<unk>  can be difficult to diagnose. In a 2002 survey of 44 people with<unk> , it took almost three months to recognize and diagnose the condition after it had begun.<unk>  may mimic loss of consciousness in patients, or, in the case that respiratory control is lost, may even resemble death. People are also unable to actuate standard motor responses such as withdrawal from pain; as a result, testing often requires making requests of the patient such as blinking or vertical eye movement. Brain imaging may provide additional indicators of<unk> , as brain imaging provides clues as to whether or not brain function has been lost. Additionally, an EEG can allow the observation of sleep-wake patterns indicating that the patient is not unconscious but simply unable to move. Similar conditions * Amyotrophic lateral sclerosis (ALS) * Bilateral brainstem tumors * Brain death (of the whole brain or the brain stem or other part) * Coma (deep or irreversible) * Guillain–Barré syndrome * Myasthenia gravis * Poliomyelitis * Polyneuritis * Vegetative state (chronic or otherwise)
Locked-in syndrome
Say–Meyer syndrome
Nicolau–Balus syndrome
Achard syndrome
Cole-Carpenter syndrome
Dorian Gray syndrome
Shapiro syndrome
Lamb-Shaffer syndrome