Motor neuron disease (MND) is a serious and incurable form of progressive neurodegeneration-over time the nerves in the spine and brain progressively lose function. In the case of motor neuron disease, motor neurons-types of nerve cells-are affected.The renowned English physicist, Stephen Hawking, and guitar virtuoso Jason Becker are living with motor neuron disease. In all three MND forms symptoms are very similar.However, they progress at different speeds.otor neurons are found in the brain and spine. When motor neurons relay signals from the brain to the muscles and bones, the muscles move. Motor neurons are also involved in many of our automatic movements, such as swallowing and breathing.