Parkinson’s disease

What is Parkinson's disease?

It is a chronic degenerative disease in which the destruction of cells located in the substantia nigra of the brain region responsible for the synthesis of dopamine occurs.

Parkinson's disease mainly affects individuals over 65 years of age with a prevalence of 1% in this age group and 2% in There are some cases of Parkinson's disease in younger ages (4th decade of life). It affects males slightly more.

How is it produced?

It is a disease of unknown cause in which several factors probably act, from genetic, infectious and above all environmental, together with the degeneration of age.

At the anatomo-pathological level, depigmentation of the substantia nigra, significant neuronal loss and inclusion of Levy's bodies in the substantia nigra is observed. This leads to a deficit of dopamine, a neurotransmitter in charge of controlling movements mainly.

Symptoms of Parkinson's disease

Initially the symptoms are very varied and range from pain in the neck, back or extremities to the appearance of the main symptoms of Parkinson's disease which are tremor, bradykinesia (slowing down of movements) and muscle stiffness.

Tremor is the most characteristic clinical manifestation and is the first symptom in 70% of cases. It usually begins in one hand (unilateral) until it reaches other territories such as the head and lower extremities. It is a tremor at rest, which decreases with movement and sleep and increases in stressful situations. Remember the action of counting coins.

Bradykinesia is the slowing of movement (akinesia is the difficulty in initiating a movement), causing the loss of ability to perform voluntary movements with the characteristic amimic facies, in addition to the loss of balance of the upper extremities during walking, alterations of the language with monotonous speech and a weak voice, difficulty in performing activities of daily daily life such as dressing, shaving, etc., writing with small print (micrograph) and difficulty in getting up from a chair, being the most disabling symptom of Parkinson's disease.

muscle stiffness occurs in the face of resistance from the passive mobility of a limb. It affects both the cervical muscles and the extremities, producing the characteristic "cogwheel stiffness." It causes pain, makes walking difficult and causes muscle contractures in advanced stages of the disease.

Instability or loss of postural reflexes causes difficulty in walking and maintaining balance. The patient adopts a characteristic posture consisting of flexion of the head and trunk initially and as the disease progresses, with flexion of the upper and lower extremities. In standing, the body moves forward and when starting to walk, the patient does so with the body bent, with short steps and dragging the feet.

Other common symptoms are: dementia (up to 10%), depression (40%), excessive salivation, postural hypotension, decreased blinking and sleep disorders.

Parkinson's disease is progressive, with differences between patients in response to treatment. In patients with a good response to treatment, life expectancy can be 20 to 30 years, although it is estimated that approximately 25% will have severe disabilities at 5 years despite treatment.

Diagnosis

In a clinical diagnosis. It is essential to take a good clinical history of the patient with the help of the family, who will guide us on the evolution time and the onset of the different signs and symptoms, as well as a complete neurological examination.

The disease is universally considered when the following criteria are met:

Presence of at least two of the cardinal symptoms: tremor, stiffness, and bradycenesia for at least one year

Response to treatment with L-dopa (precursor of dopamine) considerable and with an effect of at least one year (lack of response to L-dopa should cause reconsideration of the diagnosis)

There are no laboratory data or imaging tests to guide Parkinson's disease. The only certainty of the disease is a neuropathological data, that is, after an autopsy was carried out, where the decrease in dopaminergic and dopamine neurons in the substantia nigra, as well as Levy's bodies, is demonstrated.

Treatment

Treating Parkinson's disease is not easy. In fact, there is no agreement on what is the best strategy at the onset of the disease. It is customary to delay as much as possible, if possible, when the disease begins to interfere with daily life, especially in patients with a long life expectancy. This is due to the loss of efficacy of L-dopa (after 5 years its efficacy decreases by around 50%) and due to the appearance of the secondary effects of the appearance that would force the withdrawal or change of the medication.

L-dopa is the treatment of choice for Parkinson's disease. It produces an improvement in 80% of patients during the first years. It mainly improves bradykinesia and stiffness, and in some patients, tremor. Its main side effects are :, nausea, dyskinesias, motor fluctuations and psychosis.

Anticholinergics can have an additive effect to L-dopa and act mainly on tremor in the early stages of the disease. However, they have side effects especially in older people such as dry mouth, dry eyes, urinary retention, cognitive impairment and others that make their use difficult in this group of patients.

Dopamine agonists (bromocriptine, pergolide, lisuride, ropinirole, selegiline) can be useful as monotherapy or associated with L-dopa, especially in more benign forms of the disease. Its usefulness is observed on stiffness and bradykinesia, with improvement of these symptoms.

amantadine (an antiviral substance with anticholinergic and dopaminergic properties) increases dopamine receptors but has the disadvantage of loss of efficacy after 3-6 months of treatment, which recovers after leaving it for 2-3 weeks.

Other useful drugs are inhibitors of the COMT enzyme (entacapone), which reduces fluctuations in the patient and decreases the need for L-dopa.

Surgery in Parkinson's disease is indicated in patients under 70 years of age, with very disabling symptoms with important side effects of the medication, together with the failure of the available pharmacological treatment. The surgical techniques used are pallidotomy or pallid stimulation.

Physiotherapy is very beneficial for patients in whom stiffness predominates, for the improvement of mobility and daily activity.

CONSULT OUR SPEcialisTS

To improve the quality of life in the event of Parkinson's disease, MAPFRE offers specialized medical assistance, as well as a complementary 24-hour medical guidance service for the most urgent cases.