Aphasia, what it is and how to deal with it

By Cristiano Antonino On Jan 30, 2023

Aphasia (from the Greek: ἀφασία i.e. lack of speech) defines in neurology the condition in which one loses the ability to communicate, which may affect both the ability to express oneself and the ability to understand language, and may involve only speech, in the sense of structuring a full-length discourse, or even only the ability to write

The disorder may be

expressive type, i.e. the patient knows what he/she wants to say but does not know how to say it,
of the receptive type, i.e. the patient does not understand all or part of what is said to him as if he were being spoken to in a foreign language.

Aphasia was first described in 1861 by the French physician Paul Broca

The doctor performed an autopsy of a patient who could only pronounce the words ‘tan tan’ (and was therefore called Tan) and detected the presence of a lesion in the inferior portion of the third frontal circumvolution, which was therefore considered to be involved in the faculty of speech and was named Broca’s area (or area of articulate speech).

Similarly, in 1874, the German neurologist Carl Wernicke discovered that damage to part of the temporal lobe, at the confluence of the temporal, parietal and occipital associative areas, caused a particular type of aphasia in which speech comprehension was involved, i.e. spoken language was fluent, but logical sense was missing.

Wernicke’s area, or perceptual language area, is connected to Broca’s area by a neural pathway called the arcuate fasciculus.

Types and symptoms of aphasia

Aphasia is therefore caused by lesions in the areas of the brain responsible for language processing, as we have said, Broca’s area or Wernicke’s area, which are located in the dominant hemisphere, which is the left hemisphere for right-handed subjects while in left-handed subjects they are located in the right hemisphere and is traditionally classified as Broca’s or Wernicke’s aphasia.

Broca’s aphasia

Broca’s aphasia is a non-fluent aphasia characterised by “agrammatism”, i.e. articles, prepositions and syntactic-grammatical and phonological disturbances such as phonemic and phonetic paraphasias are missing; comprehension is less impaired than verbal expression and the patient is aware of his situation and a reaction of frustration and depression is not uncommon.

Wernicke’s aphasia

Wernicke’s aphasia is a fluent aphasia that involves problems in both speech comprehension and production.

The ability to process speech fluently is maintained, but speech is paraphasic and full of circumlocutions with neologisms.

In this form of aphasia the patient does not realise that his speech is unintelligible and can understand elementary commands, such as to stand up or to close his eyes, but he does not understand simple questions such as to say his name.

Global aphasia

Global aphasia is a non-fluent aphasia, i.e. a severe deficit in the production, comprehension and processing of linguistic messages: speech is limited to recurring syllabic fragments, but comprehension is severely impaired and reading and writing are practically absent.

The patient is generally aware of his difficulties and reacts with expressions of despair and often refuses to communicate.

Finally, it should be remembered that aphasia can also manifest itself in written language, both in writing (agraphia) and reading (alexia), in calculation (acalculia) and in the recognition of signs, shapes and colours.

What are the causes of aphasia?

Any lesion involving the dominant hemisphere and affecting the areas responsible for language processing is capable of causing aphasia.

The most frequent causes are:

Ischaemic stroke in the territory of the left sylvian artery (aphasia is severe and immediate).
TIA (Transient Ischaemic Attack) in which, however, the aphasia regresses within a few hours.
Cerebral haemorrhage.
Tumours in the left frontal or temporal lobe, which cause progressive aphasia.
Neuro-degenerative diseases such as Alzheimer’s, multiple sclerosis or fronto-temporal dementia, in which speech disorders are only part of the symptoms.
Head traumas causing intracranial haematomas or lacerated contusions particularly in the left temporal lobe.
Infectious processes responsible for brain abscesses or encephalitis.
An epileptic seizure may produce fleeting aphasia.

A migraine may have an aura characterised by aphasia of the order of a few minutes.

How to diagnose aphasia?

The diagnosis of aphasia after a brain injury is almost always easy, but in milder cases it can be detected by means of specific tests.

Often, even when the initial aphasia is thought to have regressed, it is still possible to find severe disturbances evident only in more complex tests.

For a correct test, however, it is necessary to exclude the coexistence of disorders capable of altering language, as a consequence of altered brain functioning such as in cases of dementia, or sensory dysfunction (blindness, deafness) or major psychiatric disorders.

Oral language assessment

Expression:

spontaneous language,
repetition of words and sentences of increasing length,
production of automatic series (days of the week and months),
naming of pictures, shapes and objects,
description of a complex image,
repetition of a story.

Comprehension (requires the patient, from a motor point of view, to be able to carry out the given orders):

pointing to objects and images,
execution of simple orders (close eyes, open mouth),
execution of complex orders (touch left elbow with right hand),
three-sheet test (precise delivery assigned to each sheet).

Written language assessment

Reading:

identification of letters, syllables, words,
reading aloud,
understanding written language: execution of written orders,
matching written words with pictures, written sentences with actions.

Writing:

spontaneous,
copying,
dictation.

Elaborate tests

definition of words, idioms and proverbs,
construction of a sentence with two or three words provided to the patient,
criticism of absurd stories,
interpretation of a text heard or read.

How can aphasia be treated?

The prognosis is not inauspicious in the majority of strokes: in fact, after a few weeks the aphasia may regress, but in some cases the language may remain altered or sometimes characterised by a kind of foreign accent because certain phonetic laws typical of the original language are violated. In a third of cases, the problem resolves within a year; in a minority of cases, it remains for life.

Age can be an important factor in recovery.

Multiple epidemiological studies of stroke aphasics show that patients older than 70 years have a lower chance of recovery than younger patients.

However, at any age, recovery of varying degrees can occur even many years after the occurrence of the brain lesion that caused the aphasia.

Due to the neuro-plastic capacities of the Central Nervous System, which are more evident in children and young individuals, lost language skills can sometimes be recovered through the vicarious function of adjacent or interconnected brain areas.

The therapy of aphasia is identified with the treatment of the disease that triggered the problem.

In a second phase, it is necessary to rely on a speech therapist to recover language skills or alternative communication methods and tools.

Research is currently underway to develop drugs for the treatment of aphasia, but further scientific confirmation will be needed before they can enter clinical practice.

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