What is Aphasia?

Jul 27

Aphasia is any type of compromised language skill, including the ability to understand or express speech or test. It usually results from damage to the regions of the brain responsible for language expression or comprehension. It impairs the ability to speak, or may compromise understanding of speech. This may apply to reading and writing as well. There may be other speech disorders present alongside aphasia, such as dysarthria or apraxia of speech (2).

How Common is Aphasia?

Aphasia is present in about 1 million people in the United States. Approximately 180,000 Americans acquire it each year and 40-60% of stroke survivors sustain aphasia (19). It is typically present in middle-aged or older people, but sometimes children acquire it as well.

What is the Cause of Aphasia?

Aphasia is usually caused by stroke or traumatic brain injury, but may also be the result of a tumor or progressive neurological disease affecting the regions of the brain responsible for language. Temporary loss of language abilities may occur following a transient ischemic attack (2). In such cases language is usually is restored after a couple of hours.

What are the Symptoms of Aphasia?

There are two broad categories of aphasia and then several types within each group, depending on the location of the damage or dysfunction (2). The two categories are fluent and nonfluent aphasia.

Wernicke’s aphasia is from damage to the posterior superior temporal lobe. It is a fluent aphasia that results in people essentially babbling long sentences that have little or no meaning, and sometimes they even make up words. People with fluent aphasias are often unaware of their nonsensical statements, and usually struggle with understanding speech.

Broca’s aphasia is the most common type of nonfluent aphasia. Broca’s aphasia sufferers have damage in their left frontal lobe. It is often accompanied by right arm or leg weakness or paralysis since the frontal lobe is also utilized in movement. They may be able to understand speech and know what to say, but they usually struggle to express it. Typically, they omit small words and can only speak in short phrases that require a lot of effort.

Global aphasias are a result of extensive damage to the regions of the brain required for language. They struggle with both language comprehension and expression. They may struggle with saying very simple words, they may repeat words or phrases and they may struggle with understanding even simple written or spoken language.

What Causes Aphasia?

Most aphasias are the result of suffering a stroke. As there is a short critical window of time to address the most severe consequences of an acute stroke, it is important to be able to recognize the symptoms of such a vascular injury.

According to the American Stroke Association, when any of the symptoms in the mnemonic FAST become suddenly present, a stroke needs to be suspected and treated as a medical emergency.

FAST stands for:

Face Drooping: this can become obvious when a person is asked to smile
Arm Weakness: ask the person to raise both arms, see if one drifts downward
Speech: does speech become slurred, are they hard to understand, or unable to speak?
Time to call 911: If any of these symptoms present, even if they go away, call 911 and get them to the hospital immediately.

Some additional symptoms of stroke:

Sudden numbness: sudden numbness or weakness of the face, arm, or leg, especially on one side of the body
Sudden confusion: sudden confusion, trouble speaking, or trouble understanding speech
Sudden trouble seeing: sudden difficulty seeing with one or both eyes, or in one field of vision
Sudden trouble walking: sudden difficulty with balance, gait, dizziness, or coordination
Sudden severe headache: Sudden onset severe head pain with no evident cause

Any of these symptoms should also be considered a medical emergency, and 911 should be called (1).

It is important to address aphasia as communication abilities are associated with life dependence, correlate with less social participation, poorer rehabilitation outcomes and a decrease in quality of life in the chronic stages (19).

What Happens in the Brain with Aphasia?

The brain is composed of many cell types. The ones we usually think of as brain cells are called neurons, which are the primary functional units of the brain. In order to survive, all neurons need a constant supply of blood to provide oxygen and glucose.

This blood supply is disrupted during a stroke or neurological disease process. This can lead to an ischemic cascade, where energy production within neurons that depends on the availability of oxygen starts to fail. This leads to a sudden release of glutamate, a neurotransmitter chemical that causes neurons to fire faster than their metabolic machinery can sustain. The result of this process is the production of many damaging free radicals, calcium rushing in and triggering the breakdown of proteins in the neuron, and ultimately death of the neuron (20).

Blood vessel walls can also break down from the release of cellular enzymes that destroy connective tissue. This can lead to breakdown of the blood-brain barrier and cerebral swelling, which can create secondary brain injuries (4).

The regions of the brain responsible for language are ultimately impacted in this way and begin to degenerate. The injury may be mild, or the entire region may be impacted. With fluent aphasias such as Wernicke’s aphasia, the area of the brain injured is the posterior superior temporal lobe, whereas with Broca’s nonfluent aphasia, the left frontal lobe is injured. Both of these arise from an injury to the left middle cerebral artery, with Broca’s resulting from involvement of the superior division of the artery, and Wernicke’s resulting from involvement of the inferior division. In many cases of chronic aphasia, both of these regions are injured.

Broca’s and Wernicke’s areas are connected by the arcuate fasciculus pathway, and damage to this can also create mixed aphasia symptoms. This is a common mechanism of aphasia secondary to concussion or traumatic brain injury.

Language functions are distributed through many regions of the brain, and while Broca’s and Wernicke’s regions are necessary for language production, many other areas may be involved that can influence speech production and comprehension. Newer research has revealed the existence of the dorsal and ventral stream pathways involved in language. The dorsal stream is involved in language production, whereas the ventral stream is involved in language comprehension. The extent of the damage to dorsal and ventral language streams will determine the ultimate presentation of any aphasia (22).

How is Aphasia Usually Diagnosed?

A physical and neurological examination can reveal signs associated with a stroke, such as disturbances in gait, problems with speech, and so on. Advanced imaging techniques such as MRI and CT are useful to identify the region of damage and blood vessel involved (23). The physician will also typically test the person’s ability to understand and produce language by asking the patient to follow commands, answer questions, name objects and continue on a conversation. Lab tests to evaluate for vascular inflammation and levels of cholesterol are commonly employed as well.

How is Aphasia Usually Treated?

Patients with aphasia usually see a speech-language pathologist who performs a comprehensive examination to understand limitations and capabilities with communication. Sometimes people regain their communication without treatment on their own in the months following their injury. Speech-language therapy is then used to help patients regain their communication abilities (2).

How is the NeuroRescue Program Different?

One of the fundamental problems seen in stroke or brain injury is what is called a diaschisis. In a diaschisis, neurons that have been damaged or lost lead to damage in remote neurons and pathways that rely on the injured tissue for stimulation.

Neurons need 3 main things to survive: glucose, oxygen, and activation. Neurons need to be continuously stimulated in order for them to continue replicating all of the protein and cellular components they need to survive and keep firing efficiently. When someone suffers a stroke, neurons that are supplied by the involved blood vessel are deprived of glucose and oxygen. Unfortunately, most of these will die off unless blood flow is rapidly restored.

There is nothing that we or anyone else can do to bring back the neurons that have been lost. However, the dead neurons are usually not entirely responsible for the symptoms seen after a stroke.

This is because of the diaschisis phenomenon. Each neuron receives activation signals from an average of 10,000 other neurons. This input will either excite or inhibit the neuron, but either way, the presence of this activation causes it to keep replicating protein and stay healthy. If the neuron is outside of the vascular distribution of a stroke, it may still be affected if enough of the neurons that activate it are lost.

When neurons die in a stroke, the neurons that they stimulate, even though they have a different blood supply and are not directly affected by the stroke, will undergo diaschisis and start to break down. They will lose endurance, will not be able to sustain high rates of firing, and will tend to fatigue and fail. This will be the case even though they still have a normal supply of glucose and oxygen.

If these remaining fragile neurons affected by diaschisis are not properly activated, they will ultimately die off. If they are overstimulated and caused to fire at a rate that they cannot withstand, they will also be lost (24).

However, if another neuron or pathway that supplies input to the fragile cells can be found, and these can be stimulated to activate the damaged neurons at a rate that they can withstand, they can be used to rebuild the function in the injured cells.

This is exactly the basis of all of our NeuroRescue aphasia rehabilitation therapies. We use cutting edge neurodiagnostic technologies and examination procedures to not only identify what areas of your system are damaged, but also what systems are still present but impacted by diaschisis. We identify pathways that we can harness to rebuild the function of the fragile systems. We determine the exact frequency and intensity of stimulation of these pathways that leads to positive plastic changes without overstimulation. We then employ several of a vast array of therapies, chosen specifically for the unique needs of your system, to maximize your functional recovery.

Our therapies are constantly evolving, and are on the cutting edge of neurorehabilitation. Everything we do for rehabilitation is supported by the latest neuroscience research.

We use a wide array of neurostimulation strategies in restoring function after a stroke, brain injury or during a disease process. Electrical therapies can be harnessed to stimulate neurons in the brain through the peripheral nervous system. There are many different kinds of currents and applications that we employ, but these are collectively known as repetitive peripheral sensory stimulation. RPSS has been demonstrated to be effective in restoring function in patients suffering from stroke aphasia (5).

Photobiomodulation is another form of neurostimulation, using low level laser and LED light frequencies to help rebuild endurance and metabolic function in neurons after stroke. We use several different types of laser and LED systems for stroke rehabilitation. Research shows that these can be very helpful to improve function in strokes and vascular injuries (6,7).

Hyperbaric oxygen therapy can prove useful in cases of stroke. Cells that have been deprived of oxygen for a time but not lost have been shown to improve in function when patients receive hyperbaric (above normal atmospheric pressure) oxygen treatment. Hyperbaric therapy can be an important adjunct to our therapies, and allows us to rehabilitate patients faster and more effectively without fatigue (8).

We regularly use transcranial magnetic stimulation (or TMS), which is an extremely effective form of neurostimulation in the treatment of stroke. TMS uses an MRI-strength magnet to apply a focused beam of electromagnetic energy through the skull and directly to the injured areas of the brain. This treatment is safe, comfortable, with minimal rare side effects. More importantly, it is extremely effective for helping people with aphasia after stroke or brain injury (9, 10). We have such great success with our TMS treatment that we installed our second TMS unit this year.

It is extremely common that people can develop balance difficulties after suffering a stroke. This greatly increases the risk of injury from falls, including further traumatic brain injuries. We go to great lengths to ensure that all of our patients have their fall risk reduced through precise vestibular therapy, which is part of every NeuroRescue program. Vestibular therapy has been shown to be very effective to improve balance after a stroke (11).

Vision can very commonly be impaired after suffering a stroke. It is common for people to develop difficulty visually mapping their world, holding their eyes still on targets, following moving objects, and processing complicated visual environments. In many cases, an entire visual field can be lost through damage to visual pathways. We use several types of visual exercises and rehabilitation to help resolve these difficulties, tailored to the unique needs of the patient. The effectiveness of visual therapies has solid support in neuroscience literature (12).

Specific types of eye movement exercises have been shown to be helpful in not only restoring visual function, but also in restoration of cognitive and executive function. Specific eye movement therapies have been shown help with cognitive retraining (13), and have demonstrated significant improvement in brainwaves and reduction in symptom scales after strokes (14).

We also use a number of unique therapies to help your brain remap your body and restore movement patterns after strokes. The brain has maps of the body and maps of the arms are close to those for the face, tongue and throat. With that in mind, sometimes the best way to restore movement in a paretic limb is to constrain the movement of the opposite limb while engaging in high intensity motor retraining exercises. Movement constraint therapy can be very helpful to restore motor function over time, and has expanded into being helpful for cognitive therapies and aphasia therapy (15). Using different visual representations of the impaired limb by mirroring the good limb while engaging in movement exercises can be very helpful as well (16). Mirror therapy is particularly helpful when employed in a virtual reality environment (17), and we regularly see rapid changes in motor function when using our Virtualis VR system. And physical exercises and soft tissue rehabilitation techniques can be helpful once central neurological function has been addressed. In particular, joint manipulation can often lead to significant improvement in motor function after stroke (18).

While some of these therapies are seemingly unrelated to aphasia, it is important to remember that by facilitating regions of the brain around the area that has been directly impacted by the injury, we can improve the consequences of the diaschisis, and thus improve neuroplasticity of the regions involved in aphasia as well.

How Does the NeuroRescue Program Work?

We design your unique NeuroRescue Program to be among the most comprehensive diagnostic and therapeutic protocols available today. We create individual NeuroRescue Programs based on a comprehensive analysis of every relevant neurological system and pathway, using gold-standard, cutting edge neurodiagnostic technologies and examination procedures and state-of-the-art therapies.

We begin with your Discovery Day, wherein we perform a comprehensive history of not only your condition, but also of your life on a timeline. This allows us to dive deeply into your case and see all of the factors that led to where you are now. It helps us uncover hidden problems and associated conditions that may be making it difficult for you to move your recovery forward.

Our examination allows us to identify the areas and pathways of your brain that have been directly and indirectly affected by your stroke, brain injury or disease process. We do this by precisely quantifying the function of your visual, vestibular, and proprioceptive systems through computerized analysis of your eye movements, your inner ear reflexes, and your balance in a host of different sensory conditions.

We employ technologies including Videooculography and Saccadometry to measure several classes of eye movements. We use Video Head Impulse Testing to measure the function of your inner ear, and Computerized Dynamic Posturography to assess your balance in different sensory conditions.

We use NeuroSensoryMotor Integration testing to evaluate hand-eye coordination and cognition, and Virtualis testing to assess dynamic eye tracking and perception of vertical in a virtual reality environment.

We combine all of this with a comprehensive physical and neurological examination of your sensory, motor, autonomic, and cognitive systems. We review any relevant laboratory testing, radiological imaging, and prior neurodiagnostic testing, and integrate that information with our findings.

We use this information to identify which parts of your nervous system are working properly, which systems are struggling, and the precise point at which your systems fatigue.

We can then design a NeuroRescue Program that is unique and specific to your brain, and yours alone. Your NeuroRescue Program works to rejuvenate and reintegrate the damaged neurons and pathways in your central nervous system. It works to improve energy, endurance, and functional capacity within your involved fragile systems.

We use our technologies and procedures to not only see what we need to address, but also when it is time to stop and let you rest. We address your impaired neurological function from multiple angles of therapy, and provide metabolic support to improve neurological recovery.

While we cannot bring back neurons that have been lost, your NeuroRescue Program allows us to take the pathways that remain and maximize their efficiency and endurance. And by focusing on the integration of systems, we can do more than just get pathways working better, we can get them working together again. This gives us our best opportunity to improve the consequences of your injury, and return you to living a healthy, vibrant, and fulfilling life.

Your Next Best Step:

Living with aphasia can be challenging, but there is hope for functional recovery. To see if the NeuroRescue Program is right for you, contact one of our patient care coordinators to schedule your Discovery Day.

And remember, it’s never too late to start getting better.