A 47-year-old man is brought to the emergency department due to a fall down a flight of stairs. The patient was inebriated and missed a step. He did not lose consciousness but had neck and shoulder pain afterward. The patient also reports numbness and weakness of the left upper extremity. He has no prior medical conditions and takes no medications. Temperature is 37 C (98.6 F), blood pressure is 144/88 mm Hg, and pulse is 94/min. Physical examination reveals neck tenderness. There is mild, left-sided weakness of elbow extension and wrist flexion, with decreased pain sensation of the index and middle fingers. Lower extremity muscle strength and sensation are intact. Plantar reflex is down going bilaterally. CT scan of the cervical spine is shown in the exhibit. Which of the following is the most likely diagnosis?

Question

A 47-year-old man is brought to the emergency department due to a fall down a flight of stairs.  The patient was inebriated and missed a step.  He did not lose consciousness but had neck and shoulder pain afterward.  The patient also reports numbness and weakness of the left upper extremity.  He has no prior medical conditions and takes no medications.  Temperature is 37 C (98.6 F), blood pressure is 144/88 mm Hg, and pulse is 94/min.  Physical examination reveals neck tenderness.  There is mild, left-sided weakness of elbow extension and wrist flexion, with decreased pain sensation of the index and middle fingers.  Lower extremity muscle strength and sensation are intact.  Plantar reflex is down going bilaterally.  CT scan of the cervical spine is shown in the exhibit.  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

Explanation: 11ec25c8_d5cd_e465_bc81_758fe42616d6_MD0003_00 This patient's CT scan of the cervical spine demonstrates anterior subluxation of the C6 vertebral body relative to C7, which is consistent with unilateral C6 facet dislocation. Cervical facet dislocation typically occurs with forced flexion of the cervical spine (eg, falling onto a flexed neck). A single facet is usually dislocated and results in radiculopathy of the corresponding nerve root. The following are the most commonly affected vertebral bodies: C5/C6: Results in C6 radiculopathy with weakness of wrist extension and numbness of the forearm and thumb. C6/C7: Results in C7 radiculopathy with weakness of triceps extension and wrist flexion, as well as numbness of the index and middle finger, as seen in this patient. Bilateral dislocations are less common and usually present with significant spinal cord compression, often resulting in paralysis and upper motor neuron signs (eg, upgoing plantar reflex). Management includes spinal precautions (eg, neck stabilization) and surgical intervention. (Choice A) Although a burst fracture could cause radiculopathy and may often follow significant trauma, it typically occurs at L1. In addition, a burst vertebral body is visible on CT scan. (Choice B) Cervical strain would cause neck pain but would not likely cause the focal neurologic deficits or anterior dislocation of vertebral bodies seen on imaging. (Choice D) Cervical stenosis can cause radiculopathy and symptoms may be preceded by trauma; the anterior dislocation of C6 on CT scan is consistent with cervical facet dislocation, not cervical stenosis, which would demonstrate narrowing of the spinal canal. (Choice E) Syringomyelia (fluid-filled cavity in the spinal cord) can occur as a result of trauma but typically presents months to years after the initial insult; symptoms typically include a capelike loss of pain and temperature sensation, which may be associated with flaccid paralysis. Educational objective: Cervical facet dislocation typically occurs with forced flexion of the cervical spine (eg, falling onto a flexed neck); a single facet is usually dislocated and results in radiculopathy of the corresponding nerve root. The most commonly affected vertebral bodies are C5/C6, which lead to C6 radiculopathy, and C6/C7, which lead to C7 radiculopathy. Imaging demonstrates anterior subluxation of the vertebral bodies. References: Traumatic subaxial cervical facet subluxation and dislocation: epidemiology, radiographic analyses, and risk factors for spinal cord injury. (http://www.ncbi.nlm.nih.gov/pubmed/28739474)

A 47-Year-Old Man Is Brought to the Emergency Department Due