This article deals with spasticity-based cerebral palsy chiefly affecting the lower extremities, which is the most common. For other types of cerebral-palsy-based spasticity affecting other limbs in varying combinations, see spastic cerebral palsy.
Spastic diplegia, historically known as Little's Disease, is a form of cerebral palsy (CP) that is a chronicneuromuscular condition of hypertonia and spasticity — manifested as an especially high and constant "tightness" or "stiffness" — in the muscles of the lower extremities of the human body, usually those of the legs, hips and pelvis. Doctor William John Little's first recorded encounter with cerebral palsy is reported to have been among children who displayed signs of spastic diplegia.
Spastic diplegia accounts for about 22% of all diagnoses of cerebral palsy, and together with spastic quadriplegia and spastic triplegia make up the broad classification spastic cerebral palsy, which accounts for 70% of all cerebral palsy diagnoses.