By: PATRICE WENDLING
What if you could scan your patients for stroke-susceptibility loci or implant a device in their brains to repair stroke-damaged pathways?
Those novel approaches may sound far-fetched, but such forward-thinking concepts are achievable, according to some of the best minds in the field of stroke medicine, who put forth these and other proposals at a special session at the International Stroke Conference.
It sounds like something out of a science-fiction fantasy, but U.S. neuroscientists say the day they can implant a microchip in the brain to restore people’s memories is almost here. The team’s methods, which focus on the hippocampus (where short-term memories become long-term ones), are already being tested on rats and monkeys. Researchers project the first implants in humans who’ve had strokes or local brain injuries could happen in the next two years, with broader availability within five to 10 years. “I might not benefit from it myself,” said University of Southern California professor Ted Berger, part of the breakthrough team. “But my kids will.” Somewhere, in some remote hotel room, Leonard from “Memento” is putting down his tattoo needle and rejoicing
To spice things up even more, session organizers limited presentations to just 5 minutes and relied on the audience in some cases to keep on schedule and enthusiastically applaud the speakers off the stage. Here are just a few of the fascinating insights offered during the session, entitled “The Next Big Thing in Stroke.”
Just 2 decades after scientists demonstrated the plasticity of the brain after stroke, the restorative processes that occur after the acute phase of stroke continue to be teased out, opening up potential targets for new drugs. At the same time, neurotechnology is maturing.
“We’re very quickly entering a brave new world of neuroengineering in the brain after stroke,” said Randolph J. Nudo, Ph.D., director of the Landon Center on Aging at the University of Kansas Medical Center, Kansas City.
In the emerging field of robotics, a neural interface system implanted in two humans with long-standing tetraplegia recorded neural signals from the brain as input commands to control a robotic arm (Nature 2012;485:372-5).
A miniaturized closed-loop system implanted in the cerebral cortex of brain-injured rats has been shown to improve recovery. Dr. Nudo sees the potential of these advances for neurotransmitter sensing, open-and closed-loop drug delivery, and control of stem cell integration.
Dr. Joel Stein, chair of rehabilitative and regeneration medicine at Columbia University, New York, said robotics are being used to deliver rehabilitation therapy. Exoskeletal work stations (Hocoma) incorporate engaging games or virtual reality experiences to provide a large number of repetitions for the patient without therapist fatigue. Wearable “bionic legs” (Tibion) provide external force to supplement muscle strength and improve motor skills through practice.
Not all robotics have panned out, however. In a study of veterans, robot-assisted therapy provided only modest effects on poststroke upper-limb impairment (N. Engl. J. Med. 2010;362:1772-83). The robotic therapy also was somewhat more expensive than intensive human therapy ($9,977 vs. $8,269).
Robotics are not necessarily always going to be better; but when they are equally as good as traditional approaches, they provide us with new efficiencies in terms of delivery, said Dr. Stein. “The bottom line is that robots are coming, we should prepare for them and expect them to become a key piece of clinical practice in this field in the future.”
It’s still the early days in the search for genetic susceptibility loci for stroke, but we’re getting closer, said Dr. Ralph Sacco, professor and chair of neurology at Miller School of Medicine at the University of Miami.
The collaborative METASTROKE study offered some findings. The big push now, as the cost of these studies comes down, is moving from common variants to rare variants using next-generation sequencing and even whole-genome studies.