Parkinson's disease, classified as a movement disorder, affects at least 500,000 people in the United States, according to the National Institute of Neurologic Disorders and Stroke. Parkinson's disease occurs due to nerve cells in the brain becoming damaged, resulting in a chronic degeneration of the central nervous system. Those with Parkinson's disease experience four main symptoms that include tremors, bradykinesia--slowness of movements, postural instability--the inability to balance and rigidity, also known as stiffness. Other diseases cause similar symptoms that often look like Parkinson's.
Essential Tremor
Essential tremor describes a progressive neurological condition that affects approximately 10 million Americans, according to the International Essential Tremor Foundation. Doctors also call essential tremor familial tremor or hereditary tremor because parents can pass this disease to their children. Essential tremor causes rhythmic trembling of the hands, heads, legs or trunk and can also cause the voice to tremble. The characteristic trembling often causes doctors to misdiagnose essential tremor as Parkinson's disease. Essential tremor remains the most common cause of tremors, the International Essential Tremor Foundation says.
Normal Pressure Hydrocephalus
Normal pressure hydrocephalus, NPH, describes a condition that occurs when cerebral spinal fluid accumulates in the ventricles in the brain but fails to cause a continual increase in intracranial pressure. Although hydrocephalus can occur at any age, normal pressure hydrocephalus typically affects adults. NPH causes gait disturbances, mild dementia and impaired bladder control, according to the Hydrocephalus Association. Although the symptoms of NPH appear similar to Parkinson's disease, a computed tomography--CT or magnetic resonance image--MRI scan of the brain reveals the enlarged areas, a feature not found in the brain of Parkinson's patients.
Steele-Richardson-Olszewski Syndrome
Steele-Richardson-Olszewski syndrome, also known as progressive supranuclear palsy or PSP, occurs when brain cells located in the base of the brain or brain stem slowly deteriorate. A rare brain disease, PSP causes balance problems, gait instability, alterations in mood and mild dementia. PSP affects areas of the brain that control eye movement, resulting in the inability to aim the eyes correctly. This symptom--which patients often describe as a blurring effect, according to the National Institute of Neurologic Disorders and Stroke--sets PSP apart from diseases with similar symptoms, such as Parkinson's disease.
Dementia
Doctors use the general term dementia to describe a group of symptoms that affect intellectual thinking and social abilities severely enough to interfere with daily activities, according to MayoClinic.com. Dementia associated with the presence of Lewy bodies--abnormal protein deposits--causes symptoms that cause the disease to look like Parkinson's. As the proteins abnormally deposit in areas of the brain, symptoms such as slow movements, rigidity, tremors and shuffling occur. Patients may also experience psychiatric disturbances including hallucinations and depression.
References
- National Institute of Neurological Disorders and Stroke: Parkinson's Disease
- International Essential Tremor Foundation: Facts About Essential Tremor
- Hydrocephalus Association: About Normal Pressure Hydrocephalus
- National Institute for Neurologic Disorders and Stroke: Progressive Supranuclear Palsy
- MayoClinic.com: Dementia
