Parkinson's disease is a movement disorder characterized by progressive loss of muscle control. Destruction of dopamine-producing nerve cells in specific areas of the brainstem leads to the development of Parkinson's disease symptoms. The disorder usually presents in middle to late adulthood with mild symptoms, such as a resting hand tremor and physical slowness. As the disease advances, symptoms become increasingly debilitating. Medical professionals frequently use the Hoehn and Yahr staging scale to describe Parkinson's disease progression; stages 3 through 5 represent advanced disease.
Hoehn and Yahr Stage 3
People with Hoehn and Yahr stage 3 Parkinson's disease have moderately severe symptoms and disability, reports Massachusetts General Hospital. Both sides of the body exhibit symptoms, including tremors and stiffness. Movement is slow and a delay commonly occurs before movement begins. For example, getting out of a chair may involve a few seconds of hesitancy before the patient can initiate the physical movement required to stand.
The emergence of balance problems is a distinguishing characteristic of Hoehn and Yahr stage 3 Parkinson's disease. Several reflexes help keep the body upright when a sudden change in posture or position occurs, throwing the body off balance. These automatic body corrections, or postural reflexes, enable a person to "catch" herself and prevent a fall. In people with Hoehn and Yahr stage 3 Parkinson's disease, the postural reflexes begin to fail, leading to an increased frequency of falls. Patients remain physically independent and able to walk at this stage, although the walking pattern is often abnormal, with a shortened stride and limited arm swing.
Hoehn and Yahr Stage 4
People with Hoehn and Yahr stage 4 Parkinson's disease have severe, disabling symptoms and are no longer able to live independently. Patients retain the ability to stand and walk without assistance, although walking at this stage is limited. Rigidity, physical slowness and lack of coordination interfere with the ability to perform the tasks of daily living, such as bathing, dressing, cooking and eating.
Rigidity of the facial muscles typically causes lack of facial expression, notes Penn State College of Medicine's Milton S. Hershey Medical Center. Difficulty speaking and swallowing often occur due to stiffness and the slow muscular response of the mouth and throat. Notably, tremors may decrease with stage 4 Parkinson's disease.
Hoehn and Yahr Stage 5
Loss of the ability to stand or walk independently marks the transition from Hoehn and Yahr stage 4 to stage 5, the final phase of Parkinson's disease. People with stage 5 disease remain wheelchair or bed-bound and require round-the-clock care, reports the Movement Disorder Society Task Force on Rating Scales for Parkinson's Disease. Poor muscle control of the mouth and throat severely limit speech and eating. Maintaining adequate nutritional intake often requires use of a feeding tube. Difficulty swallowing also frequently leads to drooling. Urinary and fecal incontinence prove common with stage 5 Parkinson's disease.
References
- National Institute of Neurological Disorders and Stroke: Parkinson's Disease, What is the Prognosis?
- Massachusetts General Hospital: Hoehn and Yahr Staging of Parkinson's Disease, Unified Parkinson Disease Rating Scale (UPDRS), and Schwab and England Activities of Daily Living
- Penn State Milton S. Hershey Medical Center: Parkinson's Disease
- "Movement Disorders"; Movement Disorder Society Task Force Report on the Hoehn and Yahr Staging Scale: Status and Recommendations; Christopher G. Goetz, M.D., et al.; 2004
- Cleveland Clinic Center for Continuing Education: Parkinson's Disease
