Neurophysiology is a sub-specialty of Neurology. It is the study of how nerve cells (neurones) receive and transmit information. This information is most commonly either sensory (sensation in skin) or motor (control of muscle function) and impairments in the transmission of this information can lead to sensory and or motor impairment (numbness, tingling, weakness). Neurophysiology is the assessment of the electrical signals being generated in the above processes. Although the electrical currents/voltages are very small, it is possible to study the brain, peripheral-nerves and muscles by recording and analysing these electrical signals. This is done through neurophysiology testing. The above processes result in electrical signals being generated. Although the voltages are very small, it is possible to study the brain, peripheral-nerves and muscles by recording and analysing these electrical signals. This is done through neurophysiology testing.