Hyperbaric Oxygen Therapy

Can Help Patients Recover From Stroke

New scientific research has changed the way we treat and think about a stroke. The old theory of all the disabled cells being dead is no longer valid in the light of new discoveries made possible by newly developed tools for diagnosis. In the past, whatever return to normal function a stroke patient got in the first 6-12 months as all that they could expect, but now a new use of an old therapy is giving return of function to patients whose strokes have occurred as long as 14 years in the past.

What happens when someone has a stroke?

Let's look at what happens in the brain when someone has a stroke, in the light of current understanding of brain physiology. When a stroke occurs, an area of brain cells dies because of an interruption of blood flow. Optimal blood flow is vital because the blood brings oxygen, nutrients, and blood sugar to the cells. The brain needs a constant supply of blood as it cannot store either oxygen or blood sugar.

When the stroke occurs, the brain cells with extremely low blood flow, less than 15% of normal, die within a few minutes. Their cell walls begin to break down and more fluids move into these cells causing swelling in the area. This swelling presses on other cells and blood vessels in the surrounding area, damaging more cells and causing further constriction of blood vessels. This spreads the damage further out from the initial injury. Both the dead and damaged cells in the brain cause loss of functions such as inability to move, think, speak, and other physical symptoms, as well as emotional problems including depression.

The stroke and subsequent swelling create a damaged, swollen area around the area of dead cells. In this outer area the cells get some blood flow, but not enough to be able to carry on full function. With less than 50% of normal blood flow these cells cannot carry signals to help you speak, move, or think, but do not die. This is the area that can be helped with hyperbaric treatment. This type of brain pathology is similar to that of patients with traumatic head injuries and other injuries that cause lack of oxygen to the brain such as near drowning, asphyxiation, and heart attack.

During the first 6-12 months, some of the swelling in the brain will go down and some of the blood vessels can open up to a normal extent and carry a full blood supply to the cells around the stroke area. Thus, the patient may gradually regain the function of some of the cells in the surrounding area and may have improved speech, thinking, mobility, ect. Therefore, during the first year after the stroke is when the patient will notice the most improvement.

Some of the cells around the perimeter of the injury receive enough blood supply to trigger them to release chemicals that stimulate new capillary growth. The new capillaries can then bring in new blood supply to let these cells regain normal function. However, cells closer to the injury are not getting even enough blood flow to allow them to send out these "distress chemicals" to stimulate growth of a new blood supply. These cells are still alive, but cannot perform their functions in the brain. Cells such as these have been found in the brain as much as 14 years after a stroke has occurred. This area stays so constricted that the red blood cells, which carry the oxygen cannot fit through, and so the cells get only minimal nutrients from plasma trickling into the area. (Your blood has two main components: the liquid portion, or plasma and the larger cells which float in the plasma, such as the red blood cells and the white bloods cells.)

The outcome for stroke victims with the usual treatments is not very encouraging. Medications, and various therapies help to regain some function, but after the 6-12 months healing period, these therapies usually cease to give improvement. Only 10% of stroke victims recover to the point of having no disability, 40% are left with mild disability, 40% with severe disability, and 10% need continuing institutional care. With the old thinking that only dead brain cells are causing loss of function, this has been the end of the line for stroke victims. However, hyperbaric oxygen therapy can revive the areas of cells with poor blood flow and the stroke patient can recover some, if not all, of the functions they had lost.

How do hyperbaric treatments help patients recover?

Your brain is the hungriest organ in your body - consider these figures: your brain is only about 2% of your body weight, but uses about 20% of your body's total oxygen needs. When brain cells die, the messages carried by the damaged cells don't work right. Then we see the result as poor movement, ect. What we see tends to fool us - we see a patient with problems throughout their body - poor speech, poor or difficulty writing, difficulty walking, and muscle coordination control problems - all of these problems LOOK like they are in the body BUT the cause of the problem is in the brain. What needs to happen is to restore normal function of those brain cells that control the functions of movement, thinking, speech, emotions, ect.

A new use for an old therapy has emerged from better understanding of brain pathology. Hyperbaric therapy for acute and chronic strokes is based on Henry's Gas Law which states that the amount of gas (for example, oxygen) that is dissolved in a liquid is proportional to the pressure on the solution. This means that the more pressure that is put on the air we breathe, the more oxygen the body fluids, including the blood plasma, will carry.

Hyperbaric therapy is breathing oxygen in a pressurized chamber. Oxygen is essential for healing and under pressure it is able to penetrate into parts of the body where blood flow is limited. Under increased pressure additional oxygen enters the body. The red blood cells already carry 98% of their capacity of oxygen so the additional oxygen dissolves in the body fluids. This includes the blood plasma, which is half the volume of the blood and can now carry oxygen to the cells. Where blood vessels are constricted so that red blood cells cannot get through, the plasma can bring in sufficient oxygen so that the cells can produce a burst of ATP and begin a normal metabolism with oxygen. Then as the oxygen falls within four hours after treatment, the stressed cells release the adenosine which stimulates new blood vessel growth. Repeated treatments cause a permanent new blood supply for an area to form so that the cells can get back normal blood supply and permanently regain normal function. This process takes time, as once the blood supply is established, there must be repair of cell bodies and regrowth of nerve cells to reconnect the area to the rest of the brain. Improvements continue to occur after treatment as these repairs take place.

In acute stroke patients, hyperbaric therapy can reduce the damage caused by swelling and supply the oxygen to keep more cells alive while the healing process is going on, thus salvaging more brain cells and minimizing the initial loss of function. In chronic stroke patients, hyperbaric treatment can allow them to begin to make progress again in regaining lost functions as this new blood supply and new nerve connections grow in the brain.

Patient results vary according to the extent and severity of the stroke and the time that lapse between the stroke and when hyperbaric treatment is started. The sooner that hyperbaric treatment is started the better the results. Clinically we see that patients have better use of their arms and legs, and spasticity is reduced. Swallowing, speech, thinking, memory, and emotions are other areas that also improve.

Studies show improvement with hyperbaric oxygen therapy

Since the early 1970's, scientific journalists have reported more than 1,000 cases demonstrating a 40%-100% rate of improvement for stroke patients treated with hyperbaric oxygen therapy.

Dr. Neubauer is the leading authority in the United States using hyperbaric oxygen therapy to treat stroke patients. In a 1980 report, he wrote about 79 patients to whom he gave treatment. These patients received treatment anywhere from 5 months to 9 years after their stroke. Sixty-five percent reported improvement in their quality of life.

In another study, in 1987, Dr. Jain documented the response of 50 patients receiving hyperbaric oxygen therapy at a clinic in Germany. The shortest period of time from the stroke episode to receiving treatment was 3 weeks and the longest was 5 years. All of these patients showed some response to hyperbaric oxygen therapy. The degree of improvement varied according to the severity of the stroke and how long it had been between the onset of the stroke and the start of treatment. The most marked improvement occurred when the treatment started earlier.

Looking into your brain with SPECT scans shows that hyperbaric oxygen therapy improves areas of poor blood flow....

There are several ways to look into your brain. The different imaging techniques have long names that have been abbreviated. Some of these abbreviations have become everyday language as more and more people have them performed. You're probably familiar with their names - MRI and CAT scans. These technologies are excellent for detecting problems with brain anatomy such as tumors or accumulations of fluid like that found in hydrocephalus. However, MRI's and CAT scans give little or no information about the activity in your brain. Using these techniques is like looking at the parts of a car's engine without being able to run in on.

As our understanding of the brain has improved we now know that many neurological problems are not disorders of the brain's anatomy but problems in how it functions. For example, patients with Parkinson's or Alzheimer's disease do not show any problems on MRI or CAT scans. SPECT technology is a technology that allows scientists to look directly at blood flow in your brain. SPECT scans are a special type of picture that can be taken of your brain that indeed has allowed us to see areas of poor blood flow and also have documented improvement in blood flow after hyperbaric oxygen therapy. This scan measures the amount of blood flow in the brain, both normal and abnormal and becomes an indirect measure of brain function that can be used to study any brain disease.

MRI and CAT scan technology nearly eliminated the use of SPECT studies because the early SPECT cameras took a long time to scan a person's brain - up to an hour. People had trouble holding still that long and the images were fuzzy and hard to read and they did not give much information about the functioning deep within the brain. Then, two technological advancements encouraged the use of SPECT scans again- 1) higher resolution cameras that scans the brain in approximately 15 minutes with better clarity and an ability to look into the deeper areas of the brain and 2) the advancement of computer technology that can construct elegant three-dimensional snapshots giving us a sophisticated blood brain map. Thus, SPECT images show what CAT scans and MRI's cannot- how your brain actually functions.

After hyperbaric treatment, SPECT scans have shown which areas have better blood flow, giving an idea of how much recoverable tissue exists in the brains of various stroke victims studied. SPECT scans have been very useful in research and have shown that a stroke indeed causes areas of poor blood flow surrounding the dead tissue. The SPECT scans have also demonstrated improvement of blood flow to these areas after hyperbaric treatment, which correlates with the gains in function that patients experience.

What is hyperbaric treatment like?

The patient lies comfortable in a pressurized chamber and breathes oxygen. Treatments last about one hour and the patient can read, listen to music, or nap. There is communication through an intercom and the patient can see the surrounding area. There may be a feeling of pressure in the ears as would be felt in an airplane at takeoff or landing, but special earplugs and raising and lowering the pressure gradually assure the comfort of the patient.

Get your questions answered

Call Dr. Grams at (215) 679-5915 and get your questions answered regarding hyperbaric oxygen therapy. The best time to call is Monday, Wednesday, or Friday at 11:30 am or 7:30 PM Eastern Standard Time