Your brain on drugs: imaging of drug-related changes in the central nervous system

Drug abuse is a substantial problem in society today and is associated with significant morbidity and mortality. Various drugs are associated with serious complications affecting the brain, and it is critical to recognize the imaging findings of these complications to provide prompt medical management. The central nervous system (CNS) is a target organ for drugs of abuse as well as specific prescribed medications. Drugs of abuse affecting the CNS include cocaine, heroin, alcohol, amphetamines, toluene, and cannabis. Prescribed medications or medical therapies that can affect the CNS include immunosuppressants, antiepileptics, nitrous oxide, and total parenteral nutrition. The CNS complications of these drugs include neurovascular complications, encephalopathy, atrophy, infection, changes in the corpus callosum, and other miscellaneous changes. Imaging abnormalities indicative of these complications can be appreciated at both magnetic resonance (MR) imaging and computed tomography (CT). It is critical for radiologists to recognize complications related to drugs of abuse as well as iatrogenic effects of various medications. Therefore, diagnostic imaging modalities such as MR imaging and CT can play a pivotal role in the recognition and timely management of drug-related complications in the CNS.