The nerve shows a decrease to both galvanic and faradic stimulation is associated with which reaction?

• A. Accompanies absolute reaction of degeneration
• B. Reaction of degeneration is not involved
• C. Accompanies partial reaction of degeneration
• D. Accompanies full reaction of degeneration

Answer: (C)

Electrical excitability after nerve injury follows a progression known as reactions of degeneration. Initially there is an absolute reaction, where there is no response to either galvanic or faradic stimulation. As degeneration advances and some axons remain or begin to recover, the muscle shows a reduced response to both types of stimulation—this is the partial reaction of degeneration. Only with further regeneration do responses approach normal again, described as the full reaction of degeneration. So a decrease to both galvanic and faradic stimulation fits the partial reaction of degeneration because it indicates diminished, but not completely lost, excitability.