Primary Lateral Sclerosis (PLS)

Primary lateral sclerosis (PLS) is an upper motor neuron disease that is only one of a larger group of motor neuron diseases. More specifically, with PLS the upper motor neurons that are affected are located in the arms, legs and face, which also directly is related to the order in which the disorder begins to affect the body, starting with the muscles in the leg, moving up to the speech and swallowing muscles. Although PLS is not a fatal disorder, according to the National Institute of Neurological Disorders and Stroke, it can cause symptoms such as, “weakness, muscle stiffness and spasticity, clumsiness, slowing of movement, and problems with balance and speech.”