Aphasia

Original Editor - Cindy John-Chu

Top Contributors - Nupur Smit Shah, Cindy John-Chu, Niha Mulla, Shaimaa Eldib, Mahbubur Rahman, Alexandra Stead, Kim Jackson, Candace Goh, Rucha Gadgil, Chelsea Mclene and Pacifique Dusabeyezu  

Introduction

Aphasia is a multimodal language disorder resulting from acquired brain damage, most commonly involving the left hemisphere, that compromises an individual's capacity for effective communication. This condition impairs the ability to listen, read, write and speak but it does not affect the intelligence. Aphasia contributes to one of the most common and disabling neuropsychological consequences of stroke and is also seen after head injury or brain tumour. Aphasic symptomatology can manifest in neurological diseases such as Alzheimer's disease or frontotemporal dementia, infections like encephalitis, and other focal cerebral lesions.

Anatomy

Following are the areas of the brain which are responsible for language:

• Wernicke's area: primarily responsible for language comprehension.
• Broca's area: this area is located in the frontal lobe of the brain and is responsible for motor execution of speech and sentence formation.
• Arcuate fasciculus: this is the neural connection between both areas.

Causes of aphasia

Aphasia can occur from a number of brain injuries and conditions, such as:

• Stroke

• Traumatic brain injury

• Severe blows to the head
• Brain tumours
• Gunshot wounds
• Brain infections
• Alzheimer's disease
• Frontotemporal lobar degeneration
• Vascular dementia
• Pick's disease

Types of aphasia

Aphasia can be broadly classified as either fluent or non-fluent:

Non-Fluent aphasia

Non-Fluent aphasia includes:

Broca's aphasia

• Results from damage to the frontal lobe.
• Patients may understand what is being said to them and know what response to give, but often reply with short phrases, produced with great effort.
• Patients may become frustrated by their difficulty communicating clearly, and some may develop depression.
• Often presents with right hemiparesis/hemiplegia as the frontal lobe is also important for motor movement.
• Also referred to as expressive aphasia.

Transcortical motor

Results from lesions located around, but not directly affecting, Broca's area. Patients tend to remain silent and may repeat only one to two words at a time. They are often able to repeat long, complex phrases although their speech remains non-fluent.

Mixed transcortical

Results from lesions around the language areas of the brain but that do not affect them. Patients in this category have severe speaking and comprehension impairment but can repeat long, complex sentences.

Global Aphasia

Results from extensive damage affecting both Broca's and Wernicke's areas, typically due to a large lesion in the frontal and temporal lobes. Patients may have trouble understanding simple words and sentences. Patients may present with a limited ability to speak and comprehend language.

Fluent aphasia

Fluent aphasia types include:

• Wernicke's

• Transcortical sensory
• Conduction
• Anomic

Wernicke's aphasia

• Occurs from damage to Brodmann area 22 of the temporal lobe, also known as Wernicke's area.
• It is characterised by patients composing and speaking long, complete sentences that have no meaning. They may even formulate non-existent new words to express themselves.
• They experience difficulty in understanding speech.
• These patients are often unaware of their speech errors.
• It is also known as receptive aphasia.

Transcortical Sensory Aphasia

It results from lesions located around, but not affecting the Wernicke's area. Patients may be able to repeat speech fluently but have difficulties with comprehension.

Conduction Aphasia

It is caused by lesion located in the arcuate fasciculus. Patients with this type of aphasia experience difficulties with or are unable to repeat words spoken to them. They realise the errors they make and endeavour to correct them.

Anomic aphasia

This is the mildest form of aphasia and it is due to damage to angular gyrus. The patient usually has difficulty in finding words.

Symptoms of aphasia

People with aphasia have difficulty understanding language, which makes it difficult for them to read, write, speak, listen, or type. Speaking is most commonly affected, and the person with aphasia struggles to choose the right word to speak. They either pronounce words incorrectly or use the wrong word. Patients often speak in short or incomplete sentences that don’t make sense, or use unrecognisable words as they have difficulty finding words to use. They may also have difficulty understanding other people's conversations, struggle to understand what they read, and produce writing that doesn't make sense. Aphasia can occur all by itself or in conjunction with other disorders, like visual difficulties, mobility problems, limb weakness, and problems with memory or thinking skills.

Important to note: Aphasia affects a person's ability to communicate, it does not affect their intelligence.

Diagnosis of aphasia

As per the NHS, diagnosis of aphasia is carried out by either a speech and language therapist or a doctor. It can be done by performing a simple exercise where the patient is asked to name objects in the room, repeat words and sentences, and read and write. The aim of the tests is to understand a person's ability to comprehend basic speech and grammar along with expressing words, phrases and sentences. It also tests the patient's ability to communicate, read and write. Making a diagnosis may also involve the use of imaging procedures such as Computed Tomography (CT), Magnetic Resonance Imaging (MRI) and Positron Emission Tomography (PET).

Differential diagnoses

When evaluating a patient of suspected aphasia, it is important to rule out the following conditions:

• Dysphonia
• Dysarthria
• Cognitive communication disorder
• Altered mental status from encephalopathy or delirium
• Apraxia of speech
• Deafness

Outcome measures for aphasia

The following outcome measures are commonly used to screen and assess conditions like anxiety and depression, in individuals with aphasia:

• Stroke Aphasia Anxiety and Mood Screen (SAAMS)
• Stroke Aphasic Depression Questionnaire (SADQH10)
• Behavioural Outcomes of Anxiety (BOA)

Treatment of aphasia

Recovery of language skills is usually a slow process, though if the brain damage is minimal, it is possible to reverse it without treatment. Although most people make significant progress, few regain full pre-injury communication levels.

Speech and Language Therapy

• Most people undergo speech and language therapy to rehabilitate their language skills and improve communication. The prognosis is poor for the patients with aphasia resulting from a progressive neurological condition. Therapy is beneficial for patients with aphasia; however, no single treatment has proven most advantageous. It mainly aims to improve the ability to communicate. It helps by restoring as much language as possible, teaching patients how to compensate for lost language skills and helping them find other methods of communicating.
• Speech and language therapy is most effective when it begins soon after a brain injury. Treatment often incorporates the use of computer assisted tools which are particularly useful for helping patients relearn vocabulary. These exercises are designed to improve a patient's ability to recall word meanings and how words relate to one another.
• For the patients having expressive language difficulties, therapy usually begins with basic activities like naming the pictures, identifying rhyming words, and recognising synonyms and antonyms. Patients also practise repeating words spoken by the therapist, with prompting provided as needed. If the patient is able to complete tasks with single words, the therapist will work on patients ability to construct sentences further progressing to brief paragraphs.

Compensatory Strategies

A Patients therapist typically use physical cues like self positioning, verbal modifications such as slowed speech, visual support such as diagrams, and environmental adaptations like providing extra time for sessions.

Pharmacological agents

There are promising strategies for reducing permanent language deficits being studied, such as pharmacological agents, for example, drugs known to improve blood flow to the brain and support recovery by helping replenish depleted neurotransmitters. However, more research is needed before these treatments can be recommended.

Brain Stimulation

Brain stimulation is another treatment being studied for aphasia. Research has shown that it may help improve the patient's ability to name things but no long-term research has been conducted yet.

Role of Family members

Family involvement is a crucial component in treatment and family members are encouraged to participate in therapy sessions, simplify their language, clarify meaning as needed, minimise distractions (such as a loud radio or TV) during the conversation where possible. They are also asked to include the patient in conversations and ask for their opinion in family matters; family members are asked to avoid correcting the patients' speech and give them plenty of time to talk. It is also important to help the patient stay involved outside the home and seek out support groups.

Relevance to physiotherapy

Physiotherapists manage patients with neurological conditions that can often lead to aphasia. It is important to be knowledgeable about the condition and its types, to aid appropriate referral if/when it is detected during the patient care, and to optimise interaction with patients.

Summary

Aphasia is a multimodal language disorder usually seen after stroke. It is also seen in gunshot wounds, brain tumours, head injury, and neurodegenerative diseases. Common subtypes include Broca's aphasia, Wernicke's aphasia, Global aphasia, and Conduction aphasia. Patients have difficulty articulating words, forming sentences, and finding the correct words, in varying combinations depending on the location of brain damage. As part of the multidisciplinary team, physiotherapists manage the physical and motor impairments (such as hemiparesis, balance, and gait deficits) resulting from the same underlying brain injury, while working alongside speech and language therapists, who take primary responsibility for assessing and managing the language disorder itself.