What is aphasia?
Aphasia is a term derived from Greek, more specifically from the word aphasia – the prefix “a” in this case means without, while “phasis” is translated as speech. In its simplest translation, therefore, aphasia can be understood as an inability to speak, but in practice, the problem can run this way, but also somewhat different.
Because spoken language is unquestionably very important for human communication, speech difficulties are picked up quite quickly both by the person experiencing them and those around them.
For this reason, the first description of aphasia dates back a very long time – in fact, references to this problem can already be found in ancient Egyptian papyri, which describe the disorder in a person who suffered damage to the temporal lobes of the brain as a result of head trauma.
Aphasia – due to its causes – is mainly found in middle-aged and elderly people. However, it is possible for it to occur at any point in life, even in a few years old.
Aphasia – causes
Aphasia develops in people when there is damage to structures in the central nervous system. A key aspect needs to be emphasised here, however – the problem originates from defects in the brain itself, as the motor system of speech, i.e. the tongue and laryngeal parts, among other things, function perfectly well in people with aphasia.
In the past, it was thought that aphasia could only be caused by damage to specific brain regions. This refers to the so-called speech centres, which are:
- Broca’s centre (known as the speech motor centre, located in the frontal lobe of the brain)
- Wernicke’s centre (otherwise known as the speech sensory centre, located in the temporal lobe of the brain).
It is indeed the direct damage to the speech centres that is most likely to cause aphasia, but in practice it turns out that damage to e.g. the nerve fibres that connect these centres to other brain regions can also result in speech disorders.
The disease that most often causes aphasia is stroke – it is estimated that up to 40 per cent of all patients who develop this condition eventually struggle with a speech disorder.
However, aphasia can occur as a result of and other conditions, such as:
- head injury
- neuroinfection (such as herpes encephalitis)
- neurodegenerative diseases (such as Alzheimer’s disease)
- brain tumours
- atherosclerosis of the arteries supplying blood to the brain
These are the most common causes of aphasia. The problem can also arise from epilepsy, although much less frequently (in which case aphasia is usually temporary and persists for a short time), and cases of aphasia as a side effect of painkillers containing fentanyl have also been described.
Aphasia – symptoms and types
Aphasia is usually not difficult to recognise – the speech disorder is usually clearly visible to those around the patient and often to the patient himself. The course of the problem can include the following:
- considerable difficulty in forming even the simplest sentences
- problems with naming certain objects – it can seem as if the patient cannot remember what an object is called
- using bizarre words in conversation or forming sentences that make absolutely no sense at all
- uttering only single, completely incomprehensible words
It should be emphasised here, however, that even if the patient only utters a few fragments of words, he or she usually has what he or she wants to say “in his or her head” – aphasia is not the result of memory problems or intellectual deficiencies, but is simply a speech disorder.
It should also be added here that the course of aphasia can vary greatly:
- motor aphasia: this is when the patient loses the ability to speak – they would like to say something, but are unable to do so
- sensory aphasia: this is when the patient can speak on their own, but is unable to understand the speech of others
- Mixed aphasia: in mixed aphasia the patient has difficulty both speaking and understanding sentences that he or she hears
- agnostic aphasia (also known as nominal aphasia): this is characterised by the fact that the patient has difficulty in finding the right words for conversations, and also has difficulty in naming various objects
Aphasia and dysarthria
It is worth emphasising that not only aphasia, but also another problem – dysarthria – can lead to speech disorders. However, as already mentioned, aphasia is caused by damage to the brain structures involved in language functions, while dysarthria results from the malfunction of the speech motor apparatus, e.g. the muscle structures involved in vocal emission (which can be caused by damage to them, but also by paralysis of the nerves that supply them).
Aphasia – diagnosis
The occurrence of aphasia – especially sudden – should always be consulted with a doctor.
After all, the cause of this problem can even be a stroke, which requires that the appropriate therapeutic treatment be implemented for the patient as soon as possible.
If aphasia occurs, a neurological examination is first carried out on the patient – other abnormalities detected during this examination (such as sensory disturbances or paresis, for example) may suggest exactly which illness the patient has suffered or which part of his or her brain has been damaged.
Later, imaging examinations of the head, such as CT scans or MRI scans, are usually ordered – these make it possible to identify, for example, foci of ischaemia within the brain or the existence of some intracranial tumour in the patient.
Aphasia – treatment
Aphasia itself is not a disease, but a symptom – the treatment that is implemented for the patient must therefore focus on the cause of the aphasia. In the case of patients who have suffered a stroke, the speech disorder may also disappear along with the general improvement in their condition.
However, the degree of improvement can vary – for some patients the aphasia even disappears completely, while for others the problem persists. Speech training is very important for many aphasic patients, and with the help of a speech therapist it is often possible to reduce the extent of the speech disorder.
The treatment of aphasia is very different for people whose aphasia has occurred due to a brain tumour. In this case, an effective therapy, e.g. the removal of the entire lesion, is sometimes sufficient, as the tumour presses on the speech centres in the brain and the resection of the tumour, which removes this pressure, leads to the aphasia disappearing.
Aphasia – prognosis
As much as aphasia affects the quality of life (after all, it is not difficult to guess that the sudden loss of the ability to speak takes a significant toll on the patient’s psyche), it alone does not affect the survival of patients. However, the exact prognosis of people who develop aphasia cannot be determined – it all depends here on the reason for the problem.
The overall prognosis is better for people who have a neuroinfection (especially one that can be successfully treated), but much worse, for example, for those patients who develop aphasia in connection with a very malignant brain tumour.