Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
Carpus is a word derived from the Greek word karpos, which means "wrist." The wrist is surrounded by a band of fibrous tissue that normally functions as a support for the joint. The tight space between this fibrous band and the wrist bone is called the carpal tunnel. The median nerve passes through the carpal tunnel to receive sensations from the thumb, index, and middle fingers of the hand. Any condition that causes swelling or a change in position of the tissue within the carpal tunnel can squeeze and irritate the median nerve. Irritation of the median nerve in this manner causes tingling and numbness of the thumb, index, and the middle fingers -- a condition known as "carpal tunnel syndrome."
Anatomy similar to that of the wrist and hand exists in the ankle and foot. Tarsal is a word derived from the Latin word for "ankle." When the sensory nerve that passes through the tarsal tunnel is irritated by pressure in the tunnel, numbness and tingling of the foot and toes can be felt. This condition is referred to as "tarsal tunnel syndrome." Tarsal tunnel syndrome is analogous to, but far less common, than carpal tunnel syndrome. It is treated similarly.
What conditions and diseases cause carpal tunnel syndrome?
For most patients, the cause of their carpal tunnel syndrome is unknown. Any condition that exerts pressure on the median nerve at the wrist can cause carpal tunnel syndrome. Common conditions that can lead to carpal tunnel syndrome include obesity, pregnancy, hypothyroidism, arthritis, diabetes, and trauma. Tendon inflammation resulting from repetitive work, such as uninterrupted typing, can also cause carpal tunnel symptoms. Carpal tunnel syndrome from repetitive maneuvers has been referred to as one of the repetitive stress injuries,
although this relationship remains controversial in the evidence based
literature. Some rare diseases can cause deposition of abnormal substances in and around the carpal tunnel, leading to nerve irritation. These diseases include amyloidosis, sarcoidosis, multiple myeloma, and leukemia.
Medical Author: William C. Shiel Jr.,
MD, FACP, FACR
The other day I was flying across the country and exited the
in-flight lavatory to find my flight attendant standing in the back
kitchen. She was holding an ice pack over her wrist. She
spontaneously blurted out in explanation, "My carpal tunnel is acting
up." She then showed me where she was having pain and tenderness
along the tendon of the thumb side of her wrist.
Carpal tunnel syndrome is numbness, tingling pain, and weakness in the thumb,
index and middle fingers as a result of irritation of the median nerve being
irritated at the wrist.
In fact, as I next explained to her, she did not have carpal tunnel syndrome
at all. She was suffering from a common form of inflammation of the tendon
(tendinitis) that extends the thumb called De Quervain's tendinitis. Her
treatment for the acutely injured tendon was correct (rest and ice), but her
diagnosis was not. If her symptoms persisted, they could be completely
cured by simple splinting and possibly by a cortisone injection.