A 37 year old man with β thalassaemia major presented to the haematology day unit with a three week history of increasing back pain. The pain was aggravated by movement and the patient found it increasingly difficult to walk. He said he felt “wobbly” on his feet. He had no history to indicate sphincter dysfunction. He was regularly transfused and his haemoglobin at presentation was 11.3 g/dl.

On neurological examination, his tone was normal, and he had normal power (5/5) in all muscle groups of his lower limbs. He had brisk knee jerks and, to a lesser extent, ankle jerks bilaterally, with an upgoing plantar response on the right side and an equivocal reaction on the left. He had hypoaesthesia of his legs and torso with a sensory level at T5. He showed no signs of cerebellar dysfunction. His gait was not assessed. The rest of the examination was unremarkable. An urgent MRI scan of the whole spine was performed the same day.⇓