CORTICAL AND SUBCORTICAL ATROPHY: SYMPTOMS, CAUSES AND REGIONS - GEOGRAFÍA - 2025

The cortical atrophy refers to the degeneration of the upper regions of the brain, especially the structures of the cerebral cortex. In contrast, subcortical atrophy is characterized by affecting the innermost regions of the brain.

Brain atrophy is a neurological condition characterized by the progressive death of neurons in the brain. This pathology is characterized by affecting specific regions of the brain, which is why it can be divided into cortical atrophy and subcortical atrophy.

Cortical atrophy in the brain of a patient with Alzheimer's.

Because the functions performed by the cortical regions of the brain are different from those performed by the subcortical structures, the symptoms of cortical atrophy are often different from those of subcortical atrophy.

In general, the symptoms of cortical atrophy usually cause memory failures, language impairment, decreased learning capacity, decreased concentration and attention and, in some cases, behavioral disturbances.

On the other hand, subcortical atrophy usually affects other functions such as psychological factors, the movement process or some systems related to the physical functioning of the organism.

This article reviews the general characteristics of brain atrophy. The brain structures that are involved in each of these alterations are explained and the etiological and symptomatological differences between cortical atrophy and subcortical atrophy are discussed.

General characteristics

Brain atrophy refers to a decrease and / or loss of brain functionality. This condition can be caused by different diseases.

Most of them are usually neurodegenerative pathologies, although other conditions such as trauma or situations such as aging can also give rise to this neuronal alteration.

Another important element of brain atrophy is that it affects specific regions of the brain. For this reason, one can distinguish between cortical atrophy (affecting the upper regions of the brain) and subcortical atrophy (affecting the lower regions).

In general, certain pathologies such as Alzheimer's disease or Lewy body dementia are characterized by affecting the cortical regions and, therefore, causing cortical atrophy. Instead, pathologies such as Parkinson's or multiple sclerosis tend to generate subcortical atrophy.

However, as the majority of pathologies that cause brain atrophy are characterized by being neurodegenerative, despite the fact that brain deterioration begins in one area or another (cortical or subcortical), the atrophy tends to generalize throughout all structures with the passage of the weather.

For this reason, when we speak of cortical atrophy or subcortical atrophy, we do not refer to a specific disease, but rather the brain damage caused by a specific pathology is specified.

Cortical atrophy

Cortical atrophy is probably the best studied and most well-defined type of atrophy. This condition is characterized by affecting the upper structures of the brain and causes mainly cognitive symptoms.

Regions involved

As its name suggests, cortical atrophy is characterized by affecting the cerebral cortex. This region of the brain can be divided into four large lobes:

1. Frontal lobe: it is located in the frontal region of the skull. It is the largest structure of the cortex and is responsible for carrying out functions such as planning, the elaboration of abstract thinking and the development of behavior.
2. Parietal lobe: it is the second largest lobe of the cortex. It is located in the upper part of the skull and is responsible for integrating and giving meaning to sensitive information.
3. Occipital lobe: it is the smallest lobe of the cortex, it is located in the back and mainly carries out the transmission of visual information.
4. Temporal lobe: It is located in the lower region of the skull and plays a major role in the development of memory and thought.

Main symptoms

The main symptoms of cortical atrophy are related to cognitive functions, since these are regulated mainly by the cerebral cortex. In this sense, the most important manifestations are:

1. Memory impairment
2. Language dysfunction.
3. Decreased attention span and concentration.
4. Disorientation.
5. Deterioration of executive functions.
6. Behavioral and personality disturbances (when the frontal lobe is affected)

Related diseases

The main disease that can cause brain atrophy is Alzheimer's, since this pathology affects the temporal lobe causing a strong deterioration in memory.

Other pathologies such as Pick's disease (affects the frontal lobe) or Lewy Body Dementia can also cause this type of atrophy.

Subcortical atrophy

Subcortical atrophy, unlike cortical atrophy, is characterized by not causing deterioration of cognitive functions. This type of atrophy affects the lower regions of the brain and causes other types of manifestations.

Regions involved

Subcortical atrophy can affect a large number of brain structures, although the most typical are the thalamus and hypothalamus.

The midbrain, cerebellum, pons, or medulla oblongata are other regions that can deteriorate in this type of atrophy.

Main symptoms

The symptoms of subcortical atrophy can be divided into three large groups:

1. Psychological disorders: atrophy originating in the thalamus or hypothalamus can generate depression, motivational deficits or anxiety disorders.
2. Movement disorders: the most typical symptoms of subcortical atrophy have to do with movement. Pathologies such as multiple sclerosis or Parkinson's generate difficulties in coordination of movement and muscle tension.
3. Physical alterations: atrophy in the most subcortical regions of the brain (brainstem) can cause symptoms such as: alterations in the cardiovascular system, decreased muscle tone, or violations in metabolic and thermoregulation processes.

Related diseases

The pathologies that can cause subcortical atrophy are much more numerous than those that cause cortical atrophy. The most prevalent are: Parkinson's disease, Huntington's disease, multiple sclerosis, encephalitis, and acquired immunodeficiency syndrome.

References

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5. Bryan Kolb, Ian Q. Whishaw (2006): Human Neuropsychology. Editorial Médica Panamericana, Barcelona.
6. Jódar, M (ed). (2005). Language and memory disorders. Editorial UOC.