What are the signs and symptoms of locked-in syndrome in vertebrobasilar stroke?

Updated: Aug 09, 2021
  • Author: Vladimir Kaye, MD; Chief Editor: Stephen Kishner, MD, MHA  more...
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This dramatic clinical syndrome occurs when there is an infarction of the upper ventral pons. Locked-in syndrome can result from occlusion of the proximal and middle segments of the basilar artery or from hemorrhage involving that region. It can also be caused by trauma, central pontine myelinolysis, encephalitis, or a tumor.

Bilateral ventral pontine lesions involving corticospinal and corticobulbar tracts lead to quadriplegia. The patient is unable to speak, to produce facial movement (damage to the corticobulbar tracts), or to look to either side (horizontal eye movement is impaired due to a lesion of bilateral CN VI nuclei). Because the tegmentum of the pons is spared, the patient's consciousness is preserved, with the patient fully awake, sensate, and aware. The only movements preserved are vertical eye movements and blinking. The patient is paralyzed completely and communicates only by blinking. Some recovery of facial muscle movement and horizontal gaze may occur with time or in an incomplete form of this syndrome.

Coma may occur with bilateral involvement of the pontine tegmentum or with lesions of the midbrain reticular formation. Coma generally is associated with oculomotor abnormalities, and motor abnormalities may be present. A comatose patient is unresponsive, and the coma may be prolonged when it is due to basilar artery occlusion. Sleep-wake cycles are absent in patients with coma.

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