Just a few ideas...
I had this with a Beardie who was doing the same thing..
Fill your sink with warm water and put the snake in it supporting it's head..
Massage it's under belly and this will encourage it to go to the toilet..that will at least get one thing out of the way..
Calcium deficiencies can show symptoms of head shaking and thrashing around..There ia a product called "Reptile One-Reptacal"..this is a liquid Calcium which you dot on the snakes body and it gets absorbed quickly...Combine it with "Reptile One-Reptavite" and you will see improvement within 2 weeks..Both bottles cost about $14-
Just something else worth mentioning---The mice that you are feeding it..Have they been gassed down? If yes, Leave them in the freezer for about 1 month as this dissapates the gasses in the mouse....The gasses could be toxic....Also check the hygiene conditions that the mouse has been kept in whilst alive if you can...Has the person had pesticides around them or poor hygiene control as this can produce problems..
Remember-What you feed your prey feeds your snake...
Other things could be: Internal Parasite, Viral,Bacterial Infections, Dehydration (as previously mentioned), Tumours, Trauma, Toxins or Poisons and the list goes on...
WORST OPTION
Is that it could be a Neurological Disorder...
I have read that there is a disease called "Inclusion Body Disease" which results from an unknown virus that attacks the brain and spinal tissues..Symptoms include "Stargazing" and other strange postures that are maintained for extended periods of time. To date there is no known treatment..
If you have a copy of Reptile Australia-On page 42 of Volume 1-Issue 6 there is a report on Neurological Problems in Reptiles that could help you..
Hope this helps..If you have any more q's about where I got this info from-Don't hesitate to PM me...
OF COURSE I AM NOT A VET...AND SO THIS INFO SHOULD BE USED AS SUCH...
Let us know how it goes..
P.S-My Beardie recovered and hasn't done it since...
:wink: