I would stretch the introduction over several days. I recently experienced the exciting first day at a new workplace and was introduced to approx. 50 co-workers. I was so overwhelmed that I forgot each and every name at the end of the day.

At the first day, introduce the new employee to everyone, but don't get into any details. After the great introduction, tell the new member only about health isues of the one or two persons they regularily and directly interact with.

In the following days, plan additional rounds of introductions. Visit one or two employees with special needs a day and let them explain how they want / need to be treated. This avoids the feeling of "I already explained that to you and you forgot / ignore my special needs".  
You as the employer / manager should make a list of all employees with special needs to be able to create introduction appointments in the calender of the new employee and tutor without forgetting about someone.