DeQuervain's Syndrome (Tenosynovitis of the Abductor Pollicus Longus and Extensor Pollicus Brevis tendons) is a common disorder that has received a lot of press lately as BlackBerry Thumb or Gamer's Thumb.
This condition can be diagnosised by the Finklestein test [Have the patient bend their thumb into the palm of their hand, and then make a fist. They should then ulnar deviate their wrist. Pain along the tendons secures the diagnosis.]
The pain of DeQuervain's syndrome is typically along the distal end of the radius at the base of the thumb.
Intersection syndrome is a less common disorder though closely related to DeQuervain's Syndrome
The pain is usually felt on the top of the forearm about three inches proximal to the wrist.
The pain from this condition is due to tenosynovitis of the Extensor carpi radialis longus and Extensor Carpi radialis brevis muscles/tendons caused by the intersection of them with the Extensor pollicus brevis and Abductor pollicus longus tendons.
Occurs due to excessive wrist movements.
Intersection syndrome can be seen in weight lifters, skiers, and can be seen in homeowners in the fall and winter when they rake a lot of leaves or shovel snow.
Treatment is the similar for both conditions and consists of:
Cortisone injections can be effective
Thumb and wrist immobilization with a Thumb Spica Splint or Cock Up Wrist Splint