Parkinson's dementia: symptoms, causes and treatment

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

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

• Related article: "Types of dementias: the 8 forms of loss of cognition"

Parkinson's dementia: characteristics

Parkinson's dementia arises from Parkinson's disease. Specifically, between 20 and 60% of people with Parkinson's disease also end up developing Parkinson's dementia.

Regarding its course, its onset occurs between the ages of 50 and 60. 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 people per 100,000 (older than 79 years).

Parkinson's disease

Parkinson's disease generates certain motor alterations, such as tremor at rest, slowness of movements, postural instability, Difficulty starting and stopping an activity, stiffness and festive gait (shuffling and taking short steps).

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

Symptoms

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

1. Decreased motivation

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

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2. Bradypsychia

Another typical symptom of Parkinson's dementia is bradypsychia, which involves a slowdown in the thought process. In addition, an impoverishment of language is also associated.

3. Bradykinesia

It implies the slowness of movements, something that has to do with both the Central Nervous System and the Peripheral Nervous System.

4. Visuospatial and visuoconstructive alterations

There is also an affectation in the visuospatial and visoconstructive areas, which translates into difficulties to move and position in the space, drawing, locating objects in space, etc., as well as difficulties to build (for example a tower with cubes) and dress.

5. Depression

Parkinson's dementia too it is accompanied, very frequently, by depressive disorders of greater or lesser severity.

• You may be interested: "Types of depression: its symptoms, causes and characteristics"

6. Neuropsychological disorders

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

Regarding the encoding and retrieval of information, there are major flaws in the memory retrieval processes.

Causes

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

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

Risk population

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

Treatment

Today, Parkinson's dementia is a degenerative disease with no cure. Treatment will be based on trying to delay the onset of symptoms and in treating or compensating those that already exist, so that they affect as little as possible.

For it cognitive neurorehabilitation program will be used, and external strategies that can help the patient in their environment (use of agendas and reminders for memory, for example).

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

Antiparkinsonians

On a pharmacological level and to treat motor symptoms of the disease (not so much of dementia), antiparkinsonians are commonly used. These are aimed at re-establishing the balance between the dopamine system (dopamine), which is deficient, and the cholinergic system (Acetylcholine), which is overexcited.

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

Parkinson's as subcortical dementia

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

But, continuing with subcortical dementias, they include in addition to Parkinson's dementia (dopamine deficiency), Huntington's dementia (involving GABA deficiencies) and HIV dementia (involving changes in the substance White).

Characteristic symptoms of all subcortical dementias are motor disturbances (extrapyramidal symptoms), slowing down, bradypsychia, and decreased motivation.

Bibliographic references:

• Belloch, A., Sandín, B. and Ramos, F. (2010). Manual of Psychopathology. 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