Boston classification  

Major characteristics of different types of aphasia according to the Boston
classification  [61]  [62]  Type of aphasia  |   Speech repetition
 |  Naming  |  Auditory
comprehension  |  Fluency
---|---|---|---|---
 Expressive aphasia  (Broca's
aphasia)  |  Moderate–severe  |  Moderate–severe  |  Mild difficulty  |  Non-
fluent, effortful, slow
 Receptive aphasia  (Wernicke's
aphasia)  |  Mild–severe  |  Mild–severe  |  Defective  |  Fluent paraphasic
 Conduction aphasia  |  Poor
|  Poor  |  Relatively good  |  Fluent
 Mixed transcortical aphasia  |  Moderate  |  Poor  |  Poor  |  Non-fluent
 Transcortical motor aphasia  |  Good  |  Mild–severe  |  Mild  |  Non-fluent
 Transcortical sensory aphasia  |  Good  |  Moderate–severe  |  Poor  |
Fluent
 Global aphasia  |  Poor  |  Poor  |
Poor  |  Non-fluent
 Anomic aphasia  |  Mild  |
Moderate–severe  |  Mild  |  Fluent

* Individuals with  receptive aphasia  (  Wernicke's  aphasia), also referred to as fluent aphasia, may speak in long sentences that have no meaning, add unnecessary words, and even create new "words" (  neologisms  ). For example, someone with receptive aphasia may say, "delicious taco", meaning "The dog needs to go out so I will take him for a walk". They have poor auditory and reading comprehension, and fluent, but nonsensical, oral and written expression. Individuals with receptive aphasia usually have great difficulty understanding the speech of both themselves and others and are, therefore, often unaware of their mistakes. Receptive language deficits usually arise from lesions in the posterior portion of the left hemisphere at or near Wernicke's area.  [9]  [63]  : 71  It is often the result of trauma to the temporal region of the brain, specifically damage to  Wernicke's area  .  [64]  Trauma can be the result from an array of problems, however it is most commonly seen as a result of stroke  [65]
* Individuals with  expressive aphasia  (  Broca's  aphasia) frequently speak short, meaningful phrases that are produced with great effort. It is thus characterized as a nonfluent aphasia. Affected people often omit small words such as "is", "and", and "the". For example, a person with expressive aphasia may say, "walk dog", which could mean "I will take the dog for a walk", "you take the dog for a walk" or even "the dog walked out of the yard." Individuals with expressive aphasia are able to understand the speech of others to varying degrees. Because of this, they are often aware of their difficulties and can become easily frustrated by their speaking problems.  [66]  While Broca's aphasia may appear to be solely an issue with language production, evidence suggests that it may be rooted in an inability to process syntactical information.  [67]  Individuals with expressive aphasia may have a speech automatism (also called recurring or recurrent utterance). These speech automatisms can be repeated lexical speech automatisms; e.g., modalisations ('I can't..., I can't...'), expletives/swearwords, numbers ('one two, one two') or non-lexical utterances made up of repeated, legal but meaningless, consonant-vowel syllables (e.g.., /tan tan/, /bi bi/). In severe cases, the individual may be able to utter only the same speech automatism each time they attempt speech.  [68]
* Individuals with  anomic aphasia  have difficulty with naming. People with this aphasia may have difficulties naming certain words, linked by their grammatical type (e.g., difficulty naming verbs and not nouns) or by their  semantic  category (e.g., difficulty naming words relating to photography but nothing else) or a more general naming difficulty. People tend to produce grammatic, yet empty, speech. Auditory comprehension tends to be preserved.  [69]  Anomic aphasia is the aphasial presentation of tumors in the language zone; it is the aphasial presentation of Alzheimer's disease.  [70]  Anomic aphasia is the mildest form of aphasia, indicating a likely possibility for better recovery.  [69]  [ _ additional citation(s) needed   _ ]
* Individuals with transcortical sensory aphasia, in principle the most general and potentially among the most complex forms of aphasia, may have similar deficits as in receptive aphasia, but their repetition ability may remain intact.
* Global aphasia is considered a severe impairment in many language aspects since it impacts expressive and receptive language, reading, and writing.  [71]  Despite these many deficits, there is evidence that has shown individuals benefited from speech language therapy.  [72]  Even though individuals with global aphasia will not become competent speakers, listeners, writers, or readers, goals can be created to improve the individual's quality of life.  [66]  Individuals with global aphasia usually respond well to treatment that includes personally relevant information, which is also important to consider for therapy.  [66]
* Individuals with conduction aphasia have deficits in the connections between the speech-comprehension and speech-production areas. This might be caused by damage to the  arcuate fasciculus  , the structure that transmits information between  Wernicke's area  and  Broca's area  . Similar symptoms, however, can be present after damage to the  insula  or to the  auditory cortex  . Auditory comprehension is near normal, and oral expression is fluent with occasional paraphasic errors. Paraphasic errors include phonemic/literal or semantic/verbal. Repetition ability is poor. Conduction and transcortical aphasias are caused by damage to the white matter tracts. These aphasias spare the cortex of the  language centers  but instead create a disconnection between them. Conduction aphasia is caused by damage to the arcuate fasciculus. The arcuate fasciculus is a white matter tract that connects Broca's and Wernicke's areas. People with conduction aphasia typically have good language comprehension, but poor speech repetition and mild difficulty with word retrieval and speech production. People with conduction aphasia are typically aware of their errors.  [66]  Two forms of conduction aphasia have been described: _reproduction conduction aphasia_ (repetition of a single relatively unfamiliar multisyllabic word) and _repetition conduction aphasia_ (repetition of unconnected short familiar words.  [73]
* Transcortical aphasias include transcortical motor aphasia, transcortical sensory aphasia, and mixed transcortical aphasia. People with transcortical motor aphasia typically have intact comprehension and awareness of their errors, but poor word finding and speech production. People with transcortical sensory and mixed transcortical aphasia have poor comprehension and unawareness of their errors.  [66]  Despite poor comprehension and more severe deficits in some transcortical aphasias, small studies have indicated that full recovery is possible for all types of transcortical aphasia.  [74]