A 26-year-old woman comes to the emergency department due to back pain and weakness in her legs. Four days ago, she began experiencing pain in her lower back and difficulty moving her feet. Today, she could not stand on her legs due to the weakness. She describes the pain as a sensation of an electrical shock radiating from the buttocks to the feet. She has no difficulty with bowel or bladder function. The patient reports no chronic medical conditions or previous back injury. Two weeks ago, she had an upper respiratory infection that resolved with symptomatic treatment. Temperature is 37 C (98.6 F), blood pressure is 130/82 mm Hg, pulse is 88/min, and respirations are 16/min. On physical examination, motor strength is 3/5 and deep tendon reflexes are absent in bilateral lower extremities. Light touch and pain sensation is normal. There is no tenderness in the spine. Which of the following is the most likely spine MRI finding in this patient?

Question

A 26-year-old woman comes to the emergency department due to back pain and weakness in her legs.  Four days ago, she began experiencing pain in her lower back and difficulty moving her feet.  Today, she could not stand on her legs due to the weakness.  She describes the pain as a sensation of an electrical shock radiating from the buttocks to the feet.  She has no difficulty with bowel or bladder function.  The patient reports no chronic medical conditions or previous back injury.  Two weeks ago, she had an upper respiratory infection that resolved with symptomatic treatment.  Temperature is 37 C (98.6 F), blood pressure is 130/82 mm Hg, pulse is 88/min, and respirations are 16/min.  On physical examination, motor strength is 3/5 and deep tendon reflexes are absent in bilateral lower extremities.  Light touch and pain sensation is normal.  There is no tenderness in the spine.  Which of the following is the most likely spine MRI finding in this patient?

Quizplus · Accepted Answer

11ec25c8_d53c_530d_bc81_3388a5c1d987_MD0003_00 This patient has rapidly progressive, symmetric, ascending muscle weakness with absent deep-tendon reflexes, that occurred after an upper respiratory infection. This is consistent with Guillain-Barré syndrome (GBS), an immune-mediated polyneuropathy caused by demyelination of peripheral nerve fibers. Although GBS is primarily a motor polyneuropathy, sensory symptoms such as paresthesias and mild sensation deficits may be present. Radicular pain, which can be severe, is due to nerve root inflammation and commonly accompanies the initial presentation. GBS is primarily diagnosed based on clinical findings, cerebrospinal fluid (CSF) analysis, and electrodiagnostic studies. However, imaging studies (eg, MRI) are often performed to exclude other conditions. In patients with GBS, MRI of the spinal cord is often normal because GBS primarily affects the peripheral nerves. If significant nerve root inflammation is present, MRI may show enhancement of the anterior (ie, motor) nerve roots or the cauda equina (ie, lumbosacral nerve roots). (Choice A) Epidural fluid collection with rim enhancement is characteristic of a spinal epidural abscess, which can cause cord compression due to the expanding infection. This can lead to diverse neurologic deficits, including motor weakness and sensory changes; however, patients also classically have fever and severe pain worsened by palpation or percussion. spinal epidural abscess (Choice B) Vertebral metastases can be seen on MRI as extradural bony lesions with cord compression. These can cause severe back pain with motor weakness and/or sensory deficits. However, symptom onset typically progresses over weeks rather than days, and affected patients usually have a history of (or significant risk factors for) malignancy. Vertebral metastases (Choice C) Hyperintense T2 signal of a spinal cord segment is characteristic of transverse myelitis, which can present with rapidly progressive ascending weakness that is difficult to distinguish from GBS. However, transverse myelitis typically also presents with severe sensory deficits affecting all somatosensory systems (often with a distinct sensory level) and autonomic dysfunction that often includes bowel and/or bladder incontinence. In addition, radicular pain (ie, electric shock-like sensations radiating from buttocks down the leg) does not commonly occur with TM. distinguish from GBS Educational objective: Guillain-Barré syndrome presents with rapidly progressive ascending motor weakness due to immune-mediated demyelination of peripheral nerve fibers. Because it primarily affects peripheral nerves, MRI of the spinal cord is often normal. References: Spinal MRI findings of Guillain-Barre syndrome. (http://www.ncbi.nlm.nih.gov/pubmed/31338675)

A 26-Year-Old Woman Comes to the Emergency Department Due to Back