Hyperbaric oxygen therapy after stroke

You sit or lie in a specially built chamber while the pressure is raised above normal atmospheric pressure, and you breathe pure oxygen, usually through a mask or hood. At higher pressure more oxygen dissolves in the blood plasma, so more can reach the tissues.

Oxygen is essential for the energy production and normal function of cells. The thinking is that a higher oxygen level may support biological processes in tissue whose oxygen supply and metabolism have been affected.

A stroke damages some areas of the brain, but the brain can relearn some lost skills by forming new connections between surviving nerve cells — a property called neuroplasticity. The proposed effects of hyperbaric oxygen after stroke are to raise oxygen delivery to brain tissue, support the energy production of brain cells, contribute to forming and reorganising nerve connections, and help regulate some of the inflammatory and cellular responses that follow a stroke.

These effects are the scientific rationale for studying it in neurological rehabilitation. It is not certain that they turn into functional improvement in every patient.

In acute ischaemic stroke, a 2014 Cochrane review of 11 randomised trials with 705 participants found no good evidence that hyperbaric oxygen improves clinical outcomes, though it noted that a benefit has not been ruled out 1.

For the later, chronic stage, a 2013 trial enrolled 74 people who had had a stroke 6 to 36 months earlier. Neurological function and quality of life improved after 40 sessions, while no change was seen during a two-month period without treatment 2. The comparison was with no treatment rather than a sham session, so participants knew when they were being treated, and studies in this field differ considerably from one another.

This is why hyperbaric oxygen is not a standard stroke treatment, and its added benefit to rehabilitation has not been established.

Yes. Recovery is often thought to be limited to the first few months, but the brain's capacity to relearn can continue for much longer. In an intensive arm and hand rehabilitation programme, 224 people treated a median of 18 months after their stroke made clinically important gains, and those gains continued over the following six months 3.

Interest in hyperbaric oxygen at the chronic stage comes from its possible effects on brain metabolism and neuroplasticity. Positive changes in neurological function and daily activities have been reported in some patients 2, but that does not mean every patient will improve to the same degree.

Rehabilitation after stroke aims to improve movement, increase independence in daily activities and support quality of life. Physiotherapy, robotic rehabilitation, balance and gait training, occupational therapy and speech and language therapy carry this work, and recovery depends on a sustained programme delivered by a coordinated team 4.

Hyperbaric oxygen is considered for what it may add alongside these approaches. It does not replace evidence-based rehabilitation.

It is not suitable for everyone. A physician assesses your general health, other conditions and the risks before recommending it. Some lung and ear problems need extra precautions, and an untreated collapsed lung (pneumothorax) rules it out 5. There is no standard protocol for hyperbaric oxygen after stroke, so its use is decided case by case, with safety first.

The most common side effect is pressure injury to the middle ear. Short-sightedness can develop over a course of sessions and usually returns to normal within three to six weeks of finishing. Seizures caused by oxygen toxicity are rare — about 1 in 2,000 to 3,000 treatments in recent reports — and stop when the oxygen is withdrawn 5. If you are anxious in enclosed spaces, tell us beforehand.

Stroke rehabilitation is planned around each patient's needs and current function. Programmes are coordinated by physical medicine and rehabilitation specialists and draw on robotic gait rehabilitation, arm and hand rehabilitation, balance and coordination work, occupational therapy, speech and language therapy and other neurorehabilitation methods.

The goal is to help each patient make full use of their remaining potential, move better and reach the greatest possible independence in daily life.