MND stands for Motor Neurone Disease, which is basically a neurological disorder due to which those cells are destroyed that control voluntary muscle activities like speaking, breathing, swallowing etc. On the other hand MS stands for Multiple Sclerosis disease which effects the central nervous system and causes muscle weakness, depression, coordination difficulties etc. They are different diseases. For more information on MND, see the link below:
www.mndassociation.org
www.mndassociation.org