Hands can probably tell the health of an individual, hence sometimes doctors try to shake hands with a patient. Well, hands also seem to be capable of predicting attention deficit hyperactivity disorder (ADHD) severity in children. In a major breakthrough, investigators found that measurements of hand movement control can determine the severity of ADHD among kids.

In the first study, authors assessed mirror overflow movements among 25 boys and girls suffering from ADHD between the age group of 8 to 13 years. The results were then compared with 25 boys and girls without the condition. Generally mirror movements may be described as the inability to move one side of the body without moving the other. None of the subjects were left-handed. During the study, a video was used along with a device for recording finger position and measuring the differences in how the children tapped their fingers.

It was observed that kids diagnosed with ADHD experienced more mirror movements than those without the disorder. In the left-handed finger tapping, those with ADHD reported more than twice as much mirror overflows than children without ADHD. The differences appeared significantly strong among boys with ADHD, who revealed almost four times as much mirror overflow than boys without ADHD on one of the two measures put to use during the investigation.

“These studies are an important step toward understanding how ADHD affects communication between the brain and other parts of the body,” remarked Jonathan W. Mink, MD, PhD, with the University of Rochester Medical Center in New York in an accompanying editorial. Mink is also an associate editor of Neurology. “These findings show that mirror movements are likely a marker of abnormal development of motor control that improves with age and is more prominent in boys. They also provide a more specific way to measure ADHD. The hope is that, ultimately, these studies and others will guide us toward development and testing of new therapies.”

In the course of the second study, experts applied transcranial magnetic stimulation (TMS) to the motor control area of the brain in 49 children with ADHD and 49 without the condition. All the participants belonged to the age group of 8 to 12 years. Having employed the TMS technology, scientists were supposedly able to activate brain cells with magnetic pulses to calculate brain activity. The brain’s short-interval cortical inhibition (SICI) was allegedly decreased by 40 percent in kids with ADHD than those without the condition.

Scientists also conducted motor development tests during which those with ADHD seemingly scored nearly 60 percent worse as compared with kids without the condition. The amount of reduced inhibition in the motor area of the brain was supposedly linked with the severity of ADHD symptoms. It was concluded that keeping a track on the hand control movement of children with ADHD may help understand the severity of the disease.

The study is published in the February 15, 2011, print issue of Neurology, the medical journal of the American Academy of Neurology.