Q. Is that deductible under a medical expense since he has a disability?
A. Yes.
But, medical deductions are only an itemized deduction. You only get to deduct that portion of you medical deductions that exceed 7.5% of your AGI. To get any benefit, the total of all your itemized deductions must also exceed your standard deduction ($14,600 Single, $29,200 Married filing jointly).