Question #132

A patient complaining of weakness and tingling in her right upper limb is diagnosed with a cervical rib. Which of the following signs is she most likely to have?

Wasting of the thenar eminence

Sensory symptoms over the medial forearm

Wasting of biceps brachii

Arm held in the ‘waiter’s tip’ position

Inability to extend the wrist

As the name suggests a cervical rib is one which arises at the level of the cervical vertebrae. It is seen in 1 in 200 people and most commonly arises at the level of C7. It results in narrowing of the thoracic outlet where the brachial plexus and axillary vessels run. This may cause compression of the lower trunk or the C8 and T1 nerve roots (in addition to the vascular symptoms).

The neurological symptoms will therefore result in numbness in the C8 and T1 dermatomes, and weakness in the muscles supplied by the ulnar nerve.

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