Q: I am 25 years old male who had done a nerve conduction velocity test recently. The test gave the CMAP amplitude value of 10.4 mV for my right tibial nerve and 12.3 mV for my left tibial nerve. The doctor says it is a mild case of motor neuropathy as the amplitude values are slightly less than normal. All other nerves are perfectly fine. However, I have read on internet that the normal CMAP amplitude value for tibial nerve should be between 5.8 and 32 mV. Hence, according to this range, my tibial nerves are perfectly fine. What is the normal range for CMAP amplitude for the tibial nerves?

A:The values you have quoted are normal. There are many physiological and technical factors that can affect these studies, and minor differences between two sides are acceptable. However, if the amplitudes are low on the side where you have symptoms pertaining to this particular nerve, they may be significant. The usual cause of such Mononeuropathy (single nerve disease) is compression or injury. It should be examined by a Neurologist, and the cause should be determined at the earliest.