Thalamus

Eloquence

• The thalamus is listed as eloquent in the Spetzler-Martin grading and in Sawaya's grading of tumour location. (Spetzler and Martin 1986; Sawaya et al. 1998)

What it does

• A paired nuclear complex made up of many nuclei; the aseg segmentation shown here labels the thalamus as a whole and does not distinguish them. (Morel et al. 1997; Fischl et al. 2002)

Arterial supply

• Supplied by four main arterial territories: tuberothalamic, paramedian, inferolateral and posterior choroidal. (Schmahmann 2003)

Venous drainage

• Drains to the deep venous system, including the internal cerebral and basal veins, which converge on the great cerebral vein. (Rhoton 2002)

Deficits if injured

• Thalamic infarction produces syndromes that depend on the arterial territory involved, including sensory loss, memory and behavioural change, and impaired arousal. (Schmahmann 2003)

Surgical relevance

• Classed with the basal ganglia and internal capsule among the eloquent deep structures in arteriovenous malformation and tumour grading. (Spetzler and Martin 1986; Sawaya et al. 1998)

On the template

FreeSurfer aseg. 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. Morel A, Magnin M, Jeanmonod D. Multiarchitectonic and stereotactic atlas of the human thalamus. The Journal of Comparative Neurology 1997;387(4):588-630. doi:10.1002/(SICI)1096-9861(19971103)387:4<588::AID-CNE8>3.0.CO;2-Z
4. Fischl B, Salat DH, Busa E, Albert M, Dieterich M, Haselgrove C, et al.. Whole Brain Segmentation. Neuron 2002;33(3):341-355. doi:10.1016/S0896-6273(02)00569-X
5. Schmahmann JD. Vascular Syndromes of the Thalamus. Stroke 2003;34(9):2264-2278. doi:10.1161/01.STR.0000087786.38997.9E
6. Rhoton AL. The Cerebral Veins. Neurosurgery 2002;51(suppl_4):S1-159-S1-205. doi:10.1097/00006123-200210001-00005