Evoked Potential Testing in Clinical Neurotoxicology

Publisher Summary This chapter reviews the use of evoked potential (EP) in clinical neurotoxicology. EPs are electrical cortical responses produced by specific stimulation of specific sensory pathways or by complex endogenous events. Sensory-evoked potentials (SEPs) refer to those responses produced by peripheral sensory stimuli. Event-related potentials (ERPs) are produced by the processing of complex data or by motor planning. Although ERPs provide interesting information about cognitive processing, they have little clinical utility. In contrast, SEPs are commonly used to assess the function of sensory pathways. Clinically, the most frequently used of these tests are the visual-evoked potentials, brain stem- or auditory-evoked responses, and the somatosensory-evoked potentials. These fundamental tests are used in practice to screen for multifocal diseases and to uncover clinically silent lesions. Chemosensory-evoked potentials are used to test additional sensory pathways in patients exposed to inhaled toxins. Unlike EEG activity, EPs are time-locked to the stimulus and are reproducible. They can therefore, provide a means of following the effect of a toxin over time. This chapter reviews the use of EPs in neurotoxicology, discusses the anatomical basis of the tests, and indicates the effect of various known toxins.