Trauma
Locked-in syndrome can also occur as a result of traumatic brain injury. This type of injury is commonly seen after a blunt or penetrating trauma that causes damage or blockage in the circulation to the back part of the brain. In a rare case, the brainstem remained undamaged, but the patient developed a post-traumatic contusion that exerted pressure on the brainstem.
Brain Masses and Locked-In Syndrome
Locked-in syndrome can be caused by brain masses that affect the pons or midbrain. The pons is responsible for various crucial functions, such as swallowing, chewing, biting, and horizontal eye movement. On the other hand, the midbrain is associated with hearing, vision, and motor control. In medical literature, several types of cancers can lead to the development of masses in these areas of the brain. Some examples include fibrillary astrocytomas, which are slow-growing brain tumors, as well as metastasis from lung adenocarcinoma and malignant melanoma.