Chapter 8 - Toxic and deficiency states

Abstract

This chapter reviews the evidence on memory functioning in alcoholic Korsakoff's syndrome and examines the findings regarding the memory performance of subjects with a history of chronic alcoholism but who have not developed an alcoholic Korsakoff's syndrome. Chronic toxic conditions form recognized cerebral disease states. These toxic states may often be accompanied by a variable degree of vitamin deficiency, and some conditions such as alcoholic Korsakoff's syndrome usually represent the sequelae of both chronic alcohol consumption and prolonged thiamine deficiency. Patients with alcoholic Korsakoff's syndrome exhibit memory impairment on tasks that exceed a patient's immediate memory span or where retention for subspan information is tested after an interval filled with distracting activity. Interestingly a long-term alcohol abuse, without the occurrence of a Wernicke's encephalopathy, which is characteristic of the initial stages of the Korsakoff's Syndrome, may also lead to some degree of memory impairment. A neither definite cause nor explanation has been provided to account for the occurrence of these deficiencies. Chronic marijuana abuse and toxic encephalopathies related to long-term solvent exposure also tend to lead to a deficiency of memory function.