*2.5.1.1 Cervical rib syndrome*

**Anatomy:** The cervical rib is the accessory or extra rib originating from the 7th cervical vertebra. It can be found bilaterally or unilaterally and in varying sizes. The cervical rib is usually asymptomatic and is noticed incidentally on chest X-rays. Sometimes it can be palpated like a mass during the deep palpation of the supraclavicular region on physical examination. When it compresses the brachial plexus or subclavian vessels, it causes thoracic outlet syndrome or brachial plexopaty. This syndrome often causes pain in the hands when raising the arms (**Figure 2**) [18–20].

**Description:** It is a clinical congenital condition characterized by sensory and motor losses in the hand as a result of compression of the cervical rib or the C7 transverse extension to the C8 and T1 roots of the brachial plexus [18–20].

**Causes:** The accessory or extra rib originating from the 7th cervical vertebra.

**Clinical features:** Generally, there is a loss of sensation in the inner surface of the forearm and the last two fingers (ring and little fingers). Tingling and numbness could be in patients forearm and hand ulnar part. Pain in the upper extremity, atrophy of the intrinsic muscles of the hand, and vasomotor changes may occur. Cervical ribs may be associated with a weak pulse from the radial region, especially when the arm is abducted [20].
