Question #1: A 65 year old gentleman is referred to you from the GP as he developed shoulder pain and thought that one of his eyelids was drooping. On exam you notice that he is frail, has a left-sided partial ptosis and a constricted, non-reactive pupil on that side. His ocular movements are normal and visual acuity is intact. On examining his arms you notice that the he has some wasting of the dorsal interossei on the left and weakness of finger ab and adduction. The rest of the examination is normal. What is the most likely diagnosis?

Question #2: What would be the characteristic lower limb findings in a Brown-Sequard syndrome?

Question #3: What is the mechanism of action of carbidopa?

Question #4: A well 50 year old gentleman presents to his GP with episodes a short, sharp, electric-shock like pains in his jaw which occur frequently whenever he feels a cold breeze or touches his cheek. On examination the function of his cranial nerves is normal, and he has no focal neurological abnormalities in his arms or legs. What is the most appropriate first-line treatment?

Question #5: A 56 year old man with known ALS presents to A&E having become increasingly short of breath over the last few weeks. His breathing is now so bad that he cannot get dressed without getting of breath. What acid-base abnormality on arterial blood gas best fits this presentation?