Globally one in four adults over the age of 25 will have a stroke in their lifetime. There are many types of stroke and an even greater number of causes. All strokes happen due to arterial clots in the brain resulting in the tissue downstream from that blockage to be deprived of oxygen and blood flow.
The common belief is that a stroke is only treatable if therapy can be delivered within four to five hours. This is simply not true. Stroke patients can respond to hyperbaric oxygen therapy (HBOT) at all phases of the injury: acute, subacute (weeks to months), and chronic (greater than 6 months). The key is resupplying oxygen to the damaged tissue and HBOT does this like no other therapy.
The immediate area surrounding the clot which is deprived of blood flow dies, however the closest surrounding area and damaged tissue will receive partial oxygen and blood so cells can live but not function as normal by sending out electrical messages. This area is called the ‘ischemic penumbral’ area. The further away from the clot, the more blood supply and oxygen levels become normalised.
The ‘ischemic penumbral’ area is where the rapid application of HBOT may have the most positive benefits and, if applied quickly enough, even the central dying area may be partially salvageable in an acute stroke with increased available oxygen to the tissue preventing or even reversing non-lethal damage. Once the brain has begun to heal the patient can be more responsive to physical, occupational and speech therapy.
Dr Edward Teller (a renowned scientist known for being the creator of the hydrogen bomb) suffered a stroke in 1995 that devastated his short-term memory. Six weeks later he gained access to a hyperbaric chamber which he continued to use on a daily basis for the rest of his life. He regained full cognitive function and worked at the highest level of physics in the Lawrence Livermore Laboratories until his death at 95 years old.
Source: “ The Oxygen Revolution” by Paul. G Harch M.D and Virginia McCulough
Further reading: https://hbot.com/conditions/stroke/