Cortical thickness: Difference between revisions
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In [[neuroanatomy]], '''cortical thickness''' is a [[brain morphometric]] measure used to describe the combined thickness of the layers of the [[cerebral cortex]] in [[mammal]]ian [[brain]]s, either in local terms or as a global average for the entire brain. In other [[anatomical]] contexts, the term is also used on occasion to refer to the thickness of the [[renal cortex]] or of [[cortical bone]]. | In [[neuroanatomy]], '''cortical thickness''' is a [[brain morphometric]] measure used to describe the combined thickness of the layers of the [[cerebral cortex]] in [[mammal]]ian [[brain]]s, either in local terms or as a global average for the entire brain. Given that cortical thickness roughly correlates with the number of [[neuron]]s within an [[ontogenetic column]], it is often taken as indicative of the [[cognitive]] abilities of an individual, albeit the latter are known to have multiple determinants. In other [[anatomical]] contexts, the term ''cortical thickness'' is also used on occasion to refer to the thickness of the [[renal cortex]] or of [[cortical bone]]. | ||
In the brain, cortical thickness is commonly determined on the basis of the [[grey matter]] set in [[image segmentation|segmented]] [[neuroimaging]] data, usually from the local or average distance between the [[white matter surface]] and the [[pial surface]]. It changes only minimally with [[brain size]], both within and across [[species (biology)|species]]. Its variation across the [[human brain]] follows [[small world|small-world]] principles<ref name=He2007>{{CZ:Ref:He 2007 Small-World Anatomical Networks in the Human Brain Revealed by Cortical Thickness from MRI}}</ref>, and while overall [[sex differences]] in terms of cortical thickness are small in humans, women have slightly higher values in [[temporoparietal]] regions than men<ref name=Sowell2007>{{CZ:Ref:Sowell 2007 Sex differences in cortical thickness mapped in 176 healthy individuals between 7 and 87 years of age}}</ref>. Typical values in adult humans are between 1.5 and 3 [[millimetre|mm]], and during [[aging]], a decrease (also known as [[cortical thinning]]) on the order of about 10 [[micrometre|μm]] per year can be observed <ref name=Salat2004>{{CZ:Ref:Salat 2004 Thinning of the cerebral cortex in aging}}</ref>. Deviations from these patterns can be used as diagnostic indicators for [[brain disorder]]s: While [[Alzheimer's disease]], even very early on, is characterized by pronounced cortical thinning<ref name=Dickerson2009>{{CZ:Ref:Dickerson 2009 The cortical signature of Alzheimer's disease: regionally specific cortical thinning relates to symptom severity in very mild to mild AD dementia and is detectable in asymptomatic amyloid-positive individuals}}</ref>, [[Williams syndrome]] patients exhibit an increase in cortical thickness of about 5-10% in some regions <ref name=Thompson2005>{{CZ:Ref:Thompson 2005 Abnormal Cortical Complexity and Thickness Profiles Mapped in Williams Syndrome}}</ref>, and [[lissencephalic]] patients show drastic thickening, up to several centimetres in occipital regions<ref name=Guerrini2006>{{CZ:Ref:Guerrini 2006 Genetic malformations of cortical development}}</ref>. | In the living brain, cortical thickness is commonly determined on the basis of the [[grey matter]] set in [[image segmentation|segmented]] [[neuroimaging]] data, usually from the local or average distance between the [[white matter surface]] and the [[pial surface]]. It changes only minimally with [[brain size]], both within and across [[species (biology)|species]]. Its variation across the [[human brain]] follows [[small world|small-world]] principles<ref name=He2007>{{CZ:Ref:He 2007 Small-World Anatomical Networks in the Human Brain Revealed by Cortical Thickness from MRI}}</ref>, and while overall [[sex differences]] in terms of cortical thickness are small in humans, women have slightly higher values in [[temporoparietal]] regions than men<ref name=Sowell2007>{{CZ:Ref:Sowell 2007 Sex differences in cortical thickness mapped in 176 healthy individuals between 7 and 87 years of age}}</ref>. Typical values in adult humans are between 1.5 and 3 [[millimetre|mm]], and during [[aging]], a decrease (also known as [[cortical thinning]]) on the order of about 10 [[micrometre|μm]] per year can be observed <ref name=Salat2004>{{CZ:Ref:Salat 2004 Thinning of the cerebral cortex in aging}}</ref>. Deviations from these patterns can be used as diagnostic indicators for [[brain disorder]]s: While [[Alzheimer's disease]], even very early on, is characterized by pronounced cortical thinning<ref name=Dickerson2009>{{CZ:Ref:Dickerson 2009 The cortical signature of Alzheimer's disease: regionally specific cortical thinning relates to symptom severity in very mild to mild AD dementia and is detectable in asymptomatic amyloid-positive individuals}}</ref>, [[Williams syndrome]] patients exhibit an increase in cortical thickness of about 5-10% in some regions <ref name=Thompson2005>{{CZ:Ref:Thompson 2005 Abnormal Cortical Complexity and Thickness Profiles Mapped in Williams Syndrome}}</ref>, and [[lissencephalic]] patients show drastic thickening, up to several centimetres in occipital regions<ref name=Guerrini2006>{{CZ:Ref:Guerrini 2006 Genetic malformations of cortical development}}</ref>. | ||
==References== | ==References== | ||
{{reflist|2}} | {{reflist|2}} | ||
Latest revision as of 10:08, 6 April 2010
In neuroanatomy, cortical thickness is a brain morphometric measure used to describe the combined thickness of the layers of the cerebral cortex in mammalian brains, either in local terms or as a global average for the entire brain. Given that cortical thickness roughly correlates with the number of neurons within an ontogenetic column, it is often taken as indicative of the cognitive abilities of an individual, albeit the latter are known to have multiple determinants. In other anatomical contexts, the term cortical thickness is also used on occasion to refer to the thickness of the renal cortex or of cortical bone.
In the living brain, cortical thickness is commonly determined on the basis of the grey matter set in segmented neuroimaging data, usually from the local or average distance between the white matter surface and the pial surface. It changes only minimally with brain size, both within and across species. Its variation across the human brain follows small-world principles[1], and while overall sex differences in terms of cortical thickness are small in humans, women have slightly higher values in temporoparietal regions than men[2]. Typical values in adult humans are between 1.5 and 3 mm, and during aging, a decrease (also known as cortical thinning) on the order of about 10 μm per year can be observed [3]. Deviations from these patterns can be used as diagnostic indicators for brain disorders: While Alzheimer's disease, even very early on, is characterized by pronounced cortical thinning[4], Williams syndrome patients exhibit an increase in cortical thickness of about 5-10% in some regions [5], and lissencephalic patients show drastic thickening, up to several centimetres in occipital regions[6].
References
- ↑ He, Yong; Zhang J. Chen & Alan C. Evans (2007), "Small-World Anatomical Networks in the Human Brain Revealed by Cortical Thickness from MRI", Cerebral Cortex 17 (10): 2407-2419, DOI:10.1093/cercor/bhl149 [e]
- ↑ Sowell ER, Peterson BS, Kan E, Woods RP, Yoshii J, Bansal R et al. (2007). "Sex differences in cortical thickness mapped in 176 healthy individuals between 7 and 87 years of age". Cereb Cortex 17 (7): 1550-60. DOI:10.1093/cercor/bhl066. PMID 16945978. PMC PMC2329809. Research Blogging. [e]
- Demonstrates that cortical thickness, while overall similar in both sexes in humans, has significantly greater values in women than in men for temporoparietal regions. The effect is age-independent for adults.
- ↑ Salat DH, Buckner RL, Snyder AZ, Greve DN, Desikan RS, Busa E et al. (2004). "Thinning of the cerebral cortex in aging". Cereb Cortex 14 (7): 721-30. DOI:10.1093/cercor/bhh032. PMID 15054051. Research Blogging. [e]
- ↑ Dickerson BC, Bakkour A, Salat DH, Feczko E, Pacheco J, Greve DN et al. (2009). "The cortical signature of Alzheimer's disease: regionally specific cortical thinning relates to symptom severity in very mild to mild AD dementia and is detectable in asymptomatic amyloid-positive individuals". Cereb Cortex 19 (3): 497-510. DOI:10.1093/cercor/bhn113. PMID 18632739. PMC PMC2638813. Research Blogging. [e]
- ↑ Thompson, Paul M.; Agatha D. Lee & Rebecca A. Dutton et al. (2005), "Abnormal Cortical Complexity and Thickness Profiles Mapped in Williams Syndrome", Journal of Neuroscience 25 (16): 4146–4158, DOI:10.1523/JNEUROSCI.0165-05.2005 [e]
- ↑ Guerrini R, Marini C (2006). "Genetic malformations of cortical development". Exp Brain Res 173 (2): 322-33. DOI:10.1007/s00221-006-0501-z. PMID 16724181. Research Blogging. [e]