[Locked-in Syndrome due to Primary Brainstem Injury:A Case Report].

Most cases of the primary brainstem injuries(PBSI)are fatal, and disturbance of consciousness is often prolonged even if lifesaving is obtained. The mechanisms of PBSI are as follows: diffuse axonal injury from acceleration/deceleration, shear strain at the midbrain, direct injury of neurovascular structures by tentorial margin, and lower brainstem injury by hyperextension of the cervical vertebrae. Though we can use both CT and MRI to diagnose, MRI is more helpful than CT in detecting, localizing, and characterizing PBSI. When the location of PBSI is limited in the ventral side of pons, it may occasionally result in locked in syndrome(LIS). Generally it is difficult to diagnose LIS with severe trauma due to the rarity of this syndrome caused by head injury. Here, we report a case of an elderly man with traumatic brainstem hemorrhage, who transiently presented LIS and finally improved.