Stroke & Hyperbaric Oxygen


Definition of Stroke

A stroke is a non-convulsive episode of neurologic dysfunction that last longer than 24 hours.  The symptoms of a stroke can be a sudden weakness or paralysis due to disturbance of the blood flow to the brain. 


Average outcomes of Strokes:

  • 10% of the stroke survivors return to work without disability

  • 40% have mild disability

  • 40% are severely disabled

  • 10% are institutionalized


Stroke May Include:

A - An ischemic event (low oxygen) due to a blockage or reduction of blood flow occurring at the brain inflow or outflow of blood supply.


B - An ischemic event due to an arterial spasm resulting from hypertension or a migraine. 

C - A hemorrhagic episode (leaky or ruptured vessels) due to a rupture of an aneurysm (ballooning vessel) at an inflow or outflow of blood supply to the brain.


Oxygen Requirements of Brain

One liter of blood circulates to the brain each minute, representing 25% of the body’s total oxygen consumption.  With complete blood flow loss to the brain:

  • Neural function is affected within 6 seconds

  • Brain activity ceases after 2 minutes

  • Brain damage begins after 5 minutes


The Recoverable Brain

A portion of stroke-associated function loss is due to cellular death referred to as the ‘Umbra’.  A portion of function loss also relates to a living but non-functional zone around the Umbra, referred to as the ‘Penumbra’. The ‘Penumbra’, to varying degrees, is recoverable.

Affected Site of Stroke



















Umbra (dark gray core)

  • Receiving less than 20% of normal blood flow.

  • Results in primarily dead, non-salvageable brain tissue.

Marginal Function Area (grey area surrounding dark core)

  • Receiving only 50% of normal blood flow.

  • Marginal oxygen levels of living, marginally active cells.


Penumbra (red outer area)

  • Receiving only 30% of normal blood flow.

  • Results in some dead, but mostly living brain cells in a ‘stunned’ or nonfunctional state.

  • Much of the ‘penumbra’ is salvageable through the oxygenation process of hyperbaric oxygen.

  • Has potential to become functional and retrained to take over a portion of function lost in the Umbra.

  • This area may remain alive in a stunned condition for many years.

What is a Hyperbaric Oxygen Chamber?

The Hyperbaric Oxygen Chamber provides a pressurized environment in which pure oxygen is breathed. 


Why is Pressure Necessary?

Increased pressure causes oxygen to dissolve into the plasma (body fluid) providing an efficient means of distributing a high saturation of oxygen into areas of poor circulation such as a Stroke.

Mechanisms of Healing with HBO


  • Swelling Reduced

Swelling is associated to injury. The presence of high levels of oxygen has a constricting effect on vessels, giving relief to injury related cranial pressure by temporarily reducing the amount of fluid able to enter the skull area. 


  • Vessel Repair

The oxygen induced vessel constriction gives the torn, leaky vessel walls temporary relief while oxygen rich plasma continues to flow through them, stimulating healing. As the capillaries heal, plasma leakage into the surrounding tissue stops.


  • New Blood Supply

Daily Hyperbaric Oxygen stimulate new blood vessel growth where brain tissue bleeding has occurred, sufficient to maintain brain function and ongoing healing in the injured area. 


  • Revives the Brain

The oxygen-revived brain cells reestablish communication pathways, a form of retraining.  The brain must be challenged to regain lost functions during the course of HBO. This should include appropriate therapies such as physical, speech and occupational. 


Hyperbaric Oxygen Produces:

  • Increased energy production.

  • Improved alertness.

  • Less need for sleep during the day.

  • Higher functioning emotions.

  • Functional progress beginning where there has been little or none.

  • Notable improvements in motor function, clarity of speech and thought process.

  • Notable improvements of independence.Hyperbaric


Oxygen Protocols

Hyperbaric oxygen for neurological injury, is typically required once daily, five days per week for eight weeks.  Eight weeks of Hyperbaric Oxygen provides time for the brain to reestablish sufficient new blood vessels to maintain brain function and ongoing healing processes.


In some cases, subtle improvement in function becomes more noticeable within the first week or two of treatment. For others changes become apparent near the end of the course of forty treatments as well as in the following four weeks after cessation of the treatments.  Depending on the original degree of injury, it may be appropriate to repeat a second course of 40 hyperbaric treatments, four to eight weeks after the first course has been completed.


Brain Injury & Recovery of Function with Reference to Hyperbaric Oxygen, Dr. Philip James MD. Scotland

Qibio W & Hongiun et al.: Treatment of Children's Epilepsy by Hyperbaric Oxygenation: Analysis of 100 cases. Proceedings of the 11th International Congress on Hyperbaric Medicine 1995, p79-81.

Neubauer RA, Gottlieb SF, & Kangan RL: `Enhancing Idling Neurons',The Lancet, 3 March 1990, p542.

Neubauer RA, Gottlieb SF & Miale A: Identification of Hypometabolic Areas in the Brain using Brain Imaging and Hyperbaric Oxygen, Clinical Nuclear Medicine Vol.17, June 1992 p477-481.

Sukoff M & Raguix R: Hyperbaric Oxygenation for the Treatment of Acute Cerebral Edema Neurosurgery, Vol.10 no.1.

Machado JJ: Clinically observed Reduction of Spasticity in Patients with Neurological Diseases and Children with CP from Hyperbaric Oxygen Therapy. "Centro Bradileiro de Medicina Hyperbarica", San Paulo, Brazil, 1984.


Stroke ischemic hemorrhagic.png
Stroke Umbra penumbra.jpg