Hey Lisa,
I too have a vp shunt, it was reviewed/replaced surgically twice last year, and things have not been good since. I've been trialled on all sorts of meds from painkillers, which work but knock me so badly I can not function, anti seizure medication, migraine treatments, which just put my mind in a fog.
I've tried accupunture, chiropractic therapies and massage. I've seen ENT specialists, eye doctors and attended a pain clinic. With very little success.

I have also tried Botox. I found the actual treatment quite painful. The injections were in my forehead, jawline and the back of my neck and shoulders.
My previous headaches were extremely intense, covering the whole of my head. Some people are able to define their headaches to certain regions eg frontal, posterior and types eg. squeezing, throbbing, I was not able to do this as the pain was 'my whole head'.
Since having Botox things have improved in that the headache at the back of my head has reduced, not gone, but reduced. The pain in the frontal area has not improved at all. The pressure I feel within my face is massive, like my eyes are going to explode.
I have been told my insurance will only cover if the treatment gives me a higher than 70% improvement. Unfortunately, at this point, it has not. I have been told that I can have one further treatment, then if that treatment does not give me the 70% improvement, the treatment will be ceased. I am not hopeful. I understand that Botox will treat the tension within the neck and face but I do not believe my pain is related to tension and I am running out of options.
I hope you and Dean have much better luck and although for some people Botox has been the miracle cure, unfortunately not for me. I do hope Dean's headaches are tension related as often the pain is beyond belief along with the stresses on my wife, which you would have an understanding of.

The very best of luck
Merl1n