Additive effects of sequential excitatory and inhibitory theta burst stimulation in improving cortical excitability following ischaemic stroke

ABSTRACT

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

Methods: 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.

Results: 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.

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

KEYWORDS:

• Transcranial magnetic stimulation
• theta burst stimulation
• stroke
• rehabilitation

Declaration of Interest

The authors report no conflicts of interest.