see also Central sulcus region
The central sulcus is a fold in the cerebral cortex in the brains of vertebrates. Also called the central fissure, it was originally called the fissure of Rolando or the Rolandic fissure, after Luigi Rolando. It is sometimes confused with the medial longitudinal fissure.
The central sulcus is a prominent landmark of the brain, separating the parietal lobe from the frontal lobe and the primary motor cortex from the primary somatosensory cortex.
The central sulcus joins the Sylvian fissure in only 2 % of cases.
During neurosurgical procedures, it is sometimes difficult to understand the cortical anatomy of this region.
In 68/82 hemispheres, the central sulcus did not reach the posterior ramus of the lateral sulcus. A knob on the second curve of the precentral gyrus was reliably identified in only 64/82 hemispheres 1).
Computed tomography scans of 71 adult patients with no pathological imaging were analyzed. The position of the bregma and the central sulcus was determined. The distances from bregma to the pre-central and post-central sulci were calculated. The relationships from the nasion and glabella to cortical structures were also assessed.
The mean distances between the bregma and the pre-central, central and post-central sulci were 26.8 ± 7.2; 47.8 ± 5.9 and 60.6 ± 5.7 mm, respectively, without gender discrepancy. The mean distance nasion-bregma and the nasion-related measures showed significant differences among sexes.
The central sulcus was located accurately, on average 47.8 mm behind the bregma, which should be used instead of nasion in order to avoid gender discrepancy. The data obtained provide useful and reliable information to guide neurosurgical procedures 2).
Central sulcus on axial imaging
Identification of the central sulcus is important to localize the motor strip (contained in the precentral gyrus). The central sulcus (CS) is visible on 93% of CTs and 100% of MRIs 3).
It curves posteriorly as it approaches the interhemispheric fissure (IHF), and often terminates in the paracentral lobule, just anterior to the pars marginalis (pM) within the pars bracket 4) (i.e. the CS often does not reach the midline).
The inferolateral portion is difficult to identify if unable to trace the sulcus superoinferiorly. Su et al. observed that the cortex abutting the central sulcus appears isointense to the adjacent white matter on DWI, they named this the ‘invisible cortex sign’ and a study evaluated whether it could be used to identify the inferolateral central sulcus.
This observational study of 108 consecutive ‘normal’ MRI studies was performed from May 2016 to January 2017. A single axial DWI image – obtained in the anterior commissure–posterior commissure plane – was selected from each scan just above the subcentral gyrus such that it included the most inferolateral portion of the central sulcus. These single images were given to 10 readers (neuroradiologists, a neuroradiology fellow and radiology trainees) who marked the central sulcus based on the presence of the ‘invisible cortex sign’. Their accuracy in identifying the central sulcus was compared with that of the principal investigators, who used tri-planar T1 volumetric MRI sequences.
One hundred and eight consecutive patients (55 female, 53 male) were selected, ranging from 18 to 81 years old (mean = 40.5, σ = 18.2). The central sulcus was correctly identified in 95.5% of cases (σ = 3.7%; range 89.4-99.1%).
The ‘invisible cortex sign’ is a highly accurate method of identifying the inferolateral central sulcus on a single axial DWI slice without relying on the more superior aspects of the sulcus 5)
Focal cortical dysplasias (FCDs) are mainly located in the frontal region, with a particular tropism for the central sulcus.