Question
Nerve tested by using clinical test as shown in the photograph below is ?
A. Median nerve.
B. Radial nerve.
C. Axillary nerve.
D. Ulnar nerve.
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Correct Answer » A Explanation |
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Ans: A. Median Nerve
The clinical test shown in the picture above represents Pen touching test for Abductor pollicis brevis.
This test is used for Median nerve.
Median Nerve Injury
- Injury of median nerve at different levels causes different syndromes with varying motor and sensory deficits.
Above the elbow
- Common mechanism of injury: A supracondylar humerus fracture
Motor deficit:
- Loss of pronation of forearm
- Weakness in flexion of the hand at the wrist
- Loss of flexion of radial half of digits and thumb
- Loss of opposition of thumb.
- Loss of abduction
- Pen touching test:The patient lies his hand flat on a table with his palm facing upwards. The patient is asked to abduct his thumb to touch the examiner’s pen which is held above it. This test is for the function of abductor pollicis brevis
- Loss of first 2 lumbricals.
- Thenar Atrophy
- Presence of an ape hand deformity when the hand is at rest, due to an hyperextension of index finger and thumb, and an adducted thumb.
- Presence of benediction sign when attempting to form a fist, due to loss of flexion of radial half of digits.
Sensory deficit:
- Loss of sensation in lateral 3 1⁄2 digits including their nail beds, and the thenar area.
At the wrist
- Carpal Tunnel or laceration
- Presents without benediction hand and with normal wrist flexion,digital flexion and pronation.