Parkinson's disease: All you wanted to know about the illness and its treatment

Parkinsonism is a syndrome in which a person develops slowness in activities. Along with slowness of activities at least one among the following three symptoms such as tremor, stiffness of muscles and postural imbalance should be present to make a diagnosis of parkinsonism. World over Parkinson's day is observed on April 11th of every year. This is the 200th year of the description of Parkinson's disease.

The syndrome of parkinsonism can be produced by many diseases. They are broadly classified into Parkinson's disease and Atypical Parkinsonism. Among these diseases, the most common and hence the most important disease is Parkinson's disease. Parkinson's disease is a degenerative disease of the brain. Atypical parkinsonism includes a group of degenerative diseases of the brain which are not as common as Parkinson's disease.

Atypical parkinsonism also includes non-degenerative diseases which produce parkinsonism. They are called secondary parkinsonism. Parkinsonism produced by small blood clots in the brain (vascular parkinsonism) and parkinsonism produced by certain medicines (drug-induced parkinsonism) are examples of secondary parkinsonism.

What is Parkinson's disease?

Parkinson's disease is a degenerative disease of the brain. Because it is a degenerative disease, it persists throughout the life of the person. The symptoms and disability caused by the disease worsen over time. The disease occurs because of the destruction of nerve cells in an area of the brain called substantia nigra. These nerve cells produce an important chemical called dopamine. Because of the death of these dopamine-producing nerve cells, there will be a decrease in the amount of dopamine in the brain. When the symptoms of Parkinson's disease begin in a person, 70 – 80% of the dopamine-producing cells might have already got damaged. The depletion of dopamine mainly affects the activities of an area called basal ganglia in the brain. Basal ganglia is the area of the brain which is primarily responsible for controlling the movements of the body. Thus depletion of dopamine in the brain produces the symptoms of parkinsonism.

The first description of the disease and nomenclature.

This disease was first described by a British doctor by name of James Parkinson in 1817. He called the disease 'Shaking Palsy'. Later the disease was named after him based on the suggestion of the famous French Neurologist named Charcot. This is the 200th year of description of the disease.

What produces Parkinson's disease?

The exact cause of degeneration of nerve cells in Parkinson's disease is unknown. It is suspected that genetic factors and environmental factors like pollution, excessive use of chemicals and pesticides may produce Parkinson's disease.

Who develops Parkinson's disease?

Usually, Parkinson's disease occurs in people older than fifty years. It is estimated that 1% of people above the age of 50 years, 1.8% of people above the age of 65 years and 2.6% of people above the age of 85 years develop the disease. The life expectancy of the people in our country is increasing. This means that as the ageing population in our society increases, we are likely to see more people with Parkinson's disease. Although this is a disease of the elderly, about 10% of patients develop the disease before 40 years of age. The role of genetic factors is more likely in persons who develop the disease at a young age.

Symptoms of Parkinson's disease

The symptoms of Parkinson's disease are broadly divided into movement-related symptoms and non-movement-related symptoms. The movement-related symptoms are further divided into cardinal manifestations of the disease and other movement-related symptoms. The four cardinal manifestations of the disease are given below.

Tremor

In majority of patients, tremor is the first symptom noticed by the patient and relatives. The tremor in Parkinson's disease is usually seen during the resting condition of the patient. When the patient performs some activities, the tremor usually stops or decreases in severity. Hence this tremor in Parkinson's disease is called 'rest tremor'. This tremor usually worsens during periods of mental stress.

Stiffness of muscles

In Parkinson's disease, patients develop stiffness of the body which affects the ease of doing activities.

Slowness of activities

In Parkinson's disease, routine activities like brushing, bathing, dressing, eating, walking etc. become slow

Imbalance on walking

Due to imbalance on walking, the patient develops a fear of falling while walking, Parkinson's disease patients may also develop the following other movement r e l a t e d s y m p t o m s . Because of the decreased movement of the muscles of the face, they lose their facial expression and have decreased eye blinking. The combination of these produces a vacant staring look on them. They also develop a low-volume speech. They develop difficulty in writing and their handwriting becomes small. They bend forward while standing and do not swing their hands while walking. They walk en bloc like a log of wood. Their foot may shuffle like children while walking. During walking, their speed may increase without control and may go like running. They may also get stuck without any reason while walking. As disease advances, they may also develop falls.

Parkinson's patients also develop many non-movement-related symptoms. These symptoms occur because of the degenerations of nerve cells outside the substantia nigra. Psychiatric symptoms like depression, anxiety, delusions and hallucinations may occur. They may develop memory loss and decline in other higher mental functions and abilities. Sleep disorders like sleeplessness, and excessive daytime sleepiness are common. They may have vivid dreams and may scream or enact out their dreams during sleep. Urinary problems like increased frequency of passing urine, difficulty in controlling urine once they get the sensation and incontinence are common . Constipation is very common. Excessive sweating and feeling of giddiness while standing may occur. Because they develop difficulty in swallowing they commonly develop drooling of saliva from mouth. They may also develop excessive tiredness and feeling of generalized weakness and numbness. They usually lose their sense of smell. They may also have sexual problems.

How is the disease diagnosed?

Diagnosis of Parkinson's disease requires a detailed examination by a neurologist. Sometimes the examination by a movement disorders specialist may be required to differentiate Parkinson's disease from other neurological diseases which may resemble Parkinson's disease. A brain scan may be required in some cases. In young patients some other investigations may also be required.

When to treat?

Treatment is required when the disease affects the activities of daily living of the patient. In the initial stages of the disease, milder medicines like dopamine agonists (pramipexole, ropenirole) or rasagiline may be enough. But as disease advances, almost all patients will require levo dopa treatment. Levo dopa enters the brain and gets converted to dopamine. Thus the deficiency of dopamine in the brain can be rectified.

Stages of levo dopa treatment

Parkinson's patients usually go through 3 stages when they use levo dopa. The first stage is called ''honeymoon period''. During this stage, the disease symptoms are milder and the response to levo dopa is very good. The patient gets round a clock benefit with 3 doses of levo dopa. Thoug the level of levo dopa in the blood decreased with in few hours, brain cells can store dopamine and can release it continuously into the brain.

The second stage of the disease is called stage of motor fluctuations. During this stage, the benefit of one dose of levo dopa lasts only less than 4 hours. As disease advances this duration may go down to one hour or so. This occurs because as age advances, the nerve cells lose their ability to store and use dopamine. From this stage onwards, the time during which the patient experiences the benefits of levo dopa is called “on” time and the period during which the patient does not experience the benefits of levo dopa is called ''off'' time. From this stage the patient will require more frequent doses of levo dopa or the addition of other medicines.

The third stage is called the stage of dyskinesia. During this stage the patient develops uncontrolled movements of the body (dyskinesia) during ''on'' stage. Dyskinesia may affect the ability to do activities.

Limitations of levo dopa treatment

The long term treatment with levo dopa has some limitations. As disease advances the duration of benefit with each dose of levo dopa may reduce up to 1 hour. Some doses may not give any benefit at all. Thus the duration of ''off'' time increases and the disability due to the disease increases. If the patient has dyskinesia, the dose of levo dopa cannot be further increased. Dyskinesia occurs because of the rapid fluctuations in the amount of dopamine in the brain. To control dyskinesia, the dose of levo dopa may have to be reduced. Drugs like amantadine may also be added to reduce dyskinesia.

Surgical treatment

Surgical treatment is used in patients with advanced Parkinson's disease who develop the above-mentioned limitations of levo dopa treatment. The surgical treatment is called ''deep brain stimulation''. Two electrodes are inserted into the sub thalamic nucleus situated deep in the brain through two small holes made on the scalp. This is done through an advanced surgical technique called stereotactc surgery. The tract of electrode insertion is decided by doing an MRI scan of the brain and integrating it with computer software. After that the electrodes are stimulated by a current from a battery inserted inside the body of the patient. Because of this the patient usually develops more than 50% improvement in symptoms of the disease. The requirement of levo dopa also comes down. Reduction in levo dopa dose reduces dyskinesia. As the current stimulation occurs continuously, they don't develop ''off'' stage. Thus the quality of life of the patient improves substantially.

But surgical treatment has some limitations also. It is an expensive treatment. Surgery cannot cure the disease. It can only improve the symptoms of the disease. It cannot be done in all patients also. The patients who will be benefited from surgery can be selected only by a movement disorders specialist.

Diet and Exercise

There are no dietary restrictions for Parkinson's patients. As constipation is common in this disease, it is better to take more fruits and fiber-rich diet. They should take a lot of water also. Physiotherapy is helpful in reducing the stiffness of the body. Physiotherapy can also help in improving their gait and balance. For this, they should get the help of a physiotherapist.

Parkinson's patients should enquire their doctor about the disease and its treatment in detail. This will help the patient to get adjusted to reality and develop confidence in treatment. If they live according to the suggestions of a movement disorders specialist, it is possible for them to lead a happy and peaceful life.

(Dr. Sreeram Prasad A V is the senior consultant - neurologist & movement disorders specialist, Meitra Hospital, Kozhikode.)