July 2017

A 55-year-old man with left upper extremity weakness following a gunshot wound

History

A 55-year-old, right-hand dominant male presents to the outpatient clinic six weeks after suffering a gunshot wound to the left neck with persistent left upper extremity weakness.

Exam

• Cranial nerves intact, including symmetric shoulder shrug. Diffuse weakness of left  arm 0/5 Shoulder abduction, external rotation – shoulder passively subluxed. 1/5  elbow flexion and supination. 4/5 Weakness of elbow and wrist extension, intact grip    and interosseous.
• Well-healed entry wound in the left neck posterior to the SCM, midclavicular 2 cm    rostral to the clavicle.
• Absent C5 and C6 sensory.
 

Follow-up Physical Exam

• Three month follow–up.
• 0/5 shoulder abduction, 0/5 external rotation. 3 /5 elbow flexion.
• 5/5 wrist extension, triceps, finger flexors, and intrinsics.
• No change in sensory.
 
Imaging
 
CT Angiogram-evidence of previous extensive vascular injury intact stent and patient vascularity. C6 and C7 transverse process fractures. Retained bullet fragment lateral to the C7 transverse process. Distal occlusion of radial artery with intact ulnar artery and good collateral.
 

 

Electrodiagnostics

 
1.Based on the information available, what is the likely dominant injury pattern to the musculocutaneous nerve?
2. What is the optimal timing for the treatment of gunshot wound associated brachial plexus injuries?
3. What surgery will be required to address his injuries?
4. Which of the following describes you?
5. I practice in one of the following locations.
6. Comments

Case Explanation: Explanation of Answers

•This patient sustained a traumatic GSW blast injury to the brachial plexus with imaging evidence of an associated vascular injury. 
Question 1 – (A) The musculocutaneous nerve is showing clinical evidence of recovery at  3 months, suggesting predominantly a neuropraxic injury pattern. Ischemia related to the vascular injury does not provide an assessment of nerve injury severity.

Question 2 – (C)The patient underwent outside stabilization and vascular stenting, while early surgery at the time of exploration for initial tagging of the nerves can be done, definitive repair acutely is not indicated since it is not possible to clearly define the true extent of the zone of injury. Most authors would advocate 3 -4  months as the ideal time to explore, with 6 months being the latest for optimal outcomes.

Question 3 – (B)All 3 options could be undertaken, with many surgeons moving toward a combined plexus exploration and distal transfers. In this particular case, the presence of previous vascular injury, nerve transfers alone may provide a safer approach than a plexus exploration. Free muscle transfer could be utilized as a delayed salvage procedure.

References:
Gunshot wounds involving the brachial plexus: surgical techniques and outcomes. Kim DH, Murovic JA, Tiel RL, Kline DG. J Reconstr Microsurg. 2006;22(2):67-72

Direct plexus repair by grafts supplemented by nerve transfers. Kline DG, Tiel RL. Hand Clin. 2005;21(1)55-69

Surgical Outcomes of the brachial plexus lesions caused by gunshot wounds in adults. Secer HI, Solmaz I, Anik I, Izci Y, et al.J Brachial Plex Peripher Nerve Inj. 2009;4:11

Penetrating injuries due to gunshot wounds involving the brachial plexus. Kim DH, Murovic JA, Tiel RL, Kline DG. Neurosurg Focus. 2004;16(5) E

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