The brain, the heart and skeletal muscles are prime sources of electric and magnetic fields that can be recorded and the resulting patterns can give insight on what ailments the subject may have.
Although the development of MRI has allowed for very effective detection of brainstem lesions, evoked potentials measurements are also an electrophysiological technique that has been used for over 30 years in this context.
[5] Alzheimer's disease and other types of dementia diagnosis is being improved through the use of electroencephalogram (EEG) and event-related potentials(ERP).
[7] Parkinson's disease is a degenerative ailment that affects the central nervous system and is typically identified initially by its motor related symptoms.
Accurate differentiation of PD from any other neurological disorder and the identification of the disease course is important in establishing an appropriate antiparkinsonian therapy.
[citation needed] The measurement of the naturally occurring magnetic fields produced by the brain's electrical activity is called magnetoencephalography.
However, data from MEG and MRI can be combined to create images that approximately map the estimated location of the natural magnetic fields.
In order for the heart to contract in a regular, organized manner, specific electrical signals are sent to the myocardium from the pacemaker cells.
EKGs can be used to aid in the diagnosis of myocardial infarction, arrhythmia, left ventricular hyptertrophy, valvulopathies, and coronary artery disease.
[11] The most commonly affected muscles are those that oppose gravity, the elbow and wrist flexors, knee extensors and ankle plantarflexors.
[14][15] The demyelination and scarring of axons in the neurons of the nervous system can affect their conduction properties and seriously harm the normal communication of the brain with the rest of the body.