Abstracts

Rationale: Variegate porphyria (VP) is an autosomal dominant disorder wherein heme biosynthesis is disrupted due to deficiency of PPOX enzyme. Clinical presentation for VP is similar to acute intermittent porphyria (AIP), which usually presents clinically with unexplained abdominal pain, chest pain, back pain, and confusion. Neurological complications include peripheral neuropathy, acute encephalopathy, and acute symptomatic seizures. Seizures can affect 10-20% of patients with acute porphyria; the most commonly reported are tonic-clonic and complex partial seizures. Although rare, convulsive status epilepticus and epilepsia partialis continua have been described in case reports. There are no cases previously describing non-convulsive status epilepticus (NCSE) with electroencephalogram (EEG) documentation to our knowledge. We report a unique presentation of NCSE, which resolved after administering levetiracetam in a patient with nearly 50 years of VP and without a known seizure disorder who presented in an acute porphyria crisis. Methods: We reviewed a case of nonconvulsive status epilepticus secondary to variegate porphyria crisis treated in a tertiary referral setting in Phoenix, Arizona. Results: A 71 year-old woman, with a 50 year history of hereditary variegate porphyria and a history of end stage renal disease on hemodialysis and coronary artery disease, presented to the emergency department with generalized weakness, lethargy, and confusion.Upon admission, she was combative, moving all of her extremities, had fluent speech, but was intermittently confused. Infectious work-up was unrevealing. A chest radiograph, urine toxicology screen, urinalysis, comprehensive blood count, ammonia, and a head computed tomography (CT) were within normal limits. Her comprehensive metabolic profile showed evidence of her known chronic kidney disease. Interestingly, she had three previous admissions for unexplained encephalopathy, which were attributed to her acute porphyria crisis.The next day, her neurologic exam changed and she became stuporous, responding only to noxious stimuli. A neurology consultation was placed. Her physical exam demonstrated no spontaneous movement of her extremities as well as a lack of deep tendon reflexes. She was nonverbal, and did not respond to verbal cues or follow commands. Her Glasgow Coma Scale was 9 (E3V2M4). An EEG was ordered which showed generalized triphasic and independent multifocal sharp waves, concerning for nonconvulsive status epilepticus.Her EEG pattern improved significantly upon a 2-g loading dose of levetiracetam. She continued to receive maintenance levetiracetam doses and her mental status continued to improve. Brain magnetic resonance imaging (MRI) was normal. She also received hemin infusions for her porphyria attacks. She was discharged home following return to her baseline. Two months later, she followed up in Epilepsy Clinic with plans to repeat her EEG and continue levetiracetam in the interim. Her mental status and neurological exam were within normal limits. Conclusions: This case highlights the importance of consideration of nonconvulsive status epilepticus in a patient with known porphyria and acute encephalopathy. Recognition is important, as it significantly changes clinical management, especially since many anticonvulsant medications are porphyrogenic. Additionally, only 10-20% of patients with AIP in relapse have noted acute symptomatic seizures, thus seizures largely remain underdiagnosed. Funding: None