A rare neurological disease in which a part of the brainstem is damaged (such as from a stroke) is called Locked-in syndrome (LiS). This is a serious condition in which people have total paralysis but still have consciousness and normal cognitive abilities. Most people with LiS can communicate with eye movements.
In other words, LiS is a condition in which paralysis of voluntary muscles occurs. While they can move their eyes, people with LiS cannot show facial expressions, talk, or move. It happens due to damage to a part of the brainstem called the pons. Usually, this condition goes unrecognized or misdiagnosed. That’s why it is difficult to estimate how many people develop it.
Types of Locked-in Syndrome
Healthcare professionals have divided this condition into 3 types. These include:
- Classic – This type of LiS causes total immobility, but you still can move your eyes up and down, blink, and maintain normal cognitive abilities. Some people with this form can also hear.
- Incomplete – This form of LiS is very similar to the classical form, but affected people may also have some sensations and movement functions.
- Total – In this case, people develop paralysis and a loss of eye movement. However, they still have normal cognitive abilities.
What Are The Symptoms of Locked-in Syndrome?
In general, people with this condition may experience different symptoms because they depend on several factors. For example, the type and severity of the condition, the underlying cause, age, and sex. Commonly, physicians think people with LiS are in a coma before they perform a test for consciousness. Most who develop LiS cannot speak, chew, swallow, or make facial expressions and body movements. However, they can blink and move their eyes up and down. Sometimes, people who develop this neurological disorder can hear, think, reason, have sleep-wake cycles, and understand other people when they are talking or reading.
While people with a total immobility form do not experience pain, those who develop an incomplete form may experience pain and other sensations in some parts of the body.
Causes and Risk Factors
This condition occurs when something damages the pons (a part of the brainstem). Generally, there are a lot of conditions and situations that can damage the pons. One of the most common causes of this neurological disorder is a stroke that negatively affects motor tracts in the brainstem. These include corticospinal, corticopontine, or corticobulbar tracts. Check below for less common causes of LiS:
- Demyelination – This is a process in which nerves lose their protective layer (myelin).
- Trauma to the pons
- Recreational drugs (especially long-term use of cocaine)
- Tumors or masses on the pons and brainstem
- Brain infections
- Some health conditions, including Guillain-Barré syndrome and amyotrophic lateral sclerosis (ALS)
Furthermore, doctors have identified some factors that could increase your risk of developing LiS. Examples include:
- Hypertension (high blood pressure)
- Low Sodium levels (hyponatremia)
- Traumatic brain injury (TBI)
- Multiple sclerosis (MS)
- Severe central nervous system infections
What Are The Long-Term Effects of Locked-in Syndrome?
People with this condition may also experience some complications, especially if it is poorly managed. Check some complications below:
- Problems with impulse control, mental math, problem solving, working memory, or executive functioning
- Breathing problems
- Fecal incontinence
- Bleeding
- Infections (including wound infections, perianal abscesses, and fistula formation)
- Localized pain
- Urinary retention
- Delayed healing
- Death
The previous list does not contain a full list of LiS complications. However, you can consult with your doctor about ways to reduce the risk or even prevent them. Unfortunately, the condition and risk factors cannot be prevented.
Diagnosis
Usually, it is challenging to diagnose LiS because it causes symptoms similar to other health conditions. However, doctors may perform the following tests to find the cause and confirm or rule out this neurological disorder. For example:
- Imaging tests – The following tests are used to check for damage to the pons and other parts of the brain. Physicians usually perform a CT (computerized tomography) scan or an MRI (magnetic resonance imaging) scan.
- Electroencephalogram (EEG) – This test is used to measure the electrical activity of the brain.
- Cerebral angiography – This test is used to check for a blood clot in the arteries of the brainstem.
- Electromyography – Doctors often perform this test to measure how well the muscles and nerves work. It may also help rule out damage to the muscles and nerves.
- Blood tests – Usually, physicians perform a metabolic panel to check for pontine myelinolysis, which is a cause of LiS.
- Cerebrospinal fluid (CSF) testing – During this procedure, doctors will take a sample of CSF to check for an infection or autoimmune disorder.
Treatment
Unfortunately, there is no way to cure this condition. That’s why the treatment goal is to ease the symptoms, prevent serious complications, and improve your quality of life. Doctors often recommend supportive therapy and communication training. Sometimes, intensive rehabilitation may help recover some movement functions.
Supportive Therapy
This option is very important for feeding and breathing. Most people with LiS need an artificial aid for breathing and a tracheostomy. They also need a gastrostomy tube that helps to get food and water into the stomach. Check for other supportive therapies below:
- Physical therapy
- Rehabilitation that helps with voluntary movements
- Options to prevent bedsores and complications
Communication Training
Usually, doctors recommend speech therapy to improve communication with eye movements and blinking. For instance, looking up may mean “yes” and looking down can mean “no”. They may also recommend electronic communications devices (such as infrared eye movement sensors and computer voice prosthetics).
Recovery
According to some studies, the chances of recovery are better in people with nonvascular causes, such as a tumor or infection. Moreover, early detection and prompt treatment increase recovery chances, but each case is different. For more details, discuss it with your doctor.
Frequently Asked Questions
Is Locked-in syndrome the same as a coma?
No. People with Locked-in syndrome are conscious and aware of their surroundings, unlike people in a coma. Although they cannot move or speak, they can usually think, understand conversations, and communicate through eye movements or blinking.
Can people with Locked-in syndrome recover?
Recovery depends on the underlying cause, the severity of the brainstem damage, and how quickly treatment begins. While complete recovery is uncommon, some people, especially those with nonvascular causes, may regain limited movement or communication abilities with intensive rehabilitation.
Can people with Locked-in syndrome hear and understand others?
Yes. Most people with classic Locked-in syndrome have normal hearing, memory, and thinking abilities. They are usually able to understand spoken language and are aware of what is happening around them.
What is the most common cause of Locked-in syndrome?
The most common cause is an ischemic stroke that damages the pons in the brainstem. Less common causes include traumatic brain injury, tumors, infections, demyelinating diseases, and certain neurological disorders.
How do people with Locked-in syndrome communicate?
Many people communicate by blinking or moving their eyes up and down. Advanced assistive technologies, such as eye-tracking computers, speech-generating devices, and infrared eye movement sensors, can significantly improve communication and independence.
Does Locked-in syndrome affect intelligence or memory?
In most cases, no. People with Locked-in syndrome usually retain normal intelligence, memory, and cognitive function. However, some individuals may experience mild cognitive or behavioral changes depending on the extent and location of the brain injury.
Is Locked-in syndrome painful?
The condition itself does not always cause pain. However, people with incomplete Locked-in syndrome may retain sensation and experience pain. In addition, complications such as pressure sores, muscle stiffness, or infections can also cause discomfort.
Can Locked-in syndrome be prevented?
There is no guaranteed way to prevent Locked-in syndrome. However, reducing the risk of stroke by controlling high blood pressure, diabetes, high cholesterol, and avoiding smoking and recreational drug use may lower the likelihood of developing the condition.
What is the life expectancy of someone with Locked-in syndrome?
Life expectancy varies depending on the cause, age, overall health, and quality of medical care. With appropriate supportive treatment, many people can live for years or even decades after developing Locked-in syndrome.
Is Locked-in syndrome hereditary?
Locked-in syndrome is generally not an inherited condition. It usually develops because of acquired damage to the brainstem, such as from a stroke, trauma, or infection. However, some rare inherited neurological disorders that affect the brain may increase the risk of developing symptoms similar to Locked-in syndrome. You should see or contact a doctor if you have any other questions.
