It is named after WR Kennedy, a neurologist who was among the first to describe this disease ^[1].This disorder was described by Kennedy in 1968. In 1991 it was recognized that the AR is involved in the disease process. The disease is probably more common than originally thought. A study in Scandinavia suggested a prevalence of 1.3/8,500 making KD the most common form of motor neuron disease in the specific area studied; nobody had been diagnosed before 1995. It has been suggested that some men with KD may be misdiagnosed to have amyotrophic lateral sclerosis (ALS, also Lou Gehrig’s disease).