My 5 y.o. daughter has dyspraxia and speech apraxia. I think they both fall under the heading of SPD. When I asked her OT to tell me how she arrived at that diagnosis, she told me it is her inability to plan more than 2 steps ahead. Her dyspraxia affects some of her gross motor skills, but her fine motor skills are excellent. She has made a lot of gains since she began OT. The first week, the OT gave us an exercise where she had to walk in a figure 8 pattern around two objects a few feet apart. She could not do it. She kept walking in an oval. We had to put a string on the floor in a figure 8 to get her to cross in the middle of the two objects. She also couldn't track an object with her eyes when it crossed midline. Now she is able to do that if there aren't any distractions.
She's been having speech therapy since she was three with painfully slow improvement. Then when she started OT and they gave her oral motor exercises, her speech exploded. Even my dad, who is very hard of hearing, can understand her now--that's an accomplishment.