Parkinson's disease is a progressive neurodegenerative disorder. The disease gets worse over time, and it affects the nervous system causing brain cell function to deteriorate and the cells to die. The area of the brain that is primarily affected controls movement resulting in the slowness of movement, muscle stiffness and resting tremor that are the main symptoms of Parkinson's disease. However, cell death also occurs in other areas of the brain and various signs develop earlier than the well-recognized movement disorders.
Loss of Sense of Smell
In the January 2009 issue of the journal "Movement Disorders," Dr. Carles Gaig and Dr. Eduardo Tolosa state that up to 90 percent of Parkinson's patients lose their sense of smell and in hindsight many recall that they lost it before they received a diagnosis of Parkinson's disease. Dr. Gaig and Dr. Tolosa suggest that the sense of smell can be lost two to seven years before the onset of the movement related symptoms which are clinically diagnosed as Parkinson's disease.
Rapid Eye Movement (REM) Behavior Disorder
During the REM, or dreaming, phase of sleep, the muscles become completely relaxed and immovable. With REM behavior disorder people can still move their muscles. This leads to actions such as kicking, punching, sitting up and shouting as they "act out" their dreams. According to Dr. Gaig and Dr. Tolosa this symptom can occur in up to a third of Parkinson's disease patients and in 20 percent of patients this problem started, on average, 11 to 12 years before they were diagnosed with Parkinson's disease.
Depression and Other Mood Changes
In a significant number of patients depression occurs three to six years prior to a definitive diagnosis of Parkinson's disease, state Drs. Gaig and Tolosa Other mood disorders which can be present in the early stages of Parkinson's disease include anxiety and apathy. People developing Parkinson's disease may become more nervous and agitated by situations which may not have bothered them before. They may also become withdrawn and lose their motivation to do their favorite activities.
Difficulties Moving One Side of the Body
The first movement related symptoms of Parkinson's disease often begin on one side of the body. This can include loss of manual dexterity where it becomes difficult to use a keyboard or write as they once used to. A slight stooped posture may also be observed as well as difficulty walking. In particular, the natural swinging of a person's arm during walking may be lost on one side or one leg may start to drag. This makes the act of walking look awkward and the person may also feel slightly off balance. According to the book "Parkinson's Disease: A Complete Guide for Patients & Families," another common muscular symptom is a decrease in facial expression, blinking, and power of voice.
Pain and Muscle Cramping
As well issues with moving the muscles of the face, hands, arms and legs the person may also experience pain and muscle cramps, particularly in the limbs, neck and lower back. Dr. William Weiner and colleagues state in their book "Parkinson's Disease: A Complete Guide for Patients & Families" that about 10 percent of patients develop "frozen shoulder" where the shoulder on one side of the body becomes stiff and painful. Foot cramps may also occur in the early morning as well as feelings of numbness, tingling or burning which come and go throughout the day.
Mild Tremor or 'Internal' Tremor
Before the severe resting tremor that is characteristic of Parkinson's disease develops patients report that they feel their arm or leg is trembling but no tremor will be obvious. Mild and intermittent but visible trembling of the limbs may also be observed in early Parkinson's disease, says Dr. William Weiner and colleagues.
References
- "Movement Disorders"; When Does Parkinson's Disease Begin? Carles Gaig and Eduardo Tolosa; January 2009.
- "Parkinson's Disease: A complete guide for patients & families (2nd Edition)"; William J.Weiner, Lisa M.Shulman, and Anthony E. Lang; 2007.
- National Institute of Neurological Disorders and Stroke: Parkinson's Disease
