Alcohol-dependent individuals have a five to 10 percent lifetime risk of developing delirium tremens (DT) following alcohol withdrawal. DT is characterized by a clouding of consciousness, mental confusion or disorientation, and is often accompanied by hallucinations and agitation.
Although the symptoms of DT are relatively well known, the pathophysiology of DT is less clear. A review of formerly published research has found that both genetics and the regulation of dopaminergic neurotransmission appear to play a role in the pathophysiological process of the development of DT.
Results are published in the February issue of Alcoholism: Clinical & Experimental Research.
“DT can develop one to four days after the onset of acute alcohol withdrawal in persons who have been drinking excessively for years,” said Barbara C. van Munster, a researcher at the University of Amsterdam and corresponding author for the study. DT is at the extreme end of the alcohol withdrawal spectrum; most people experience minor symptoms such as insomnia and tremulousness, or possibly more severe complications such as seizures.
“The symptoms of alcohol withdrawal relate proportionally to the amount of alcohol intake and the duration of a patient’s recent drinking habit,” van Munster added. “However, other risk factors for developing DT include concurrent acute medical illness, older age and abnormal liver function.” Although death may occur in up to five percent of patients with DT, risk of death can be reduced in patients who receive adequate medication and medical support.
As noted previously, the exact pathophysiologic mechanism for developing DT is unclear, however, the gamma-aminobutyric acid and glutamate neurosystems are believed to be involved. “My review was designed to augment knowledge about the pathophysiology of DT from genetic research and to establish commonality,” said van Munster. “Finding one association between a genetic polymorphism and DT could happen easily on coincidence. Finding it twice could really mean something”
Van Munster and her colleagues collected all studies listed on the MEDLINE and EMBASE databases until February 2006 that met the following criteria: written in English; entailed an analysis of any association between a genetic polymorphism and DT; and excluded all other alcohol-withdrawal syndromes.
“We found that of the 25 studies reviewed that dealt with 30 polymorphisms, located in 19 different genes, eight positive associations seemed to support a genetic basis for DT,” said van Munster.