A stroke is a type of acquired brain injury. It occurs when an area of the brain is deprived of oxygenated blood, causing the affected brain cells to die. The condition can be caused by a blockage in a blood vessel feeding the brain (an ischemic stroke) or when a blood vessel in the brain bursts (a hemorrhagic stroke).

The American Heart Association estimates 700,000 Americans suffer a stroke each year. It's the third leading cause of death in the U.S. and the leading cause of serious long-term disability. Most strokes (88 percent) are caused by a blockage. Strokes caused by bleeding are much rarer but are more likely to cause death.

Traumatic Brain Injury

Traumatic brain injury (TBI) is an injury to the brain caused by an external force (like a blow or jolt to the head). According to the Centers for Disease Control and Prevention, 1.4 million Americans experience a TBI annually. About 235 of the victims require hospitalization and 50,000 die.

The leading causes of TBI are falls (28 percent of cases), car accidents (20 percent) and assaults

(11 percent). Rates of injury are highest among those four and under and teens 15-19. Males are 1.5 times more likely to experience a TBI than females.

Vision Problems After a Brain Injury

When brain cells die, they don't regenerate. Depending upon the area of the brain affected, patients may experience balance problems, muscle weakness, speech and language difficulties or cognitive/mental problems.

Another complication associated with some cases of brain injury is vision loss. They eyes may work well (are capable of "seeing"), but the brain cells or muscles used to process the visual information are damaged. Researchers estimate at least 40 percent of patients with an acquired brain injury (like stroke or head trauma) experience some type of vision disturbance.

One common problem is the loss of half the visual field in each eye (hemianopsia). Other conditions that may occur include: double vision, problems with eye tracking, focusing difficulties, sensitivity to light or glare, difficulty maintaining focus or tracking objects, or problems using both eyes together.

Home Vision Therapy for Brain Injuries

Patients with an acquired brain injury may have intense physical and occupational therapy to regain lost function. For those with vision problems, special glasses with prisms may be used to shift images into areas of the visual field that are still working. But many patients find the glasses cumbersome or difficult to use.

Now some brain injury patients are getting help with a system called NovaVision VRT(tm) Vision Restoration Therapy(tm). Experts say the vision therapy program is like having physical therapy for the eyes and brain.

Neuro-ophthalmologist, Mark Moster, M.D., of Albert Einstein Medical Center, says a patient must first receive a thorough assessment of his/her visual problems. Using data from the testing, NovaVision creates a software program designed to specifically address the patient's rehabilitation needs. The software is loaded into a laptop computer.

To use the program, the patient puts his/her head into a chin rest in front of the computer screen. While maintaining focus on the center of the screen, visual stimuli (dots) appear elsewhere on the screen. The patient clicks a button on the computer each time the stimuli appear on the screen. The key is to maintain focus on the center of the screen and not look directly at the other dots. Researchers say the process stimulates visual areas of the brain that aren't working right. Patients undergo the program for an hour a day (two half-hour segments) six days a week. As the therapy progresses, the computer gradually moves those stimulating images a little further out - into the fringes of the visual field. The goal is to eventually expand the useful field of vision.

Researchers estimate about two-thirds of patients receive some benefit from the NovaVision program. However, the degree of improvement is variable. Most patients still won't gain enough vision back to drive a car. But they may regain enough vision to read, watch television or walk with more confidence (with less fear of falling or bumping into objects).

The NovaVision system was approved by the FDA in 2003. It costs around $6000 for six months of therapy and isn't usually covered by insurance. For more information, visit the company's website at http://www.novavisiontherapy.com. The home vision therapy program is currently available at the following locations:

Sharp Chula Vista Medical Center, Chula Vista, California

Sharp Memorial Hospital, San Diego, California

Morton Plant Hospital, Clearwater, Florida

Bascom Palmer Eye Institute, Miami, Florida

University of Miami, Department of Neurology, Miami, Florida

Emory Eye Clinic, Atlanta, Georgia

Wilmer Eye Institute at Johns Hopkins, Baltimore, Maryland

Kresge Eye Institute at Wayne State University School of Medicine, Detroit, Michigan

Richard H. Legge, M.D., P.C., Omaha, Nebraska

Neurological Institute of New York at Columbia University Medical Center, New York, NY

Rusk Institute of Rehabilitation Medicine at NYU Medical Center, New York, New York

Albert Einstein Medical Center, Philadelphia, Pennsylvania

SOURCES

National Institute of Neurological Disorders and Stroke, http://www.ninds.nih.gov