You will get an extra personal exemption for your mother ($2,800 for this year)if you provide over 1/2 of her support. However, there are some things to consider:

1) It sounds like you are in a high tax bracket. If your adjusted gross income (line 33 on your Form 1040) is over $189,950, all of your personal exemptions will begin to be phased-out (reduced). When your AGI reaches $312,450, the personal exemptions will be phased out completely and you will not receive a deduction for them.

2) You can also (potentially) take an itemized deduction on Schedule A for the medical expenses you pay on behalf of your mother. However, only the medical expenses paid that exceed 7.5% of your AGI are deductible. High income taxpayers usually are not able to take advantage of this because they do not exceed the 7.5% threshhold.

Unfortunately, you won't get much in terms of deductions for supporting your mother. The tax code allows child tax credits and credits for amounts paid for children's day care, etc., but doesn't allow any specific credits or deductions for supporting dependent parents.

I hope this helps. Good luck.