**1. Introduction**

Transcranial magnetic stimulation, which is commonly abbreviated as TMS, is an non-invasive method of cortical stimulation by the use of electromagnetic field. It is a safe and effective method of neuromodulation. It has been used as a tool for checking the integrity of neuronal pathway for prognosis estimation after insult. It is an FDA approved treatment for several psychiatric diseases. It is now also used for rehabilitation of different neurological deficits, like motor rehabilitation and dysphasia. Its neuromodulation property is used in treating Parkinson's disease and epilepsy. With the advancement in navigated TMS, it has been applied in cortical mapping, especially in neurosurgical operative planning.
