Postcentral 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 somatosensory cortex, with a contralateral somatotopic map that parallels the motor map of the precentral gyrus. (Penfield and Boldrey 1937)

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

• Excisions of the postcentral gyrus raise somatosensory thresholds on the contralateral side of the body. (Corkin 1970)

Surgical relevance

• It lies immediately behind the central sulcus, so identifying the central sulcus separates it from the precentral gyrus. (Rhoton 2002; Yousry 1997)

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. 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
5. Rhoton AL. The Supratentorial Arteries. Neurosurgery 2002;51(suppl_4):S1-53-S1-120. doi:10.1097/00006123-200210001-00003
6. Rhoton AL. The Cerebral Veins. Neurosurgery 2002;51(suppl_4):S1-159-S1-205. doi:10.1097/00006123-200210001-00005
7. Corkin S. Somatosensory Thresholds. Archives of Neurology 1970;23(1):41. doi:10.1001/archneur.1970.00480250045007
8. Rhoton AL. The Cerebrum. Neurosurgery 2002;51(suppl_4):S1-1-S1-52. doi:10.1097/00006123-200210001-00002
9. 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