In the U.S. it is estimated that 6.4 million adults have suffered a stroke and another 13 million may have experienced a “silent stroke,” loss of brain cells without visible symptoms. The financial burdens associated with stroke treatment and recovery (both direct and indirect) is estimated to be $73 billion dollars in 2010. In spite of modest declining rates of strokes for the last 7 years, the prevalence of this disease continues to constitute a major source of long-term disabilities for the American public, as well as an expanding cost in health care and household budgets.
Drug treatments for brain strokes are only available for patients diagnosed 1-3 hours after the onset of a clot (ischemic) induced stroke. With more than 90% of stroke patients falling outside of this treatment time window, new treatments must be developed. Therapies that focus on salvaging and protection of brain tissue in this large group of stroke sufferers is a focus for the Brain Health & Healing Foundation.
What Is A Stroke?
A stroke occurs when the blood supply to part of the brain is suddenly blocked (ischemic) or when a blood vessel in the brain bursts (hemorrhage), producing a loss of blood flow to regions of the brain. In the same way that a person suffering a loss of blood flow to the heart is said to be having a heart attack, a person with a loss of blood flow to the brain or sudden bleeding in the brain is having a "brain attack."
Brain cells die when they no longer receive oxygen and nutrients from the blood or when they are damaged by sudden bleeding into or around the brain. A stroke ultimately leads to infarction, the death of brain cells which are eventually replaced by a fluid-filled cavity (or infarct) in the injured brain. Although a stroke might affect a small area of the brain directly, it is the tissue that surrounds the core of a stroke that is at risk of dying if not treated effectively. Defined as a “penumbra”, this region surrounding the core (a doughnut shaped region) has brain tissue that is compromised, but can still be rescued. Re-establishing blood supply to the deprived brain region(s) is the major priority for doctors when a stroke is diagnosed.
Ischemic strokes are classified into focal ischemia (loss of blood supply to a small region of the brain) and global ischemia (loss of blood supply to the entire brain). Both types of stroke can be transient (loss of blood supply is reversed in a few minutes or hours) or permanent ischemia (the blood vessels are completely blocked and cannot be cleared spontaneously).
The high prevalence of strokes among the U.S population has resulted in ever increasing amounts of research to protect against and to recover from the ravages of stroke. Currently, tissue plasminogen activator (tPA; a clot dissolving protein), is the only approved drug to treat blockage that results in a stroke. Although tPA is effective, it is only recommended for patients that have been diagnosed in the first 3 hours of stroke symptoms, which accounts for ~5% of stroke patients. Patients that have had one stroke are 20-30% more likely to have a second or third stroke, even with drug treatment aimed at preventing another blockage.
The severity of the stroke and the time delay between stroke diagnosis and symptoms, will determine the amount of damage that a person will sustain to their brain, but apart from supporting physical functions and trying to prevent another stroke, little in the way of therapy exists to treat stroke damage directly. Physical and functional therapies are the only approved methods for recovery or salvaging lost motor and cognitive skills. Case studies and clinical trials support the idea that recovery of neurons in the penumbra is possible, helping to reverse and restore function to damaged brain regions.
Patients who survive a stroke have few options for rehabilitation. Eighty percent of stroke survivors are affected by brain function loss. In almost all cases mental and physical rehabilitation, learning how to walk, talk and eat, are the only treatments available. New therapies are being developed that can provide an increased margin of safety, an extension in treatment time for clot-busters and offers a potential to alleviate symptoms and reverse damage with minimal risk. We will help to make it a reality.