CEREBRAL P-31 MAGNETIC-RESONANCE SPECTROSCOPY IN PATIENTS WITH CHRONIC HEPATIC-ENCEPHALOPATHY

Cerebral phosphorus-31 magnetic resonance spectroscopy was undertaken in 33 patients with biopsy-proven cirrhosis: 6 had no evidence of neur opsychiatric impairment on standard clinical, psychometric and electro physiological testing; 8 had evidence of subclinical hepatic encephalo pathy; and 19 were classified as having overt hepatic encephalopathy. The reference population comprised 15 healthy volunteers. Unlocalized spectra were acquired from the entire head with a 45-degree pulse angl e and repetition times of 1 and 5 sec. Spectra localized to the basal ganglia were acquired with a 45-degree pulse angle and a repetition ti me of 1 sec. Peak area ratios of phosphomonoesters, inorganic phosphat e, phosphodiesters and phosphocreatine relative to beta-ATP were measu red in the spectra acquired. We noted no consistent change in the rati os of inorganic phosphate to ATP and phosphocreatine to ATP. Mean valu es of the ratios of phosphomonoesters to ATP and phosphodiesters to AT P were significantly lower in the total patient population than in the reference population, and they correlated with the patients' neuropsy chiatric status. Thus we found no significant reductions in the mean r atios of phosphomonoesters to ATP and phosphodiesters to ATP in patien ts who were neuropsychiatrically unimpaired, but significant reduction s were observed in the mean ratios of phosphomonoesters to ATP and pho sphodiesters to ATP in patients with both subclinical and overt hepati c encephalopathy. The most marked reductions in these metabolite ratio s were observed in patients with overt encephalopathy.