Parkinson’s dementia: symptoms, causes and treatment.

A type of subcortical dementia that is associated with Parkinson's disease.

Parkinson's dementia arises from Parkinson's disease.. It appears in 20-60% of cases in which this condition occurs, and involves a series of motor symptoms (tremors, slowness, etc.), impaired language and thinking, and cognitive symptoms.

It is a subcortical dementia that usually appears at older ages. Although the cause is unknown, a significant decrease in the amount of dopamine in the brain has been observed in patients with Parkinson's dementia. Let's see what are its characteristics.

Parkinson's dementia: characteristics

Parkinson's dementia arises as a result of Parkinson's disease. Specifically, between 20 and 60% of people with Parkinson's disease also develop Parkinson's dementia.

As for its course onset occurs between the ages of 50 and 60 years.. The deterioration is usually slow and progressive, and affects the cognitive, motor and autonomy skills of the person. On the other hand, its incidence is 789 persons per 100,000 (over 79 years of age).

Parkinson's disease

Parkinson's disease disease generates certain motor disturbances, such as tremor at rest, slowness of movement, postural instability, difficulty in starting and stopping an activity, and difficulty in walking.The disease is characterized by tremor at rest, slowness of movement, postural instability, difficulty in starting and stopping an activity, stiffness and fidgety gait (shuffling and short steps).

However, in this article we will focus on the dementia that arises from the disease:

Symptoms

When the disease progresses to dementia, it is characterized by a number of symptoms. According to the Diagnostic Manual of Mental Disorders (DSM-IV-TR), a dysjective syndrome linked to memory loss usually appears. In addition, other symptoms that appear are:

1. Decreased motivation.

This translates into apathy, asthenia and abulia.. That is to say, the person loses the desire to do things, the pleasure that was previously experienced with them disappears, there is no motivation or will, etc.

2. Bradypsychia

Another typical symptom of Parkinson's dementia is bradypsychia, which involves a slowing down of the thinking process.. In addition, there is also an associated impoverishment of language.

3. Bradykinesia

Implies slowness of movementsThis has to do with both the Central Nervous System and the Peripheral Nervous System.

4. Visuospatial and visoconstructive alterations.

There is also impairment in the visuospatial and visoconstructive areas, which translates into difficulties in moving and positioning oneself in space, drawing, locating objects in space, etc., as well as difficulties in building (e.g. a tower with cubes) and dressing.

5. Depression

Parkinson's dementia is also is very often accompanied by depressive disorders of greater or lesser severity..

6. Neuropsychological alterations

Alterations appear in memory and recognition, although these are less severe than in the case of Alzheimer's dementia, for example.

As for the encoding and retrieval of information, there are significant failures in the retrieval processes, there are important failures in the processes of memory retrieval..

Causes

The causes of Parkinson's disease (and thus of Parkinson's dementia) are actually unknown. However, has been related to alterations in the nigrostriatal fasciculus, specifically with a decrease of dopaminergic functioning in that structure.specifically with a decrease in dopaminergic functioning in that structure. Dopamine is a neurotransmitter that is closely related to movement and movement-related disorders characteristic of Parkinson's dementia.

In addition, it has been observed that in patients with Parkinson's disease Lewy bodies appear in the substantia nigra in the substantia nigra of the brain and in other brainstem nuclei. It is not known, however, whether this is a cause or a consequence of the disease itself.

Population at risk

The population at risk for Parkinson's dementia, i.e. people who are more vulnerable to developing it, are older people, who have had a late onset of Parkinson's disease, with greater severity in the disease itself.The population at risk for Parkinson's dementia, i.e. people more vulnerable to developing it, are older people, who have had a late onset of Parkinson's disease, with greater severity of the disease itself, and with predominant symptoms of rigidity and akinesia (inability to initiate a precise movement).

Treatment

To date, Parkinson's dementia is a degenerative disease that cannot be cured. Treatment will be based on trying to delay the onset of symptoms and to treat or compensate for existing symptoms and treating or compensating for existing symptoms, so that they affect as little as possible.

For this purpose, neurorehabilitation cognitive neurorehabilitation program will be used.and external strategies that can help the patient in his or her environment (use of diaries and memory reminders, for example).

In addition, the symptoms associated with dementia, such as depression or anxiety, will be treated at the psychological and psychopharmacological level.

Antiparkinsonians

At the pharmacological level and to treat motor symptoms of the disease (not so much of dementia), antiparkinsonian drugs are often used. These are aimed at restoring the balance between the dopaminergic system (dopamine), which is deficient, and the cholinergic system (acetylcholine), which is overexcited.

Levodopa is the most effective and widely used drug. Dopaminergic agonists are also used, which increase their efficacy in combination with levodopa.which increase their efficacy in combination with levodopa (except in very early stages of the disease, where they can be administered alone).

Parkinson's as a subcortical dementia

As we have mentioned, Parkinson's dementia consists of a subcortical dementia. consists of a subcortical dementiaThis means that it involves alterations in the subcortical area of the brain. Another large group of dementias are cortical dementias, which typically include another well-known dementia, that due to Alzheimer's disease.

But, continuing with subcortical dementias, they also include Parkinson's dementia (dopamine deficits), Huntington's dementia (involving GABA deficits) and HIV dementia (involving alterations in the white matter).

All subcortical dementias have motor disturbances (extrapyramidal symptoms), slowing, bradypsychia and decreased motivation as characteristic symptoms.

Bibliographical references:

• Belloch, A., Sandín, B. and Ramos, F. (2010). Manual de Psicopatología. Volume I and II. Madrid: McGraw-Hill.
• Demey, I. and Allegri, R. (2008). Dementia in Parkinson's disease and Lewy body dementia. Revista Neurológica Argentina, 33: 3 - 21.
• Rodríguez-Constenla, I., Cabo-López, I., Bellas-Lama, P. and Cebrián, E. (2010). Cognitive and neuropsychiatric disorders in Parkinson's disease. Rev Neurol, 50(2): S33 - S39.