Brain activity demonstrated using fMRI in stroke and other brain injured patients
Columbia University Medical Center researchers have demonstrated using functional magnetic resonance imaging (fMRI), that brain activity was increased in stroke and traumatic brain injury survivors who underwent Vision Restoration Therapy (VRT), a rehabilitative treatment that helps these patients recover lost vision. The data will be published online in the peer-reviewed journal Neurorehabilitation and Neural Repair on Aug. 14, 2007 at http://nnr.sagepub.com/pap.dtl.
Researchers, led by Randolph S. Marshall, M.D., M.S., associate professor of clinical neurology and acting director, Division of Stroke and Critical Care at Columbia University College of Physicians and Surgeons, examined the fMRIs of six patients aged 35-77 with vision loss on the same side of both eyes (called homonymous hemianopia) caused by stroke or traumatic brain injury. The therapy is based on visual stimulation, which the patient performs daily at home on a dedicated computer device. The fMRI data showed increased activity in visual processing areas of the brain as patients learned to detect stimuli in the borderzone between the seeing and non-seeing fields. This enhanced activity was identified one month after beginning treatment and suggests that the brain is responding accordingly.
"This study is encouraging because the fMRI technique allowed us to see and compare the activity levels in specific regions of the brain before and during Vision Restoration Therapy. After examining the images, the increased activity levels demonstrate progress associated with the treatment," said Dr. Marshall. "Based on these initial results, we will continue to investigate the relationship between the imaging findings and the degree to which vision is recovered."
"The publication of Dr. Marshall’s study in Neurorehabilitation and Neural Repair underscores the growing scientific evidence validating Vision Restoration Therapy. For hundreds of thousands of stroke and brain injury survivors with impaired vision, these data further show that VRT may help them regain lost sight – and ultimately help them reclaim their independence," said Navroze Mehta, president and chief executive officer of NovaVision, Inc., the maker of the device used in this study.
NovaVision VRT is approved by the U. S. Food and Drug Administration to treat vision problems in people who have been left partially blind due to stroke or brain trauma. Customized treatment is created from a comprehensive diagnostics that map the seeing and non-seeing areas of vision. Patients perform the therapy daily at home for six to seven months, gradually improving their vision through the repeated detection of light stimuli directed at the border between the seeing and blind areas of the visual field.
Through further enhancements of this therapy, the hope is to help the approximately 1 to 2 million stroke and brain injury survivors in the United States who suffer from major visual field deficits, a number that increases by more than 90,000 each year.
Columbia University Medical Center. August 2007.