23. Transcranial magnetic stimulation (TMS) in neurological diseases

Abstract

The use transcranial magnetic stimulation (TMS) in clinical settings has grown over the last three decades. Since its introduction by Barker in 1985, TMS has been used to assess central motor pathways, as well as cortical function and intrinsic circuitry. Single-pulse TMS can map motor cortical outputs, and with cervical, thoracic and lumbar spinal cord stimulation, one can study the central motor conduction time. In addition, TMS document cortical hyperexcitability, as in early phases of sporadic ALS, or hypo excitability as in ischemic infarcts or central demyelinating diseases. With Single-pulse TMS techniques, one can study the corticomotoneuronal function using motor threshold, motor evoked potential (MEP) amplitude, central conduction time, cortical silent period, intracortical inhibition, and facilitation. The magnetic field produced by the coil assess, cortico-cortical projections (IPSP and EPSP) of pyramidal cells of the firth layer, thus it is required integrity of gray matter. In this presentation, I will present the usefulness of MEPs in upper motor neuron diseases as multiple sclerosis, ALS, vascular brain injuries, abnormal movements, spinal cord lesions, early stages of facial nerve palsies, among other neurological diseases. In addition, the capacity to predict motor function recovery, after ischemic brain insults, will be discussed.