Aphasia

Aphasia is a language disorder caused by neurological injury that can affect comprehension, verbal expression, reading, or writing. It may appear suddenly due to head trauma, for example, or gradually as a result of a brain tumor, among other causes.

Since it stems from a brain alteration, aphasia is often associated with other disorders such as dysarthria (inability to articulate words) or apraxia of speech (inability to perform the movements required for speech).

The Geschwind classification divides aphasia into two main groups:

• Fluent aphasia: There is a comprehension problem, but words are produced correctly.
• Expressive or Broca’s aphasia: Characterized by difficulty expressing thoughts, resulting in a lack of fluency and errors such as omissions, substitutions, or additions.
• Mixed transcortical aphasia: Rare. Complex phrases can be repeated, but their meaning is not understood.
• Transcortical motor aphasia: The rhythm of communication is preserved, although articulating certain words (adjectives, pronouns, or verbs) is difficult. As a result, expression is simple and limited.
• Global aphasia: The most severe form, with only a few words spoken, severely limited comprehension, and loss of both reading and writing abilities.
• Non-fluent aphasia: Comprehension is generally preserved, but producing words is difficult.
• Wernicke’s aphasia: Speech is fluent but marked by numerous paraphasias (substitution of sounds) and neologisms, along with syntactic errors. There are comprehension difficulties in both auditory and written forms, though typically to a lesser degree.
• Transcortical sensory aphasia: Sound production is correct, allowing for fluent speech with few paraphasias, but words spoken by others are often echoed.
• Conduction aphasia: Repetition of heard phrases is impaired. Patients struggle to retrieve isolated words and often substitute sounds, resulting in hesitant and interrupted speech. Reading comprehension is generally preserved, but writing presents challenges in converting phonemes into graphemes.
• Anomic aphasia: A mild disorder that often allows for normal conversation. However, patients may occasionally struggle to find the right words (anomia) to express ideas or to understand longer expressions.
• Conduction aphasia (duplicate entry): Speech is fluent and comprehension is intact, but repeating heard words is not possible. Attempts to do so typically result in phoneme substitutions.

Recovery from aphasia depends on the cause and severity of the neurological injury. In general, patients show favorable progress with rehabilitation, though fully regaining pre-injury speech abilities is often difficult.

Symptoms

Aphasia symptoms vary depending on the affected brain area and, consequently, the type of condition. The most common symptoms include:

• Speaking or writing fluently but without meaning
• Expressing oneself in short phrases or isolated words
• Substituting words or sounds
• Impaired oral and reading comprehension
• Pronouncing non-existent words
• Difficulty conveying an idea

Causes

Aphasia results from brain damage, typically in the left hemisphere, which controls language. Some of the causes of this brain damage may include:

• Stroke
• Traumatic brain injury
• Infections
• Brain tumor
• Alzheimer’s disease
• Ischemic attack or seizures, often leading to transient aphasia

Risk Factors

Although aphasia can affect anyone, certain risk factors increase its likelihood:

• Age: more common after age 60
• Hypertension
• Hyperlipidemia (high levels of fat or lipids in the blood)
• Hypercholesterolemia
• Diabetes
• Obesity
• Smoking
• Alcoholism

Complications

Aphasia significantly reduces quality of life, as communication is vital in all social aspects. In addition to negatively impacting work and academic performance, it often erodes personal relationships and may lead to psychological issues such as depression or social isolation.

Prevention

Adopting a healthy lifestyle helps prevent strokes and heart disease, thereby reducing the risk of developing aphasia to some extent. Specialists recommend:

• Maintaining a balanced and healthy diet
• Engaging in regular physical activity
• Monitoring blood pressure and cholesterol and lipid levels
• Keeping a healthy weight
• Quitting smoking and limiting alcohol consumption
• Protecting the head from injury in risky situations (construction work, cycling, motorcycling, skating, baseball, etc.)

Which specialist treats aphasia?

Aphasia is usually diagnosed by neurologists, while speech therapists are responsible for its treatment.