The following are the characteristic signs and symptoms of LiS:

• Inability to control movements of the lower face
• Inability to chew, swallow and speak
• Difficulty in breathing
• Lower limbs become immobile 
• Lateral movement of eye is not possible [7]
• Individuals can only blink eyes a number of times and vertically move their eyes.
• Hearing ability is intact and patients respond by blinking their eyes.

• Pain

  Norman Medicine BMJ 1992 The range of awareness varies from being pain free but able to recall snatches of conversation or other events during the operation to being fully awake, in intense pain and unable, because of paralysis, to communicate with anyone [semanticscholar.org]

  Furthermore, as patients with LIS can feel pain, despite being unable to move, local block or general anaesthesia should be provided for sharp surgical debridement and other painful procedures. [ncbi.nlm.nih.gov]

  He presented to our pain clinic with severe burning pain in the right forearm and hand. The pain was continuous and was graded 9/10 by the patient on the visual analogue scale (VAS) score. [ijaweb.org]

  It is unlikely that a person with any of these classifications of locked-in syndrome would feel pain. [medicalmalpracticehelp.com]

• Disability

  He also uses it locally and nationally to advocate for the rights of people with disabilities beyond the Americans with Disabilities Act. [tirr.memorialhermann.org]

  Explore Thesaurus Synonyms and related words Disability and people with disabilities ableism ableist accessible ... Explore Thesaurus Definition and synonyms of locked-in syndrome from the online English dictionary from Macmillan Education. [macmillandictionary.com]

  This case report shows that specific rehabilitative approaches can be devised in severely disabled LIS patients with additional brain lesions and specific cognitive defects. [ncbi.nlm.nih.gov]

  Hosted by National Disability Services WA, the Disability Support Awards were conceived in 2009 with the aim of building the reputation of the disability sector and showcasing it as a place for a rewarding career. [thewest.com.au]

• Unconsciousness

  The locked-in state may be mistaken for coma particularly if there had been a preceding episode of unconsciousness. Moreover, the "locked-in" syndrome often passes into a state of unconsciousness or coma. [ncbi.nlm.nih.gov]

  A normal and reactive EEG rhythm should alert the physician but is not sufficient to disentangle LIS from post-comatose unconscious patients. [orpha.net]

  Trauma, infection, stroke Symptoms Inability to move or communicate verbally Mortality Rate 90% after four months Treatments Treatment of underlying condition Show Information Appearances Locked In [Source] Locked-in syndrome is the highest state of unconsciousness [house.wikia.com]

• Falling

  A man developed locked-in syndrome after delayed surgery following a fall from a bicycle, an inquest has heard. [irishtimes.com]

  This case highlights the unique dilemma when a patient falls between these two populations-conscious and cognitively intact, but completely paralyzed except for limited eye movement, afflicted by what the medical community refers to as locked-in syndrome [ncbi.nlm.nih.gov]

  The former English teacher from Spalding, Lincolnshire, moved there a decade ago after falling in love on a dating website. [dailymail.co.uk]

  Clodagh describes the feeling of falling from a Cesna airplane and hurltingtowards earth: "It blew me away just how beautiful the green chequered fields were. I don’t think I fully appreciated how beautiful our country was until I had a stroke." [rte.ie]

  I had noted Harmon's tendency for micro-management when I went to visit him in the fall of 2010. [vice.com]

• Nightmare

  It's many people's idea of a nightmare: Being so paralyzed that you can no longer communicate at all. [bigthink.com]

  It sounds like the stuff of nightmares, like it must be invented by a tortured imagination. But Locked-in Syndrome is a real affliction, a rare neurological disorder. [abebooks.co.uk]

  Health 12 May 2011 It’s the nightmare scenario: people think you are in a vegetative state when you are not. While some people with serious brain damage are totally unaware of their surroundings, others are in a “minimally conscious” state (MCS). [newscientist.com]

• Pneumonia

  People usually die because of some breath insuficience or pneumonia. Links[✎ edit | edit source] Related articles[✎ edit | edit source] Apallic syndrome Brainstem Myelin sheath Pneumonia External links[✎ edit | edit source] NINDS Study case [wikilectures.eu]

  Outcome :While admitted, patient developed ventilatory acquired pneumonia as caused of demise of patient. [iomcworld.org]

  Streptococcus pneumoniae and Haemophilus influenzae were cultured from the purulent ear discharge. The final diagnosis was locked-in syndrome consecutive to inflammatory changes compressing the basilar artery. [ncbi.nlm.nih.gov]

  Supportive care Communication training Supportive care is the mainstay of treatment for patients with locked-in syndrome and should include the following: Preventing systemic complications due to immobilization (eg, pneumonia, urinary tract infection, [msdmanuals.com]

  He subsequently refused food and died of pneumonia six days later. The key difference between locked-in syndrome and the vegetative or minimally conscious state is that someone with locked-in syndrome is mentally intact, as Derick Wade explains. [healthtalk.org]

• Dysphagia

  The patient may be able to establish effective communication through eye movements and specially adapted computers or letter boards. locked-·in syn·drome basis pontis infarct resulting in tetraplegia, horizontal ophthalmoplegia, dysphagia, and facial [medical-dictionary.thefreedictionary.com]

  The symptoms are tetraplegia, double-sided facial paresis, anarthria/dysarthrophonia, dysphagia and reactive involuntary laughing and crying. Vertical eye movements are the only commonly remaining voluntary motor function. [ncbi.nlm.nih.gov]

  Late Dysphagia After Radiotherapy-Based Treatment of Head and Neck Cancer. Cancer, 118(23), doi: 10.1002/ cncr.27631. International Dysphagia Diet Standardisation Initiative. (10 de October de 2016). Complete IDDSI framework and descriptors. [arete.ibero.edu.co]

  Clinically this syndrome is characterized by consciousness and the state of watch conserved, but there is quadriplegia, anartria, dysphagia and difficulty to coordinate the ventilatory mechanics, representing pulmonary complications the main cause of [scielo.senescyt.gob.ec]

  Management and treatment Initial management is based on respiratory assistance, gastrostomy and prevention of any immobility, dysphagia and incontinence complications. [orpha.net]

• Nausea

  Some of the common symptoms of a basilar artery stroke include the following: Balance difficulty Vertigo Double vision or loss of vision Loss of coordination Swallowing difficulty Difficulty pronouncing words Numbness Weakness in one-half of the body Nausea [thestrokelawyers.com]

  Using eye-blink yes/no communication, we could better assess him by asking sequentially if he had pain, dizziness, nausea, etc. [consultqd.clevelandclinic.org]

  You're also more likely to get it if you: Take a high dose of the drug Quickly increase your dose Get the medicine as a shot Switch from one antipsychotic drug to another Some drugs used to treat nausea and vomiting can also cause NMS, because they block [webmd.com]

  Other observed problems are decreased vital capacity in breathing, dysphagia for food and water, gaze alterations, difficulty with organization and perception of the environment, problems with balance and movement, dizziness and nausea (vertigo), and [archives-pmr.org]

• Constipation

  People with nail patella syndrome may also have: increased pressure in the eyes (glaucoma) at an early age numbness, tingling or a burning sensation in the hands and feet poor blood circulation in the hands and feet constipation or irritable bowel syndrome [nhs.uk]

  People with cerebral palsy may have associated problems or conditions including: Epilepsy Swallowing difficulties Gastro-oesophageal reflux disease Scoliosis Urinary incontinence and constipation Learning difficulties (usually intelligence is unaffected [inventhealth.co.uk]

• Thrombosis

  The incidence and treatment of traumatic basilar thrombosis and locked-in syndrome is reviewed. Rapid diagnosis of ascending thrombosis and prompt treatment with hyperdynamics and anticoagulation may improve outcome. [ncbi.nlm.nih.gov]

  A hyperdense basilar artery may be seen in basilar artery thrombosis. CT angiography allows for evaluation of the cerebral vessels and in particular to look for a filling defect in the basilar artery. [radiopaedia.org]

• Visual Impairment

  Keratitis or dry eye syndrome was present in most patients and was a major cause of pain and visual impairment. Our results suggest that the visual function is impaired in all patients with LIS. [ncbi.nlm.nih.gov]

• Suggestibility

  To be sure, well-being evaluations conducted to date do suggest that up to a third of LIS patients report being severely unhappy. [arstechnica.com]

  Clinical and radiologic evidence suggested the presence of a brain-stem tumor. Autopsy showed that the patient had a reticulum cell sarcoma. This is the first reported case of locked-in syndrome caused by a tumor. [ncbi.nlm.nih.gov]

• Stroke

  Causes of a Basilar Artery Stroke There are generally two types of strokes: (1) an ischemic stroke (where blood flow is restricted because of blockage) and (2) a hemorrhagic stroke (where blood vessels burst and there is too much blood in the brain). [thestrokelawyers.com]

  References Related articles: Stroke and intracranial haemorrhage Promoted articles (advertising) [radiopaedia.org]

  Whether sildenafil citrate may be helpful for recovery in human stroke is unknown at this time. [ncbi.nlm.nih.gov]

  In children, the most common cause is a stroke of the ventral pons. [chroniclelive.co.uk]

  Locked-in syndrome Other names Cerebromedullospinal disconnection,[1] de-efferented state, pseudocoma,[2] ventral pontine syndrome Locked-in syndrome can be caused by a stroke at the level of the basilar artery denying blood to the pons, among other causes [en.wikipedia.org]

• Quadriplegia

  A 21-year-old man presented with an extremely rare case of locked-in syndrome caused by a metastatic brainstem tumor manifesting as quadriplegia, lower cranial nerve pareses, and irregular respiration. [ncbi.nlm.nih.gov]

• Headache

  Eoin was a 17-year-old Leaving Certificate student in 2001 when he suffered headaches and was admitted to Cork University Hospital, where brain surgery was carried out. [irishexaminer.com]

  Mr O'Mahony was a Leaving Certificate student in 2001 when he had headaches and was admitted to Cork University Hospital, where brain surgery was carried out. [rte.ie]

  […] intended to block the lower cervical and upper thoracic sympathetic chain and is one of the treatment modalities for a wide range of disorders such as sudden hearing loss, Menier's disease, stroke, sudden blindness, shoulder/hand syndrome and vascular headache [ncbi.nlm.nih.gov]

• Paresis

  Locked-in Syndrome (LIS) is a rare clinical entity consisting of quadriplegia, paralysis of lower cranial nerves, mutism, and bilateral paresis of horizontal gaze. The prognosis is usually poor. [ncbi.nlm.nih.gov]

  […] a primary vascular or traumatic injury to the brainstem, normally corresponding to a ventral pons lesion due to an obstruction of the basilar artery, and characterized by upper motor neuron quadriplegia, paralysis of lower cranial nerves, bilateral paresis [doi.org]

  It is most frequently caused by stroke or central pontine myelinolysis. locked-in syndrome Neurology Flaccid tetraplegia with facial paresis and complete incapacity of expression–ie, anarthric and aphonic; LIS is due to damage or dysfunction of descending [medical-dictionary.thefreedictionary.com]

• Unresponsive to Pain Stimuli

  […] to painful stimuli (inability to withdraw an extremity from painful stimuli). [medicinenet.com]

The diagnosis of LiS often becomes difficult as the signs and symptoms of the syndrome often mimic other diseases as well. In many cases, it takes as long as 2.5 years to appropriately diagnose the disease. Various neuroimaging tests should be carried out to rule out other disease conditions [8]. In addition, imaging studies such as CT scan and MRI should be done to detect the location of the brain lesion.

Angiographic studies of the basilar veins using contrast enhanced imaging may effectively localize the lesions [9]. In addition, confirmatory tests such as PET or functional MRI need to be carried out examine the cerebral functioning. EEG is also done that shows sleep wake patterns which is a characteristic feature for patients with LiS.

Locked-in syndrome cannot be cured and there is no standard treatment regime to treat the condition. Depending on the cause of the syndrome and nature of severity of the symptoms, treatment is tailor made for each individual.

The primary goal is to treat the underlying cause and employ methods to restore cognitive and motor functioning [10]. Electrodes are used for stimulation of the muscle reflexes. In addition, Dasher technology is used for helping the individuals communicate. Recent advancements in the treatment methods have introduced mechanisms such as direct brain interface that helps patients answer yes–no questions. Treatment methods should also be channelized to prevent the onset of various systemic complications.

With appropriate initiation of treatment, the neurological functions such as horizontal eye movements begin to restore within the first four weeks. Younger individuals have a better prognosis than the adults. It has also been seen that, about 85% of affected individuals have a better survival rate with effective treatment and rehabilitation program. However, affected individuals often suffer from muscle stiffness and tightness also known as spasticity for the rest of their life.

Complications

The following are the several complications associated with Locked-in Syndrome:

• Severe oropharyngeal dysphagia
• Saliva aspiration
• Loss of control over cough
• Risk of developing infections
• Pulmonary atelectasis

Development of acute brainstem lesions is the most potential cause of Locked-in Syndrome. The lesions develop as a result of arterial thrombosis accompanied by obstruction of the affected artery. The other causes of LiS include the following:

• Brain hemorrhage
• Head injury affecting the brain
• Diseases such as multiple sclerosis
• Central pontine myelinolysis [2] 
• Overdose of certain medications leading to toxicity (eg. magnesium) [3]
• Lou Gehrig’s disease
• Disorders of the circulatory system
• Thrombosis of the basilar artery [4]
• Psychological disorders [5]
• Cerebellar infarct [6]

In addition to the above mentioned causes, there have been certain pieces of evidence suggesting an association between cervical manipulation and artery dissection. However, such a kind of relation is not sufficiently backed up with research studies.

The exact incidence of Locked-in Syndrome is not recorded. However, with the available literature, it can be estimated that the onset of acute infections in patients with LiS was the cause of death in about 40% of the cases. The development of stroke was the primary cause of death in 25% of individuals with LiS.

Locked-in Syndrome is basically divided into 3 categories:

• Total LiS characterized by complete paralysis of the limbs, facial muscles including the eyes.
• Incomplete LiS wherein there are some limb movements with eye blinks and movements.
• Classical LiS wherein only eye movements are present.

LiS occurs due to damage to the lower portion of the brain along with the brainstem. The development of brainstem lesion is known to be the major cause of this syndrome. These lesions gravely affect the corticospinal tracts and cranial nerves IV and VI. When the facial nerves and lower cranial nerves are affected it specifically leads to paralysis of the facial muscles causing impaired speech with disruption of swallowing function.

So far no guidelines have been designed to prevent the onset of LiS. However, if the disease is diagnosed in its early stages and treatment initiated then complications can be prevented and significant restoration of cognitive and motor functions can be achieved.

Locked-in Syndrome, abbreviated as LiS, is a disease characterized by a state wherein the affected individual is awake and fully aware of the surroundings but is unable to react or communicate due to paralysis of the limbs and facial muscles [1]. Such a syndrome is also known as pseudocoma and was first described in the year 1966 by Fred Plum and Jerome Posner.

In this condition limbs and facial muscles are paralyzed except the eyes. However, in total Locked-in Syndrome, the individuals are unable to move the eyes as well. Functions of breathing, phonation and swallowing may all be interrupted due to LiS.

Definition

Locked-in Syndrome (LiS) is a state of wakefulness wherein the patient is awake and aware of the surroundings but is unable to communicate due to paralysis of the limbs and facial muscles.

Cause

The development of brain lesions either due to stroke, brain hemorrhage or other disease conditions gives rise to LiS. In some cases, drug overdose can also lead to LiS.

Symptoms

LiS precipitates as paralysis of the lower limbs and the facial muscles that greatly impairs the cognitive as well as motor functioning. Patients with LiS are unable to use their lower facial muscles which in turn cause inability to swallow, eat, talk and breathe. Eyes of the affected individuals are wide opened and can communicate only through vertical eye movements. 

Diagnosis

Diagnosis is made by carefully studying the clinical features followed by determination of the location of the brain lesion through imaging studies. Neuroimaging studies are also carried out to rule out the possibility of other disease conditions. EEG tests shows sleep wake pattern that confirms LiS.

Treatment

Treatment of LiS is done by employing methods to treat the underlying disease conditions. Various methods such as Dasher technology and use of electrodes can be employed for restoring the cognitive and motor functioning. Patients are also given speech therapy to help regain their speaking ability.

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