Neurophysiology in clinical practice

Clinical neurophysiology is concerned with the recording of generation and propagation of electrical potentials of nerve and muscle cells. It can provide important information about brain and neuromuscular disorders. Electro encephalogram (EEG), Evoked potentials (EP), Nerve conduction study (NCS) and electromyogram (EMG) are the four main techniques used in clinical neurophysiology. EEG reflects the electrical activity arising from the cerebral cortex. Evoked Potentials are measurements of classic stimulus response. VEP, SSEP and BSAEP are most useful in diagnosing Multiple Sclerosis, Plexus lesions and 8(th) cranial nerve tumor, CP angle tumor respectively. Nerve conduction studies are the measurement of velocity of nerve impulse. It gives information about the lesion of a myelinated nerve. Electromyogram gives information about the integrity of innervations, condition of neuromuscular junctions and also condition of the muscle fiber itself.