Dear Ask The Doctor: Dear Ask the Doctor, I recently had an NCV diagnostic test done to my right forearm, wrist, and fingers because of a needle stick injury in an attempt to draw blood at the doctor's office. The injury occurred in mid February 2010. I have residual pain and soreness in my right wrist, numbness and tingling in my right fingers, and significant loss of strength in my right arm. Results of the NCV my primary care physician (PCP) ordered showed mildly decreased conduction velocity across the elbow, and mild right ulnar neuropathy across the elbow, but no evidence of focal median neuropathy (carpal tunnel)or polyneuropathy. Returning for a follow up with the PCP, upon questioning these findings the PCP skirted specifically answering my question if I had nerve damage. I need to know if I have nerve damage, and if the nerve damage was cause by the needle puncturing a nerve(s). The PCP told me there was no test to determine if a needle in the area of my arm had caused the damage. I didn’t believe them. The order for nerve testing the PCP gave was for (1) nerve conduction study of upper extremity bilateral, and (2) paresthesia of hands DDD of C spine & L spine. They did not order an EMG. Do you think an EMG would be beneficial to determining nerve damage, which nerve(s) is damaged, and cause of damage? Are there any other types of tests that would be appropriate to finding the above mentioned? I am further disappointed and suspicious of my PCP because when I asked why they had concluded in my chart notes that my arm status was most likely related to spinal stenosis of the C-spine, without even investigating the needle stick injury, this doctor became astoundingly defensive, saying I had offended her by challenging her findings, and that I shouldn’t even being looking in my chart notes. I feel deceived because nowhere in the three visits I had with this PCP was needle stick injury from a health care worker (not from PCP’s office) mentioned in my chart. I understand that a physician must run different types of tests to determine or rule out various causes of pathology, but I think it was underhanded of the PCP to have also had in mind ordering a C-spine MRI to “show” the MRI results “indicate” the reason of my arm condition without first investigating the blatantly obvious (sharp force trauma to nerve(s) via needle stick). I am going to a pain management specialist tomorrow, but I am wary of bringing up the prior tests. What might be the best course of action ? Yours, Adrienne Williams
Dear Patient: The most specific study to determine nerve injury is the NCV, which in your case came out with a result of a “mild ulnar neuropathy across the elbow, but no evidence of focal median neuropathy (carpal tunnel) or polyneuropathy.” Anatomically is not likely that the needle stick when drawing blood has injured the ulnar nerve, because this one goes along the back (posterior) and inner part of the elbow in its most superficial passage by that area, on the other hand, the median nerve is more anteriorly located at the level of the elbow but deeper than the vascular elements (artery and vein from which the blood is drawn), and according to the NCV this nerve has no evidence of injury. The other part of your question is if the EMG (electromyography) could have given additional information about your case, the answer is: No, because that study is performed to check the status of the electrical activity of the muscles and their response to a stimulus (needle), giving us an indirect idea how is the nerve that supply these muscles’ movement functions. The report of the NCV states: “mild ulnar neuropathy across the elbow”, so if it is “mild” is what we call “neuropraxia” which is a non-severe, reversible nerve injury with a 100% recovery potential , the healing time varies for each patient in particular and according to the extension of the nerve injury in circumference, but as a general rule, most of the peripheral nerves recover approximately : 1mm/day, measured this in circumference. Taking Vitamin B complex, specifically B-12, can help with this process.
If you keep having: “residual pain and soreness in my right wrist, numbness and tingling in my right fingers, and significant loss of strength in my right arm” (quoting you), it would be important, then, to rule out a cervical root nerve compression Vs. Carpal Tunnel Syndrome, and this time: Yes, with a EMG of the neck and upper extremity muscles assessed plus NCV of the median nerve.