After a very serious stroke, someone can be unconscious or in a coma for some time. In a coma, the person has very little or no awareness of what's going on around them.

Locked-in syndrome is a very rare condition where someone is conscious, but unable to move or speak. Some people with locked-in syndrome can communicate with others through blinking or eye movements. It is usually due to a stroke in the brain stem, a crucial area of the brain that controls movement and other vital body functions.

The brain stem and stroke

The brain stem is a small area of the brain at the base of the skull. It forms the junction between the spinal cord and the brain. A stroke in this area can have a huge impact because every nerve impulse to and from the body goes through the brain stem. It can lead to breathing difficulties and coma.

The brain stem controls some of the body's automatic functions such as sleep, awareness, breathing and blood pressure. It also controls movement. If a stroke happens in the part of the brain stem that controls movement, it's possible for the person to keep awareness but not be able to move.

Diagnosing locked in syndrome

Diagnosing locked-in syndrome can be difficult, as someone may be in a coma following a stroke and then emerge from it into a locked-in state.

Often the diagnosis of locked-in syndrome happens because a family member or care staff notice small signs of awareness.

Some people can remain in a coma for some time after a stroke. They can show basic reflexes like blinking and may sleep and breathe normally. They may be able to respond to a command or communicate at times.

Ask the doctor what the person is aware of to help you understand their condition.

You can read more about supporting someone in a coma in our guide to what happens after a very serious stroke. The NHS has some information about disorders of consciousness.

Supporting someone with locked-in syndrome

There is no specific treatment or cure for locked-in syndrome.

Someone who has a serious stroke will get all the treatment and care they need to help them make the best recovery possible for them. This includes any treatment they need for the stroke and the causes of stroke. They will have support for their health and wellbeing if they need help with functions like breathing, eating and hygiene.

Recovery is usually fastest in the first weeks and months after a stroke. It can continue for years, but at a slower rate. Because brain stem strokes are very serious, someone who recovers from a locked-in state may have severe disabilities.

Someone with locked-in syndrome should have access to rehabilitation services. Rehabilitation may focus on any small voluntary movements that are available such as finger movement, swallowing and making sounds.

Communicating with someone with locked-in syndrome speech and language therapist can help the person establish a code using eye movements or blinking to communicate. It is important for others to use effective questioning skills - for example, avoiding open-ended questions and confirming answers by repeating questions where necessary.

There are some types of assistive technology that can help someone with locked-in syndrome to communicate. These can range from simple alphabet boards to more sophisticated electronic aids.

For many people with locked-in syndrome, the severe effects of their stroke remain. However, therapy and careful planning can help to improve someone's quality of life and may even enable them to return home to live with the support of their family.

Personal accounts from survivors of locked-in syndrome

Read Clodagh Dunlop's Facebook page and book A Return to Duty to hear how she went back to her job as a police detective after recovering from locked-in syndrome.

Kate Allatt writes about her recovery from locked-in syndrome and advocates for stroke survivors today. Listen to her TED talk on YouTube.

Howard Wicks had a brainstem stroke aged 16 and has set up the Locked-in Trust charity, aiming to provide information and grants to support people with locked-in syndrome.