Transverse Myelitis

An otherwise healthy 28-year-old woman presents to the emergency department with progressive weakness that began 3 days earlier. She reports difficulty walking, numbness in the body below her breasts, and urinary urgency, and she notes that neck flexion triggers an electrical sensation that radiates to the coccyx. Physical examination reveals moderate paraparesis with hyperreflexia, a left extensor plantar response, impairment of vibratory and proprioceptive sensation, and a sensory level at T6. Magnetic resonance imaging (MRI) reveals a lower cervical cord lesion that enhances after gadolinium administration, a finding that is consistent with transverse myelitis. How should she be further evaluated and treated?