Anterior Interosseous Nerve Syndrome

Description
Anterior interosseous nerve syndrome is a nerve disorder in
the elbow and upper arm that causes pain and weakness in the
hand. It involves compression of a branch of the median nerve
in the forearm by muscles or ligament-like tissues. It may
decrease athletic performance in sports that require pinching
of the thumb and index fingers. This nerve does not supply
sensation to the skin and thus there is no numbness associated
with it.

Common Signs and Symptoms:
� Pain in the upper forearm, usually vague
� Inability to pinch your thumb to index finger tip to tip (make the OK sign)
� Thumb weakness, particularly bending the thumb, or weakness of the index finger
� Frequent dropping of objects and difficulty writing
� Weakness when turning the palm down against resistance

Causes:
� Pressure on the anterior interosseous nerve at the forearm caused by swollen, inflamed, or scarred tissue, ligament- like tissue, or pressure between muscles of the forearm
� Possibly, a vims causing inflammation and dysfunction of the nerve

Risk Increases With:
� Sports or occupations that require repetitive and strenuous forearm and wrist movements (rowing, weightlifting, body building, tennis, squash, racquetbali, carpentry), particularly rotation of the wrist and hand
� Poor physical conditioning (strength and flexibility)
� Inadequate warm-up before practice or play
� Diabetes meliitus
� Hypothyroidism (underactive thyroid gland)

Preventive Measures:
� Appropriately warm up and stretch before practice or competition.
� Maintain appropriate conditioning:
� Wrist, forearm, and elbow flexibility
� Muscle strength and endurance
� Cardiovascular fitness
� Use proper technique and have a coach correct improper technique.

Expected Outcome:
With appropriate treatment, this condition is usually curable, although resolution may occur spontaneously. Occasionally, surgery is necessary. Spontaneous recovery has been noted from 3 weeks to 18 months after the onset of symptoms.

Possible Complications:
� Permanent weakness or paralysis of the thumb or index finger in the affected hand
� Prolonged healing time if usual activities are resumed too soon

General Treatment Considerations:
Initial treatment consists of rest from the offending activity and medications and ice to help reduce inflammation. Stretching and strengthening exercises of the muscles of the forearm and elbow are important. Referral to physical therapy or an athletic trainer may be necessary for treatment. If this treatment is not successful, surgery may be necessary to free the pinched nerve. Surgery may be performed as an outpatient procedure (you go home the same day) or may require admission for ovemight stay and provides almost complete relief in most patients. Surgery is offered 8 weeks to 1 year after the onset of symptoms.

Medication:
� Nonsteroidal anti-inflammatory medications, such as aspirin and ibuprofen (do not take within 7 days before surgery), or other minor pain relievers, such as acetaminophen, are often recommended. Take these as directed by your physician. Contact your physician immediately if any bleeding, stomach upset, or signs of an allergic reaction occur.
� Pain relievers may be prescribed as necessary by your physician, usually only after surgery. Use only as directed and only as much as you need.
- Flexor digitorum superficialis muscle

Heat and Cold:
� Cold is used to relieve pain and reduce inflammation for acute and chronic cases. Cold should be applied for 10 to 15 minutes every 2 to 3 hours for inflammation and pain and immediately after any activity that aggravates your symptoms. Use ice packs or an ice massage.
� Heat may be used before performing stretching and strengthening activities prescribed by your physician, physical therapist, or athletic trainer. Use a heat pack or a warm soak.

Notify Our Office If:
� Symptoms get worse or do not improve in S weeks despite treatment
� You experience pain, numbness, or coldness in the hand
� Blue, gray, or dusky color appears in the fingernails
� Any of the following occur after surgery:
� Increased pain, swelling, redness, drainage, or bleeding in the surgical area
� Signs of infection (headache, muscle aches, dizziness, or a general ill feeling with fever)
� New, unexplained symptoms develop (dmgs used in treatment may produce side effects)