A composition, method and related systems for treating and/or preventing spasticity in a patient using negative pressure therapy. The negative pressure therapy may include intermittent application of negative pressure to a limb or portion of a body, such as alternating between periods of negative pressure and ambient pressure. The negative pressure therapy may be applied on a regular basis for a predetermined period, such that an effective amount of negative pressure for treating spasticity and other symptoms of neurogenerative diseases is administered. The negative pressure therapy may be applied to cause intermittent activation of the venous arterial reflex in the body for a sustained period, such that symptoms of neurogenerative diseases are alleviated or prevented.