A Case of Serum Amino Acid Disturbance with Hyperammonemia in a Patient with Multiple Myeloma

Hyperviscosity and hypercalcemia are the common cause of disturbance of consciousness in patients with multiple myeloma (MM). However, there have been anecdotal reports of disturbance of consciousness in MM due to hyperammonemia and serum amino acid disturbance without possible causes such as liver failure. A 45-year-old female patient with MM was admitted due to general weakness. On 7th hospital day, she showed somnolence and disorientation. On the assumption of hyperviscosity syndrome, plasma exchange was performed immediately, but no effect. At that time, rum glycine level was abnormally elevated. This type of serum amino acid disturbance was different from that usually found in chronic liver disease. After vincristine, adriamycin, and dexamethasone chemotherapy, serum ammonia level was restored to the normal range followed by improved mental status. We report, first in Korea, a case of MM with mental disturbance due to hyperammonemia and serum amino acid disturbance. (Korea J Hematol 2002;37:8487)