title: Multiple myeloma and hyperammonemic encephalopathy: review of 27 cases.
abstract: Hyperammonemic encephalopathy is a rarely reported complication of multiple myeloma (MM). We describe an illustrative case of hyperammonemia in the setting of an immunoglobulin (Ig) D-lambda MM, and perform a systematic review of the English-written literature. Our search yielded 26 more cases. Median age was 64 years, and 54% of patients were male. All presented with progressive impairment of their level of consciousness. Median ammonium concentration was 109 micromol/L (interquartile range, 73-149 micromol/L). Most were IgA type (10 cases), and there were 2 cases of IgD type. Most cases were aggressive or chemotherapy-resistant forms of MM. Eight patients were diagnosed with MM at the same time as the episode of hyperammonemia. Only 1 patient had signs of portal hypertension as a result of concomitant hyperdynamic heart failure. Determination of amino acid in 10 patients showed high levels of glycine, low levels of tyrosine, and a low Fischer ratio. Two patients did not receive chemotherapy and died. Twenty-two out of 25 patients who received chemotherapy against MM showed a decrease in ammonium blood concentration, and of those, 15 survived the episode (68%). Overall mortality was 44%. In conclusion, hyperammonemia is a severe complication of MM, associated with a high mortality. It should be considered in any patient with MM and a low level of consciousness. Chemotherapy directed against MM seems to be the most effective measure in order to achieve normal ammonium levels and clinical improvement.
authors.affiliation: Department of Internal Medicine, Hospital Universitario de Bellvitge, c/ Feixa Llarga s/n, L'Hospitalet de Llobregat, Barcelona, Spain. sirsilverdelea@yahoo.com
authors.forename: Jaime
authors.initials: J
authors.lastname: Lora-Tamayo
authors.forename: Xavier
authors.initials: X
authors.lastname: Palom
authors.forename: José
authors.initials: J
authors.lastname: Sarrá
authors.forename: Oriol
authors.initials: O
authors.lastname: Gasch
authors.forename: Virginia
authors.initials: V
authors.lastname: Isern
authors.forename: Alberto
authors.initials: A
authors.lastname: Fernández de Sevilla
authors.forename: Ramón
authors.initials: R
authors.lastname: Pujol
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003244:Consciousness Disorders / Q000209:etiology; D005260:Female; D006801:Humans; D022124:Hyperammonemia / Q000150:complications*; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000150:complications*; D020258:Neurotoxicity Syndromes / Q000150:complications*