Longitudinal fissure result from lesions to them. Diffusion tensor imaging (DTI or dMRI) along with fiber-tracking (FT) algorithms and functional Magnetic Resonance Imaging (fMRI) is used to image these bundles. For instance, occipital-callosal fiber tracts were localized with 1–2 mm precision using DTI-TF techniques - which are very important for the cooperation of visual cortices, and any lesion to them can lead to alexia, the inability to read. Longitudinal fissure The longitudinal fissure (or cerebral fissure, median longitudinal fissure, or interhemispheric fissure) is the deep groove that separates the two hemispheres of the vertebrate brain. The medial surfaces of the two hemispheres
Precentral gyrus contralateral side of the body (facial palsy, arm-/leg monoparesis, hemiparesis) - see upper motor neuron. Precentral gyrus The precentral gyrus (also known as the motor strip) is a prominent structure on the surface of the posterior frontal lobe. It is the site of the primary motor cortex (Brodmann area 4). The precentral gyrus lies in front of the postcentral gyrus - mostly on the lateral (convex) side of each cerebral hemisphere - from which it is separated by the central sulcus. Its anterior border is represented by the precentral sulcus, while inferiorly it borders to the lateral fissure ("Sylvian fissure").