Locked-in syndrome

Locked-in syndrome (LIS), also known as cerebromedullospinal disconnection, pseudocoma, or de-efferented state, is a rare and devastating neurological condition characterized by complete paralysis of nearly all voluntary muscles in the body while consciousness and cognitive function remain fully intact. The condition results from damage to the ventral portion of the pons (a part of the brainstem), most commonly caused by a basilar artery thrombosis or hemorrhagic stroke. Other causes include traumatic brain injury, brainstem tumors, central pontine myelinolysis, infections, or demyelinating diseases. Patients are typically quadriplegic and unable to speak, swallow, or produce facial movements, but retain the ability to move their eyes vertically and blink, which becomes their primary means of communication. The syndrome profoundly affects the motor nervous system while sparing consciousness, cognition, and sensation. Patients are fully aware of their surroundings but are unable to move or communicate except through vertical eye movements and blinking. Three forms are recognized: classical (quadriplegia and anarthria with preserved vertical eye movements and blinking), incomplete (remnants of voluntary movement beyond eye movements are preserved), and total (complete immobility including all eye movements, with preserved consciousness detectable only by electroencephalography or functional neuroimaging). Respiratory function is often compromised, and many patients require mechanical ventilation, particularly in the acute phase. There is currently no cure for locked-in syndrome, and treatment is primarily supportive. Acute management focuses on maintaining airway patency, respiratory support, nutritional support via gastrostomy, prevention of complications such as deep vein thrombosis, pressure ulcers, and infections, and early rehabilitation. Communication aids, including eye-tracking devices and brain-computer interfaces, have significantly improved quality of life for some patients. Physical therapy and occupational therapy are essential components of long-term care. Prognosis varies depending on the underlying cause; some patients with incomplete forms may recover limited motor function, though full recovery is exceedingly rare. Long-term survival is possible with appropriate medical care, and studies have shown that many chronic locked-in patients report an acceptable quality of life.

Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.

Common questions about Locked-in syndrome