Median Nerve - Injury

Injury

Injury of median nerve at different levels cause different syndromes:

Above the elbow

• Injury of this nerve at a level above the elbow results in loss of pronation and a reduction in flexion of the hand at the wrist.

At the elbow

• Severing the median nerve at this level or higher (at above the elbow) causes "the Blessed Hand," or "Hand of Benediction."
• Entrapment at the level of the elbow or the proximal forearm could be due to the pronator teres syndrome.
• Lesions of compression of the Median Nerve can also leads to Median Nerve Palsy

Within the forearm

• Injury to the anterior interosseous branch in the forearm causes the anterior interosseous syndrome.

At the wrist

• Injury by compression at the carpal tunnel causes carpal tunnel syndrome.

• In the hand, thenar muscles are paralyzed and will atrophy over time.
• Opposition and flexion of the thumb are lost.
• Sensory is lost:

Palm - 3 1/2 Fingers

Dorsal - Finger tips

• The thumb and index finger are arrested in adduction and hyperextension. This appearance of the hand is collectively referred as 'ape hand deformity'.