The<unk>  consists of the following components * Motor<unk>  * Sensory<unk>  * F wave<unk>  * H-reflex<unk>  The<unk>  is often combined with needle electromyography. Other The Department of Health and Human Services Inspector General recently identified the use of<unk> s without a needle electromyography at the same time a sign of questionable billing. Motor<unk>  Motor<unk>  Motor<unk>  are obtained by stimulating a motor nerve and recording at the belly of a muscle innervated by that nerve. The CMAP is the resulting response, and depends on the motor axons transmitting the action potential, status of the neuromuscular junction, and muscle fibers. The CMAP amplitudes, motor onset latencies, and<unk>  velocities are routinely assessed and analyzed. As with sensory<unk> ,<unk>  velocity is calculated by dividing distance by time. In this case, however, the distance between two stimulation sites is divided by the difference in onset latencies of those two sites, providing the<unk>  velocity in the segment of nerve between the two stimulation sites. This method of calculating<unk>  velocity thereby avoids being confounded by time spent traversing the neuromuscular junction and triggering a muscle action potential (since these are subtracted out). Sensory<unk>  Sensory<unk>  are performed by electrical stimulation of a peripheral nerve while recording the transmitted potential at a different site along the same nerve. Three main measure can be obtained SNAP ( Sensory nerve action potential)amplitude, sensory latency and<unk>  velocity. The SNAP amplitude (in microvolts) represents a measure of the number of axons<unk> g between the stimulation site and the recording site. Sensory latency (in milliseconds) is the time that it takes for the action potential to travel between the stimulation site and the recording site of the nerve. The<unk>  velocity is measured in meters per second and is obtained dividing the distance between stimulation site and the recording site by the latency:<unk>  velocity = Distance/Latency Sensory<unk> : An example screenshot showing the results of a sensory nerve<unk>  velocity<unk>  of the right median nerve. F-wave<unk>  F-wave<unk>  uses supramaximal stimulation of a motor nerve and recording of action potentials from a muscle supplied by the nerve. This is not a reflex, per se, in that the action potential travels from the site of the stimulating electrode in the limb to the spinal cord's ventral horn and back to the limb in the same nerve that was stimulated. The F-wave latency can be used to derive the<unk>  velocity of nerve between the limb and spine, whereas the motor and sensory<unk> es evaluate<unk>  in the segment of the limb. F waves vary in latency and an abnormal variance is called "chrono dispersion".<unk>  velocity is derived by measuring the limb length, D, in millimeters from the stimulation site to the corresponding spinal segment (C7 spinous process to wrist crease for median nerve). This is multiplied by 2 as it goes to the cord and returns to the muscle (2D). 2D is divided by the latency difference between mean F and M and 1 millisecond subtracted (F-M-1). The formula is . H-reflex<unk>  H-reflex<unk>  uses stimulation of a nerve and recording the reflex electrical discharge from a muscle in the limb. This also evaluates<unk>  between the limb and the spinal cord, but in this case, the afferent impulses (those going toward the spinal cord) are in sensory nerves while the efferent impulses (those coming from the spinal cord) are in motor nerves. This process cannot be changed. Specialized testing Repetitive nerve stimulation
Nerve conduction study
Nerve biopsy
Electromyography
Muscle biopsy
Optomyography
Cervicography
Myelography
Femoral nerve stretch test