Oral glutamine challenge and magnetic resonance spectroscopy in three patients with congenital portosystemic shunts.
OBJECTIVE
Congenital portosystemic shunts are rare abnormalities of liver vasculature that can cause neurological symptoms, probably secondarily to the effects of the metabolism of ammonia in the brain. Our aim was to investigate the relationship between capillary blood ammonia after oral glutamine challenge and magnetic resonance spectroscopy in three patients with congenital portosystemic shunts.


METHODS
Neuropsychological tests, oral glutamine challenge and magnetic resonance spectroscopy were performed at baseline and after 6 months of follow-up in three patients with congenital portosystemic shunts. The results were compared to those obtained in a group of six cirrhotic patients with prior episodes of hepatic encephalopathy and healthy controls.


RESULTS
Patients with congenital portosystemic shunts exhibited abnormalities of neuropsychological tests, magnetic resonance spectroscopy and a response to the oral glutamine challenge similar to those observed in patients with cirrhosis. The intensity of the rise of brain glutamine was correlated to the area under the curve of ammonia after the oral glutamine challenge (R=0.72).


CONCLUSIONS
Neurological manifestations of patients with congenital portosystemic shunts are mediated through similar mechanisms that are involved in the pathogenesis of hepatic encephalopathy. The area under the curve appears to be the better parameter that defines the response to the oral glutamine challenge.
Ortiz
María
M
Servei de Medicina Interna-Hepatologia, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Pg. Vall d'Hebron 119, Barcelona 08035, Spain.
Córdoba
Juan
J
Alonso
Juli
J
Rovira
Alex
A
Quiroga
Sergi
S
Jacas
Carlos
C
Esteban
Rafael
R
Guardia
Jaume
J
D000284:Administration, Oral; D000328:Adult; D000641:Ammonia / Q000378:metabolism; D019540:Area Under Curve; D001921:Brain / Q000378:metabolism; D018376:Cardiovascular Abnormalities / Q000150:complications / Q000175:diagnosis* / Q000523:psychology; D005260:Female; D005973:Glutamine / Q000008:administration & dosage* / Q000378:metabolism; D006501:Hepatic Encephalopathy / Q000209:etiology; D006801:Humans; D008103:Liver Cirrhosis / Q000150:complications / Q000175:diagnosis / Q000523:psychology; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D009422:Nervous System Diseases / Q000209:etiology; D009483:Neuropsychological Tests; D011168:Portal System / Q000002:abnormalities*; D036542:Tomography, Spiral Computed
D005973:Glutamine; D000641:Ammonia