Midline shift refers to displacement of the anatomical structures that separate the cerebral hemispheres from one another along an imaginary midline through the skull.
Imaging
On CT or MRI image, midline shift appears as curvature of the normally straight boundary structures.
Causes
Any space-occupying process in the brain can lead to midline shift, such as:
Clinical relevance
Depending on its extent, midline shift can be life-threatening and lead to Signs of herniation. The extent of acute midline shift correlates with the level of consciousness[^1]:
Extent of midline shift | Level of consciousness |
0 - 3 mm | Alert |
3 -4 mm | Drowsy |
6 - 8,5 mm | Stuporous |
8 - 13 mm | Comatose |
However, it is important to note that this can vary from patient to patient and can be significantly influenced, for example, by pre-existing intracranial space conditions such as cerebral atrophy[^2].