medical expense - I did something dumb

I see a chiropractor twice a week. I have for the past four years. This year we had very large additional medical expenses. They were high enough so that there will be a significant deduction after the

The person working at the chiro's office suggested I might want to make a payment in advance so I could use it as a 2007 deduction. Unfortunately I didn't do my homework. I paid an extra $1000 in December.

Now, reading publication 509 I see that I cannot deduct payments made in 2007 for treatment received in 2008.

Question: will I be able to deduct that $1000 for 2008 (assuming our medical expenses are high enough) or have I screwed myself out of a $1000 deduction?