ABSTRACT
Neurology is the branch of medicine dealing with all aspects of the nervous system. At least two types of electrophysiological measurement are usually made in a department of neurology; these are electroencephalography (EEG) and electromyography (EMG). This chapter explains the organization of the nervous system and introduces some of the terminology which is needed for an understanding of EEG and EMG. It describes the origin of some bioelectric signals and the methods of recording these electrical signals from the body. The origin of almost every electrical potential which arises within the body is a semi-permeable membrane. Changes in potentials of this type are the origin of signals such as the EEG, EMG and Electrocardiography. Many methods of signal analysis have been tried to quantify EMG patterns; some depend upon measuring the frequency content of the signals. These can be of use in quantifying the EMG and they have been shown to be helpful in identifying the carriers of muscular dystrophy.
