What is Wernicke Aphasia?
Aphasia is a condition that affects language abilities, mainly related to the side of the brain that dominates language functions. Usually, aphasia is divided into two categories: expressive aphasia (called Broca’s) and receptive aphasia (called Wernicke’s). Many people experience both types to some extent. This piece focuses on Wernicke’s aphasia, a type of receptive aphasia.
The condition was first identified in 1874 by Carl Wernicke, a German doctor. Wernicke’s aphasia is characterized by a difficulty in understanding language. Interestingly, people living with this condition may still speak normally in terms of speed, rhythm, and grammar. However, because they have trouble comprehending their own speech, they might not realize when they’re making mistakes.
What Causes Wernicke Aphasia?
The main cause of Wernicke’s aphasia, a condition that interferes with a person’s ability to understand language, is a type of stroke known as an ischemic stroke, specifically affecting the back part of the brain’s temporal lobe. This part of the brain is usually more active in controlling language skills.
Other reasons someone might develop Wernicke’s aphasia include brain injuries, tumors in the brain, infections affecting the central nervous system (which consists of the brain and spinal cord), and brain disorders that progress over time and cause brain cells to deteriorate or die.
In many patients, Wernicke’s aphasia is a result of a specific kind of stroke called an embolic stroke. This happens when a blood clot or other obstruction blocks the flow of blood in an artery that supplies blood to the part of the brain known as the temporal cortex, which is important for processing sensory information, including language.
Risk Factors and Frequency for Wernicke Aphasia
There isn’t a lot of data on how many people develop Wernicke’s aphasia each year. However, it’s estimated that around 170,000 new cases of speech and language problems, known as aphasia, are linked to strokes every year.
Signs and Symptoms of Wernicke Aphasia
Wernicke’s aphasia is a condition that affects a person’s ability to use language effectively. Even though individuals with this condition can speak fluently and normally, their speech may be hard to understand due to the presence of paraphrastic errors. These errors can be of two types:
- Semantic paraphasia, where one word is incorrectly replaced by another, for example saying “watch” when meaning to say “clock”.
- Phonemic paraphasia, where one sound or syllable is wrongly substituted for another. An example would be saying “dock” instead of “clock”.
In severe cases, these errors can result in the creation of new words (neologisms) or stringing together random words (word salad), resulting in speech that is almost unintelligible. Owing to their difficulty in using specific words, these individuals tend to stick to generic ones like “thing” or “stuff”.
Alongside speaking, reading can also be challenging in Wernicke’s aphasia due to problems with understanding written words. Additionally, they may struggle with repetition of phrases or naming objects accurately. Even when they are capable of writing fluently, their choice of words and spelling may be abnormal.
Unlike those with Broca’s aphasia (another type of speech disorder), people with Wernicke’s aphasia don’t typically experience physical weakness on one side of their body (hemiparesis) and do not exhibit strong emotional outbursts or depression. While they usually aren’t aware of their language difficulties, they can become frustrated as others struggle to understand them.
Recovery from Wernicke’s aphasia largely depends on factors such as the size and location of the brain damage, age of the patient, and health of the brain cortex on the opposite side. If the damage extends to certain areas of the brain like the middle or inferior temporal gyri, or the inferior parietal lobule, recovery is often improbable. An early sign of Wernicke’s aphasia is abnormal spelling.
Testing for Wernicke Aphasia
Whenever you visit your doctor, they may want to evaluate your language skills. This can include checking how fluently you speak, your ability to name things, repeat simple phrases, understand basic and complicated commands, as well as your reading and writing skills. The assessment usually begins with simple instructions, like “close your eyes” or “open your mouth.” As you progress, the commands get more complex, like “show me two fingers on your left hand” or “touch your right ear with your left hand.”
The Boston Diagnostic Aphasia Examination is commonly used to evaluate patients experiencing difficulties with their language skills. Sometimes doctors need to conduct additional formal tests to understand the severity and type of the language difficulties. They may also use imaging techniques such as CT scans, MRIs, or PET scans to help determine the cause of the language problems.
When evaluating patients, doctors need to distinguish between Wernicke’s aphasia, a language disorder caused by damage in the brain’s language-processing areas, and Alzheimer’s Disease. Both may affect a patient’s ability to answer basic questions. However, the key issue with Wernicke’s aphasia is comprehension (understanding), while Alzheimer’s Disease primarily affects memory. Unlike Alzheimer’s Disease, which usually comes about slowly and worsens over time, Wernicke’s aphasia usually happens suddenly, often because of a stroke. Brain imaging can help doctors tell the difference between the two conditions.
Treatment Options for Wernicke Aphasia
At this time, there is no standard treatment for Wernicke’s aphasia, a condition that impacts language comprehension. The primary method of care is speech and language therapy. However, since the understanding of language is compromised in patients with this condition, they can sometimes lack the awareness of their own communication difficulties, making therapy more challenging.
The best approach to treatment typically involves the combined efforts of a speech therapist, neuropsychologist, and neurologist. They aim to help the patient improve their remaining language function, develop skills to build language abilities, and identify alternative communication methods so the person can express their wants and needs effectively. Group therapy sessions can provide patients with the chance to practice their communication skills and may reduce feelings of social isolation. There are some commercial software products available that claim to enhance language function, but their effectiveness hasn’t been thoroughly validated with rigorous clinical trials.
Current research investigations are exploring medicinal treatments for aphasia through randomized clinical trials. Medical scientists are formulating drugs that impact the catecholaminergic system, which is involved in regulating the body’s response to stress, and nootropic drugs that may improve cognitive function. Additionally, drugs used for Alzheimer’s disease are also being tested. Some researchers are also looking at non-drug therapies like transcranial magnetic stimulation and transcranial direct stimulation, which apply magnetic fields or electric currents to specific areas of the brain. However, so far the studies have been smaller in scale with mixed results, so more research is needed to confirm the effectiveness of these approaches.
When Wernicke’s aphasia is caused by a stroke, improvement in language function usually peaks within two to six months after the event. Further progress beyond this time frame can be limited, but continued efforts to improve communication can still lead to documented improvements in aphasia even a significant time after a stroke. Support from family and the wider social network is vital for achieving a successful outcome. Treatments for post-stroke depression and cognitive issues, as well as rectification of other neurological disorders associated with the stroke – such as neglect, agnosia, and hemiparesis – should also be included during rehabilitation to optimize the recovery process.
What else can Wernicke Aphasia be?
The following conditions could be associated with certain symptoms. A healthcare professional may need to rule out these in the diagnosis:
- Cancer
- Stroke due to a clot in the heart (Cardioembolic stroke)
- Alzheimer’s disease
- Disorders related to the frontal lobe of the brain (Frontal lobe syndromes)
- Head injury (Head trauma)
- Seizure
