Diagnostic capabilities of transcranial magnetic stimulation to predict motor recovery after a stroke

Abstract

Transcranial magnetic stimulation is a method of focal non-invasive brain stimulation, characterized by high spatial and temporal resolution. To date, diagnostic transcranial magnetic stimulation has been used in clinical practice primarily to assess an involvement of the upper motor neurons and to measure the velocity of the neuronal impulse propagation. However, in the last 10 years, a possible range of transcranial magnetic stimulation diagnostic applications has significantly expanded. Many transcranial magnetic stimulation approaches are coming from scientific laboratories to clinical practice due to an increased availability of transcranial magnetic stimulation equipment, in particular, magnetic resonance imaging navigation for transcranial magnetic stimulation and a combination of the transcranial magnetic stimulation with electroencephalography and also due to an increased awareness of the clinicians. The diagnostic potential of transcranial magnetic stimulation in relation to motor recovery after a stroke can be classified into 4 directions:1) assessment of the vertical tracts integrity (primarily, the cortico-spinal tract); 2) an assessment of the cortical excitation-inhibition balance;3) probing of the functional and effective connectivity among brain regions (primarily, cortical convexity and cerebellum);4) motor mapping to evaluate cortical reorganization.In this article we will present these 4 directions of the transcranial magnetic stimulation application to study motor system pathophysiology and to predict motor outcome in stroke, including both existing and developing approaches.

Mapping of multiple muscles with transcranial magnetic stimulation: absolute and relative test–retest reliability

“…There are numerous studies showing that the MCR parameters such as excitability, size and topography reflect functionally relevant features of the motor cortex organization in healthy people (Beaulieu, Massé-Alarie, Ribot-Ciscar, & Schneider, 2017;Gentner & Classen, 2006;Nazarova, Novikov, Nikulin, & Ivanova, 2020;Tyč & Boyadjian, 2011) and in patients with motor pathology such as stroke (Lüdemann-Podubecká & Nowak, 2016;Yarossi et al, 2019), amyotrophic lateral sclerosis (Chervyakov et al, 2015;de Carvalho et al, 1999), dystonia (Schabrun, Stinear, Byblow, & Ridding, 2009), and so forth. Considering the TMS mapping of multiple muscles, the existence of the somatotopy gradient for MCRs, along with their extensive overlap, has been discussed from the earliest TMS studies (Gentner & Classen, 2006;Metman, Bellevich, Jones, Barber, & Streletz, 1993).…”

New approaches to recovery after stroke

“…TMS can also modulate cortical excitability (CE), with low-frequency TMS (<1 Hz) decreasing excitability (commonly used in the contralateral hemisphere to inhibit activity) and high-frequency TMS (>1 Hz) increasing excitability (used in the affected area to stimulate activity) [ 54 , 55 ]. The primary motor cortex, parietal cortex, and Broca-Wernicke areas are commonly treated with TMS [ 56 – 59 ]. There is a subtype of repetitive TMS called theta burst stimulation (TBS), which can enhance in intermittent mode (iTBS) or depress in continuous mode (cTBS) and has been used in stroke recovery; beyond its original description in primary motor areas, there are publications on TBS in the cerebellum, given its parietal-frontal connections, showing improvement in motor learning [ 60 , 61 ].…”

Automatic theranostics for long-term neurorehabilitation after stroke

“…In contrast to the traditional assessments, quantitative measurements of the neuro-behavioral changes via neuroimaging and kinematics/kinetics technologies, e.g., magnetic resonance imaging (MRI) and motion capture systems, provided objective and sensitive solutions for post-stroke functional evaluation (Hu et al, 2022 ). However, one of the challenges regarding the application of quantitative measurements to automatic assessments is the operational complexity of the measurement system that relies heavily on professionals, particularly for multimodal measurements that employ various standalone systems (Nazarova et al, 2020 ). The operational complexity also poses considerable challenges to self-help rehabilitation, which requires easily operable and compact devices for operation by nonprofessionals such as caregivers and the patients themselves, with quantitative measurement systems in unconventional home-based or even outdoor settings (Nam et al, 2020 ).…”