Chronic Post-Stroke Recovery

Many stroke survivors retain motor, sensory and cognitive deficits long after the acute event, and gains from conventional rehabilitation typically plateau in the months that follow. HBOT has been studied in this chronic phase as a way to reactivate neuroplasticity in brain regions that remain alive but under-functioning.

A prospective randomised trial enrolled 74 patients 6–36 months after stroke, of whom 59 were analysed (Efrati 2013): one group received 40 HBOT sessions (90 minutes, 100% oxygen at 2 ATA, five days a week), while the other served as a two-month no-treatment control before crossing over to the same HBOT course. Neurological function (NIHSS), activities of daily living and quality of life improved significantly after HBOT but not during the control period, and SPECT showed increased activity mainly in regions that appeared viable on CT yet had low metabolic activity.

An independent randomised feasibility trial in Toronto, in 27 patients 3–48 months after stroke (Schiavo 2020), found HBOT combined with an upper-limb exercise and mental-imagery programme safe and feasible, with trends toward improved upper-limb motor function; differences between the groups were not statistically significant.

This chronic-phase evidence should be distinguished from acute stroke: a Cochrane systematic review of 11 randomised trials involving 705 participants found no good evidence that HBOT improves clinical outcomes when applied during the acute presentation of ischaemic stroke, while noting that the possibility of benefit has not been excluded (Bennett 2014).

The principal chronic-phase trial had no sham control, so participants knew their allocation, and it comes from the same Israeli research group (Assaf Harofeh, now Shamir Medical Center) as the Long COVID, Fibromyalgia and PTSD entries. The protocol as studied — not a clinical recommendation — comprised 40 daily sessions of 90 minutes, 100% oxygen at 2 ATA, five days a week. HBOT for stroke recovery remains investigational and is not FDA-approved.