Brachial Plexus Palsy (BPP), manifests as arm weakness (with passive range of motion greater than active) and loss of sensation, evident at time of injury due to stretching, compression and / or rupture of nerves of the brachial plexus or injury to the more distal peripheral nerves.
When to Refer
Early referral (as soon after injury as possible) of adults with severe or extensive BPP to interdisciplinary specialty clinics can improve overall functional outcome.
Causes and Symptoms
All peripheral nerve palsy and brachial plexus injury cases are not the same and the clinical presentation may be different depending on which nerves of the brachial plexus are affected. The severity of brachial plexus palsy can vary from mild to severe nerve injury of the nerves. The brachial plexus is a very complex structure that connects the spinal nerves in the neck to their distal branches in the arm, supplying motor and sensory function. It is commonly divided into 5 anatomical sections: (1) spinal nerve roots (C5, C6, C7, C8, and T1), (2) trunks (upper, middle, and lower), (3) divisions (anterior and posterior) of each trunk, (4) cords (lateral, posterior, and medial), and (5) branches (terminal). For simplicity, the nerve roots can be indexed to the muscles in the following fashion: C5-shoulder movement, C6-elbow flexion, C7-elbow extension, C8/T1-hand and finger movement.
Treatment and Therapy
A weak arm observed at time of injury or around the time of injury warrants confirmation of the diagnosis of BP dysfunction or peripheral nerve injury by a specialist. A thorough history and physical of the injury along with presenting signs and symptoms may support the diagnosis of brachial plexus dysfunction/peripheral nerve injury. In the early days after injury or onset of symptoms, any associated skeletal injuries or fractures should be confirmed by clinical and radiographic evaluation since these injuries may preclude early occupational/physical therapy. No substantial evidence exists to support further injury to the brachial plexus with gentle handling of the neck and affected arm, and immobilization of the arm is not recommended except in the context of skeletal injuries. Determination of the extent and severity of the nerve injury is critical for prognostication and for determination of subsequent treatment. Other neurologic disorders occurring concurrently with BPP/Peripheral Nerve Injury, can be suspected with the presence of a lack of spontaneous movements and normal reflexes that suggest global neurological deficits. Alternatively, an observed asymmetric expansion of the chest cavity and difficulty with breathing, difficulty catching ones breathe, can suggest diaphragmatic palsy resulting from associated phrenic nerve injury, confirmed with plain X-rays or ultrasonography; diaphragmatic palsy can be a dangerous condition leading to respiratory distress. Will need to label With regard to the movement of the affected arm, the treating physician should assess the passive and active range of motion of the affected arm. Available assessment scales of motor function in BPP can be used to determine the extent and severity of nerve injury, to prognosticate potential functional recovery, and to guide and assess the outcomes from further treatment. Traditional assessments focus solely upon the affected arm, but more recently, assessment methods are refocusing upon the overall function of the adult affected by brachial plexus palsy or peripheral nerve palsy. Supplementing the physical examination with electrodiagnostic (EDX) / electromyography (EMG) and radiographic (magnetic resonance imaging, MRI, ultrasound, CT) findings are helpful to decide whether nerve reconstruction will be beneficial. Regardless of the need for surgical intervention, rehabilitation management is critical. Occupational/physical therapy to maintain the normal passive range of motion in all upper extremity joints (especially shoulder external rotation and forearm pronation and supination) facilitates successful functional recovery of global function. Patients themselves and caregivers should consider themselves to be the patient’s primary therapist by performing range of motion exercises regularly. Reinforced use of the affected arm while constraining the normal arm (constraint therapy) can aid the patient's recognition of the arm and strengthen the arm through increased arm use during activities. Splinting may be used during sleep to avoid the formation of contractures or to protect floppy joints. For BPP/peripheral nerve dysfunction patients who do not recover with conservative management, surgery for nerve reconstruction may be an option, usually occurring between 3-12 months after injury. Although the indications and timing for nerve reconstruction have not been absolutely established, most practitioners agree that adults with the extensive total brachial plexus palsy and those with the severe upper trunk palsy will benefit from nerve surgery. The goal of nerve reconstruction is not to regain a normal arm, but surgical intervention is a step towards a functional arm with adequate movement for activities of daily living, not power. Nerve repair using autologous nerve graft and/or nerve transfer constitute the primary options for reconstructing the brachial plexus. As nerve repair and transfer rely upon regrowth of the normal portions of the nerve through the residual pathways after the injured distal nerve is cleared away (Wallerian degeneration) and as this nerve regeneration is very slow, the ultimate functional outcome from nerve reconstruction surgery may not be apparent for 1-3 years. Patients with incomplete recovery following nerve reconstruction or conservative treatment may have functional limitations because of residual muscle weakness and soft tissue contractures, especially around the shoulder and elbow. Radiographic imaging can guide the decision to pursue orthopedic intervention. For patients with residual elbow, forearm, and hand problems, secondary procedures by a hand surgeon may help function. These procedures include soft tissue releases, joint fusions, muscle transfers, and corrective osteotomies. Restoration of elbow flexion is a main priority, and in patients with a flail wrist/hand, the order of priority is restoration of wrist extension, thumb flexion, finger flexion, followed by thumb and finger extension. For all surgical interventions, the most important factor in producing the optimal result is a cooperative patient with intense investment. The patient must understand the objectives of the surgical procedures and work diligently in post-operative rehabilitation -- by being their own primary therapists. Surgery alone without subsequent rehabilitation management and therapy without diligence is unlikely to yield the desired outcome along with compliance of not smoking.
Overall, the majority of adult patients with BPP have a fair to good prognosis for recovering adequate functional use of the affected arm, with rehabilitation management and therapy supplemented with surgical intervention when and where appropriate and desired. Early occupational/physical therapy supports the spontaneous recovery of function and minimizes consequent musculoskeletal comorbidities. Therefore, our program exists not only to find new medical treatment techniques but also to increase awareness, to address and improve the quality of life for patients with BPP via traditional and recent technology-assisted modalities. For BPP patients with extensive or severe nerve palsies, we strongly suggest early referral to an interdisciplinary specialty brachial plexus clinic to avail the patient of the most current treatment paradigms to achieve the optimal outcome.