60-year old female presented with decreased movements for the last 2 years with rigidity and veical large square wave jerks. The most likely diagnosis is

Progressive supranuclear palsy, also called Steele-Richardson-Olszewski syndrome, is an uncommon brain disorder that causes serious problems with walking, balance and eye movements. The disorder results from deterioration of cells in areas of your brain that control body movement and thinking Ref Harrison20th edition pg 2456