Severe CAS

Severe CAS indicates that the deficit in motor planning/programming for speech is severe, seriously limiting speech production.

Young children with severe CAS may be pre-verbal (not yet speaking) or only have a few words and rely mostly on gestures like pointing to communicate.
Older children with severe CAS typically will have obvious struggle to produce single words and phrases. Speech intelligibility (understandability) may be greatly reduced and it may be very hard to understand the child as they try to express simple thoughts and ideas.
Children with severe CAS require intensive treatment with a motor-based therapy approach and often treatment will be necessary for several years. You can generally expect to see progress monthly for a child with severe CAS.
Dynamic Temporal and Tactile Cueing (DTTC) and Nuffield Dyspraxia Program (NDP3) have been studied and shown to be effective treating severe CAS.
Your child's needs determine the appropriate treatment and your child's needs may change over time. Given that the deficit in motor planning/programming is severe, your child's approach may always need to include motor-based therapy, such as DTTC. Your child will likely have other needs, such as language, that may be addressed with more traditional speech therapy methods.