Dyskinesia is an umbrella term encompassing a range of different movements. These are all movements that can be out of your control. Dyskinesia is very common in cerebral palsy.
Spasticity is usually caused by central nervous system injuries, such as brain injuries or spinal cord injuries. Spasticity is a little different from stiffness.
Cerebral palsy is an injury to the brain, but what we find is that it has a lot of effects on how you use your muscles.
Let me tell you about multimodal communication. We, as typical communicators, all use many different strategies. We use speech, gestures, facial expressions, technology, and no-tech solutions. As communicators, we all size up the situation based upon our communication partners, the context, the environment and then we choose to use the most effective communication strategy.