Noncirrhotic portal vein thrombosis exhibits neuropsychological and MR changes consistent with minimal hepatic encephalopathy.
Hepatic encephalopathy can arise from portal-systemic shunting in the absence of intrinsic liver disease. However, there are few descriptions of this form of encephalopathy. Portal vein thrombosis is an infrequent disease that causes portal-systemic shunting. Episodic hepatic encephalopathy has been described in patients with portal vein thrombosis, but it is not known if these patients develop minimal hepatic encephalopathy. We designed a study to investigate the neurological consequences of portal vein thrombosis in patients without cirrhosis and no clinical signs of encephalopathy. For this purpose, 10 patients underwent neuropsychological tests, an oral glutamine challenge test, and brain magnetic resonance (MR) imaging. The results were compared with those obtained in 10 healthy controls. Patients with portal vein thrombosis exhibited abnormalities in the results of neuropsychological tests, oral glutamine challenge test, and MR similar to those described in hepatic encephalopathy associated with cirrhosis. MR spectroscopy revealed a decrease in myo-inositol and an increase in glutamine. The increase in glutamine correlated with an increase in ammonia following the oral glutamine challenge test, signs of increased brain water (decrease in magnetization transfer ratio), and impairment of attention tests. In conclusion, patients with noncirrhotic portal vein thrombosis develop subclinical neurological abnormalities compatible with minimal hepatic encephalopathy. These disturbances, which include signs of increase in brain water and a compensatory osmotic response (decrease in brain myo-inositol), appear to be secondary to brain exposure to ammonia induced by portal-systemic shunting.
Servei de Medicina Interna-Hepatologia, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain.
Beatriz
B
Mínguez
Juan Carlos
JC
García-Pagán
Jaume
J
Bosch
Juan
J
Turnes
Juli
J
Alonso
Alex
A
Rovira
Juan
J
Córdoba
D000284:Administration, Oral; D000328:Adult; D000641:Ammonia / Q000097:blood; D001288:Attention; D001834:Body Water / Q000378:metabolism; D001921:Brain / Q000378:metabolism; D016022:Case-Control Studies; D005260:Female; D005973:Glutamine / Q000008:administration & dosage / Q000378:metabolism; D006501:Hepatic Encephalopathy / Q000175:diagnosis / Q000209:etiology* / Q000378:metabolism / Q000523:psychology*; D006801:Humans; D007294:Inositol / Q000378:metabolism; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011169:Portal Vein; D020246:Venous Thrombosis / Q000097:blood / Q000150:complications* / Q000175:diagnosis* / Q000523:psychology
D005973:Glutamine; D007294:Inositol; D000641:Ammonia