Increased Cortical Excitability: A Mechanism for Alcohol Withdrawal Symptoms? (P07.145)

Abstract

Objective: We used transcranial magnetic stimulation (TMS) to investigate whether motor cortical excitability changes in relation to the amount of chronic alcohol ingestion. Background Experimental data suggesting that chronic alcohol exposure induces brain neuroadaptative changes within the excitatory and inhibitory neuronal circuits but this has never been proven. This because of the lack until recently of measuring the excitatory/inhibitory balance non-invasively in humans. Design/Methods: 43 participants divided according to the amount of alcohol they regularly consumed within the preceding 12 months into high, moderate and low risk groups were studied twice, (i) during regular pattern of alcohol consumption and (ii) after abstaining from alcohol for at least 24 hours. Motor threshold, short intracortical inhibition ([SICI] paired pulse TMS at 2, 5 ms interstimulus intervals [ISIs]), intracortical facilitation ([ICF] 10, 15 ms ISIs) and long intracortical inhibition ([LICI] 100- 300 ms ISIs) were measured on both occasions. The results were compared to those of 20 controls with no history of exposure to alcohol. Results: During regular alcohol consumption, there was reduced ICF (p Conclusions: Chronic alcohol consumption is associated with alterations within the intracortical excitatory and inhibitory systems. These changes may be a mechanism underlying alcohol withdrawal symptoms. Disclosure: Dr. Badawy has nothing to disclose. Dr. Cook has received research support from UCB Pharma. Dr. Vogrin has nothing to disclose. Dr. Norman has nothing to disclose. Dr. Currie has nothing to disclose.