A new app can tell if tremors are real or are related to substance abuse.

Many patients quit drinking alcohol and experience symptoms of withdrawal, which is potentially fatal and can be treated with benzodiazepine drugs, the University of Toronto reported. These drugs are also easily abused, so healthcare providers are often reluctant to write prescriptions.

"There's so much work to do in this field," researcher Narges Norouzi said. "There is other work out there on Parkinson's tremors, but much less on tremors from alcohol withdrawal."

Tremors in the hands and arms are one of the most commonly used clinical symptoms of withdrawal. Determining tremor severity requires medical expertise and even seasoned doctors have been known to make mistakes. Chronic alcohol abusers often visit the Emergency room claiming to be in withdrawal, but are just faking to get the drugs; this new app could help single out which patients are faking it.

The research team tested their app on 49 patients going through withdrawal in the emergency room and 12 nurses mimicking the symptoms. They found three-quarters of the patients had tremors with an average cycle of seven per second and only 17 percent of the nurses were able to fake it. The app uses data from the iPod's built in accelerometer to measure the frequency of hand tremors of a 20 second period.

The team filmed the participants'' hand tremors while using the app and showed it to doctors afterward. They found the app was just as effective as the junior doctors' ability to distinguish between real and fake tremors, although senior doctors determined it with slightly more accuracy. The team hopes to tighten up the app in the future and improve its effectiveness.

The exciting thing about our app is that the implications are global," said Professors Bjug Borgundvaag of the Faculty of Medicine and Parham Aarabi of The Edward S. Rogers Sr. Department of Electrical & Computer Engineering at the University of Toronto. "Alcohol-related illness is commonly encountered not only in the emergency room, but also elsewhere in the hospital, and this gives clinicians a much easier way to assess patients using real data."