Final answer:
In a repetitive nerve stimulation study, an increase greater than 60% in the amplitude of muscular contraction over the baseline is considered abnormal and may indicate a neuromuscular disorder.
Step-by-step explanation:
In a repetitive nerve stimulation study, any increase in muscular contraction amplitude up to approximately 60% is considered normal. Therefore, a pseudofacilitation increment that is greater than 60% over the baseline amplitude could be considered abnormal. In clinical neurophysiology, such an increase usually requires further investigation as it may indicate a neuromuscular disorder. However, it is important to interpret these results in the context of the entire study, including comparing to normal values and taking into account the variability between individuals.