Locked-in syndrome

Locked-in syndrome is one of the brainstem stroke syndromes and can occur as a result of a pontine stroke that damages the ventral brainstem, pyramidal bundles and corticobulbar tracts .

Clinical presentation

Individuals who are "locked-in" are conscious with preserved cognitive function but cannot move or communicate due to the complete paralysis of all voluntary muscles of the body including those of respiration. Mechanical ventilation is therefore required.

As the stroke spares the midbrain and therefore the oculomotor nerve, affected individuals can open his/her eyes and vertical eye movements are preserved .

Pathology

The most common cause of ventral pontine damage is basilar artery thrombosis. Other causes include blunt trauma or cardiocirculatory failure.

Radiographic features

Non-contrast CT may show hypodensity of the ventral portion of the pons. A hyperdense basilar artery may be seen in basilar artery thrombosis.

CT angiography allows for evaluation of the cerebral vessels and in particular to look for a filling defect in the basilar artery.

Practical points

For all health professionals, including the radiology staff encountering ICU patients transported for imaging, the practical application is in part to assume that, until proven otherwise, all patients in ICU are aware of you, what you say, and their surroundings.