Why do I stutter, lose my balance and slur my speech when I don't get enough sleep?

Importance of sleep. Your brain needs enough hours of sleep to go through the necessary sleep stages in order to function well. Coordination, memory, learning, problem solving and other brain-mediated functions are all affected by the quality and quantity of sleep you get.
Fatigue. Not having enough sleep tires out your body and making you lose some bodily and mental control. If this only happens when you don't get enough sleep. It would not appear to be serious. But if this happens for no reason, then you need to see a neurologist.