Lithium concentration and clinical responses.

The clinical use of measurements of drug concentrations in blood is empirical and largely confined to compliance and toxicity monitoring. As currently used in once or thrice a day dosage, lithium treatment is pulsatile, the blood concentration varying threefold over 24 hours; routine measurements reveal nothing of this and therefore do not aid therapeutic use. In a pilot study it is shown that the plasma lithium concentration can be raised from 0 to 2 mmol/l in a few hours, inducing changes in both kidney function and neuropsychological tests after only short delay.

Cognitive deficits associated with chronic hepatic encephalopathy and their response to levodopa.

A battery of computer-based psychological tests given to seven patients with chronic hepatic encephalopathy showed them to be intellectually impaired, particularly on speed-based measures, as compared with general hospital patients and with patients with cirrhosis but without clinical or electroencephalographic evidence of encephalopathy. Two of the seven patients in the latter group also showed evidence of cognitive impairment on some tests. The effects of levodopa were also evaluated by sequential assessment with these tests.