Meynert axis Last edited and medically reviewed by Alaric Steinmetz on 24.08.2026 The Meynert axis, along with the Forel axis, is crucial for describing the location of structures in the brain. DefinitionThe Meynert axis runs from rostral to caudal along the brainstem[^1].Imaging Enlarge Illustration of Meynert's axis on a sagittal MRI image of the brain.