Hyperreflexia n : Increased reflexes, as shown by clonus. Muscles showing signs of hyperreflexia are said to be spastic or show spasticity. Clinically, spasticity is shown by: (1) decreased dexterity, (2) decreased strength, (3) increased deep tendon reflexes, (4) increased resistance to slow, passive muscle stretch, and, (5) hyperactive flexor spasms.