Is it true that ALS can progress to a “waking coma”?

This situation arises only when long-term mechanical ventilation is in place and life-sustaining measures are implemented over an extended period. In this scenario, ALS—which is generally confined to the motor nervous system—can also spread to other areas of the brain. In addition to complete paralysis of the body and the eye muscles (ophthalmoplegia) and the associated locked-in syndrome (LIS), areas of the brain responsible for cognitive and other complex brain functions may also degenerate.

In these patients, ALS progresses from a disease of the motor system to a “multisystem degeneration.” Patients lose their ability to speak, their memory, their recall, their cognitive abilities, their consciousness, and other brain functions. This condition was previously referred to as a “vegetative state” and has been replaced by the medical term “unresponsive wakefulness syndrome.” Only in rare, isolated cases do patients consciously decide to continue existing long-term mechanical ventilation even while in a state of unresponsive wakefulness syndrome. The vast majority decide against continuing life-sustaining measures when ALS has progressed to such an extent that the development of unresponsive wakefulness syndrome becomes foreseeable.