Abstract

70-year-old female receptionist presented with acute onset lower back pain whilst sitting down. She tried to weight bear but felt her left leg ‘gave way’. There were no sensory complaints and no sphincter disturbance. Positive examination findings in her left lower limb include reduced tone, power 2/5 throughout, and left extensor plantar. In addition, she had absent knee and ankle reflexes bilaterally and loss of pinprick and temperature sensation on the right side up to L1 dermatome, with preservation of vibration and proprioception. She had a normal sensory examination of her left lower limb and rectal examination was unremarkable. Clinically, she has an atypical form of Brown-Séquard syndrome with weakness in the left lower limb and sensory loss in the right lower limb with a sensory level. MRI lumbar/sacral spine showed L3 slipped anteriorly with L3/4 disc bulge resulting in cauda equina syndrome. She was re-scanned five days later including thoracic spine and found to have an acute left hemi-cord infarct at T8/9. This case demonstrates the importance of scanning the relevant sections of the cord and to keep a broad differential in mind, as there can be two aetiologies at work which might misguide the clinician at first glance.