Functional MRI Evaluation of Hyperbaric Oxygen Therapy Effect on Hand Motor Recovery in a Chronic Poststroke Patient 4356

Abstract

Objectives

To investigate neural mechanisms and reorganization underlying hyperbaric oxygen therapy in a patient with chronic stroke.

Design

Study included a 61-year-old right-handed male who suffered hemiparesis and physical weakness in the right upper limb, 2 years after acute insult treated with 60 daily HBOT sessions. Motor task fMRI activation and resting-state functional connectivity (rsFC), Fugl–Meyer assessment (FMA) and handgrip maximum voluntary contraction (MVC) were assessed at baseline and the end. Results were compared with a matched healthy control subject.

Setting

Study was conducted within a hospital-based research facility using a multiplace Starmed-2700 chamber to administer HBOT protocol.

Participants

One 61-year-old right-handed man with right hemiparesis, speech, and cognitive impairments due to left frontal chronic ischemic stroke. One 64-year-old, right-handed man without history of neurologic impairments or upper-limb movement limitations participated. Participants signed written informed consent.

Interventions

HBOT protocol comprised of 60 daily sessions, 5 per week over 2 months. Protocol included breathing 100% oxygen by mask at 2ATA for 90-min with 5-min air breaks every 20-min. Compression/decompression rates were 1.0 m/min. Patient received physical and occupational therapy twice a week during therapeutic phase. The physical therapy focused on lower limb mobility, transitions between body positions, enhancing walking pace with and without a cane, proprioceptive training to augment coordination, reflexes, and balance. Occupational therapy incorporated activities of daily living (ADLs).

Main Outcome Measures

Primary study outcome was functional activation changes using motor task fMRI.

Results

After HBOT, the FMA score improved from 17 (severe) to 31 (moderate). After the intervention during trials involving the affected hand, there was an observed increase in fMRI activation in both the supplementary motor cortex (SMA) and the premotor cortex (PMA) bilaterally. The lateralization index (LI) decreased from 1 to 0.63, demonstrating the recruitment of the contralesional hemisphere. The region of interest, ROI-to-ROI, analysis revealed increased postintervention interhemispheric connectivity (P=.002) and a between-network connectivity increase (z-score, 0.35±0.21 to 0.41±0.21; P<.0001). Seed-to-voxel-based rsFC analysis using the right SMA as seed showed increased connectivity to the left posterior parietal cortex, the left primary somatosensory cortex, and the premotor cortex.

Conclusions

Study provides additional insights into HBOT-induced brain plasticity and functional improvement in patients with chronic poststroke.

Disclosures

AH, VE, and SE work for AVIV Scientific Ltd. SE is a shareholder at AVIV Scientific Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.