Parkinson’s: Causes, Symptoms, Treatment And Prevention
Parkinson’s is the most common neurodegenerative disease after Alzheimer’s. It is estimated that approximately 1% of people over 60 years of age suffer from this disorder.
Although Parkinson’s disease is believed to have genetic causes and therefore it can hardly be prevented or cured, there are treatments capable of relieving its symptoms and delaying the physical and cognitive deterioration that it entails, especially medications such as levodopa.
Parkinson’s disease affects regions of the brain that produce dopamine, a neurotransmitter that allows voluntary and precise (fine) movements in addition to other functions not related to motor skills.
The main symptoms of this disease, described by James Parkinson in 1817, include resting tremors, muscle stiffness and impairment of speech and walking.
Parkinson’s It usually starts between 50 and 60 years of age.although it is not uncommon for it to begin in the 30s. The course of this disease is chronic and normally causes severe disability in the person who suffers from it after about 10 years.
While some treatments can relieve symptoms, once Parkinson’s disease develops there is no cure.
Causes of this pathology
Parkinson’s symptoms They are a consequence of the degeneration of subcortical brain structures. The destruction of dopaminergic neurons in the basal ganglia, especially in the region known as the “substantia nigra,” hinders multiple cognitive and motor functions.
The causes of Parkinson’s disease are unknown. It is known that there is a genetic component, since 15% of people diagnosed have close relatives who also suffer or have suffered from this disorder.
The development of Parkinson’s is probably due to combination of mutations in several genes. Exposure to some toxins, such as those present in pesticides, herbicides and heavy metals, is also considered a risk factor, although the importance of these environmental factors seems less than that of genetic factors.
Early symptoms of Parkinson’s disease often include slight tremors that gradually intensify. The same happens with the rest of the symptoms, which are also related to movement.
Other early signs are stiffness of the arms when walking, difficulties articulating sounds and lack of facial expressiveness (the “mask face” characteristic of this disease).
Subsequently, all these symptoms will worsen as the degree of brain involvement increases, evolving in many cases to the diagnosis of dementia caused by Parkinson’s disease.
1. Resting tremors
Rest tremors are slow and large and occur in a part of the body that is not making any movement. They are very characteristic of Parkinson’s disease, to the point that in many cases they are called “Parkinsonian tremors.”
They normally begin in one of the hands, but as the disease progresses they spread to both arms and can also affect the legs and head.
In general, rest tremors occur together with muscle rigidity and motor slowness, and occur to a lesser extent during voluntary movements.
2. Muscle stiffness
The increased muscle tone that occurs as a result of Parkinson’s disease in turn leads to stiffness in the muscles, which limits movement and causes pain.
A characteristic of Parkinson’s is what we know as “cogwheel rigidity,” which consists of the fact that when another person moves the patient’s affected limbs, they stop, showing excessive resistance, as if there were something blocking the joints. However, the problem is not in the joints, but in the muscle activation patterns that the nervous system orders in real time.
3. Bradykinesia (motor slowness)
Parkinson’s disease progressively makes movement more difficult, especially in the extremities. This decreases the ability to carry out simple manual taskswhich are increasingly carried out more slowly. It also makes it more difficult to get up and walk.
On the other hand, the difficulties caused by these motor difficulties also mean that there is little willingness to move, so a psychological effect is added to the motor symptoms that overlaps with the above.
4. Loss of automatic movements
Involvement of the basal ganglia causes a progressive loss of automatic movements in people with Parkinson’s. This is manifested in the absence of blinking, smiling, and swinging arms when walking.
5. Posture and balance problems
In Parkinson’s disease, postural reflexes are affected, leading to a hunched and flexed posture which in turn causes lack of balance or postural instability, facilitating falls and making movement more difficult. Furthermore, in the case of falls, avoiding falling to the ground with all your weight and then getting up is also more difficult.
6. Gait impairment
One of the most visible consequences of the motor problems that we have mentioned are changes in gait. People with Parkinson’s They usually take shorter steps, shuffle their feet and they move their arms less when walking.
Difficulties occur in all phases of walking, so that not only is walking complicated, but the ability to start walking, turn and stop also decreases.
7. Speech difficulties
Some of the most common speech problems in Parkinson’s cases are decreased volume and difficulties in pronouncingderived from motor impairments in the articulatory organs.
Likewise, prosody is altered, speech can be accelerated (tachyphemia) and some words and phrases can be compulsively repeated (palilalia). These symptoms seem to be more frequent in cases where Parkinson’s disease presents with dementia.
As a consequence, the person’s social life is damaged, and sometimes predisposes them to seek isolation.
8. Dementia
The alterations that Parkinson’s causes in the brain can cause it to develop a form of dementia specific to this disease.
Dementia is diagnosed in 20-60% of Parkinson’s cases, although a lower degree of cognitive impairment may also occur in the rest. Dementia caused by Parkinson’s disease is especially likely if the patient is a man, his age is advanced, the onset of his disorder has been late, or he does not respond well to medication.
Compared to Alzheimer’s disease, the most common cause of severe cognitive impairment, in Parkinson’s dementia the motor alterations are more relevant at the beginning. This It is due to dopamine deficiency typical of Parkinson’s. On the contrary, cognitive symptoms are more intense in the initial stages of Alzheimer’s.
However, as parkinsonian deterioration progresses, cognitive symptoms such as memory loss and delusions increase. The different types of dementia are less differentiated when they are in an advanced stage.
Prevention and treatment
It is not clear whether the onset of this disease can be prevented. Some studies suggest that caffeine and green tea consumption reduce the risk of Parkinson’s.
Furthermore, it has been related practicing moderate intensity aerobic exercise in adulthood with a lower probability of developing this disease in old age. However, at the moment it has not been possible to confirm the preventive effectiveness of sport, and the same happens with caffeine and green tea.
Once Parkinson’s disease has developed, its symptoms can be alleviated using different types of treatment. The management of this disorder is carried out mainly with medication that increases the levels of dopamine in the body.
Levodopa is the drug most used to treat Parkinson’s, especially in its initial stages. This compound increases the concentration of dopamine. As the disease progresses, levodopa may lose effectiveness, in which case it is replaced by dopamine agonists such as pramipexole and ropinirole.
Other forms of treatment, such as surgery, are less effective than levodopa and similar drugs. Physical exercise and relaxation techniques also help maintain mobility to a greater extent, slowing the progression of Parkinson’s disease.
