Aphasia is a disorder caused by damage to parts of the brain responsible for language. It typically occurs suddenly, often following a stroke or head injury, but it can also develop gradually as a result of a brain tumor or a progressive neurological disease. The disorder affects language expression and comprehension as well as reading and writing. Aphasia may coexist with speech disorders, such as dysarthria or apraxia of speech, which are also consequences of brain damage.
Prevalence and Common Causes of Aphasia
Aphasia is most commonly caused by a stroke. However, any alteration in the brain can lead to aphasia, including traumatic brain injury. Other causes may include brain infections, tumors, and other brain disorders that can worsen over time.
Most people who develop aphasia are middle-aged or older, but it can affect anyone, including young children. Approximately one million people in the United States live with aphasia, and nearly 180,000 Americans acquire it each year, according to the National Aphasia Association.
In Spain, over 350,000 people have aphasia and around 70% of those who suffer a stroke experience language impairments. Among these, 40% to 60% recover during the first year, while the remainder develop chronic aphasia.
Types of Aphasia
Global Aphasia
This is the most severe form of aphasia, where patients can produce few recognizable words and understand little or none of spoken language. Individuals with global aphasia cannot read or write. It is often observed immediately after a stroke and may improve quickly if the damage is not too extensive. However, if the brain damage is more significant, severe and lasting disability may occur.
Broca's Aphasia ("Non-Fluent Aphasia")
In this type of aphasia, speech production is minimal, often restricted to short utterances of fewer than four words. Vocabulary access is limited, and sound formation by individuals with Broca’s aphasia is usually laborious. The person may understand speech relatively well and be able to read, but writing abilities are limited. Broca’s aphasia is often called «non-fluent aphasia» due to the effortful quality of speech.
Conduction Aphasia
This form of aphasia is characterized by difficulty producing isolated words. It resembles Broca’s aphasia but is restricted to single-word production.
Wernicke's Aphasia ("Fluent Aphasia")
In this type of aphasia, the ability to grasp the meaning of spoken words is significantly impaired, while the ease of producing connected speech is less affected. For this reason, Wernicke’s aphasia is called «fluent aphasia.» However, the speech is far from normal. Sentences are often incoherent and interspersed with irrelevant words, sometimes to the point of jargon in severe cases. Reading and writing are usually severely impaired.
Anomic Aphasia
This term applies to individuals with a persistent inability to provide the words for things they wish to talk about, particularly meaningful nouns and verbs. As a result, their speech, while grammatically fluent and well-formed, is full of vague circumlocutions and expressions of frustration. They understand spoken language well and, in most cases, read adequately. Word-finding difficulty is as evident in writing as in speech.
Primary Progressive Aphasia (PPA)
Primary progressive aphasia is a neurological syndrome in which language capabilities gradually and progressively deteriorate. Unlike other forms of aphasia caused by strokes or brain injuries, PPA is caused by neurodegenerative diseases, such as Alzheimer’s disease or frontotemporal lobar degeneration. PPA results from the degeneration of brain tissue critical for speech and language. Although the initial symptoms involve speech and language difficulties, other problems associated with the underlying disease, such as memory loss, often appear later.
Transcortical Motor Aphasia
This type of aphasia is characterized by difficulties with speech initiation, spontaneity, and organization. Although language production and comprehension are preserved, the individual struggles to initiate speech and to structure ideas coherently when communicating.
Assessment and Diagnosis
Aphasia is typically first identified by the physician treating the individual for their brain injury. Most individuals undergo an MRI or CT scan to confirm the presence of brain damage and determine its precise location. The physician usually evaluates the person’s ability to understand and produce language by assessing their ability to follow commands, answer questions, name objects, and engage in conversation.
If aphasia is suspected, the patient is often referred to a speech and language therapist, who conducts a comprehensive evaluation of the person’s communication abilities. This evaluation includes assessing the individual’s capacity to speak, express ideas, engage in social conversation, comprehend language, read, and write.
Speech and language therapists may use static assessments (designed to describe current functioning levels across relevant domains) and/or dynamic assessments (a continuous process involving hypothesis testing to identify potentially effective intervention and support strategies).
Evaluation protocols may include standardized and non-standardized tools and data sources. When assessing individuals with aphasia, speech and language therapists consider various factors that may impact intervention and outcomes, including:
- Languages and Dialects Used: Ensuring the assessment is culturally and linguistically appropriate.
- Coexisting Speech Motor Disorders: Such as dysarthria or apraxia of speech.
- Oral and Limb Apraxia: Which may interfere with gestural communication and other skills.
- Hearing Ability: To rule out hearing-related difficulties.
- Cognitive Impairment: That may affect memory, attention, or reasoning.
- Visual Deficits: Including visual agnosia, visual field cuts, or reduced visual acuity.
- Upper Limb Hemiparesis: Which may affect writing, pointing, and gesturing.
- Chronic Pain: Related to pre-existing or recent conditions, which could impact participation.
- Mental Health Disorders: Such as anxiety or depression, which may influence motivation and performance.
- Endurance and Fatigue: Potential reasons to divide testing into shorter sessions.
The Role of the Speech and Language Therapist in Aphasia Intervention
Speech and language therapy is essential in helping individuals with aphasia regain their language abilities. This specialized therapy aims to enhance communication skills by focusing on various linguistic processes, such as speech production, comprehension, and expression. Recovering speech and language abilities allows patients to express themselves, participate in conversations, and convey their thoughts and emotions. Speech and language therapists work closely with patients to achieve these goals.
Aphasia can impact a person’s confidence and self-esteem. During speech therapy sessions, patients practice and develop their communication skills in a safe environment. As they progress, their self-confidence often improves, enhancing their overall quality of life. Communication skills are vital for everyday life, and speech therapy helps individuals with aphasia perform daily tasks such as ordering food at a restaurant, making phone calls, or participating in family gatherings, thereby restoring their independence.
Aphasia can strain relationships by increasing frustration and misunderstandings. Speech therapy benefits both patients and their loved ones by teaching friends and family how to better understand and interact with them. This fosters stronger, more fulfilling relationships. Feelings of loneliness, sadness, and worry are common side effects of aphasia. Beyond language development, speech therapy also provides indirect emotional support.
Individualization is a key component of speech therapy. Each person with aphasia has unique needs and goals, so therapists tailor strategies to meet these specific requirements. This personalized approach ensures that therapy is more effective and beneficial for the individual. Patients with aphasia who receive speech therapy acquire practical skills, improving their ability to communicate their needs and preferences more effectively.
Therapeutic Approaches and Treatments for Aphasia
Treatment approaches for aphasia target various aspects of language and communication. Some of the most common strategies employed by speech and language therapists are outlined below:
- Constraint-Induced Language Therapy (CILT): This approach encourages verbal communication by limiting non-verbal strategies, thereby promoting the use of spoken language.
- Semantic Feature Analysis (SFA): Focuses on improving word retrieval by emphasizing semantic properties such as category, usage, or characteristics of words.
- Phonological Component Analysis (PCA): Targets the phonological aspects of words, helping individuals retrieve them through sounds, syllables, and rhymes.
- Verb Network Strengthening Treatment (VNeST): Concentrates on verbs and their associated nouns to enhance sentence formulation and broader linguistic structures.
- Melodic Intonation Therapy (MIT): Uses musical elements like rhythm and melody to improve verbal expression, particularly for individuals with non-fluent aphasia.
- Response Elaboration Training (RET): Encourages more elaborate speech by expanding the patient's spontaneous responses, fostering more detailed and flexible communication.
These approaches are tailored by the speech and language therapist to suit each patient’s specific strengths and needs, ensuring a personalized and effective therapy plan.
Importance of Family and Social Participation
A crucial component of aphasia treatment is family involvement, as it helps loved ones learn the best ways to communicate with the person affected by aphasia. Family members are encouraged to:
- Participate in therapy sessions whenever possible.
- Simplify language by using short, simple phrases when comprehension is impaired.
- Repeat words or write down key phrases to clarify meaning when necessary.
- Maintain natural, age-appropriate conversations.
- Include the person with aphasia in discussions.
- Ask for and value the person’s opinion, especially on family-related matters.
- Encourage any form of communication, whether verbal, gestural, pointing, or drawing.
- Avoid correcting the person’s speech.
- Allow sufficient time for the person to speak.
In conclusion, the goal of speech and language therapy for individuals with aphasia is to help them regain their speech and language abilities as much as possible (reducing impairment), support them in communicating as effectively as they can (enhancing activity and participation), identify alternative communication methods (using compensatory strategies or aids), and provide information about aphasia to patients and their families.
The approach to therapy will vary based on individual circumstances. Some individuals may benefit from intensive speech therapy, while others might be better suited to shorter, less intensive sessions. The appropriate path of treatment is determined based on a thorough evaluation. Progress largely depends on the severity of each person’s condition and the intervention provided.
Sinews MTI
Psychology, Psychiatry and Speech Therapy