Delirium tremens and related clinical states: psychopathology, cerebral pathophysiology and psychochemistry: a two-component hypothesis concerning etiology and pathogenesis

Abstract

Clinically, patients with Delirium Tremens (DT) and acute alcohol hallucinosis (impending DT) appear excited with vivid false perception. Cerebral blood flow and eeg correspondingly point to hyperexcitability in the CNS during these conditions. Clinical trials with barbital treatment in alcohol withdrawal shows that the amount of drug and the drug plasma concentration is the same no matter whether the physical signs of withdrawal are accompanied by hallucinations and clouding of consciousness. The psychotic signs in DT and acute alcoholic hallucinosis develops after many years of alcoholism as does seizures. We hypothesize that physical withdrawal is determined by the degree of physical dependence developed during the most recent drinking period whereas the psychotic signs and seizures are due to a cumulated CNS hyperactivity developed over many years of repeated alcohol intoxication and withdrawal. Changes of electrolyte concentrations in plasma or CSF do not play an important role in the pathogenesis of DT and related clinical states except that changes in calcium and inorganic phosphate metabolism indirectly point to changes in membrane excitability. A new model for a study of rapidly repeated intoxication and withdrawal episodes in rats has shown that repetition of episodes augments the convulsive component of withdrawal whereas the non-convulsive signs are dependent on the most recent episode only. The augmentation of the convulsive component correlates with regional differences in brain glucose consumption. Furthermore, synaptic proteins and acidic phospholipids may be involved in the development of CNS hyperexcitability during alcohol withdrawal. In conclusion both clinical and experimental studies indicate that severe alcohol withdrawal reactions may consist of two components: 1) Physical withdrawal signs determined by recent physical dependence. 2) A long term cumulated CNS hyperexcitability relating to seizures and psychotic signs during withdrawal. This state is elicited by alcohol withdrawal but it represents a cumulated and permanent or long lasting CNS dysfunction in alcoholics. The precise biochemical/pathophysiological mechanisms for the development of the two-component dysfunction still remain to be clarified in detail.