Parkinson’s dementia: symptoms, causes and treatment

Parkinson’s dementia occurs as a result of Parkinson’s disease. This appears in 20 to 60% of cases in which this condition occurs, and involves a series of motor symptoms (tremors, slowness …), impoverishment of language and thought and cognitive.

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

    Parkinson’s dementia: characteristics

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

    As for its course, its onset occurs between 50 and 60 years. Deterioration is usually slow and gradual, affecting a person’s cognitive, motor and independent skills. On the other hand, its incidence is 789 people per 100,000 (over 79 years).

    Parkinson’s disease

    Parkinson’s disease generates certain motor disorders, such as tremors at rest, slowness of movement, postural instability, Difficulty starting and stopping an activity, stiffness and gait for partying (dragging your feet and taking small steps).

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


    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), dysexecutive syndrome associated with memory loss usually appears. In addition, the other symptoms that appear are:

    1. Decreased motivation

    This results in apathy, asthenia and abulia. That is, the person loses the desire to do things, the pleasure that was previously experienced with him disappears, has no motivation and no will, etc.

      2. Bradypsychia

      Another typical symptom of Parkinson’s dementia is bradypsychia, which involves a slowdown in thinking. In addition, the impoverishment of languages ​​is also associated.

      3. Bradykinesia

      This implies slowness of movement, Something that has to do with the central nervous system and the peripheral nervous system.

      4. Visuospatial and visoconstructive alterations

      There is also an impact on visuospatial and visoconstructive areas, which results in difficulties of movement and positioning in space, drawing, placement of objects in space, etc., as well as difficulties of building (eg a tower) with cubes) and dressing.

      5. Depression

      Parkinson’s dementia too it is very frequently accompanied by more or less serious depressive disorders.

        6. Neuropsychological disorders

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

        In terms of encoding and retrieving information, there are significant errors in the garbage collection process.

        the causes

        The causes of Parkinson’s disease (and therefore Parkinson’s dementia) are in fact unknown. however, has been associated with alterations of the nigroestriado fascicle, More precisely with a decrease in dopaminergic functioning in this structure. Dopamine is a neurotransmitter that has a lot to do with movement and associated disorders typical of Parkinson’s dementia.

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

        Population at risk

        The population at risk of developing Parkinson’s dementia, i.e. those most vulnerable to the elderly, who have had a late onset of Parkinson’s disease, With greater severity in the disease itself, and with predominant symptoms of stiffness and akinesia (inability to initiate precise movement).


        Today, Parkinson’s dementia is an incurable degenerative disease. Treatment will be based on trying to delay the onset of symptoms and by treating or compensating for those that already exist, so that they affect as little as possible.

        for that a cognitive neurorehabilitation program will be used, And external strategies that can help the patient in his environment (use of journals and memory reminders, for example).

        In addition, symptoms associated with dementia, such as depression or anxiety, will be treated psychologically and psychopharmacologically.


        At the pharmacological level and to treat the motor symptoms of the disease (not so much dementia), antiparkinson drugs are generally used. They aim to restore the balance between the dopaminergic system (dopamine), which is deficient, and the cholinergic (acetylcholine), which is overexcited.

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

        Parkinson’s disease as subcortical dementia

        As we mentioned, the dementia associated with Parkinson’s disease consists of subcortical dementia; this means that it causes alterations in the subcortical area of ​​the brain. Another large group of dementias are cortical dementias, which generally include another well-known dementia, that caused by 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 alterations in the substance. white).

        All subcortical dementias have characteristic symptoms of motor alterations (extrapyramidal symptoms), slowing down, bradypsychia and decreased motivation.

        Bibliographical references:

        • Belloch, A., Sandín, B. and Ramos, F. (2010). Manual of psychopathology. Volumes I and II. Madrid: McGraw-Hill.
        • Demey, I. and Allegri, R. (2008). Dementia in Parkinson’s disease and Lewy body dementia. Argentine Neurological Journal, 33: 3 – 21.
        • Rodríguez-Constenla, I., Cap-López, I., Belles-Lama, P. and Cebrián, I. (2010). Cognitive and neuropsychiatric disorders in Parkinson’s disease. Rev Neurol, 50 (2): S33 – S39

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