While there is no direct answer on this topic from the IRS, I believe we can infer that the costs of the state-required driver rehab program would be a deductible medical expense in the year paid.
The IRS defines medical expense as follows:
"Medical expenses are the costs of diagnosis, cure, mitigation, treatment, or prevention of disease, and the costs for
treatments affecting any part or function of the body.
These expenses include payments for legal medical services rendered by physicians, surgeons, dentists, and
other medical practitioners. They include the costs of
equipment, supplies, and diagnostic devices needed for
these purposes."
A case can certainly be made that the driver rehab program serves to mitigate the effects of your disability.
If we look at the documented IRS treatment of the expenses for a guide dog for the blind, we can build an analogy to your circumstances. The IRS permits a deduction for the training of guide dogs, and that training includes a component in which the visually-impaired person is paired with, and trained to manage and receive cues from, the dog. In your case, it appears entirely reasonable that you should be able to deduct the cost of training to operate, and respond to, the newly-installed hand controls of your vehicle, which allow you to return to a state of independence you enjoyed prior to your disability.
