What is parkinsonism?
Parkinsonism is a movement disorder with the following characteristics:
- Slowness of movements (bradykinesia)
- Muscle stiffness (rigidity)
- Tremor that appears when the limb is at rest
- Impaired postural reflexes (imbalance and falls)
- Stooped posture (camptocormia)
- Freezing of movements (short lasting episodes during which movements are blocked – e.g. legs feel like they are “glued” to the ground)
Not all of the above need to be present in order to diagnose the condition. Symptoms may vary, especially in the early stages of a slowly developing parkinsonism. The first manifestations of the syndrome may be a “pill-rolling” tremor of the thumb and index, loss of hand dexterity, a progressively deteriorating gait, etc.
The typical, full-blown clinical picture of parkinsonism, is usually that of a person who:
- Walks with a slow, shuffling gait with reduced arm swing
- Makes slow movements and has difficulty initiating them
- Has a masked facial expression (hypomimia)
- Speaks with a soft, monotonous voice (sometimes with a whispering quality)
- Exhibits tremor in his or her hands when they are relaxed (i.e. resting on the arms of a chair).
Sometimes, the constellation of these symptoms and signs is referred to as “extrapyramidal syndrome”. However, this is a rather broad term; extrapyramidal movement disorders include various conditions besides parkinsonism.
What are the causes of parkinsonism?
By far the most common cause of parkinsonism is Parkinson’s disease. Other causes include:
Parkinson-plus syndromes (atypical parkinsonian syndromes)
These are a group of neurodegenerative diseases that may present with a clinical picture similar to Parkinson’s. However, as they progress, additional symptoms emerge (hence the “plus” in the term). As a general rule, these diseases do not respond satisfactorily to treatment with antiparkinsonian medication (in contrast to Parkinson’s disease). The Parkinson-plus syndromes are:
- Multiple System Atrophy (MSA)
- Progressive Supranuclear Palsy (PSP or Steele-Richardson-Olszewski syndrome)
- Corticobasal Degeneration (CBD)
- Dementia with Lewy Bodies (DLB)
Certain drugs may cause parkinsonism. Following their discontinuation, symptoms resolve completely. Medications that may potentially lead to extrapyramidal symptoms include:
- Neuroleptics (antipsychotics – dopamine receptor blockers)
- Flunarizine and cinnarizine
Vascular lesions of the brain
This condition is called “vascular parkinsonism”. It usually emerges as a result of multiple ischemic lesions in an area of the brain named “basal ganglia”.
A significant number of uncommon genetic diseases can result in parkinsonism. They tend to present at a young age (occasionally during the first two decades of life) and are usually accompanied by additional symptoms. Some of these are:
- Wilson’s disease
- Huntington’s disease (Westphal variant)
- Dopa-responsive Dystonia (Segawa disease)
- Spinocerebellar ataxias 1-3
- Neurodegeneration with brain iron accumulation syndromes
Parkinsonism may result from infections of the central nervous system (prion diseases), toxins (carbon monoxide and methanol poisoning), exposure to heavy metals (manganese), parathyroid disorders, etc.