A 19-year-old man is brought to the emergency department after being stabbed in the back. Vital signs are normal. He is alert and oriented, with a Glasgow Coma Score of 15. Neurologic examination demonstrates the absence of motor activity in all muscle groups of the right lower extremity, as well as decreased muscle tone. Left leg motor function is normal. Right patellar reflex, Achilles reflex, and Babinski sign are absent. There is loss of light touch and proprioception below the right costal margin. Pinprick sensation is absent on the left side at the level of the umbilicus and below. Which of the following is the most likely location of this patient's injury?

Question

A 19-year-old man is brought to the emergency department after being stabbed in the back.  Vital signs are normal.  He is alert and oriented, with a Glasgow Coma Score of 15.  Neurologic examination demonstrates the absence of motor activity in all muscle groups of the right lower extremity, as well as decreased muscle tone.  Left leg motor function is normal.  Right patellar reflex, Achilles reflex, and Babinski sign are absent.  There is loss of light touch and proprioception below the right costal margin.  Pinprick sensation is absent on the left side at the level of the umbilicus and below.  Which of the following is the most likely location of this patient's injury?

Quizplus · Accepted Answer

Explanation: 11ec25c8_d537_7108_bc81_8f22bb7ffd59_MD0003_00 This patient who was stabbed in the back has a variety of neurologic deficits concerning for Brown-Séquard syndrome. This syndrome typically occurs due to hemisection (ie, disruption to half) of the spinal cord. Findings include the following: Ipsilateral hemiparesis: lateral corticospinal tract (LCT); occurs at the level of the cord injury and below Ipsilateral diminished proprioception, vibratory sensation, and light touch: dorsal columns; occurs at the level of the cord injury and below Contralateral diminished pain and temperature: lateral spinothalamic tract (LST); occurs 1-2 levels distal to the cord injury and below because LST sensory neurons send axon projections up 1-2 levels prior to decussating (crossing over) In this patient, a right spinal hemisection at T8 would cause a contralateral (left-sided) LST deficit beginning around T10 (ie, the level of the umbilicus according to the dermatomes). Such a lesion is less likely to affect contralateral pain and temperature sensation at T8 because the left-sided T8 fibers decussate to the right-sided spinal cord 1-2 levels above T8 (eg, T6, proximal to the site of injury). dermatomes When Brown-Séquard syndrome occurs in the cervical region, there may be associated ipsilateral Horner syndrome (ptosis, miosis, anhidrosis). In addition, ipsilateral reflexes (including Babinski) may be initially absent due to spinal shock (ie, temporary loss of all distal spinal cord function, including spinal cord reflexes); after the spinal shock resolves, ipsilateral hyperreflexia and positive Babinski are typically present. (Choices A and B) An anterior spinal artery injury at T8 or T10 can cause anterior cord syndrome; this is characterized by distal paralysis (LCT) and decreased pain and temperature sensation (LST) bilaterally, with preserved distal proprioception, vibratory sensation, and light touch due to sparing of the dorsal columns. anterior cord syndrome (Choices C and D) Complete spinal transection at T8 or T10 would likely cause bilateral paralysis and complete loss of sensation below the level of injury. (Choices E, F, and H) Left spinal hemisection at T8 or T10 would cause Brown-Séquard syndrome; however, it would be opposite to this patient's presentation (eg, left leg paralysis). Right spinal hemisection at T10 would cause Brown-Séquard syndrome, but the contralateral (left-sided) LST deficit would begin around the T12 level. Educational objective: Hemisection of the spinal cord can cause Brown-Séquard syndrome, which is characterized by the following: Ipsilateral hemiparesis and diminished proprioception, vibratory sensation, and light touch at the level of the spinal cord injury and below Contralateral diminished pain and temperature sensation 1-2 levels distal to the cord injury and below References: Incomplete cord syndromes: clinical and imaging review. (http://www.ncbi.nlm.nih.gov/pubmed/29995620) Radiographic and intraoperative imaging of a hemisection of the spinal cord resulting in a pure Brown-Séquard syndrome: case report and review of the literature. (http://www.ncbi.nlm.nih.gov/pubmed/23584224) Assessment and management of acute spinal cord injury: from point of injury to rehabilitation. (http://www.ncbi.nlm.nih.gov/pubmed/28571527)

A 19-Year-Old Man Is Brought to the Emergency Department After