A 21-year-old man comes to the emergency department due to unsteady gait and difficulty urinating for a day. Over the past 4 days, the patient has noticed numbness beginning in both feet and gradually progressing to the thighs, buttocks, and abdomen. He has no pain. Temperature is 37 C (98.6 F), blood pressure is 120/70 mm Hg, pulse is 88/min, and respirations are 18/min. On examination, sensation to light touch, temperature, and pinprick is reduced below the midthoracic region. Vibration and joint position sensation are absent in both feet. Muscle bulk and tone are normal, but strength in both lower extremities is 4/5. Deep tendon reflexes in the lower extremities are brisk with bilateral upgoing plantar reflexes. Upper extremity examination is normal. Which of the following is the most likely diagnosis?

Question

A 21-year-old man comes to the emergency department due to unsteady gait and difficulty urinating for a day.  Over the past 4 days, the patient has noticed numbness beginning in both feet and gradually progressing to the thighs, buttocks, and abdomen.  He has no pain.  Temperature is 37 C (98.6 F), blood pressure is 120/70 mm Hg, pulse is 88/min, and respirations are 18/min.  On examination, sensation to light touch, temperature, and pinprick is reduced below the midthoracic region.  Vibration and joint position sensation are absent in both feet.  Muscle bulk and tone are normal, but strength in both lower extremities is 4/5.  Deep tendon reflexes in the lower extremities are brisk with bilateral upgoing plantar reflexes.  Upper extremity examination is normal.  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

Explanation: 11ec25c8_d5d2_9f5c_bc81_9f84c6f03a7e_MD0003_00 This young patient has rapidly progressive, bilateral lower extremity weakness accompanied by upper motor neuron (UMN) signs (eg, hyperreflexia, upgoing Babinski), sensory defects with a localizing (midthoracic) spinal sensory level, and autonomic (bladder) dysfunction. This presentation is most consistent with transverse myelitis (TM). TM is an immune-mediated disorder that often follows a recent infection (eg, gastroenteritis, upper respiratory infection) and leads to a rapidly progressive myelopathy characterized by the following: Motor weakness that may be accompanied by UMN signs (due to involvement of the long tracts) or lower motor neuron signs (due to involvement of the gray matter of the spinal cord) Sensory dysfunction affecting all somatosensory systems (eg, touch, pain/temperature, vibration/proprioception) with a distinct sensory level (ie, lowest spinal cord level with intact sensation) Autonomic dysfunction that often includes bowel/bladder incontinence or retention To confirm the diagnosis, cord compression should be excluded via imaging (MRI). MRI in TM shows T2 hyperintensity; evidence of inflammation (pleocytosis and elevated IgG) is seen on cerebrospinal fluid analysis. (Choice A) Acute inflammatory demyelinating polyneuropathy (ie, Guillain-Barré syndrome) can present with rapidly progressive, ascending weakness in a young patient. However, UMN signs (eg, hyperreflexia, upgoing Babinski) and a distinct sensory level would not be present. (Choice B) Infarction of the anterior spinal artery can result in motor weakness and loss of pain and temperature sensation below the level of the infarction. However, vibration and proprioception would be spared, unlike in this patient, because they are controlled by the posterior columns. (Choice C) A spinal epidural abscess can present with progressive myelopathy due to cord compression from an expanding infection in the spinal column. Associated neurologic deficits may have significant overlap with TM; however, patients classically have localized back pain and fever. (Choice E) Vitamin B₁₂ deficiency can cause degeneration of the dorsal and lateral spinal tracts (ie, subacute combined degeneration), resulting in sensory ataxia with progressive spastic paraparesis and incontinence. However, it does not present acutely and would not cause a distinct sensory level. ₁₂ Educational objective: Transverse myelitis is an immune-mediated disorder that causes a rapidly progressive myelopathy characterized by motor weakness (with upper and/or lower motor neuron signs), sensory disturbances (characterized by a distinct sensory level), and autonomic dysfunction (including bowel or bladder dysfunction). References: Guillain-Barré syndrome, transverse myelitis and infectious diseases. (http://www.ncbi.nlm.nih.gov/pubmed/29375121)

A 21-Year-Old Man Comes to the Emergency Department Due to Unsteady