HYPERAMMONEMIA AS A CAUSE OF SEIZURE

Abstract

SESSION TITLE: Medical Student/Resident Critical Care Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Hyperammonemia is a metabolic disturbance characterized by excess ammonia in the blood and a life-threatening condition that can affect patients of any age. It is a dangerous condition that may lead to cerebral edema, brain injury, and death. It is commonly associated with acute or chronic liver failure with or without hepatic encephalopathy, inborn errors of metabolism, upper gastrointestinal bleeding, and non-hepatic causes include chemotherapy, valproic acid, ureterosigmoidostomy, UTIs. Elevations of ammonia in plasma indicate its increased production and/or decreased detoxification. CASE PRESENTATION: An 83-Year-old female with a past medical history of hypertension, gout, chronic kidney disease presenting to emergency with acute motor loss in bilateral lower extremities with a power of 0/5 and areflexia in all lower extremity muscle groups. The initial diagnosis was cord infarct vs compression. Lumbar puncture, blood work, and imaging of the spinal cord were non-significant. She was started on pulse dose steroids for potential cord compression. On Day 3 of hospitalization, she developed streptococcus and enterococcus bacteremia, later developing into septic shock and AKI at which time she became altered and lethargic. She was transferred to ICU for further monitoring. in the ICU she was found to have extremely elevated levels of ammonia, 595µmol/L (normal15 – 63 µmol/L) with worsening septic shock and multi-organ failure, AKI, liver failure and encephalopathy with seizure-like activity and two vasopressor medications requirement. Subsequent ammonia levels trended down after lactulose treatment to 252 and 161 µmol/L. Due to her unstable condition, the patient was not able to tolerate RRT. With poor prognosis and unstable conditions, she expired. DISCUSSION: There is a relatively poor correlation with symptoms based on ammonia level, and severe symptoms generally occur with higher levels of ammonia. Previous studies showed ammonia levels around 500, sustained ammonia levels of 150 to 200 µmol/L greatly increase intraneuronal osmolality and hence the risk for intracranial hypertension and encephalopathy. An absolute ammonia level above which dialysis is needed among adults is not well defined and relies heavily on clinical evaluation. Monitoring ammonia levels, neurologic status, arterial or venous pH, and hemodynamic parameters in hyperammonemia patients will prompt for the acute need for the dialysis. Intermittent and Continuous modalities of renal replacement therapy (RRT) are indicated for hyperammonemia. Dialysis can be discontinued once the mental status is restored to the baseline and ammonia levels are declining or have stabilized. CONCLUSIONS: In the case of unexplained encephalopathy, idiopathic seizures hyperammonemia must be excluded. Early detection and prompt treatment is the key. Early evaluation for RRT as a treatment modality for hyperammonemia, as it is a dialyzable agent. Reference #1: Daughtry, DO JT, Boehm, DO, MSc KM. Transient Hyperammonemia Seen in Post Seizure Activity: A Series of Six Case Reports. SMRJ. 2017;1(2). Reference #2: Clemmesen JO, Larsen FS, Kondrup J, et al. Cerebral herniation in patients with acute liver failure is correlated with arterial ammonia concentration. Hepatology 1999; 29:648. Reference #3: Nakamura K, Yamane K, Shinohara K, et al. Hyperammonemia in an idiopathic epileptic seizures. Am J Emerg Med. 2013;31(10):1486-1489. DOI:10.1016/j.ajem.2013.08.003 DISCLOSURES: Speaker/Speaker's Bureau relationship with pfizer Please note: $1001 - $5000 Added 06/11/2020 by Yizhak Kupfer, source=Web Response, value=Consulting fee No relevant relationships by kiran para, source=Web Response No relevant relationships by Ratnam Santoshi, source=Web Response