[Transcranial magnetic stimulation (TMS) in clinical neurology]

To date, various kinds of transcranial magnetic stimulation (TMS) methods have been widely used in clinical neurology. For the clinical examination, single-pulse TMS is generally used, whereas, for the future therapy, repetitive TMS (rTMS) is widely researched. To evaluate the function of corticospinal tract, central motor conduction time (CMCT) is measured using single-pulse TMS. For precise analyses, single-pulse and double-pulse magnetic brainstem stimulation are performed to measure the cortical-brainstem conduction time and brainstem-spinal conduction time. To evaluate corticospinal tract function for leg muscles, cortico-conus motor conduction time (CCCT) is considered to be more accurate than CMCT. Magnetic cerebellar stimulation is effective to distinguish the cerebellar afferent pathway dysfunction from cerebellar efferent or cerebellar cortical dysfunctions. In animal research, rTMS releases the dopamine in monkey's brain and induces functional changes lasting over one week. In fact, as compared to sham-rTMS, high-frequency rTMS (5Hz) over the supplementary motor area has been shown to be significantly effective in the patients with Parkinson's disease. A new patterned rTMS protocol, quadripulse stimulation (QPS), can produce a bidirectional motor cortical plasticity depending on the interval of the pulses within a burst. rTMS including QPS might relieve symptoms in patients with neurological and psychiatric disorders.