Hoehn and Yahr Scale for Classifying Patients with Parkinson's Disease

Which Hoenhn and Yahr stage is defined as "Unilateral involvement only, usually with minimal or no functional impairment?"

Which Hoenhn and Yahr stage is defined as "Bilateral or midline involvement, without impairment of balance?"

Which Hoenhn and Yahr stage is defined as "First signs of impaired righting reflexes. This is evident as the patient turns or is demonstrated when he or she is pushed from standing equilibrium with the feet together and eyes closed?"

Which Hoenhn and Yahr stage is defined as "Fully developed, severely disabling disease; the patient is still able to walk and stand unassisted but is markedly incapacitated."

Which Hoenhn and Yahr stage is defined as "Confinement to bed or wheelchair unless aided."