summary Brachial plexus injuries (BPIs) can involve any degree of injury at any level of the plexus and range from obstetric injuries to traumatic avulsions. Diagnosis requires focused physical examination with EMG/NCS and MRI studies used for confirmation as needed. Treatment can be conservative versus operative depending on the age of patient, chronicity of injury, degree of injury and nerve root involvement. Epidemiology Anatomic location supraclavicular injuries login to view 6 more bullets Etiology Mechanism high speed vehicle accidents (mostly motorcycle) login to view 1 more bullet caudally forced shoulder login to view 2 more bullets forced arm abduction (as in grabbing onto something while falling) login to view 1 more bullet Brachial Plexus injuries include traumatic injury (this topic) obstetric brachial plexus injury login to view 2 more bullets burners and stingers Parsonage-Turner Syndrome Anatomy Anatomy brachial plexus motor and sensory innervation Classification Preganglionic vs. postganglionic preganglionic login to view 20 more bullets postganglionic login to view 8 more bullets Classification based on location Upper Lesion: Erb's Palsy (C5,6) Introduction Most common obstetric brachial plexopathy Results from an excessive displacement of head to opposite side and depression of shoulder on the same side producing traction on plexus. Occurs during a difficult delivery in infants or fall onto shoulder in adults Best prognosis Physical Exam Clinically, the arm will be adducted, internally rotated, at shoulder; pronated, extended at elbow (“waiter’s tip”) C5 deficiency -axillary nerve deficiency (weakness in deltoid, teres minor) -suprascapular nerve deficiency (weakness in supraspinatus, infraspinatus) -musculocutaneous nerve deficiency (weakness to biceps) C6 deficiency -radial nerve deficiency (weakness in brachioradialis, supinator) Lower Lesion: Klumpke Palsy (C8,T1) Introduction Rare in obstetric palsy Usually avulsion injuries caused by excessive abduction (person falling from height clutching on an object to save himself) Other causes may include cervical rib, or lung mets in lower deep cervical lymph nodes Frequently associated with a preganglion injury and Horner's Syndrome Poor prognosis Physical Exam Deficit of all of the small muscles of the hand (ulnar and median nerves) Clinically, presents as “claw hand” -wrist held in extreme extension because of the unopposed wrist extensors -hyperextension of MCP due to loss of hand intrinsics -flexion of IP joints due to loss of hand intrinsics Total Palsy (C5-T1) Introduction A form of brachial plexopathy Worst prognosis Physical Exam Leads to a flaccid arm Involves both motor and sensory Presentation History high energy injury Physical exam Horner's syndrome login to view 6 more bullets severe pain in anesthetized limb login to view 1 more bullet important muscles to test login to view 2 more bullets pulses login to view 2 more bullets Imaging Radiographs chest radiograph login to view 5 more bullets cervical spine series login to view 3 more bullets scapular and shoulder series login to view 3 more bullets clavicle login to view 3 more bullets CT myelography indications login to view 1 more bullet avulsion of cervical root causes dural sheath to heal with meningocele scan should be done 3-4 weeks after injury login to view 1 more bullet MRI indications login to view 3 more bullets findings login to view 6 more bullets Studies Electromyography (EMG) tests muscles at rest and during activity fibrillation potentials (denervation changes) login to view 2 more bullets can help distinguish preganglionic from postganglionic login to view 4 more bullets Nerve conduction velocity (NCV) performed along with EMG measures sensory nerve action potentials (SNAPs) login to view 7 more bullets Nerve action potential (NAPs) often intraoperative tests a nerve across a lesion if NAP positive across a lesion login to view 2 more bullets can detect reinnervation months before EMG login to view 2 more bullets Sensory and Motor Evoked Potential more sensitive than EMG and NCV at identifying continuity of roots with spinal cord (positive finding) login to view 1 more bullet perform 4-6 weeks after injury to allow for Wallerian degeneration to occur stimulation done at Erb's point and recording done over cortex with scalp electrodes (transcranial) Treatment Nonoperative observation alone waiting for recovery login to view 5 more bullets Operative immediate surgical exploration (< 1 week) login to view 10 more bullets early surgical intervention (3-6 weeks) login to view 1 more bullet delayed surgical intervention (3-6 months) login to view 6 more bullets Techniques Direct nerve repair rarely possible due to traction and usually only possible for acute and sharp penetration injuries Nerve graft commonly used due to traction injuries (postganglionic) preferable to graft lesions of upper and middle trunk login to view 1 more bullet donor sites include sural nerve, medial brachial nerve, medial antebrachial cutaneous nerve vascularized nerve graft includes ulnar nerve when there is a proven C8 and T1 avulsion (mobilized on superior ulnar collateral artery) Neurotization (nerve transfer) transfer working but less important motor nerve to a nonfunctioning more important denervated muscle use extraplexal source of axons login to view 4 more bullets intraplexal nerves login to view 5 more bullets Muscle or tendon transfer indications login to view 1 more bullet priorities of repair/reconstruction login to view 7 more bullets technique login to view 1 more bullet Prognosis Recovery of reconstructed plexus can take up to 3 years nerve regeneration occurs at speed of 1mm/day Good prognostic variables infraclavicular plexus injuries have better prognosis than supraclavicular injuries upper plexus injuries have improved prognosis login to view 1 more bullet Poor prognostic variables root avulsion (preganglionic injuries) have worst prognosis login to view 2 more bullets