Parkinson's disease is a chronically progressive movement disorder. The four primary features of Parkinson's disease include slow movement, stiffness, tremors and balance disturbances. The Hoehn and Yahr staging system categorizes the severity of the disease, with stage I representing the earliest form, and stage V representing end-stage disease. The National Institute of Neurological Disorders and Stroke reports at least one-half million American adults have Parkinson's disease.
Stage I
Hoehn and Yahr stage I Parkinson's disease involves movement-related symptoms limited to one side of the body. The Parkinson's Disease Foundation reports that a resting tremor occurs in approximately 70 percent of people with early-stage disease. A resting tremor occurs when the affected muscles are not in use. With the initiation of purposeful movement, the tremor typically abates. Tremor most commonly affects a hand or foot at the onset of Parkinson's disease. Less commonly, the jaw or muscles on one side of the face may be involved. With stage I Parkinson's disease, symptoms typically do not cause significant disability.
Stage II
The presence of symptoms on both sides of the body marks the transition from stage I to stage II Parkinson's disease, explains the Cleveland Clinic. A second tremor may appear on the opposite side of the body as the presenting tremor. Muscle rigidity may develop in both arms or legs. Noticeable slowness in initiating movement, decreased facial expression and changes in walking may present. Balance remains intact at this stage of the disease. Favorable response to medication with symptom improvement normally occurs during stage II Parkinson's disease.
Stage III
Progression from stage II to stage III Parkinson's disease represents a transition from mild to moderate disease severity. The onset of balance disturbances distinguishes stage III from earlier stages of Parkinson's disease. Falls occur with increasing frequency. According to Johns Hopkins Medicine, slow or reduced capacity to make rapid positional adjustments upon tripping or encountering obstacles may underlie the balance disturbances that characterize Parkinson's disease. People with stage III disease typically remain physically independent.
Stage IV
Severe disability due to progression of rigidity, slow movement, and walking and balance problems typifies stage IV Parkinson's disease, explains the National Institute of Neurological Disorders and Stroke. Speech changes may be pronounced, and swallowing difficulties may interfere with eating. Fatigue, sleep disturbances, muscle cramps, constipation, frequent falls and decreased effectiveness of medication are common with stage IV Parkinson's disease. People with stage IV disease require substantial assistance to conduct the activities of daily living.
Stage V
Stage V represents end-stage Parkinson's disease. People with stage V disease are confined to a wheelchair or remain bedridden due to loss of movement and motor control, notes the National Institute of Neurological Disorders and Stroke. Round-the-clock assistance proves necessary, as those affected cannot independently accomplish the tasks associated with meeting their most basic needs.
References
- National Institute of Neurological Disorders and Stroke: Parkinson's Disease
- Cleveland Clinic Center for Continuing Education: Parkinson's Disease
- Johns Hopkins Medicine: Neurology and Neurosurgery, Parkinson's Disease
- Merck Manual for Healthcare Professionals: Parkinson's Disease, Signs and Symptoms
- Mayo Clinic: Parkinson's Disease, Symptoms
