Aphasia vs Dementia

Naomi Carr
Author: Naomi Carr Medical Reviewer: Dr. Jenni Jacobsen, PhD Last updated:

Aphasia, referring to deficits in speech and communication abilities, and dementia, a collective name of cognitive disorders, are both related to damage or degeneration of the brain, but they are distinct conditions. Typically, neither aphasia nor dementia can be cured, but both may be managed with therapeutic and practical support.

What is dementia?

Dementia is the collective name of a group of conditions caused by damage to parts of the brain, including Alzheimer’s, Lewy body, vascular, and frontotemporal dementias. These conditions can cause impairments in cognitive abilities, impacting speech, concentration, memory, understanding, and language, as well as potentially causing behavioral and mood changes [1].

Different parts of the brain have different functions, such as the hippocampus being involved in memory, Broca’s area being involved in speech, and the prefrontal cortex being involved in mood and planning [2]. As such, certain functional impairments are caused by damage to specific areas of the brain.

Dementia is usually caused by damage to brain cells and neurons, impacting the whole brain and therefore, causing impairments in several aspects of functioning, including cognition, behavior, and movement [3].

Depending on the severity of impairment, a person with dementia might require constant support, aiding with eating, dressing, bathing, and movement [4].

What is aphasia?

Aphasia is a common symptom of dementia and other conditions that affect the brain [5]. It is typically caused by damage to specific areas of the brain, called the Broca’s area and Wernicke’s area, which are both involved in speech and language [6].

As aphasia typically affects only these parts of the brain, it does not cause impairments in all aspects of functioning, like dementia, but rather only impacts the individual’s ability to communicate and understand language [7].

Someone may have other speech and language impairments as well as aphasia, or they may experience aphasia as part of a condition in which other symptoms are present [5][6].

Aphasia vs Dementia: Symptoms

Broca aphasia, Wernicke aphasia, and global aphasia are the three main types of aphasia, caused by damage to specific areas of the brain [7].

Broca aphasia

Broca’s area is a part of the frontal lobe. This type of aphasia is also referred to as expressive aphasia, as it impacts the individual’s ability to express their thoughts and feelings.

Symptoms include [5][6]:

  • Missing out small words such as ‘the’, ‘is’, or ‘and’ within sentences
  • Using only short sentences
  • Struggling to find words and speaking slowly
  • Using an incorrect word but that is related to the right word, such as saying ‘house’ when meaning ‘building’
  • Generally being able to understand others
  • Having an awareness of their own incorrect speech or grammar

Wernicke aphasia

Wernicke’s area is a part of the temporal lobe. This form  of aphasia is also referred to as receptive aphasia, as it impacts the individual’s ability to understand others’ speech [7].

Symptoms include [6][7]:

  • Speaking in incomprehensible sentences, using jumbled or unrelated words
  • Adding words to sentences that don’t make sense, or making up words
  • Having a limited ability to understand others when they are speaking
  • An impaired ability to understand written words
  • A lack of awareness of their unusual or incorrect use of language

Global aphasia

This type of aphasia is caused by extensive damage to the brain and results in severe impairments in speech and understanding, often resulting in the individual being unable to communicate more than a few words [6].


Often, the symptoms of dementia start slowly and gradually worsen as the condition develops [3]. The various types of dementia can cause differing symptoms, but aphasia is a common symptom of Alzheimer’s, vascular, and frontotemporal dementia [5][6]. Symptoms will vary depending on the part of the brain that is damaged and the stage of dementia.

Common symptoms of dementia include [1][3][8]:

  • Mixing up words or names
  • Struggling to find the right word
  • Difficulty expressing thoughts or feelings
  • Memory loss
  • Confusion
  • Impairments in concentration
  • Difficulty problem-solving
  • Movement problems, such as stiffness and unsteadiness, especially with Lewy body dementia
  • Behavioral changes, such as agitation, low mood, anxiety, or inappropriate behavior, especially with frontotemporal dementia
  • Hallucinations or delusions may occur with Lewy body dementia

Aphasia vs Dementia: Causes

Both aphasia and dementia are caused by damage to parts of the brain [3][6]. Causes of this damage and risk factors related to the development of these conditions may vary from person to person.


Some of the potential causes and risk factors of aphasia include [5][6][7][9]:

  • Dementia: Aphasia is a common symptom of several types of dementia, in which the symptoms of aphasia tend to worsen over time, as the dementia worsens and the brain degenerates.
  • Stroke: When there is a disruption in the blood flow to the brain, oxygen is decreased, thus causing damage to specific areas of the brain and cell death, resulting in a stroke. If this occurs in the areas of the brain that impact language and speech, aphasia can occur, with the onset of symptoms occurring immediately.
  • Head injury: Damage to the brain from an injury can result in several different symptoms. If an injury occurs to the parts of the brain responsible for speech and language, symptoms of aphasia can occur immediately after.
  • Tumor: A tumor in the parts of the brain responsible for speech and language can cause a slow onset of symptoms of aphasia, which may worsen as the brain tumor grows.
  • Infection: Infection in parts of the brain can cause a slow onset of the symptoms of aphasia, which may worsen as the infection spreads or causes increasing damage to this area.


Some of the potential causes and risk factors of dementia include [1][3][4][8]:

  • Brain changes: Dementia can be caused by damage to brain cells or blood vessels, a build up of proteins, or degeneration of parts of the brain.
  • Genetics: In some cases, dementia can be hereditary, causing an increased risk of dementia in those who have a parent or direct relative with dementia.
  • Age: The risk of dementia increases with age, with most cases occurring after the age of 65. However, not all people will develop dementia as they age.
  • Traumatic brain injury: Injury to the brain can increase the risk of dementia, especially repeated injuries, such as may occur with rugby players or boxers.
  • Stroke: Vascular dementia can be caused by a stroke, following a reduction of oxygen to the brain.
  • Heart conditions: Poor cardiac health can increase the risk of dementia.
  • Other: Vitamin deficiency, thyroid problems, or excessive use of alcohol can cause symptoms of dementia to occur but may be reversible if treated or reduced.

Aphasia vs Dementia: Treatment

Depending on the cause, some symptoms seen with aphasia or dementia may be prevented, reduced, or slowed by certain treatments, so early diagnosis and intervention is important. However, in many cases, the symptoms cannot be cured, and treatment is provided to help the individual function as best as possible with their condition.

Treatment of aphasia

  • Speech and language therapy: A speech and language therapist can teach techniques to regain speech and language skills where possible, learn new communication skills or alternative ways to communicate, such as using pictures or gestures, and provide education to the individual and their family on how to manage symptoms and give support [7][10].
  • Computer and device programs: There are various forms of technological programs that can aid in communication for those who have cognitive impairments, such as a voice output communication aid (VOCA), which plays words or phrases that have been typed or chosen via the mechanism [10].
  • Group therapy: People with aphasia can attend groups to learn and practice new communication skills with others, while providing an opportunity to support one another and share experiences [6][7].

Treatment of dementia

  • Medication: Different types of medications can be prescribed to people in various stages of dementia, such as cholinesterase inhibitors or memantine, an NMDA receptor agonist, which can help to improve communication between, or protect, nerve cells in the brain, thus potentially reducing the speed of decline [3][11].
  • Care: People in the later stages of dementia may require constant care to manage their daily life, including eating, drinking, bathing, and dressing, as well as potentially requiring assistance with movement. This can be provided in the individual’s home or in a facility. For those who are still able to manage somewhat independently, a carer may visit the home to provide sporadic support when required [1][12].
  • Talking therapy: Therapy, such as cognitive behavioral therapy (CBT), can be useful for people in the early or middle stages of dementia, to provide support with symptoms of depression or anxiety that may occur within the context of a dementia diagnosis and provide skills to manage emotional distress [12].
  1. World Health Organization. (2022). Dementia. WHO. Retrieved from https://www.who.int/news-room/fact-sheets/detail/dementia
  2. John Hopkins Medicine. (n.d). Anatomy of the Brain. Hopkins Medicine. Retrieved from https://www.hopkinsmedicine.org/health/conditions-and-diseases/anatomy-of-the-brain
  3. Alzheimer’s Association. (2023). What is Dementia? Alzheimer’s Association. Retrieved from https://www.alz.org/alzheimers-dementia/what-is-dementia
  4. NIH National Institute on Aging. (Reviewed 2022). What is Dementia? Symptoms, Types, and Diagnosis. NIH. Retrieved from https://www.nia.nih.gov/health/what-is-dementia
  5. National Health Service. (Reviewed 2021). Symptoms – Aphasia. NHS. Retrieved from https://www.nhs.uk/conditions/aphasia/symptoms/
  6. National Institute of Health. (2015, Updated 2017). Aphasia. NIH. Retrieved from https://www.nidcd.nih.gov/health/aphasia
  7. John Hopkins Medicine. (n.d). Aphasia. Hopkins Medicine. Retrieved from https://www.hopkinsmedicine.org/health/conditions-and-diseases/aphasia
  8. Centers for Disease Control and Prevention. (Reviewed 2019). About Dementia. CDC. Retrieved from https://www.cdc.gov/aging/dementia/
  9. Stroke Association. (n.d). Aphasia and Dementia. Stroke Association. Retrieved from https://www.stroke.org.uk/what-is-aphasia/aphasia-and-dementia
  10. National Health Service. (Reviewed 2021). Treatment – Aphasia. NHS. Retrieved from https://www.nhs.uk/conditions/aphasia/treatment/
  11. Jones, R.W. (2011). Drug Treatment for People with Dementia. Clinical Medicine (London, England), 11(1), 67–71. Retrieved from https://doi.org/10.7861/clinmedicine.11-1-67
  12. Alzheimer’s Society. (2023). Talking Therapies for People with Dementia and Carers. Alzheimer’s Society. Retrieved from https://www.alzheimers.org.uk/about-dementia/symptoms-and-diagnosis/talking-therapies
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Naomi Carr
Author Naomi Carr Writer

Naomi Carr is a writer with a background in English Literature from Oxford Brookes University.

Published: Mar 30th 2023, Last edited: Sep 22nd 2023

Dr. Jenni Jacobsen, PhD
Medical Reviewer Dr. Jenni Jacobsen, PhD LSW, MSW

Dr. Jenni Jacobsen, PhD is a medical reviewer, licensed social worker, and behavioral health consultant, holding a PhD in clinical psychology.

Content reviewed by a medical professional. Last reviewed: Mar 30th 2023