Differential Hemodynamic Response to Repetitive Transcranial Magnetic Stimulation in Acute Stroke Patients with Cortical versus Subcortical Infarcts

Abstract

Objective: To assess the cerebral vasomotor response to ipsilesional repetitive transcranial magnetic stimulation (rTMS) on transcranial Doppler (TCD) in patients with recent ischemic stroke without carotid occlusive disease, and to compare this response in patients with cortical and subcortical infarcts. Methods: Consecutive patients with first-ever anterior circulation acute ischemic stroke (<3 days) and no extra- or intracranial arterial stenosis were prospectively recruited. Patients were divided into 2 groups: cortical infarct (CI, n = 15) and subcortical infarct (SI, n = 16). TCD cerebral blood flow velocity (CBFV) and pulsatility index were measured before and after 10-Hz suprathreshold rTMS over the dorsolateral prefrontal cortex. Results: ANOVA showed a greater percentage increase in middle cerebral artery (MCA) CBFV in the SI group than in the CI group following rTMS (p = 0.01). The percentage change in CBFV was significantly correlated between both MCAs in SI patients but not in CI patients (r = 0.8, p < 0.001 vs. r = 0.05, p = 0.9, respectively). Conclusions: 10-Hz rTMS induces significant bilateral hemodynamic changes in patients with acute ischemic stroke, which appear to be less prominent and less synchronous in patients with cortical infarcts. These findings may allow optimization of the use of TMS in acute stroke.

Repetitive Transcranial Magnetic Stimulation Induces Quantified Functional and Structural Changes in Subcortical Stroke: A Combined Arterial Spin Labeling Perfusion and Diffusion Tensor Imaging Study

“…To sum up, the CBF of the injured side increased while the uninjured side decreased after high-frequency rTMS treatment, which increased the inhibition of the injured side to the contralesional hemisphere, so as to reach the goal of hemispheric rebalance. But this is inconsistent with Khaleel et al’s (2010) findings, who indicated that CBF velocity increased both in ipsilateral and contralateral in middle cerebral artery after high-frequency rTMS in acute ischemic stroke. The reasons for the difference may be as follows.…”

Evidence for a Window of Enhanced Plasticity in the Human Motor Cortex Following Ischemic Stroke

“…28,29 Furthermore, the hemodynamic response to brain stimulation differs between cortical and subcortical lesions with an increase in blood flow velocity after stimulation in subcortical stroke, while this was less prominent in cortical stroke. 57 We conclude that lack of change in neural plasticity in ipsilesional cortex could be the result of either a bias toward LTP and/or cortical damage produced by the stroke.…”

Transcranial Direct Current Stimulation to Facilitate Lower Limb Recovery Following Stroke: Current Evidence and Future Directions

“…Patients with lesions that involve the cortex did not appear to respond to stimulation and demonstrated reduced improvement in motor activity compared to those with subcortical lesions only [80]. Furthermore, it has been shown that the hemodynamic responses to brain stimulation also appear different between cortical and subcortical lesions with velocity of blood flow significantly increased after stimulation in subcortical stroke, but was less prominent in cortical stroke [81]. Different stages of stroke recovery also appear to influence neuroplasticity processes, with a spontaneous upregulation in neuroplasticity emerging early after stroke [2,3,5].…”