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Locked-in
syndrome is a state of wakefulness and awareness with quadriplegia
and paralysis of the lower cranial nerves, resulting in inability to
show facial expression, move, speak, or communicate, except by coded
eye movements.
Locked-in syndrome typically results from a pontine hemorrhage or infarct that causes quadriplegia and disrupts and damages the lower cranial nerves and the centers that control horizontal gaze. Other disorders that produce severe widespread motor paralysis (eg, Guillain-Barré syndrome) are a less common cause.
Patients have intact cognitive function and are awake, with eye opening and normal sleep-wake cycles. They can hear and see. However, they cannot move their lower face, chew, swallow, speak, breathe, move their limbs, or move their eyes laterally. Vertical eye movement is possible; patients can open and close their eyes or blink a specific number of times to answer questions.
Diagnosis
Diagnosis is primarily clinical. Because patients lack the motor responses (eg, withdrawal from painful stimuli) usually used to measure responsiveness, they may be mistakenly thought to be unconscious. Thus, all patients who cannot move should have their comprehension tested through requesting eye blinking or vertical eye movements.
Tests are chosen for the same indications as persistent vegetative state (see Coma and Impaired Consciousness: Diagnosis). Brain imaging with CT or MRI is done and helps identify the pontine abnormality. PET or SPECT may be done if the diagnosis is in doubt. In patients with locked-in syndrome, EEG shows normal sleep-wake patterns.
Prognosis
Prognosis is usually dire. However, locked-in syndrome due to transient ischemia or a small stroke in the vertebrobasilar artery distribution may resolve completely. When the cause is partly reversible (eg, Guillain-Barré syndrome), recovery can occur over months but is seldom complete. Favorable prognostic features include early recovery of lateral eye movements and of evoked potentials in response to magnetic stimulation of the motor cortex. Irreversible or progressive disorders (eg, cancers that involve the posterior fossa and the pons) are usually fatal.
Treatment
There is no specific treatment, but supportive care should include the following:
Speech therapists may help establish a communication code using eye blinks or movements. Because cognitive function is intact, patients should make their own health care decisions if communication can be established.
Last full review/revision January 2008 by Kenneth Maiese, MD
Content last modified January 2008
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