Additive effects of sequential excitatory and inhibitory theta burst stimulation in improving cortical excitability...

To study the effects of sequential excitatory and inhibitory theta burst stimulation (TBS) on cortical excitability in patients with subacute ischaemic stroke.

Fifteen patients with first-ever middle cerebral artery ischaemic stroke within last three months were subjected to intermittent TBS over the hand area (M1) of the stroke hemisphere (iTBS_SH) followed by continuous TBS over the intact hemisphere M1 (cTBS_IH). The study measured motor evoked potential (MEP) amplitude, resting motor threshold (RMT) and contralateral cortical silent period (cCSP) at baseline and after 7 minutes of each TBS session.

The mean age of the patients was 62.4 ± 8.0 years. The absolute changes in baseline motor physiological parameters were significantly greater after cTBS_IH than after iTBS_SH (p = 0.001). Following iTBS_SH, there was a significant decrease in mean RMT (7.4%; p < 0.001). Following cTBS_IH, there was further 18.3% increase in mean MEP amplitude and decrease in mean RMT (4.7%; p < 0.001) and cCSP (5.6%; p < 0.001) of the stroke hemisphere. Similar changes of smaller magnitude were noted in 12 age-matched controls.

The results indicate that combining iTBS_SH and cTBS_IH can have additive effect in increasing cortical excitability in subacute ischaemic patients with stroke.