Yes, the diagnosis of Alzheimer's is considered a permanent disability. It is recognized by the Social Security Administration, and therefore, the IRS.
It also qualifies taxpayers to deduct care expenses as medical expenses because the person cannot be unsupervised.
I am sorry your family is facing this issue.
For more information, follow this link:
https://www.alz.org/help-support/caregiving/financial-legal-planning/social-security-disability