Aphasia is an impairment of language, affecting the production or comprehension of speech and the ability to read or write. Aphasia is always due to
injury to the brain-most commonly from a stroke, particularly in older individuals. But brain injuries resulting in aphasia may also arise from head
trauma, from brain tumors, or from infections.
Individuals with Broca’s aphasia have trouble speaking
fluently but their comprehension can be relatively
preserved. This type of aphasia is .also known as non-fluent
or expressive aphasia
Broca’s aphasia results from injury to speech and language brain areas such the
left hemisphere inferior frontal gyrus, among others. Such damage is often a
result of stroke but may also occur due to brain trauma.
Patients have difficulty producing grammatical sentences and their speech is limited
mainly to short utterances of less than four words. Producing the right sounds or
finding the right words is often a laborious process. Some persons have more difficulty
using verbs than using nouns.
In this aphasia the ability to grasp the meaning of spoken words and sentences is
impaired, while the ease of producing connected speech is not very affected.
Persons with Wernicke’s aphasia, often what they say doesn’t make a lot of sense or they pepper
their sentences with non-existent or irrelevant words. They may fail to
realize that they are using the wrong words or using a non-existent word and
often they are not fully aware that what they say doesn’t make sense.
Patients with this type of aphasia usually have profound language
comprehension deficits, even for single words or simple
Reading and writing are often severely impaired.
As in other forms of aphasia, individuals can have
completely preserved intellectual and cognitive
capabilities unrelated to speech and language.
. The term is applied
to persons who are left with a persistent inability to supply the words for
the very things they want to talk about, particularly the significant nouns
and verbs. Their speech is fluent and grammatically correct but it is full of
vague words (such as ‘thing’) and circumlocutions (attempts to describe the
word they are trying to find). The feeling is often that of having the word on
the tip of one’s tongue, which results in their speech having lots of
expressions of frustration
People with anomic aphasia understand speech well
and they can repeat words and sentences. In most
cases they can read adequately. Difficulty finding
words is as evident in writing as it is in speech.
conduction aphasia results from damage
to the arcuate fasciculus, a bundle of nerve fibers that lies below
the supramarginal gyrus in the temporal lobe and connects
Broca's and Wernicke's areas. Both Broca's and Wernicke's areas
are left intact. Lesions are also found in the left perisylvian area of
the cortex. Effected areas may include superior temporal gyrus,
the insula (Island of Reil), the primary auditory cortex
(Brodmann's areas 41 and 42), auditory association areas
(Brodmann's 21 and 22), and the supramarginal gyrus
(Brodmann's area 40).
Spontaneous speech is usually fluent. Auditory comprehension and reading comprehension are fairly good. Poor
repetition, in comparison to problems with comprehension and spontaneous expression, is the hallmark of this syndrome.
Spontaneous speech is better than repetition. Patients typically produce many paraphasias when trying to repeat. They
may be able to reproduce short utterances, however, they will be unable to repeat polysyllabic words or syntactically
complex utterances. Patients with this syndrome have difficulty repeating even the high probability sentences included in
the repetition subtest of the Boston. Patients' ability to repeat numbers is typically much better than their ability to repeat
Global Aphasia This is the third most common aphasic syndrome after Broca's and Wernicke's. Site of
Lesion This type of aphasia occurs when there are both anterior and posterior lesions. Characteristics All
aspects of language are so severely impaired that there is no longer a distinctive pattern of preserved vs.
impaired components. Articulation may be adequate in the context of stereotypical utterances. Prognosis
Mixed Nonfluent Aphasia This diagnosis is given to patients who produce language that is similar to the
telegraphic speech characteristic of Broca's aphasia, but cannot be categorized as actually having Broca's
aphasia due to the severity of their auditory comprehension deficits.
Subcortical Aphasia Lesions in the anterior subcortical area involving the limb of the internal capsule and
putamen are associated with sparse language output and impaired articulation. Posterior subcortical
lesions are associated with fluent forms of aphasia, while lesions of the thalamus may cause a global