Clinical testing such as electroencephalography, somatosensory evoked potentials (SSEP), brainstem auditory evoked potentials (BSER) and visual evoked potentials (VEP).

EEG (Electroencephalography) Brain testing   

SSEP (Somatosensory evoked potentials) Spinal cord and peripheral nerve testing

BSER (Brainstem/hearing screening testing)   

VEP (Visual evoked potential testing)