A 50-year-old right-handed retired family business manager developed progressive left-sided weakness over 5 days after a mechanical fall. She remembered catching her foot on the carpet and falling down a flight of stairs, followed by severe neck pain over C4-C5 and inability to get up for nearly an hour. Over the subsequent month her symptoms progressed and she presented to hospital with an asymmetric spastic paraparesis, loss of pinprick sensation in her arms and legs, loss of vibration sense to both hips, and double incontinence.