Is there any chance of halting the process of neuron degenerating disorder?

Degenerative brain disorders have an interesting characteristic - insufficient amount of certain neurotransmitters in the brain. For example, Alzheimer's Disease is characterized with lack of ACh, while Parkinson's with lack of dopamine. Because of this, a common approach to reduce the rate of degeneration is by increasing these neurotransmitters in the body, but it does not stop or prevent these diseases.