Do you ever wake up in the middle of the night with numbness in your hands and arms and feel the overwhelming urge to shake them? Do you ever experience intermittent numbness and tingling in the first three and-a-half fingers of your hands? These are the common presenting features of carpal tunnel syndrome, a common neuromuscular disorder.
Carpal tunnel syndrome is an entrapment of the median nerve, or a squeezing of the nerve, as it travels through the carpal tunnel in the wrist on its way into the hand. The most common symptoms are numbness, tingling, burning sensation, and pain in the first three fingers of the hand. Symptoms sometimes also include pain in the wrist or knuckles, and in advanced cases, patients can develop hand weakness and the inability to hold onto heavy items. The pain associated with carpal tunnel often occurs at night, and most believe that the symptoms are precipitated by flexion, or bending, of the wrists while sleeping, and prolonged flexion may decrease the required blood flow to the median nerve resulting in nerve damage.
In most cases, the cause of carpal tunnel syndrome is unknown. However, some common medical conditions or medications that can lead to carpal tunnel syndrome include obesity, use of oral contraceptives, pregnancy, hypothyroidism, arthritis, diabetes, pre-diabetes (impaired glucose tolerance) and trauma. Although popularly associated with typing or other repetitive activity, the relationship between such activity and carpal tunnel syndrome remains controversial, and a direct link between the two has yet to be established.
Neurologists evaluate patients for carpal tunnel syndrome by performing a detailed neurologic assessment of the median nerve using electro-diagnostic testing (electromyography and nerve conduction studies), in which an electrical current is sent down the nerve and the conduction of the current is measured. With these tests, neurologists can determine the extent of the injury to the median nerve and the proper course of treatment.
The first line of treatment for carpal tunnel syndrome is the use of night time wrist splints. The splints keep the wrists straight, preventing them from prolonged flexion during sleep. Injections of corticosteroids into the carpal tunnel can also be effective in providing significant relief from symptoms. In more advanced cases, carpal tunnel release surgery can be used to relieve the pressure on the median nerve.
Carpal tunnel syndrome is the most common nerve entrapment, occurring in about one out of every 20 people in the U.S., and most patients treated for carpal tunnel syndrome have minimal long-term residual nerve damage, with resolution of most symptoms. However, symptoms such as numbness and tingling in the fingers can also be signs of more serious neuromuscular disorders, and patients should consult with a neurologist trained in the diagnosis and treatment of neuromuscular diseases if they experience these symptoms.
Beth Stein, MD is an Attending Neurologist and the Director of Neuromuscular Disorders at St. Joseph’s Regional Medical Center. She lives in Teaneck, and cares for patients in Clifton, Wayne and Paterson, NJ. She can be reached at 973-754-2433. www.stjosephshealth.org
By Beth Stein, MD
