Parkinson’s disease: treatment and prognosis

Parkinson’s disease is a degenerative disease of the nervous system that leads to difficulty in movement, balance disorders and disorders of coordination.


Diagnosis of Parkinson’s disease

Diagnosis of Parkinson’s disease is difficult, especially in the initial stages.
About 40% of people with this disease have no diagnosis and 25% have an incorrect diagnosis.

The progression of the disease and symptoms are difficult to assess and can also occur with other conditions.
The changes in posture can be underestimated and seen as signs of aging or osteoporosis.
Some doctors believe that tremor is the basic prerequisite for the diagnosis of Parkinson’s.
In fact, however, they are wrong, because about a third of patients do not suffer from the initial symptom of tremor.
In addition, one must keep in mind that there are currently no blood or laboratory tests available to diagnose the disease.

In these circumstances, a physician must observe the patient for an extended period of time to detect tremor and muscle stiffness (rigidity) and associate them with other characteristic symptoms of this condition.
The doctor collects a medical history (anamnesis) with:

  • symptoms of the patient,
  • activities carried out,
  • medication taken,
  • other diseases,
  • potential contact with chemical-toxic substances.

The doctor then performs a physical examination and makes an evaluation of the functions of the nervous system and brain.
The study relates to:

  • reflexes of the patient,
  • Coordination
  • Brawn
  • mental abilities.

Some signs that need to be considered when diagnosing Parkinson’s disease include:

1) The tremor occurs in the resting position, not during movement.
2) At first, the disease manifests itself only on one side, only in the advanced and terminal phase it manifests itself on both sides.
3) The stiffness makes it possible to rule out other disorders, such as an essential tremor.
4) Specific motor tests can be performed, for example, the neurologist asks the patient to touch the thumb with the other fingers one by one (touch the fingertips with the tip of the thumb) and perform a rapid flexion/extension with the forearm. If the movement is slow and restricted, the test is positive.

To exclude parkinsonism, the neurologist may prescribe a dose of levodopa (100-250 mg). A patient response to this administration is an 80-90% reliable diagnostic criterion. However, there are certain risks and side effects when administering this drug to a healthy person.

The doctor may order cerebral PET or myocardial scintigraphy to support the diagnosis.

PET makes it possible to rule out Parkinson’s syndrome because it indicates the presence of anatomical changes, such as injuries to blood vessels.

At what age does Parkinson’s disease occur?
Generally, the first symptoms appear between the ages of 60-65, but one in ten people develop symptoms at a young age between the ages of 20 and 50.

Family history and genetics
In 80% of cases, no family members of patients suffer from this disease. But there is also a genetic form of Parkinson’s disease in which there is a gene mutation:

  • LRRK2
  • SNCA

Research has shown that one in 60 patients has a mutation of the LRRK2 gene.

Treatment for Parkinson’s disease

Medications can help treat movement disorders and tremor by increasing dopamine levels.
Dopamine cannot be administered directly because it cannot penetrate the brain, so the doctor prescribes L-DOPA (a precursor), which can penetrate the outer membrane of the brain.
Over time, the drug benefits may wear off, but sometimes they remain the same throughout life.

The doctor may prescribe various medications, including:

Carbidopa and levodopa
The most commonly prescribed drug in Western countries is levodopa (L-DOPA), which is most effective in Parkinson’s disease.
This natural chemical substance enters the brain and is converted into dopamine. Side effects are.

  • Nausea;
  • Decrease in blood pressure while standing.

After a few years of ingestion, the effect of levodopa may diminish and tends to weaken.
After increased dose intake of levodopa, involuntary movements (dyskinesias) may also occur.
The doctor can:

  • reduce the dose;
  • regulate intake times to bring these effects under control.

Dopamine agonists Unlike levodopa, dopamine agonists
do not turn into dopamine, but mimic its action in the brain.
They stimulate the dopamine receptors located on the outside of the cell membrane.
The effect is the same as that dopamine would have produced.
These drugs are just as effective as levodopa in treating symptoms and the effects last longer.
Dopamine agonists include:

  • Sifrol® (pramipexole),
  • Requip® (ropinirole).

The side effects of dopamine agonists are similar to those of levodopa, including:

  • Hallucinations
  • Sleepiness
  • Compulsive behaviors such as hypersexuality and gambling addiction.

MAO-B inhibitors
These drugs include selegiline (Selepark®) and rasagiline (Azilect®); they inhibit monoamine oxidase type B (MAO B), which degrades cerebral dopamine.
Side effects are rare, there may be nausea, sleep disturbances, orthostatic hypotension (low blood pressure when getting up) or headache.

Catechol-O-methyltransferase inhibitor (COMT inhibitor) Entacapone (Comtess)
is the most important drug of this class.
This drug slightly prolongs the effect of levodopa therapy by blocking an enzyme that breaks down levodopa.
Tolcapone (Tasmar) is a COMT inhibitor that is rarely prescribed because of the risk of serious liver damage and hepatic insufficiency.

These drugs have been used for many years to bring the tremor associated with Parkinson’s disease under control.
There are various anticholinergics, including benzatropin and trihexyphenidyl.
Unfortunately, the moderate benefits are often overshadowed by side effects, such as:

  • Disturbances of memory
  • Confusion
  • Hallucination
  • Constipation.

Amantadine increases the production and release of dopamine.
Doctors may prescribe amantadine only for short-term relief from the symptoms of incipient Parkinson’s syndrome.
In the advanced phases of Parkinson’s disease, it can also be added to carbidopa/levodopa therapy to control levodopa-induced arbitrary movements (dyskinesias).
Side effects may include blurred vision and hallucinations.

Surgical intervention for Parkinson’s disease

The surgical techniques have been in development for several years to help people with Parkinson’s. While surgery does not cure people with Parkinson’s, it can alleviate symptoms if the medication is no longer effective.

For example, deep brain stimulation is a technique that consists of inserting a pulse generator (comparable to a pacemaker) into the chest wall.
Subcutaneously thin wires are implanted that travel to the brain, where electrodes are placed.
The electrodes stimulate the brain regions affected by Parkinson’s and can help relieve symptoms.
There are no long-term findings about the effectiveness of this form of treatment.

The brain pacemaker is a neurostimulator (similar to a pacemaker) that is about the size of a clock.
It blocks abnormal nerve signals that cause tremor and other symptoms of Parkinson’s disease.
Before surgery, the neurosurgeon performs magnetic resonance imaging (MRI) or computed tomography (CT) scans to determine the exact area for the procedure.

It is usually performed on:

  • Thalamus
  • subthalamic nucleus,
  • Globus pallidus.

The device emits electrical impulses that interfere with and block the nerve signals that cause the symptoms of Parkinson’s disease.

The brain pacemaker consists of three components:

  1. The electrode – a thin wire is inserted into the skull through a small opening. The electrode tip is placed in the affected area of the brain.
  2. An insulated wire runs under the skin of the head, neck and shoulder to the neurostimulator.
  3. The neurostimulator is implanted under the skin near the collarbone.

Today, the devices have a battery that can be charged from the outside without having to be replaced.
It can take several months until the stimulator is properly adjusted and the required dosage for the medication to be taken has been determined.

In many patients, symptoms diminish and they can reduce the use of medication, which can avoid additional side effects.

Side effects

  • infection in 1 to 3% of cases,
  • Stroke
  • Brain haemorrhage

For which patients is this procedure indicated?
The brain pacemaker is indicated when the patient:

  • Has been suffering from the symptoms for at least five years.
  • A reduction in symptoms when taking the medication carbidopa / levodopa is felt, even if this effect lasts only for a short time.
  • Has already tried other drugs such as entacapone, tolcapone, selegelin or amantadine without success.
  • Suffers from symptoms that interfere with everyday activities.

What is the prognosis for Parkinson’s disease? What is the life expectancy?

The severity of symptoms of this disease varies considerably from person to person and it is not possible to predict the progression of Parkinson’s disease.
Parkinson’s is not a fatal disease in itself and the average lifespan does not change.
Secondary complications include pneumonia and injuries from falls.
There are many therapeutic options that can alleviate some of the symptoms and improve the quality of life of a person with Parkinson’s disease.

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