Be respectful toward all students, including the student who's misbehaving. Children learn by example, and in order for a child to learn respect, he must see it being practiced. When addressing the student's disrespectful behavior, be sure to approach him respectfully.
Speak with the child in private. It's not necessary to humiliate a student, especially if she has a neurological disorder. When speaking with her, tell her that you're aware of her condition, and that you're there for her. Sometimes children with neurological disorders such as Tourette's syndrome, or TS, may seem as though they're misbehaving even though they're really just experiencing a tic.
Acquaint yourself with the child's specific neurological disorder so that you may better accommodate him, both educationally and disciplinarily. A child with attention-deficit/hyperactivity disorder (ADHD), for example, may need frequent discipline for small outbursts, whereas a child with TS may have some tics that should just be ignored.
Have a conversation with your classroom when the student with the disorder is absent. Let them know that she is a person, just like they are, and that she needs to be treated with respect. It's also important that they be aware of any strange behaviors that may result from the disorder.
Consult the student and ask him what he thinks will help make him a better classmate. Explain to him that his behaviors can't be tolerated, but that there are things he can do to improve. Use this more positive approach rather than attempting to list the things that are wrong with him.
Be calm in your demeanor. Speak softly and slowly regardless of how frustrating the child is. Remember that she has a disability and that she needs to be treated with extra care. Being aggressive or losing your temper will most likely increase the child's anger or misbehavior.