Locked-in
Locked-in syndrome (LIS), is a rare neurological disorder characterized by complete paralysis of voluntary muscles, except for those that control the eyes. People with LIS are conscious and can think and reason, but are unable to speak or move.
LIS is a catastrophic condition caused most often by ischemic stroke or hemorrhage, affecting the corticospinal, corticopontine, and corticobulbar tracts in the brainstem. The syndrome is caused by damaged to the pons, a part of the brainstem that contains nerve fibers that relay information to other areas of the brain. The Basilar artery occlusion can cause LIS.
LIS, also known as pseudocoma, is a condition in which a patient is aware but cannot move or communicate verbally due to complete paralysis of nearly all voluntary muscles in the body except for vertical eye movements and blinking.
The syndrome is usually characterized by quadriplegia and the inability to speak in otherwise cognitively intact individuals. Those with LIS may be able to communicate with others through coded messages by blinking or moving their eyes, which are often not affected by the paralysis. The symptoms are similar to those of sleep paralysis.
Individuals with LIS classically cannot consciously or voluntarily chew, swallow, breathe, speak, or produce any movements other than those involving the eyes or eyelids.
Stephen Hawking had a progressive motor neuron disease related to amyotrophic lateral sclerosis (ALS) that began developing in the early 1960s. He was almost entirely paralyzed and communicated using a speech generating device.
Patients who have LIS are conscious and aware, with no loss of cognitive function. They can sometimes retain proprioception and sensation throughout their bodies. Some patients may have the ability to move certain facial muscles, and most often some or all of the extraocular muscles. Individuals with the syndrome lack coordination between breathing and voice. This prevents them from producing voluntary sounds, though the vocal cords may not be paralyzed
Unlike persistent vegetative state, in which the upper portions of the brain are damaged and the lower portions are spared, LIS is caused by damage to specific portions of the lower brain and brainstem, with no damage to the upper brain.
LIS can be difficult to diagnose. Neither a standard treatment nor a cure is available. It is extremely rare for any significant motor function to return. New brain-computer interfaces (BCIs) may provide future remedies.
In 2006, researchers created and successfully tested a neural interface which allowed someone with locked-in syndrome to operate a web browser. Some scientists have reported that they have developed a technique that allows locked-in patients to communicate via sniffing.
LIS typically results from a stroke (pontine hemorrhage or infarct) that causes quadriplegia and disrupts and damages the lower cranial nerves and the centers that control horizontal gaze.
LIS affects around 1% of people who have as stroke. It is a condition for which there is no treatment or cure, and it is extremely rare for patients to recover any significant motor functions.
There are two main causes of stroke:
- Ischemic stroke is the most common type of stroke. It happens when the brain's blood vessels become narrowed or blocked, causing severely reduced blood flow (ischemia).
- Hemorrhagic stroke occurs when a blood vessel in your brain leaks or ruptures.
Classic warning signs of stroke:
- Weakness or numbness in the face, arm or leg, usually on just one side.
- Difficulty speaking or understanding language.
- Decreased or blurred vision in one or both eyes.
- Unexplained loss of balance or dizziness.
- Severe headache with no known cause.
Other studies have shown that up to 20 percent of patients in various vegetative states can hear and respond on at least some level. But at least some of the responses seen could be dismissed as simple reflexes, or at best akin to someone in a dream state responding to stimuli.
While acupuncture is an effective tool for promoting recovery of disorder of consciousness (DOC) following traumatic brain injury (TBI), there have been no comprehensive meta-analyses and/or systematic reviews addressing this topic…
Food for thought!