Due to worsening neurological status and active seizures, he was transferred to the intensive care unit and intubated for airway protection. CSF analysis was obtained which showed WBC 4, RBC 30, glucose 187, protein 52. Culture showed no growth; pathology negative for malignancy. A meningitis panel including Listeria, Neisseria meningitidis, S. agalactiae, S. pneumoniae, HSV-1, HSV-2, HHV-6 and Cryptococcus was negative. Autoimmune encephalitis panel also returned negative. MRI showed hyperintensities in the left parieto-occipital area suggestive of PRES. He was managed with levetiracetam, fosphenytoin and methylprednisolone. His waxing and waning mental status prompted an increase in steroid dosing, which consequently led to recovery of his cough reflex and ability to follow verbal commands. Spontaneous awakening and breathing trials were done daily; however, despite minimal ventilator settings and oxygen requirements, he failed extubation twice, raising concerns about his neurological recovery and respiratory drive. Discussion PRES is a neurological disorder characterized by a range of symptoms, most of which were noted in this patient and is frequently associated with high blood pressure. Although the overall prognosis is favorable, patients with severe presentations often require intensive care and may experience persistent neurological deficits. In our case, the patient failed extubation due to fluctuating mental status. There is no published detailed analysis of lung compliance, resistance, driving pressures or ventilator-induced lung injury specifically in PRES patients. Further research is warranted to better understand the pathophysiology of PRES, optimize trigger management in severe cases, and improve patient outcomes. This abstract is funded by: None