The American Academy of Neurology (AAN) has published new guidelines on mapping of the brain prior to epilepsy surgery, following a systematic review of available evidence.The guidelines were published in the academy’s journal Neurology and compared results of functional magnetic resonance imaging (fMRI), a type of scan that assesses brain activity by measuring blood flow, with data obtained from the more commonly used intracarotid amobarbital procedure (or Wada test), where a drug called sodium amytal is injected into the main artery in the neck (called the carotid artery) to put one side of the brain to sleep.Both procedures are aimed at locating brain regions involved in language and memory, to ensure that they are not affected by epilepsy surgery. Unlike the Wada test, which is an invasive method causing discomfort and has risks associated with it, fMRI is non-invasive and considered safe.The principal author of the guidelines, Dr Jerzy Szaflarski, a neurologist at the University of Alabama, said in a press release: “Because fMRI is becoming more widely available, we wanted to see how it compares to the Wada test. While the risks associated with the Wada test are rare, they can be serious, including stroke and injury to the carotid artery.”The researchers suggest that fMRI could be used as an alternative to the Wada test. However, it is difficult to generalise the recommendations to the wider population of people with epilepsy because much of the evidence in the review came from studies that recruited small numbers of patients with similar types of epilepsy from a single institution only.According to Dr Szaflarski larger studies are needed to increase the quality of the evidence that is available. “Doctors should carefully advise patients of the risks and benefits of fMRI versus the Wada test,” he added.Epilepsy surgery is an option for some people with epilepsy who do not respond to treatment with antiepileptic drugs. The seizure focus (the area of the brain where seizures are generated) may be removed or the spread of seizure activity may be reduced using different surgical techniques.Author: Dr Özge ÖzkayaClick here for more articles about other treatments for epilepsy.