Mysterious stabbing pain may be nerve-related

DEAR DR ROACH >>

For a 40-hour period last weekend, I experienced approximately 200 very sharp stabs of pain at the junction of my left thigh and my torso at the very front of the thigh. They began as I was sleeping and continued at various frequencies, varying from three in 20 seconds to one an hour throughout the following 40 hours. They occurred no matter what I did — sit, walk, stand still or lie down.

I have had these sharp stabs of pain before, but the episodes have lasted between 15 minutes and an hour, not for 40 hours. Each stab lasts about a second. My physician had X-rays taken of my lower spine to see if a nerve was pinched, but nothing showed up. There were no symptoms associated with the pain, such as fever, rash, changes in urine or bowel movement, etc. This pain is not associated with a sprain, spasm or bruise. I am 72 and weigh 180 pounds; I’m 5 feet, 8 inches tall. Your thoughts would be greatly appreciated. — D.J.

DEAR READER >> Sharp pain in a specific location like you are describing makes me think, as your physician did, of nerve pain. Unfortunately, an X-ray is not a great test to see if a nerve is being “pinched” (we prefer the term “entrapped,” but it really means the same thing); even a CT or MRI typically doesn’t show the problem.

The location you are describing is not far from the usual location of the lateral femoral cutaneous nerve. Compression of this nerve is well-described; it’s called meralgia paresthetica. A sense of numbness on exam in the thigh would help confirm this diagnosis. Your case is unusual in the sudden onset and the discrete stabs of pain, but the location and the absence of other symptoms make me think it’s the most likely diagnosis.

Most often, the pain goes away as mysteriously as it came. An injection of topical anesthetic around the area of the nerve confirms the diagnosis and provides effective treatment if symptoms persist.

DEAR DR. ROACH >> Why are yawns contagious? — D.H.H.

DEAR READER >> The reason that we yawn remains controversial, but one theory, confirmed in animal studies, is that it is a means of temperature regulation in the brain. About 60 to 70 percent of people are susceptible to yawning when they see others yawn, and the more empathetic a person is, the more predisposed he or she is to yawn when others do.

DEAR DR. ROACH >> Do you have any experience with lockjaw caused by radiation? After almost a year and a half, my brother still is dealing with the difficulty of opening his mouth more than 12 millimeters. He has had physical therapy, acupuncture and use of a TheraBite to try opening his mouth. Will this ever improve, or has the damage caused from radiation become permanent? — D.V.

DEAR READER >> Trismus, or lockjaw, is an uncommon but not rare complication of radiation treatment to the head and neck. I have no personal experience with it, but have read that although there are some treatments, much of the time the symptoms are irreversible. Besides the TheraBite system, which is helpful for many, other treatments have included microcurrent electrotherapy and pentoxifylline, which is a medication often used in people with blockages in the arteries.

However, 18 months is a long time, and I am, unfortunately, pessimistic about improvement from this point. I would consider seeking a consultation at a referral cancer center to find the most expertise.