A pilot study of hyperbaric oxygen in the treatment of human stroke.

Abstract

We administered hyperbaric oxygen or air in a double-blind prospective protocol to 39 patients with ischemic cerebral infarction. We interrupted the study when we noticed what appeared to be a trend favoring the air-treated patients, whose neurological deficits were less severe (mean±SEM score on graded neurological examination: air, 25.6±4.9; oxygen, 34.5±7.5) and whose infarcts were smaller (air, 29.0±12.2 cm 3 ; oxygen, 49.2 ±11.7 cm 3 ) at 4 months. The trend, we decided, was probably an artifact of the randomization process. Nevertheless, we chose not to resume the trial because the treatment was difficult to administer by schedule (for various reasons the treatment protocol was broken in 15 of the 39 patients), was poorly tolerated (eight of the 39 patients refused to continue treatments), and did not produce dramatic improvement (Stroke 1991^2:1137-1142)

Hyperbaric Oxygen Combined With Intravenous Edaravone for Treatment of Acute Embolic Stroke: a Pilot Clinical Trial

“…3,8,10,13,15,20) HBO was reportedly difficult to administer by schedule and to tolerate, but all of our patients except one underwent HBO on schedule, with no patient refusal to continue. 3) As intravenous edaravone administration also had no major adverse reactions, combined treatment could be performed safely in patients with embolic stroke.…”

“…14) However, previous randomized controlled human studies of HBO therapy have demonstrated no benefit, 3,15,20) and the American Stroke Association guidelines for the early management of patients with ischemic stroke suggest that the evidence does not support the general use of HBO therapy in patients with acute ischemic stroke. 2) Precisely why our combined treatment achieved a favorable clinical outcome is unclear.…”

“…In previous studies, patients with various ischemic stroke subtypes were included in the group treated unsuccessfully with HBO, 3,15,20) whereas we studied only patients with embolic stroke. As about 40% of occluded arteries recanalize spontaneously within a few days after the embolic stroke onset, 9) HBO may minimize brain damage adjunctively 8,10) by maintaining the viability of the ischemic penumbra until spontaneous recanalization.…”

“…This delay to HBO was shorter than in some previous studies. 3,15) Twelve of our 19 patients received initial HBO therapy within 6 hours of symptom onset. Treatment of a rat model of 2-hour MCA occlusion with HBO within 6 hours of reperfusion was found to decrease the area of infarction.…”

“…3,8,10,13,15,20) The experimental studies suggested considerable potential, 5,12,18,24) but the clinical effectiveness in patients with acute ischemic stroke has been controversial. With the exception of three studies, 3,15,20) the major criticism of most clinical investigations has been the lack of controlled prospective analysis. 14) Oxygen free radicals, which may be produced by HBO therapy 6) or by breathing 100% oxygen, 11) are likely to be important in the mechanism of damage caused by cerebral ischemia.…”