There are several courses on PhysioBob's Jobs & Courses Website that deal with learning and disability. Some are more general approaches, others more specific but all would give useful information.

Take a look at some examples and browse the course list:

Evaluations and outcomes in aphasia care: Making your case

Groups Work: How to design, implement and evaluate group therapy

Develop your communication skills and make a difference

Meeting the Challenges of Severe Aphasia

best of luck 8o