OVERVIEW

What is aphasia?

Aphasia is an acquired language disorder caused by focal brain lesions. Patients with aphasia experience impaired or lost language expression and comprehension abilities while remaining conscious.

Patients can hear sounds or see written words but cannot understand their meaning. They have no difficulty in articulation but may speak unclearly or produce speech that fails to convey the correct meaning.

Is aphasia common?

Yes.

Are aphasia, language delay, and dysarthria the same condition?

No.

Language delay refers to poor language ability due to intellectual disability caused by impaired brain development during childhood growth, which is a congenital developmental disorder. Aphasia, even in children, is acquired, resulting from brain tissue damage due to various causes that affects previously normal language function.

Dysarthria is caused by neurological or muscular disorders affecting speech articulation, leading to unclear or absent speech without errors in language content. In contrast, aphasia involves clear articulation but incorrect speech content or an inability to comprehend others.

SYMPTOMS

What are the types of aphasia manifestations?

Patients with aphasia experience language impairments, which include auditory comprehension, expression, repetition, reading, and writing. Different types of language impairments have distinct characteristics. According to anatomical-clinical classification, aphasia can be divided into the following types:

Motor Aphasia (Broca's Aphasia):

• Also known as Broca's aphasia, this type results from damage to the posterior part of the inferior frontal gyrus in the dominant hemisphere of the brain (for right-handed individuals, the left hemisphere is usually dominant; for left-handed individuals, the left hemisphere is also dominant in most cases, though a minority may have right hemisphere dominance). Patients primarily exhibit significant speech production difficulties while auditory comprehension remains intact—they "can understand" but "cannot speak fluently or clearly."

• Speech is telegraphic, with unclear articulation and effortful, short phrases or single-word utterances. Familiar words may be uttered with effort (1–2 content words), while unfamiliar words are more challenging, leading to distorted pronunciation. In severe cases, speech may be reduced to incomprehensible grunting.

• Repetition is partially impaired, with difficulties in naming and word-finding. Reading comprehension is preserved, but reading aloud is difficult. Writing is laborious, with poor handwriting and greater difficulty in forming sentences, often lacking grammatical words or containing structural errors.

Sensory Aphasia (Wernicke's Aphasia):

• Also known as Wernicke's aphasia, this type results from damage to the posterior part of the superior temporal gyrus in the dominant hemisphere. Patients primarily exhibit varying degrees of auditory comprehension impairment—they "cannot understand."

• Patients can speak fluently with normal pronunciation and intonation but produce numerous paraphasias, empty phrases, or filler words, making their speech incomprehensible (jargon aphasia). Repetition impairment corresponds to the severity of comprehension deficits, and naming difficulties are also present.

• Reading aloud and text comprehension may be impaired to varying degrees, though some patients may perform nearly normally. Writing shows severe impairment in dictation, but copying or spontaneous writing remains possible, with relatively unaffected handwriting.

Conduction Aphasia:

• This type typically involves lesions in the supramarginal gyrus of the dominant hemisphere. Patients exhibit impaired speech production and repetition but relatively preserved auditory comprehension. Speech is fluent but filled with paraphasias, and patients are aware of their errors, leading to frequent pauses, hesitations, and self-corrections. Pronunciation, intonation, and grammar are largely intact, making speech comprehensible.

• Disproportionately impaired repetition is the hallmark feature—patients can understand what to repeat but struggle to reproduce sentences accurately. Repetition is more difficult than spontaneous speech. Naming, reading aloud, and writing may also be impaired to varying degrees.

Global Aphasia:

• The most severe type, also called mixed aphasia, involves significant impairment in all language functions, typically due to extensive damage in the dominant hemisphere.

Other Types:

• Based on specific language impairment patterns, aphasia can also be classified as transcortical aphasia, anomic aphasia, subcortical aphasia, pure alexia, pure agraphia, pure word dumbness, or pure word deafness.

What are the consequences of aphasia?

Aphasia affects patients' ability to express and comprehend, impairing daily communication.

In the short term, it may hinder patients' ability to describe their symptoms and understand medical instructions, negatively impacting diagnosis, treatment, and rehabilitation.

In the long term, chronic aphasia can lead to difficulties in daily living, increased risk of accidents (e.g., getting lost), and complications such as anxiety, depression, or pseudodementia.

CAUSES

What causes aphasia?

The language center of the brain is located around the lateral sulcus. Damage to the language center can lead to language dysfunction, with different forms of impairment manifesting as varying clinical types.

Common causes of language center damage include stroke, tumors, inflammation, trauma, etc.

DIAGNOSIS

What tests should be done for aphasia?

• All newly identified aphasia patients should undergo structural brain imaging, typically MRI. If sudden onset suggests an acute cerebrovascular event or if other findings indicate an intracranial space-occupying lesion, the examination should be performed as soon as possible.

• Further evaluation is required in cases of ischemic stroke. If other structural brain lesions are identified, additional testing is usually necessary.

• For transient aphasic episodes, investigations should target possible seizures or transient ischemic attacks (TIA). EEG and/or cerebrovascular imaging may be helpful for these patients.

• For some patients with aphasic status epilepticus, prolonged EEG monitoring may be needed to detect active seizure activity.

What conditions should aphasia typically be differentiated from?

Clinically, aphasia may be confused with delirium, acute and chronic psychiatric disorders. However, careful clinical examination usually allows differentiation.

• Metabolic encephalopathy or delirium: Patients with metabolic encephalopathy or delirium may exhibit naming difficulties and an inability to follow commands. Paraphasic errors, though relatively rare, may occur in agitated delirium. The condition can be identified by fluctuating attention, level of consciousness, agitation, hallucinations, and/or asterixis. Other neurological focal signs (e.g., visual field deficits) accompanying fluent aphasia are typically absent in metabolic encephalopathy.

• Akinetic mutism: This condition can result from medial frontal lobe lesions. Patients demonstrate reduced speech output and poor response to commands, which may mimic aphasia. Observation of bilateral motor hypoactivity (not limited to speech) helps identify akinetic mutism. Hypophonia is common in akinetic mutism but not in aphasia.

TREATMENT

Which department should I visit for aphasia?

Neurology.

Can aphasia heal on its own?

Usually not.

Does aphasia require hospitalization?

Yes.

How should aphasia be treated specifically?

The treatment of aphasia mainly includes three aspects:

• First is etiological treatment, which targets the underlying cause, such as surgical intervention for cerebral hemorrhage or tumors, and antithrombotic therapy, improving circulation, and nourishing brain tissue for cerebral infarction.

• Second is treatment specifically for aphasia, primarily involving language rehabilitation, including oral expression training, reading-repetition exercises, auditory comprehension training, etc. Transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) may also be considered during rehabilitation.

• Finally, for patients who cannot recover basic language skills and their caregivers, augmentative communication methods can sometimes be used to convey information (e.g., books or communication boards with pictures or symbols of daily needs, or computerized devices).

DIET & LIFESTYLE

What should aphasia patients pay attention to in their diet?

It mainly varies depending on the cause. For example, stroke patients need a low-salt, low-fat diet, drink more water, and eat fiber-rich foods.

What should aphasia patients pay attention to in daily life?

Due to difficulties in expression or comprehension, aphasia patients may require assistance in daily life. Avoid going out alone, and strengthening speech training in daily routines can aid recovery.

Maintain a regular schedule, a positive mindset, ensure smooth bowel movements, and engage in moderate exercise.

Does aphasia require follow-up? How is it done?

Usually yes. The follow-up method depends on the underlying cause.

PREVENTION

Can aphasia be prevented?

Prevention mainly targets the underlying causes, such as quitting smoking and alcohol, regular physical examinations, actively controlling blood pressure, blood sugar, and lipid levels, maintaining a healthy and regular lifestyle to reduce the risk of stroke and early detection of tumors, avoiding infections and colds, and boosting immunity to minimize infection risks.

How can aphasia patients prevent other diseases?

Family members should provide increased care, boost the patient's confidence, and offer emotional support. At the same time, strengthening speech training can aid in symptom recovery.