Difference Between Cortical and Subcortical Dementia

cortical and subcortical dementia

An in-depth look at the differences and similarities between cortical and subcortical dementia and what you should do about it.

Also known as a major neurocognitive disorder, dementia is a group of symptoms that causes problems with memory, reasoning, and thinking.

It occurs when parts of the brain responsible for memory, decision-making, language, and learning are diseased or damaged.

The illness mostly affects elderly persons who are above the age of 65.

Some persons will, however, receive dementia diagnosis when they are younger.

There are over fifty causes of dementia the most common ones being:

Cortical vs Subcortical Dementia

Depending on the part of the brain that has been affected, a majority of dementias are either considered to exhibit cortical or subcortical patterns.

Initially, subcortical dementia was described in 1912. However, the term was not used until 1970.

Cortical dementia, on the other hand, accounts for the highest number of dementia cases (between 60-80%).

Various studies indicate that there are some prominent differences between cortical and subcortical dementia.

Both qualitative and quantitative differences exist across several cognitive domains like memory, visuospatial abilities, executive functions, attention, and semantic knowledge.

Let’s look at some of the disparities between the two groups of dementias below.


Cortical dementia describes the types of dementia that develop as a result of disorders that affect the cerebral cortex in the brain.

This is the outermost layer of the brain responsible for several essential functions like language, memory, creativity, abstraction, emotion, attention and judgment.

The illnesses that are progressive in nature starts to cause changes in the brain before the symptoms start showing up.

Experts believe that the illness brings about an increase in the number of lesions in the brain, which then leads to complications like personality changes and loss of memory.

Subcortical dementias represent the types of dementias that showcase themselves without any language or memory problems in individuals who have Alzheimer’s disease.

Disorders that affect the section of the brain that is below the cerebral cortex cause this dementia.

The regions of the brain that this type of dementia affects include the midbrain, striatum, thalamus, and striatofrontal projections.

In most cases, persons who get subcortical dementia display challenges with concentration, attention, and motor function.

Causes Cortical and Subcortical Dementia

Cortical dementia as aforementioned, occurs where there are problems with the cerebral cortex.

Additionally, it is primarily associated with the gray matter in the brain, which mainly consists of nerve cells.

Persons who develop this type of dementia experience serious memory loss issues where they cannot understand language or remember words.

Examples of cortical dementia include Creutzfeldt-Jakob and Alzheimer’s disease.

Subcortical dementia, on the other hand, is brought about when there are problems in the part of the brain located under the cortex.

This is mostly associated with the white matter of the brain that predominantly consists of axons that are in charge of transmitting signals.

Individuals who have this type of dementia typically show changes in their ability to start activities and speed of thinking. HIV, Parkinson’s and Huntington’s disease are possible causes of this dementia type.

Some studies also suggest that prolonged alcohol abuse may be the cause of subcortical dementia.

This is because persons who are diagnosed with alcohol dependence have a significant reduction in the brain’s white matter and the weight of the brain also becomes lighter.

Features of Cortical and Subcortical Dementia

features of cortical and subcortical dementia
Both dementias showcase different features that further explain their main differences like:

Basic function deficit

With cortical dementia, you can expect specific deficits like aphasia, which is an impairment of language that affects comprehension or production of speech and the ability to write and read.

Apraxia affects motor function and agnosia, which affects the ability to process sensory information.

Subcortical dementia presents progressive supra-nuclear palsy, a syndrome that can lead to severe problems with eye movement, balance, swallowing, mood and walking, etc.

Memory impairment

Persons with cortical dementia will often experience learning deficits and poor recognition. Individuals with subcortical dementia do not go through severe memory loss issues.

Caregivers and loved ones can use cues to help the affected individuals recall information without too much difficulty.

Motor Symptoms

motor symptoms
Cortical dementia does not showcase any motor symptoms, especially in the early stages of the illness. Motor speed also remains relatively healthy, but it might change at a later course.

Problems with motor symptoms are common with subcortical dementia that presents extrapyramidal symptoms that can include continuous muscle contractions and spasms also known as dystonia, motor restlessness, rigidity, slowness of movement, and tremor amongst others.


Individuals with subcortical dementia, for the most part, will have normal speech while it may be slow or abnormal in cortical dementia cases.

Symptom Profile

Cortical and subcortical dementia have different sets of symptoms.

Clinically, cortical dementia exhibits symptoms that are suggestive of abnormalities with various cortical functions like amnesia and language issues.

With subcortical dementia, the symptoms will manifest mainly as poor abstraction, issues in recall, mood disorders, and problems with strategy formation. Other symptoms to look into include:


Memory dysfunctions tend to occur in both groups of dementia.

Studies, however, propose that the nature of memory impairment is different in subcortical and cortical dementia.

Cortical dementia showcases more severe memory loss, which is depicted by difficulties in recalling information and learning new details.

When it comes to subcortical dementia, things are not black and white.

While there is evidence of challenges with procedural learning, the impairment is not uniform in regards to all kinds of perceptomotor learning.

For example, a person who has Parkinson’s disease might have issues with skill or habit learning but have no problem in intact learning tasks such as artificial grammar and dot pattern prototype.

Memory loss patterns also come into play when differentiating these two forms of dementia.

With cortical dementia, recent literature indicates that memory impairment evolution happens in a temporal gradient, which results in progressive or extensive remote memory loss.

This is especially true for autobiographical memory.

On the contrary, the memory loss pattern in subcortical dementia is considered to be a lot more diverse. The specific type of dementia will determine the memory loss pattern.

For instance, persons who have Parkinson’s disease normally have challenges when dating events in the past.

Note that memory decline is faster in Parkinson’s dementia than in AD as reported by Selective Reminding Test and Boston naming test.

It is also important to point out that with subcortical dementias, learning impairments are subject to correction with the use of more prominent aid recognition cues.

Executive Functions

executive functions
Executive functions usually involve the frontal lobes and other subcortical structures. This means that it is only natural for executive function problems to be present in both subcortical and cortical dementia.

This, however, happens at a different rate.

AD is normally characterized by the impairment of various executive functions like problem-solving and concept formation.

Persons who have cortical dementia will experience impaired elementary calculation skills earlier than those who have subcortical dementia.

Persons with cortical dementia also remain alert for more extended periods than those with subcortical dementia.


Several studies indicate that the language problem is often seen in cortical dementia.

Individuals with Alzheimer’s disease exhibit several progressive language issues. These normally start with an inability to recall names of familiar objects before it deteriorates to terminal language syndrome.

Prognosis of Cortical and Subcortical Dementia

The prognosis of cortical and subcortical dementia also significantly varies. Because different types of dementias fall under these two categories, multiple factors commonly affect prognosis.

Among these include general health, age of onset, and other illnesses that the person suffers from. These can affect not only prognosis but life expectancy as well.


Currently, there is no specific cure for both cortical and subcortical dementia.

However, a majority of the disorders that are listed for the two groups of dementia will respond to appropriate treatment.

These can include different types of medication and other alternative therapies that can help to slow down the progression of the illness.

Lifestyle changes can also help to improve the life quality of people who are experiencing different types of dementia.

Closing Thoughts

Understanding the differences between the two main groups of dementias is essential because it helps to create a better understanding of how the brain behaves regarding neurodegenerative illnesses.

This can also help medics improve the ability to differentiate multiple dementia disorders clinically.

There is also a need for more clinical studies that will examine the differences between subcortical dementia and cortical dementia. These are bound to give a clearer picture of the factors that distinguish the two forms of dementia.

The Alzheimer’s Association indicates that about 90% of the information available about dementia has been discovered in under twenty years.

Experts in the industry continue to do more research, tests, and studies on this disease that affects millions of people in different parts of the globe.

Fresh information may continue to roll out detailing the differences or similarities of cortical and subcortical dementia so that people can get a better understanding of these illnesses.

Subcortical Dementia – What Is It?

subcortical dementia

There are different types of dementia, one of them being subcortical dementia.

According to many studies and researches, this is a type of dementia that affects the white matter of the brain affecting structures below the cortex.

This type of dementia is a clinical syndrome that includes multiple diseases that primarily affects the subcortical structures that include:

  • The midbrain (mesencephalon)
  • Cerebellum
  • Thalamus & hypothalamus (diencephalon)
  • Basal ganglia

The above are responsible for various functions, including procedural learning, eye movement, voluntary motor movement control, arousal, emotions, visuospatial skills learning of habits, and cognition.

History of the Clinical Syndrome

history of the clinical syndrome
In 1817, James Parkinson wrote an essay where he recognized depression as one of the symptoms of the disease named after him.

He described a man who was once a confident with an active mind and cheerful disposition appearing dejected, emancipated and stopping.

Despite all this, the power of his mind and his senses remained unimpaired.

He remained attentive, was able to listen to conversations and had a desire to join in though he was struggling with speech, and he could even read and write.

Years later, in 1861, Vulpian and Charcot observed cognitive impairments in persons who have Parkinson’s and Huntington’s diseases.

However, it was not until 1912, when Wilson became the first person to observe a distinction between dementia that involve subcortical structures, and other kinds of cognitive impairments.

Wilson described the impairment of Wilson’s disease as one that showed the narrowing of mental horizons.

He went on further to state that the impairment did not include agnosia and apraxia. Wilson also compared this pattern to the one presents in Huntington’s disease.

As research went on by other experts on the subject, the concept of subcortical dementia was finally crystallized into a clinical entity in the mid-1970s.

Examples of Subcortical Dementia

examples of subcortical dementia
This dementia type is in connection with numerous diseases. These include Parkinson’s disease, Huntington’s disease, Wilson’s disease, Multiple System Atrophy, and progressive supranuclear palsy, etc.

The conditions fall into the category of subcortical processes that are characterized by deterioration of mental abilities.

The concept of this type of dementia has led to a lot of debate where researchers are seeking to divide cognitive dysfunction into the subcortical and cortical dichotomy.

Over the years, experts have been collecting evidence that supports the idea of the clinical syndrome being classified as its clinical entity.

The evidence touches base on distinct patterns of neuropathology, neurological, and neuropsychological profiles.

Symptoms of Subcortical Dementia

symptoms of subcortical dementia
Various symptoms may suggest a person has this type of dementia. Some of them include:

  • Slowness when it comes to mental processing
  • Depression
  • Abnormal movements
  • Tremors
  • Lack of initiation
  • Apathy
  • Loss of social skills
  • Mild intellectual impairment
  • Inertia
  • Difficulties solving problems

In a majority of cases, the clinical entity does not affect perception and language. Although persons with the illness may experience forgetfulness, amnesia is usually not severe.

Looking at a Neurobehavioral Perspective of This Dementia

looking at a neurobehavioral perspective of this dementia
Subcortical dementias have a common neurobehavioral change pattern even though the subcortical structures usually affect different areas of the subcortical pathology.

This is because of the disruption that happens to the frontal-subcortical systems. The clinical presentations include abnormalities in different areas like:


With this type of dementia, it appears like the ability to retain information, which can also be referred to as immediate memory is spared while it affects the ability to recall information.

Personality and Mood

Personality and mood changes have been recognized in persons with this clinical syndrome. About 90% of persons with Parkinson’s experience depression at one point in the illness.

General Appearance

Because of significant extrapyramidal motor deficits, the general appearance of people with this type of dementia is different from that of cortical dementia. For example, Parkinson’s disease is often marked by a shuffling gait, hypomimia, and tremor.

Chorea is common with Huntington’s disease while a “surprise” look is seen with people who have supranuclear palsy.


There is no record of significant changes in language when talking about subcortical dementia. People with the illness may, however, experience deformities with speech.

For instance, an individual with Parkinson’s disease may have reduced phrase length and dysarthria.

Subcortical Dementia Treatment Options

Although this kind of dementia remains highly controversial, some researchers believe that they are part of the dementias that can be treated. This is because most disorders that are associated with dementia respond to appropriate treatment and some may be reserved completely.

Consulting your physician will give you a better idea of which treatment route to take while dealing with this dementia type.

Closing Remarks

While some physicians will use the classifications of subcortical or cortical dementia, others argue that it is not worth categorizing the neurodegenerative illness into groups depending on the location of brain damage.

As new evidence emerges, it is only a matter of time before the experts can put the matter into rest as to whether it is important to classify dementia into two major groups.

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