Just I thought I would mention the neck problem associated with PSP. Some have mentioned it on this forum and I believe it exacerbates the swallowing difficulties people with PSP face in the latter stages of this disease. The back of the head is either pulled back or falls back, and the neck itself becomes more rigid and stiff over time too. My mum would sometimes complain about pain in the neck and it would appear others with PSP suffer from it too. I found if I massaged her neck muscles slightly it seemed to give her some relief and in the end it got so bad I had to lift the back of the head up to make swallowing slightly easier.
A number of suggestions I have read on this forum that may help the neck problems seem to be:
1. Botox injections into the back of the neck muscles, thus reducing the contracting of the neck muscles.
2. Muscle relaxants. Again relaxing the neck muscles.
3. Possibly a neck brace or soft collar to support the back of the head and neck.