Parkinson’s Disease: All You Need to Know
Parkinson’s disease is a degenerative disease of the brain which largely occurs in those over the age of 60 years. It is named after Dr James Parkinson, who described the earliest cases. It is also called “The Shaking Palsy” which sums up its clinical presentation of tremors and motor slowing which was thought of as weakness of the muscles.
Young onset Parkinsonism occurs in 10-15% of patients below the age of 45.
The brain regions affected in Parkinsonism are the basal ganglia, particularly the substantia nigra, where the neurotransmitter dopamine is deficient. This part of the brain is part of the extrapyramidal system which enables motor movements to be smooth and fluid.
Often, other neurotransmitters may also be involved through dopamine deficiency is the main problem. This results in the motor symptoms of tremors, slow movements and stiffness (rigidity) and nonmotor symptoms of apathy, depression and sometimes pain.
When the neurotransmitter noradrenaline is also deficient, the Parkinson’s symptoms manifest as immobility, rigidity and involuntary movements called dyskinesias, accompanied by apathy, depression and anxiety.
The neurotransmitter acetyl choline is important for memory, and in some patients with Parkinson’s this is deficient and the patient has cognitive decline, dementia and even urinary dysfunction. These patients also may have more episodes of ‘freezing’ when treated with levodopa – the replacement drug used to treat Parkinsonism.
When the neurotransmitter serotonin is deficient with dopamine, patients experience fatigue and disturbed sleep together with the above symptoms.
In summary, the following are the supportive features to consider in a diagnosis of Parkinsonism:
Three or more are required the for diagnosis of definite PD in combination.
- Unilateral onset
- Rest tremor present
- Progressive disorder
- Persistent asymmetry affecting side of onset most
- Excellent response (70-100%) to levodopa
- Severe levodopa-induced chorea
- Levodopa response for 5 years or more
- Clinical course of ten years or more
Hence, Parkinsonism is a complex condition and may present as a pure motor syndrome or be accompanied by memory issues, dementia, depression and a wide range of accompanying symptoms. As degeneration is an ongoing process, Parkinsonism is a progressive condition.
Other Symptoms of Parkinson’s Disease Include:
- Mood changes, such as depression and fatigue
- Trouble moving normally and completing work-related or everyday tasks (due to stiffness, especially of the limbs)
- Urinary problems
- Trouble speaking normally
- Low blood pressure
- Digestive issues, including constipation
- Trouble sleeping, including difficulty turning in bed
- Skin problems
- Drooling
- Increased sweating
- Muscle spasms and cramps
- Voice changes
- Erectile dysfunction
Why Does Someone Get Parkinsonism?
A combination of genetic factors (heredity) and environmental modifications of the genes (epigenetics) play a role. Environmental factors like pesticides, manganese, carbon monoxide and an addictive drug called MPTP can all worsen the proneness to develop the disease. Brain circulation reduction, as in atherosclerosis also contributes. Recurrent head injury in boxers (Muhammad Ali) can also lead to Parkinsonism.
What Tests Are Needed to Diagnose Parkinsonism?
Parkinsonism is largely a classical clinical diagnosis but neuroimaging is useful.
Neuroimaging with MRI brain will show degeneration in the brain, presence of multiple small infarcts (lacunar infarcts) or multiple larger infarcts (multi-infarct syndrome) and brain atrophy or other changes, especially in Parkinson-dementia complex.
A special scan called the Trodat scan can identify dopamine deficiency and confirm if it is primary or secondary Parkinsonism.
Since most patients are over 60 years of age, attention has to be paid to chronic lifestyle diseases like diabetes, hypertension, heart disease, etc., and kept under control.
What Treatment Is Available for Parkinsonism?
There are specific and nonspecific treatments.
Specific treatment is with levodopa which replaces the dopamine in the brain.
Supplementary symptomatic management is done with other drugs to control tremors, delay progression and improve rigidity. If associated vascular pathology is present, blood thinners, control of abnormal fats with statins and drugs to help memory and cognitive decline are given.
A less common form of Parkinson’s syndrome can occur after prolonged psychotic use and in such patients the treatment as above for Parkinsonism may actually worsen some of the psychiatric symptoms. Treatment to keep both the psychosis under control and to treat the Parkinsonism satisfactorily can be a challenge.
Regular physical activity and specific balance training can go a long way in slowing progression and keeping the patient functional for activities of daily living without falls and good quality of life.
An interesting observation for which the explanation is not clear is that many patients even with considerable difficulty in walking, can cycle with ease, and an exercise cycle may be a useful tool for exercise.
There is no need to get dejected and lose hope even if Parkinsonism is a progressive, degenerative neurological disease. The disease in most patients progresses slowly over many years and with modern treatment with drugs and even surgery (deep brain stimulation) they can live long, useful lives.
