Causes
Unlike persistent vegetative state, in which the upper portions of the brain are damaged and the lower portions are spared, locked-in syndrome is essentially the opposite, caused by damage to specific portions of the lower brain and brainstem, with no damage to the upper brain. Injuries to the pons are the most common cause of locked-in syndrome. Possible causes of locked-in syndrome include:

Poisoning cases – More frequently from a krait bite and other neurotoxic venoms, as they cannot usually cross the blood–brain barrier
Brainstem stroke
Diseases of the circulatory system
Medication overdose
Damage to nerve cells, particularly destruction of the myelin sheath, caused by disease or osmotic demyelination syndrome (formerly designated central pontine myelinolysis) secondary to excessively rapid correction of hyponatremia [>1 mEq/L/h])
A stroke or brain hemorrhage, usually of the basilar artery
Traumatic brain injury
Result from lesion of the brain-stemCurare poisoning mimics a total locked-in syndrome by causing paralysis of all voluntarily controlled skeletal muscles. The respiratory muscles are also paralyzed, but the victim can be kept alive by artificial respiration. Diagnosis
Locked-in syndrome can be difficult to diagnose. In a 2002 survey of 44 people with LIS, it took almost three months to recognize and diagnose the condition after it had begun. Locked-in syndrome may mimic loss of consciousness in patients, or, in the case that respiratory control is lost, may even resemble death.
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. For the first time in 2020, a 34- year-old German patient, paralyzed since 2015 (later also the eyeballs) managed to communicate through an implant capable of  reading brain activity. See also
Akinetic mutism
List of people with locked-in syndrome
The Diving Bell and the Butterfly: memoirs of journalist Jean-Dominique Bauby about his life with the condition
Johnny Got His Gun, novel about a soldier who loses all of his limbs and senses after being wounded fighting in WWI

References
25. Injuries to the pons are the most common cause of locked-in syndrome,Harrison’s principles of internal medicine 21st edition vol 2 page 3332. Further reading
Piotr Kniecicki (2014). An Art of Graceful Dying. Lukasz Swiderski ISBN 978-0-9928486-0-6 (Autobiography, written with residual wrist movements and specially adapted computer)


== External links ==