Neurologic Complications of Drug and Alcohol Use

OBJECTIVE: This article reviews the neurologic syndromes associated with substance use and suggests an approach for identifying and managing substance use disorders. LATEST DEVELOPMENTS: Substance use and overdose mortality, largely associated with fentanyl, rose sharply during the COVID-19 pandemic. Although recent data indicate modest decreases, current rates of overdose remain higher than before the pandemic. A wide variety of opioid-related toxic encephalopathies have been identified recently. Many novel psychoactive substances are unregulated and easily obtained online or in stores; several have been associated with seizures and other neurologic complications. The use of cannabis and hallucinogens is rising as more states legalize or decriminalize their use, and some studies suggest an independent association between cannabis use and ischemic stroke. ESSENTIAL POINTS: Neurologists often encounter severe complications of substance use and have an opportunity to guide patients with substance use disorders toward treatment.