Hyperammonemia after high-dose chemotherapy and stem cell transplantation

We report a patient with multiple myeloma who suffered from hyperammonemia after a second stem cell autograft, This syndrome is not well known but is associated with a high mortality rate. Considering the possibility of this diagnosis in patients developing confusion and neurological degradation wit h respiratory alkalosis after intensive chemotherapy, could allow earlier t reatment and perhaps improved survival. Possible mechanisms and potential t herapies are discussed. With rapid recognition and treatment of the syndrom e, the patient fully recovered. One and a half years later, she is still al ive and well, on interferon for persisting myeloma.