Abstracts

Rationale: To report a case of a patient with abdominal pain, hypertension, seizures, and encephalopathy associated with posterior reversible encephalopathy syndrome (PRES) on brain MRI and lateralized periodic discharges (LPDs, also termed PLEDs) on continuous EEG monitoring (CEEG), who was further diagnosed with having acute intermittent porphyria.Methods: Acute intermittent porphyria is an autosomal dominant disorder, which results from partial deficiency of porphyrobilinogen (PBG) deaminase, an enzyme of the heme biosynthesis pathway. Symptoms of acute intermittent porphyria include abdominal pain, hypertension, and seizures. There are previous reports of acute intermittent porphyria associated with PRES, which is thought to be the result of peaks of hypertension. The concomitant presentation of PRES and LPDs has been described, mostly in patients with eclampsia.Results: This is a 20 year-old female with severe recurrent abdominal pain, who was admitted with hypertension, tachycardia, and seizures. Patient was profoundly lethargic and assumed a fetal position in bed. There was left lower extremity clonus and left-sided Babinski on neurological examination. The brain MRI showed PRES and CEEG showed both LPDs plus recurrent electrographic seizures over the right temporo-parietal region. She was admitted to the ICU for tight blood pressure control and treatment with levetiracetam, acyclovir, and antibiotics. The CSF was unremarkable and comprehensive CSF studies were negative, including PCR for herpes simplex virus. Seizures completely subsided with treatment, but not the encephalopathy. Acyclovir was discontinued after CSF results and high dose steroids were started, thinking with the possibility of immunological and inflammatory etiologies. There was a progressive improvement of her mental status. Because of history of recurrent and severe abdominal pain associated with hypertension, tachycardia and seizures, we requested rapid urine PBG, urophorphyrin, and serum porphyrin, which were highly elevated. When these results were back, patient was fully alert and without any focal neurological deficits. Only a mild abdominal pain persisted, which was resolved in less than 24 hours with carbohydrate (glucose) loading and high caloric diet. It was felt that intravenous hemin was not necessary at this time. She was then discharged home. A follow-up brain MRI showed remarkable improvement.Conclusions: We report an unusual case of acute intermittent porphyria presenting with PRES and LPDs, which led to additional complexity in the differential diagnosis and management of this patient. The neurological manifestations of acute intermittent porphyria are potentially life threatening. In addition, several antiepileptic drugs, including phenytoin, may trigger or worse an acute attack. Fortunately, our patient, who had no definite diagnosis at presentation, received levetiracetam in the emergent setting.