Precentral gyrus

Eloquence

• Sensorimotor cortex is classed as eloquent in the Spetzler-Martin grading of arteriovenous malformations and in Sawaya's grading of tumour location. (Spetzler and Martin 1986; Sawaya et al. 1998)

What it does

• Contains primary motor cortex. Electrical stimulation evokes contralateral movement in a somatotopic sequence, with the leg represented medially near the vertex and the face laterally above the sylvian fissure. (Penfield and Boldrey 1937)
• The hand motor area usually lies at a knob-shaped segment of the gyrus that can be identified on axial MRI. (Yousry 1997)

Arterial supply

• The lateral convexity is supplied by cortical branches of the middle cerebral artery; the superomedial strip near the vertex is supplied by branches of the anterior cerebral artery. (Tatu et al. 1998; Rhoton 2002)

Venous drainage

• Superficial cortical veins drain upward to the superior sagittal sinus or downward to the superficial sylvian veins. (Rhoton 2002)

Deficits if injured

• Injury causes contralateral weakness whose distribution follows the somatotopic map: face and hand with lateral lesions, leg with medial lesions. (Penfield and Boldrey 1937; Keles et al. 2004)

Surgical relevance

• Resection within or adjacent to motor cortex and the descending motor pathways is commonly guided by intraoperative cortical and subcortical stimulation mapping. (Keles et al. 2004; Berman et al. 2004)

On the template

Desikan-Killiany. Values describe the fsaverage template, not an individual or a population norm.

Area: pial surface of the fsaverage average, which is smoother than individual cortex. Volume: voxel count of the fsaverage aseg segmentation at 1 mm isotropic.

References

1. Spetzler RF, Martin NA. A proposed grading system for arteriovenous malformations. Journal of Neurosurgery 1986;65(4):476-483. doi:10.3171/jns.1986.65.4.0476
2. Sawaya R, Hammoud M, Schoppa D, Hess KR, Wu SZ, Shi WM, et al.. Neurosurgical Outcomes in a Modern Series of 400 Craniotomies for Treatment of Parenchymal Tumors. Neurosurgery 1998;42(5):1044-1055. doi:10.1097/00006123-199805000-00054
3. Penfield W, Boldrey E. Somatic motor and sensory representation in the cerebral cortex of man as studied by electrical stimulation. Brain 1937;60(4):389-443. doi:10.1093/brain/60.4.389
4. Yousry T. Localization of the motor hand area to a knob on the precentral gyrus. A new landmark. Brain 1997;120(1):141-157. doi:10.1093/brain/120.1.141
5. Tatu L, Moulin T, Bogousslavsky J, Duvernoy H. Arterial territories of the human brain. Neurology 1998;50(6):1699-1708. doi:10.1212/WNL.50.6.1699
6. Rhoton AL. The Supratentorial Arteries. Neurosurgery 2002;51(suppl_4):S1-53-S1-120. doi:10.1097/00006123-200210001-00003
7. Rhoton AL. The Cerebral Veins. Neurosurgery 2002;51(suppl_4):S1-159-S1-205. doi:10.1097/00006123-200210001-00005
8. Keles GE, Lundin DA, Lamborn KR, Chang EF, Ojemann G, Berger MS. Intraoperative subcortical stimulation mapping for hemispheric perirolandic gliomas located within or adjacent to the descending motor pathways: evaluation of morbidity and assessment of functional outcome in 294 patients. Journal of Neurosurgery 2004;100(3):369-375. doi:10.3171/jns.2004.100.3.0369
9. Berman JI, Berger MS, Mukherjee P, Henry RG. Diffusion-tensor imaging-guided tracking of fibers of the pyramidal tract combined with intraoperative cortical stimulation mapping in patients with gliomas. Journal of Neurosurgery 2004;101(1):66-72. doi:10.3171/jns.2004.101.1.0066