A teenage girl, without any medical history of interest, suffered an abrupt pain in the lumbar region, distal cold limbs, weakness, and paraesthesia in lower limbs, as well as walking difficulties. These symptoms appeared after playing piggyback.
At physical examination, she was unable to move her toes and to keep on her feet, but she could move her arms and the proximal area of her legs. After 4 hours, she suffered from bilateral motor loss in flexion and extension of her ankles (grade 1/5), and in her knees as well (grade 4/5), with preserved sensitivity, normal knee-jerk reflex, and hypoactive ankle-jerk reflex. Additionally, she had urine retention and overflow incontinence that was resolved spontaneously.
In an initial laboratory test, there were no data indicative of an infection or haemostatic abnormalities. MRI of the spinal cord and echo-Doppler of limbs were normal. The autoimmune disease test in CSF and blood coagulation study was normal as well. CSF cultures and serology were negative, with the exception of M Immunoglobulin (Ig), which showed a positive result for Mycoplasma pneumonia, without any seroconversion in G Ig.
During her hospital admission, her motor strength improved; however, she kept swaying walk. After 10 days, MRI was repeated, and an increase in bone density in conus medullaris and bone infarction in vertebral lumbar L1 (in T2-weighted sequence) were observed (Figure 1). She was medicated with acetylsalicylic acid, and she completed a rehabilitation program. In one-year follow-up, she improved her mobility, being able to walk by herself.