Practice Essentials
Trauma accounts for a large proportion of brachial plexopathies. The mechanism of an injury and the magnitude, rate, and direction of deforming forces ultimately determine the extent and location of a traumatic brachial plexopathy.
Anatomy
The anterior rami of the spinal nerves C5 to T1 combine to form the brachial plexus. C5 and C6 merge into the upper trunk, C7 forms the middle trunk, and C8 and T1 merge to form the lower trunk. Anterior divisions from the upper and middle trunks form the lateral cord. The medial cord is the anterior division of the lower trunk. Posterior divisions from all 3 trunks form the posterior cord. Terminal branches originate from the C5 root, trunks, and cords to supply the upper extremity and the shoulder girdle. The spinal nerves emerge from the vertebral foramina and pass between the anterior and middle scalenes; they then pass between the clavicle and the first rib, near the coracoid and humeral head. The plexus is relatively tethered at the prevertebral fascia at its proximal aspect and by the axillary sheath in the midarm.
Signs and symptoms of traumatic brachial plexopathy
A lesion of the brachial plexus can result in motor, sensory, and sympathetic disturbances. Impairments can be transient, as in stinger or burner injuries in football players, or they may result in intractable palsy. Because of the changing arrangement of the brachial plexus as it progresses distally, injuries to it may result in diverse paralyses, anesthesias, and paresthesias, depending on the exact level of injury and the extent of injury to the various elements at that level. [1]
Workup in traumatic brachial plexopathy
Brachial plexopathies may be difficult to accurately diagnose, even with a meticulous investigation. This is not only because the anatomic design of the plexus pose challenges, but also because the types of lesions and injuries that occur are frequently incomplete and complex. Even so, establishing a precise anatomic diagnosis and estimating the severity of the lesion is imperative for prognostic, surgical, and rehabilitative purposes.
Electrodiagnosis has become a mainstay in the diagnostic evaluation of brachial plexopathies. Moreover, many peripheral nerve injuries can be associated with other soft-tissue or bone injuries that can be detected at radiography, while computed tomography (CT) scanning can be used in the investigation of occult fractures that are not depicted on plain radiographs, and conventional magnetic resonance imaging (MRI) can be employed to visualize normal and abnormal peripheral nerve structures. [2]
Management of traumatic brachial plexopathy
Depending on local expertise, a rehabilitation program may be undertaken with a physical therapist and/or an occupational therapist. The goals are to preserve range of motion (ROM), improve strength, and manage pain.
Surgery is reserved for patients in whom symptoms persist despite appropriate conservative treatment. [3, 4, 5, 6, 7, 8] Brachial plexus injuries are not always reparable, however, and in such cases, neurotizations or nerve transfers may offer a better functional outcome. [9]
Related Medscape Drugs & Diseases topics:
Obstetrical Brachial Plexus Injuries
Traumatic Brachial Plexus Injuries
Brachial Plexus Injury in Sports Medicine
Neonatal Brachial Plexus Palsies
Radiation-Induced Brachial Plexopathy
Traumatic Peripheral Nerve Lesions
Related Medscape resource:
Resource Center Trauma
Pathophysiology
In traumatic brachial plexopathy, nerve roots may be avulsed from the cord, or the plexus may be subject to traction or compression. Any injury that increases the distance between the relatively fixed points of the prevertebral fascia and the midforearm may injure the brachial plexus.
Traction or compression may result in ischemia, which initially damages the vasa vasorum. Severe compression injuries can result in intraneural hematomas, which can compress adjacent nerve tissue.
Epidemiology
Frequency
United States
The frequency with which traumatic brachial plexopathies occur varies according the etiology and severity of specific injuries. Brachial plexus injuries are estimated to account for 5% of peripheral nerve injuries. However, the true frequency of injuries to the brachial plexus is undetermined, primarily because of significant underreporting. Prospective studies performed at Tulane University revealed a 7.7% incidence of stingers in a group of college football players; however, other sources have reported a 40% incidence. [10]
International
As noted above, frequency varies according to the etiology and severity of the injury.
Mortality/Morbidity
Coexistent musculoskeletal or central nervous system injury, such as spinal cord injury (SCI) or traumatic brain injury (TBI), is common after violent trauma and presents a diagnostic challenge.
Narakas reported that 80% of patients with severe traumatic brachial plexopathy had multiple trauma to the head and skeletal system. [11]
Root avulsion and contusions of the brachial plexus and cord, which are other frequently occurring coexistent, complicating factors, pose additional diagnostic and prognostic challenges.
A hospital-based, multicenter, observational study by Ciaramitaro et al found that out of 107 patients with traumatic brachial plexus injury, 74 (69%) suffered pain, with 60 (56%) specifically having neuropathic pain. The most frequent and severe form of pain was the spontaneous, burning type. No association was found between pain and age, but pain was determined to be related to the severity of peripheral nerve damage. The investigators also found that neuropathic pain led to depression and impaired quality of life. [12]
Similarly, a study by Landers et al indicated that the prevalence of posttraumatic stress disorder (PTSD), depression, and suicidal ideation is high in adults who suffer traumatic brachial plexus injury. Evaluating 21 patients, the investigators reported that seven of them (33.3%) admitted to suicidal ideation, while evidence of PTSD and clinical depression was found in four patients (19.0%) each. [13]
Race
No race predilection is reported for traumatic brachial plexopathy.
Sex
In general, traumatic brachial plexopathy is more prevalent in men than in women because of an association with violent trauma and sports.
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Certain conditions, such as thoracic outlet syndrome (TOS), are statistically more common in women than in men. [14]
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Other regional differences influence sex- and cause-related statistics.
Age
Because of an association with violent trauma and sports-related injuries, traumatic brachial plexopathy is most prevalent in males in their midteens and in men in their early 30s.
