Neuritis refers to an inflammation of a nerve with pain and tenderness, anesthesia and paresthesia, paralysis, wasting, and disappearance of the reflexes. All radicular groups refer to the brachial plexus. The brachial plexus is formed by the 5th, 6th, 7th, and 8th cervical roots, and first thoracic root which form an upper, middle, and lower trunk. (See Diagnostic Code: 8610 Upper radicular group-Neuritis, Diagnostic Code: 8611 Middle radicular group-Neuritis, and Diagnostic Code: 8612 Lower radicular group-Neuritis.)

In some cases, the cause of neuritis may be unknown. Causes associated with the condition include: trauma; penetrating missile injury; shoulder injury; overextension of a joint; tumors; hemorrhage into a nerve; lesions; continuous pressure on a nerve such as carrying heavy objects supported at the shoulder; degenerative bone changes; nerve entrapment; or fractures. Exposure to cold or radiation; viruses; inflammatory processes; systemic malignancy; leprosy; metabolic diseases such as diabetes mellitus or alcoholism; collagen blood disorders; toxic agents; certain medications; nutritional deficiencies; and genetics may also be attributing causes.

Signs and symptoms may vary depending on the form of neuritis and the location of the lesion along the nerve. These symptoms may include: supraclavicular pain; neuralgia; hyperesthesia; paresthesia; pain; dysesthesia; hypoesthesia; anesthesia over the shoulder; inability to raise the arm at the shoulder; decreased reflexes; muscle atrophy; edema of the injured limb; and moderate to severe muscle weakness. Other manifestations may include: elbow pain; an inability to extend the elbow, wrist, finger and thumb; weakness of adduction of the hand; and wrist drop. Paralysis of forearm and finger flexion, and of abduction and internal rotation and external rotation of the arm may be evident. In addition, there may be distal paresthesias with partial sensory loss to confined areas of the outer arm, forearm, hand, thumb or index and middle fingers, and an inability to use a normal functioning hand. There may be vascular symptoms such as swelling, blanched fingers, or an aching, cold and cyanotic arm. Raynaud's disease may rarely be present. There may be other signs and symptoms depending on involvement of neighboring nerves.

Diagnostic measures may include: a complete history; physical and neurological examinations; motor, sensory, reflex, strength and resistance tests; blood studies; spinal tap; evoked responses; electromyography (EMG); x-ray; computed tomography (CT) scan; and magnetic resonance imaging (MRI).

Treatments may include management of the underlying disorder. Measures may include: splints; physical therapy; anti-inflammatory or pain medications; antibiotics; vitamin therapy; transcutaneous electrical nerve stimulation (TENS); or, in some cases, surgery may be needed.

Regeneration of the nerve may depend on the degree and site of injury. The closer the injury is to the central nervous system (CNS), regeneration of a severely damaged nerve is less likely to occur. In compression injury, complete recovery may take weeks depending on the length and severity of compression. There may be injuries to other distal peripheral nerves. Recovery from weakness may take several months. Recovery may range from return to complete function to permanent dysfunction of the arm or hand. Pain may be provoked when carrying heavy items in the hand. There may be a need for long-term pain management. There may be alteration of employment and daily activities requiring counseling intervention.