Hi, Benjamin

Patients affected by Locked-in syndrome are awake and conscious, but selectively unable to move their limbs, face or produce speech. These patients commonly present brainstem lesions (acute ventral pontine), and they begin by falling into a comatose state, needing artificial respiration. Coma can last for weeks. They eventually wake up but remain paralyzed and unable to speak. It is very difficult to evaluate the cognitive and emotional state of such patients, mainly because of the limited and inconsistent eye movements. After the acute fase, life expectancy for patients, if medically stabilized, can be long, but communication will have to rely exclusively on eye-controlled computer-based technology.

Locked in Syndrome is often discussed on neuroscience of consciousness. From a consciousness point of view, completely locked in syndrome vs partially locked in both fall right above the minimally conscious state. Where the order of consciousness goes: brain death, coma, minimally conscious state, completely locked in syndrome, partially locked in syndrome, etc..... A partially locked in syndrome might present like certain sever muscular disorders like ALS where there is minimal muscle control but still relatively preserved consciousness (ie alertness, speech, understanding, memory etc) . Therefore most people with LIS have preserved cognition. Someone who appears to have LIS with very low preserved cognition might be better diagnosed as being in a minimally conscious state. Recent work with brain computer interfaces has been crucial for correctly diagnosing patients by being able to assess their level of preserved cognition despite their apparent inability for muscle control and movement.