Aphasia is a language disorder that results from damage to portions of the brain that are responsible for language. For most people, these are parts of the left side (hemisphere) of the brain. Aphasia usually occurs suddenly, often as the result of a stroke or head injury, but it may also develop slowly, as in the case of a brain tumor. The disorder impairs both the expression and understanding of language as well as reading and writing. Aphasia may co-occur with speech disorders such as dysarthria or apraxia of speech, which also result from brain damage.
Primary signs of the disorder include difficulty in expressing oneself when speaking, trouble understanding speech, and difficulty with reading and writing. Aphasia is not a disease, but a symptom of brain damage. Most commonly seen in adults who have suffered a stroke, aphasia can also result from a brain tumor, infection, head injury, or dementia that damages the brainThe type and severity of language dysfunction depends on the precise location and extent of the damaged brain tissue.
Type of Aphasia –
- Global aphasia — People with this aphasia may be completely unable to speak, name objects, repeat phrases or follow commands.
- Broca’s aphasia — The person knows what they want to say, but can’t find the right words (can’t get the words out).
- Wernicke’s aphasia — A person with this aphasia can seldom understand what’s being said or control what they’re saying
Anyone can acquire aphasia, but most people who have aphasia are in their middle to late years. Men and women are equally affected. It is estimated that approximately 80,000 individuals acquire aphasia each year. About one million persons in the United States currently have aphasia.
A stroke that affects the left side of the brain may lead to aphasia, a language impairment that makes it difficult to use language in those ways. Aphasia can have tragic consequences.
Aphasia can be so severe as to make communication with the patient almost impossible, or it can be very mild. It may affect mainly a single aspect of language use, such as the ability to retrieve the names of objects, or the ability to put words together into sentences, or the ability to read. More commonly, however, multiple aspects of communication are impaired, while some channels remain accessible for a limited exchange of information.
Causes
Aphasia can develop after an individual sustains a brain injury from a stroke, head trauma, tumor, or infection, such as herpes encephalitis. As a result of this injury, the pathways for language comprehension or production are disrupted or destroyed. For most people, this means damage to the left hemisphere of the brain. (In 95 to 99% of right-handed people, language centers are in the left hemisphere, and up to 70% of left-handed people also have left-hemisphere language dominance.) According to the traditional classification scheme, each form of aphasia is caused by damage to a different part of the left hemisphere of the brain. This damage affects one or more of the basic language functions: speech, naming (the ability to identify an object, color, or other item with an appropriate word or term), repetition (the ability to repeat words, phrases, and sentences), hearing comprehension (the ability to understand spoken language), reading (the ability to understand written words and their meaning), and writing (the ability to communicate and record events with text)
- Stroke – during a stroke the brain is deprived of blood and oxygen, which leads to the death of brain tissue
- Severe head injury – for example, an injury as a result of a road traffic accident or following a serious fall from height
- Brain tumour – where an abnormal growth of cells develops inside the brain
- Health conditions that cause progressive loss of cells from the brain, such as dementia. Parkinson’s disease does not cause aphasia, but some very similar conditions may do so, such as progressive supranuclear palsy (PSP) or corticobasal degeneration (CBD)
- Infections that affect the brain, such as meningitis (an infection of the outer layer of the brain) and encephalitis (an infection of the brain itself), although this is a much rarer cause of aphasia
Symptoms
The main symptoms of aphasia include:
- Trouble speaking
- Struggling with finding the appropriate term or word
- Using strange or inappropriate words in conversation
Some people with aphasia have problems understanding what others are saying. The problems occur particularly when the person is tired or in a crowded or loud environment. Aphasia does not affect thinking skills. But the person may have problems understanding written material and difficulties with handwriting. Some people have trouble using numbers or even doing simple calculations.
Treatment
Initially, the underlying cause of aphasia must be treated or stabilized. To regain language function, therapy must begin as soon as possible following the injury. Although there are no medical or surgical procedures currently available to treat this condition, aphasia resulting from stroke or head injury may improve through the use of speech therapy. For most individuals, however, the primary emphasis is placed on making the most of retained language abilities and learning to use other means of communication to compensate for lost language abilities.
Speech Therapy
Speech therapy is tailored to meet individual needs, but activities and tools that are frequently used include the following –
Exercise and practice – Weakened muscles are exercised by repetitively speaking certain words or making facial expressions, such as smiling.
Picture cards – Pictures of everyday objects are used to improve word recall and increase vocabulary. The names of the objects may also be repetitively spoken aloud as part of an exercise and practice routine.
Picture boards – Pictures of everyday objects and activities are placed together, and the individual points to certain pictures to convey ideas and communicate with others.
Workbooks – Reading and writing exercises are used to sharpen word recall and regain reading and writing abilities. Hearing comprehension is also redeveloped using these exercises.
Computer – Computer software can be used to improve speech, reading, recall, and hearing comprehension by, for example, displaying pictures and having the individual find the right word.
Medication – Certain drugs are currently being studied for the treatment of aphasia. These include drugs that may improve blood flow to the brain, enhance the brain’s recovery ability or help replace depleted chemicals in the brain (neurotransmitters). Several medications, such as memantine (Namenda) and piracetam, have shown promise in small studies.
Alternative Treatment
Reference –
http://www2.academyofaphasia.org/clinical-services/
http://brain.northwestern.edu/dementia/ppa/
http://www.aphasia.org/wp-content/uploads/2014/12/Aphasia-Definitions.pdf