Effectiveness of Transcranial Magnetic Stimulation in Subacute Stroke Patients With Severe Upper Limb Paresis

Effectiveness of Add-on Inhibitory Repetitive Transcranial Magnetic Stimulation Over the Contralesional Primary Motor Cortex in Subacute Stroke Patients With Severe Upper Limb Motor Impairment

There has been A-level evidence for the effectiveness of inhibitory rTMS of the contralesional M1 hand region in stroke patients in the acute stage. However, it has been reported to be ineffective in the chronic stage. In addition, it has been reported that the patient group benefiting from rTMS is mostly those with moderate to mild motor impairment. In contrast, a recent randomized controlled study has reported that ipsilesional excitatory rTMS or contra-lesional inhibitory rTMS may also have positive effects in stroke patients with severe upper limb motor impairment. The aim of this study is to investigate the effect of inhibitory repetitive transcranial magnetic stimulation applied to the contralesional primary motor cortex, by using the rTMS parameters specified in the current recommendation guide, on motor function, activities of daily living, and quality of life in subacute stroke patients with severe upper limb motor impairment.

The level of stroke-related upper limb motor impairment varies widely among individuals, from mild to severe. Because of this heterogeneity, rehabilitation interventions are tailored individually. In recent years, many studies have been published on the effectiveness of add-on non-invasive neuromodulation methods such as transcranial magnetic stimulation (TMS) or transcranial direct current stimulation in the treatment of stroke-related upper limb motor impairment. There has been A-level evidence for the effectiveness of inhibitory rTMS of the contralesional M1 hand region in stroke patients in the acute stage. However, it has been reported to be ineffective in the chronic stage. In addition, it has been reported that the patient group benefiting from rTMS is mostly those with moderate to mild motor impairment. It has been reported that contra-lesional hemisphere inactivation impairs paretic upper extremity performance in severely infarcted animals. In humans, contra-lesional hemisphere inactivation has been reported to slow down the reaction time. In contrast, a recent randomized controlled study has reported that ipsilesional excitatory rTMS or contralesional inhibitory rTMS may have positive effects in stroke patients with severe upper limb motor impairment. However, the literature on rTMS in post-stroke rehabilitation is highly heterogeneous in terms of frequency, session duration, location, patient characteristics, and outcome scales, and this ambiguity makes it difficult to adapt rTMS to the clinical practice. In this regard, future studies are needed to determine whether rTMS provides an additional benefit to traditional/task-specific rehabilitation approaches in stroke patients with severe upper limb paresis. The aim of this study is to investigate the effect of inhibitory repetitive transcranial magnetic stimulation applied to the contralesional primary motor cortex, by using the rTMS parameters specified in the current recommendation guide, on motor function, activities of daily living, and quality of life in subacute stroke patients with severe upper limb motor impairment.

Inclusion Criteria:

• Presence of subcortical ischemic stroke affecting the middle cerebral artery territory, which has been confirmed by imaging methods
• Having a stroke for the first time
• Presence of subacute stroke (< 6 months)
• Mini-mental test score ≥ 24
• Severe upper limb motor impairment (The Fugl-Meyer Assessment Scale - Upper Extremity motor impairment score ≤ 19/60, excluding reflex assessments)
• Lack of motor evoked potential (MEP) recording from the first dorsal interosseous muscle of the paretic extremity with single-pulse transcranial magnetic stimulation of the ipsilesional primary motor cortex (hand region)

Exclusion Criteria:

• To have a clinical condition (metallic implant, cardiac pace, pregnancy, breastfeeding, claustrophobia, epilepsy, head trauma, cranial operation history) that will constitute a contraindication to transcranial magnetic stimulation
• History of psychiatric illness such as major depression/personality disorder
• History of convulsion or epilepsy or taking medication for epilepsy
• Cognitive impairment
• Pregnancy or breastfeeding
• Alcohol or drug addiction
• Previously treated with transcranial magnetic stimulation
• Moderate or mild upper extremity motor impairment (The Fugl-Meyer Assessment Scale - Upper Extremity score > 19/60, excluding reflex assessments)
• Presence of neglect