In extensive neuralgiform arm pain, the three most common cervical radicular syndromes C6, C7, and C8 must be evaluated. It should be kept in mind that the dermatomes, often only partially, and predominantly distally, show evidence of pain and/or sensory loss. This may result in misleading overlaps with areas of the peripheral nerves .

➤ C6 syndrome with painful areas in the lateral upper arm, the medial forearm, and the thumb (and index finger) can be easily distinguished clinically from carpal tunnel syndrome, in which nocturnal pain and rare tingling sensations may extend beyond the area of the median nerve in the hand, but the clinically observable sensory loss never does.

➤ C7 syndrome with painful areas in the anterior upper arm, anterior forearm, as well as the index and middle finger should also be distinguished from carpal tunnel syndrome.

➤ C8 syndrome with painful areas at the inner side of the upper arm and forearm, the medial side of the hand, as well as the ring and little fingers may occasionally be difficult to distinguish from scalenus anterior syndrome (Naffziger syndrome with lower plexus paresis, see above) or from a painful ulnar nerve lesion, if the area of the pain is only partial. Radicular provocation maneuvers, the local findings on the cervical spine, upper thoracic aperture, and ulnar nerve, and the distinct neurologic signs are definitive. C8 syndrome may be an essential part of Pancoast syndrome.

➤ The rare upper cervical radicular pain syndromes C3 and C4 are characterized by pain in the neck, cervical triangle, or the shoulder, and are easily recognized only if discernable deficits are found, e. g., sensory loss in the respective dermatomes and/or paresis of the diaphragm.

➤ C5 radicular syndrome can also cause refractory pain in the scapula. Radicular provocation maneuvers or sensory loss in the dermatome are helpful if accompanying shoulder or upper arm pain is absent.

The term neuralgic shoulder amyotrophy encompasses many acute painful arm pareses with the typical course of pain followed by paresis of predominantly one or more shoulder muscles. Radicular compression syndromes and radiculitis are most often causative, less frequently plexus neuritis. If the pain is mostly in the shoulder and upper arm, the C4 or C5 nerve roots and possible sensory disturbances in areas at the deltoid and the neck must be evaluated.