Monarch Disease Ontology id MONDO_0001167 (spastic diplegia) is a type of cerebral palsy characterized by spasticity and hypertonia of the lower extremities bilaterally, particularly the legs, hips, and pelvis; this is the most common (70%) form of cerebral palsy. Also known as: Little disease, Little's disease, cerebral spastic infantile paralysis, diplegic infantile cerebral palsy, infantile diplegic cerebral palsy, infantile spastic cerebral palsy.