What is Aphasia?

Aphasia

Aphasia is an acquired language disorder that results from damage to the parts of the brain that control language. Aphasia can cause problems with any or all of the following: speaking, listening, reading, and writing.

Damage to the left side of the brain causes aphasia for most right-handers and about half left-handers. Individuals who experience damage to the right side of the brain may have additional difficulties beyond speech and language.

Individuals with aphasia may also have problems in addition to, such as dysarthria, apraxia, or swallowing problems.


Aphasia is NOT a:

  • Loss of intelligence
  • Loss of hearing
  • Loss of identity

If the symptoms of aphasia last longer than two or three months post stroke, a complete recovery is unlikely. However, it is important to note that some people continue to improve over a period of years and even decades.Improvement is a slow process that usually involves both helping the individual and family understanding the nature of aphasia and learning compensatory strategies for communicating.



Causes

Often times Aphasia is most associated with having a stroke. That's because stroke is the most common cause of Aphasia. Approximately 35%-40% of adults admitted to an acute care hospital with a diagnosis of stroke are diagnosed with aphasia by the time they are discharged (Dickey et al., 2010; Pedersen, Jorgensen, Raaschou, & Olsen, 1995). However, the following are all causes of Aphasia:

  • stroke
  • ischemic: blockage that disrupts blood flow to a region of the brain
  • hemorrhagic: a ruptured blood vessel that damages surrounding brain tissue
  • traumatic brain injury
  • brain tumors
  • brain surgery
  • brain infections
  • other neurological diseases (e.g., dementia).



Signs and Symptoms of Aphasia

Aphasia can cause problems with spoken language (talking and understanding) and written language (reading and writing). Typically, reading and writing are more impaired than talking or understanding, but often mirror the expressive speech.  There are different types of aphasia depending on which aspects of language are most impaired, as well as varying levels of severity. Each individual with aphasia is different!  A lot of the time, the type of Aphasia diagnosed doesn't always fit into all of the characteristics described below, but instead fit closely. 

Aphasia can be mild or severe depending on the amount and the location of the damage to the brain.

Expressive Aphasia
  • Difficulty using words and sentences
  • Short or incomplete sentences (omits smaller words)
  • Use words that don't make sense (jargon)
  • May have difficulty finding words
  • May put words in the wrong order
  • May switch sounds

Receptive Aphasia
  • May struggle with both using words and understanding
  • Difficulty comprehending others

Several different types of aphasia exist depending on where the damage in the brain occurred, and the severity.  Below is a description of the several different types of aphasia disorders.

Types of Non-Fluent Aphasia
(Listed from most severe to least severe)
  1. Global Aphasia
  2. Isolation Aphasia
  3. Broca's Aphasia
  4. Transcortical Motor Aphasia

Types of Fluent Aphasia
(Listed from most severe to least severe)
  1. Wernicke's Aphasia
  2. Transcortical Sensory Aphasia
  3. Conduction Aphasia
  4. Anomia




Non-Fluent Aphasia

Damage to the language network near the left frontal area of the brain usually results in Broca aphasia, which is also called nonfluent aphasia.  Often Brocas Aphasia is accompanied by Apraxia of Speech due to the closeness in proximity in the brain. 
  • slow labored speech
  • struggle to retrieve words and/or formulate sentences
  • may have slow rate, reduced intonation, inappropriately placed, long pauses, apraxia, less varied stress patterns than typical speakers

Global Aphasia

  • Lesion in the left perisylvian Fissure or a deep subcortical area
  • No communication modality preserved
  • May have only steroptypical utterances
  • Usually in acute stage, evolves to brocas aphasia as it improves.

Isolation Aphasia

  • Lesion high in the frontal lobe
  • Some verbal output- minimal, single words
  •  Improvement is sudden
  • Can repeat
  • Naming is ok
  •  Usually occurs in the acute stage

Broca's Aphasia

  • Lesion in 3rd frontal convolution (brocas area) aka inferior frontal gyrus.
  • Relatively good auditory comprehension
  • Non-fluent, agrammatic speech= poor expression
  • Impaired repetition
  • Writing is like speech, mirrors speech
  • Frontal alexia (may have)- reading comp usually parallels aud. comprehension.
  • Awareness of errors and difficulty
  • Apraxia of speech
  • Poor naming

Transcortical Motor Aphasia

  • Mildly impaired comprehension
  • Production like brocas
  • Poor reading comprehension
  • Poor naming
  • Good repetition
  •  Lesion in motor cortex

Fluent Aphasia

Wernicke aphasia is the result of damage to the language network in the middle left side of the brain.
  • Word substitutions, neologisms, verbose verbal output.
  • Lesion in posterior portions of the left hemisphere.
  • Typical rate, intonation, pauses, and stress patterns.

Wernicke's Aphasia

  • Lesion in Heschyle’s gyrus in posterior temporal lobe
  • Speech is fluent or hyperfluent
  • Paraphasias (replacing words or sounds with others) and neologisms (making up new words)
  • No self-awareness or awareness of others
  • logorrhea (faster than press)
  • Aud comprehension is impaired
  • Repetition is poor
  • Naming is poor
  • Reading and writing is impaired and mirrors speech


Conduction Aphasia

  • Damage in the Arcuate Fasciculus
  • Speech output is fluent but there are a lot of phonemic paraphrasias which are recognized and results to unmelodic speech.
  • Poor repetition
  • Good auditory comprehension
  • Good silent reading poor aural reading (like verbal output)
  • Naming is usually impaired

Transcortal Sensory Aphasia

  • Lesion in the posterior temporal lobe extending to the visual and auditory cortex.
  • Good repetition
  • Poor auditory comprehension (varies)
  • Fluent output with some paraphasias
  • anomia (word finding difficulties)
  • Incoherent expression with circumlocutions and perseverations
  • Reading and writing impaired.


Anomic Aphasia

  • Word finding difficulties

Primary Progressive Aphasia (PPA)

  • Rare neurological syndrome in which language capabilities become slowly impaired
  • NOT Alzheimer's disease, however mental and daily living functions are most likely preserved for about two years or so. While language deteriorates, Comprehension remains intact. 
  • Most likely initially appears as an Articulation Disorder (difficulty speaking). 
  • Lesser common presents with impaired word finding and progresses to deterioration of naming and comprehension, with articulation relatively preserved.  
  • Other neurological diseases co-exist in which progressive deterioration of language is only one component such as; decline of mental functions, including memory, attention, visiospatial, reasoning, & complex motor skills.
  • Diseases such as Alzheimers, Picks, Creutzfeld - Jakob disease should be excluded by a Neurologist when a person is experiencing progressive language decline.  
  • Brain abnormality in Left Hemisphere either exclusively or to a much greater extent.  Most often brain abnormalities are associated with Fronto - Temporal- Limbic Dementia (FTLD)
  • PPA has been proven to be the cause of Alzheimer's in some patients.  In these patients, Aphasia is usually fluent.  This does NOT mean that PPA is the cause of Alzheimer's in every case.  Every individual is different.