What is the differences between Machado-Joseph Disease and Multiple Sclerosis?

Answer 1

Machado-Joseph disease (MJD), also known as Machado-Joseph Azorean disease or Joseph's disease or Spinocerebellar ataxia type 3 (SCA3), is a rare autosomal, dominantly inherited neurodegenerative disease that causes progressive cerebellar ataxia,[1] which results in a lack of muscle control and coordination of the upper and lower extremities.[2] The symptoms are caused by a genetic mutation that results in an expansion of abnormal "CAG" trinucleotide repeats in the ATXN3 gene [1] that results in an abnormal form of the protein ataxin which causes degeneration of cells in the hindbrain.[2] Some symptoms, such as clumsiness and rigidity, make MJD commonly mistaken for drunkenness and/or Parkinson's disease.

Multiple sclerosis (MS), also known as disseminated sclerosis or encephalomyelitis disseminata, is an inflammatory disease in which the insulating covers of nerve cells in the brain and spinal cord are damaged. This damage disrupts the ability of parts of the nervous system to communicate, resulting in a wide range of signs and symptoms,[1][2] including physical, mental,[2] and sometimes psychiatric problems.[3] MS takes several forms, with new symptoms either occurring in isolated attacks (relapsing forms) or building up over time (progressive forms).[4] Between attacks, symptoms may go away completely; however, permanent neurological problems often occur, especially as the disease advances.[4]

Both of these answers are from Wikipedia.