What effect do cool extremities typically have on nerve conduction parameters?

Cool extremities have a significant impact on nerve conduction parameters, primarily leading to lower amplitudes, prolonged distal latencies, and slower conduction velocities. When the temperature of the extremities decreases, nerve conduction is adversely affected due to reduced enzymatic activity and changes in nerve fiber properties.

Lower amplitudes can occur because cooler temperatures inhibit the efficiency of action potential generation and propagation, resulting in a weakened signal being detected during nerve studies. Prolonged distal latencies are observed as the time it takes for the nerve impulse to travel from the stimulation point to the recording site increases due to reduced conduction speed. Similarly, slower conduction velocities arise because cool temperatures increase the resistance of the nerve fibers and decrease the speed at which depolarization waves move along the axon.

Therefore, with cool extremities causing these specific changes in nerve conduction, the correct answer highlights the impact on amplitude, latencies, and velocities associated with decreased temperature in the extremities.