Locked-in syndrome from rostro-caudal herniation.

Locked-in syndrome (LIS) is often caused by ventral pontine injury involving the perforating pontine vessels of the basilar artery and recovery is rarely reported. We report a patient who developed LIS acutely after aneurysmal subarachnoid haemorrhage and rostro-caudal herniation from hydrocephalus. The patient's clinical course and diagnostic studies suggest that the likely mechanism of this patient's LIS is mechanical compression of the ventral pons anteriorly against the clivus. The patient's slow but full recovery allowed us to further differentiate this clinical entity from the more common LIS due to ischaemic mechanisms.