Question category: Neurology
A 32 year old female has a three day history of severe occipital headache and neck pain following a minor injury. She is then brought to A+E following development of pain and numbness on the right side of her face, dysarthria, hoarseness, dysphagia and vertigo. There is left sided loss of pain and temperature sensation and weakness. She is ataxic and there is evidence of nystagmus and a right sided horners syndrome. What is the most likely diagnosis?