Cerebrocerebellar system and Arnold's bundle: A tractographic study: preliminary results

Engelhardt, Eliasz; Moreira, Denise Madeira; Laks, Jerson

doi:10.1590/S1980-57642010DN40400007

Abstract

The cerebellum, traditionally considered a structure involved in balance and movement control, was more recently recognized as important in cognitive, emotional and behavioral functions. These functions appear to be related to the more recent parts of the cerebellum that belong to the cerebrocerebellar system. One of the key segments of this system is the (pre)fronto-[penduncule]-pontine projection that represents the Arnold's bundle. Diffusion tensor imaging and tractography (DTI-TR) has permitted in vivo virtual dissection of white matter tracts, including those of the cerebellar. Objective: To study the fronto-[peduncule]-pontine projection (Arnold's bundle), with DTI-TR. Methods: Ten normal subjects were included (mean age 30 years). Standard acquisitions in three planes were obtained with a 1.5T GE Signa Horizon scanner, complemented with DTI acquisitions. Post-processing and analysis was performed using an ADW 4.3 workstation running Functool 4.5.3 (GE Medical Systems). A single ROI was placed on the medial third of the cerebral peduncle base, considered the site of convergence of the fibers of Arnold's bundle, bilaterally. Results: Twenty tractograms were obtained. All were constituted by a significant number of fibers in correspondence to the frontal lobe, and part of them anterior to the coronal plane at the anterior commissure, which characterizes them as associated to the prefrontal region. Conclusions: For the first time, frontal lobe related projections were systematically revealed with DTI-TR seeded from cerebral peduncle base ROIs. They showed anatomic coherence with Arnold's bundle, which includes the prefrontopontine segment of the cortico-ponto-cerebellar path, one of the components of the cerebrocerebellar system, acknowledged as fundamental for non-motor functions such as cognition, emotion and behavior.

Key words:
tractography; frontopontine bundle; Arnold's bundle; cerebrocerebellar system

Resumo

O cerebelo, tradicionalmente considerado como estrutura relacionada ao equilíbrio e controle do movimento, foi mais recentemente reconhecido ser importante em funções cognitivas, emocionais e comportamentais. Tais funções encontram-se relacionadas às partes mais novas do cerebelo que pertencem ao sistema cerebrocerebelar. Um dos segmentos de relevo desse sistema é a projeção (pré)fronto-[pedúnculo]-pontina que representa o feixe de Arnold. A imagem com tensor de difusão e a tratografia (DTI-TR) vem possibilitando a dissecção virtual de feixes da substância branca, inclusive os cerebelares. Objetivo: Estudar a projeção fronto-[pedúnculo]-pontina (feixe de Arnold), com DTI-TR. Métodos: Foram incluídos dez sujeitos normais (média de idade 30 anos). Sequências padrão em tres planos foram obtidas com equipamento Signa Horizon GE de 1,5T e complementadas com aquisições de DTI. Pós-processamento e análise foram realizados em uma estação de trabalho ADW 4.3 com Functool 4.5.3 (GE Medical Systems). Foi utilizado ROI único colocado no terço medial da base do pedúnculo cerebral, considerado o local de convergência das fibras do feixe de Arnold, bilateralmente. Resultados: Foram obtidos vinte tratogramas. Todos eram constituídos por um número significativo de fibras em correspondência ao lobo frontal e parte dessas em posição anterior ao plano coronal à comissura anterior, que as caracteriza como relacionadas à região pré-frontal. Conclusões: Foram mostradas, pela primeira vez de modo sistemático, projeções relacionadas ao lobo frontal com DTI-TR através de ROIs colocados na base do pedúnculo cerebral. Apresentavam coerência anatômica com o feixe de Arnold, que compreende o segmento pré-frontopontino da via córtico-ponto-cerebelar, um dos componentes do sistema cerebrocerebelar, considerado subjacente a funções não motoras, como cognição, emoção e comportamento.

Palavras-chave:
tratografia; feixe frontopontino; feixe de Arnold; sistema cerebrocerebelar

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References

Barlow JS. The cerebellum and adaptive control [Internet]. Cambridge: Cambridge University Press, 2002:3-5. Retrieved in: 2009. Available from: Available from: http://books.google.com.br/books
» http://books.google.com.br/books
Glickstein M, Voogd J. Lodewijk Bolk and the comparative anatomy of the cerebellum. Trends Neurosci 1995;18:206-210.
Schmahmann JD. Rediscovery of an early concept. In: Schmahmann JD (Editor), The cerebellum and cognition. San Diego: Academic Press; 1997:4-30.
Leiner HC, Leiner AL, Dow RS. Does the cerebellum contribute to mental skills? Behav Neurosci 1986;100:443-454.
Rapoport M, van Reekum R, Mayberg H. The role of the cerebellum in cognition and behavior: a selective review. J Neuropsychiatry Clin Neurosci 2000;12:193-198.
Schmahmann JD, Caplan D. Cognition, emotion and the cerebellum. Brain 2006;129:290-292.
Watson PJ. Nonmotor functions of the cerebellum. Psychol Bull 1978;85:944-967.
Baldaçara L, Borgio JGF, Lacerda ALT, Jackowski AP. Cerebellum and psychiatric disorders. Rev Bras Psiquiatr 2008;30: 281-289.
Middleton FA, Strick PL. Basal ganglia and cerebellar loops: motor and cognitive circuits. Brain Res Brain Res Rev 2000; 31:236-250.
Schmahmann JD, Pandya DN. The cerebrocerebellar system. Int Rev Neurobiol 1997a;41:31-60
Axer H, Keyserlingk DG. Mapping of fiber orientation in human internal capsule by means of polarized light and confocal scanning laser microscopy. J Neurosci Methods 2000;94:165-175.
Beck E. The origin, course and termination of the prefronto-pontine tract in the human brain. Brain 1950;73:368-391.
Dejerine J. Anatomie des centres nerveux. Paris: J Rueff Ed., 1901:1-586.
Gebbink TB. Structure and connections of the basal ganglia in man. Thesis Leiden. Assen: Van Gorcum & Comp., 1967.
Marin OSM, Angevine Jr JB, Locke S. Topgrtaphical organization of the lateral segmento f the basis pedunculi in man. J Comp Neurol 1962;118:165-183.
Probst M. Zur Kenntniss des Binderarms, der Haubenstrhalung und des Regio Subthalamica. Mschr Psychiat Neurol 1901;10:288-309
Voogd J. Cerebellum and precerebellar nuclei. In: Paxinos G, Mai JK (Editors), The human nervous system. 2nd ed. Amasterdam: Elsevier; 2004:321-392.
Schmahmann JD, Pandya DN. Fiber pathways of the brain. Oxford: Oxford University Press, 2006:654.
Smith MC. Histological findings after hemicerebellectomy in man: anterograde, retrograde and transneuronal degeneration. Brain Res 1975;95:423-442.
Arnold F. Handbuch der anatomie des menschen. v. 2, 5th Book: Vom Nervensystem. Freiburg im Breisgau: Herder'sche Verlagshandlung, 1851:636-740.
Armand J. The origin, course and terminations of corticospinal fibers in various mammals. In: Kuypers GJM, Martin GF (Editors). Anatomy of descending pathways to the spinal cord. v.57, Amsterdam: Elsevier Progress in Brain Research 1982:329-360.
Clark DL, Boutros NN, Mendez MF. The Brain and behavior: an introduction to behavioral neuroanatomy. 3rd ed. Cambridge: Cambridge University Press ; 2010:325.
Ebeling U, Reulen HJ. Subcortical topography and proportions of the pyramidal tract. Acta Neurochir (Wien) 1992;118: 164-171.
Iragui VJ, McCutchen CB. Capsular ataxic hemiparesis. Arch Neurol 1982;39:528-529.
Kumar A, Juhasz C, Asano E, et al. Diffusion tensor imaging study of the cortical origin and course of the corticospinal tract in healthy children. Am J Neuroradiol 2009;30:1963-1970.
Lassek A. The human pyramidal tract: VII. A critical review of its origin. J Nerv Ment Dis 1944;99:22-28.
Martin JH. Neuroanatomy: text and atlas. 3rd ed. New York: McGraw-Hill, 2003:532.
Penfield W, Boldrey E. Somatic motor and sensory representation in the cerebral cortex of man as studied by electrical stimulation. Brain 1937;60:389-443.
Sunderland S. The projection of the cerebral cortex on the pons and cerebellum in the macaque monkey. J Anat 1940;74: 201-226.
Schmahmann JD, Pandya DN. Anatomic organization of the basilar pontine projections from prefrontal cortices in Rhesus monkey. J Neurosci 1997b;17:438-458.
Türe U, Yasargil MG, Friedman AH, Al-Mefty O. Fiber dissection technique: lateral aspect of the brain. Neurosurgery 2000;47:417-427.
Lassek AM. The pyramidal tract: its status in medicine. Springfiel: Charles C Thomas, 1954:166.
Mendoza J, Foundas AL. Clinical neuroanatomy: a neurobehavioral approach. New York: Springer Science, 2008:704.
Crosby EC, Huphrey T, Lauer EW. Correlative anatomy of the nervous system. New York: MacMillan Co, 1962:188-220.
Gray H. Anatomy of the human body [Internet]. Philadelphia: Lea & Febiger, 1918:788-796. Retrieved in: 2009. Available from: Available from: http://www.bartleby.com/107/
» http://www.bartleby.com/107/
Nieuwenhuys R, Voogd J, van Huijzen C. The human central nervous system. Berlin: Springer Verlag, 1980.
Ross ED. Localization of the pyramidal tract in the internal capsule by whole brain dissection. Neurology 1980;30:59-64.
Jissendi P, Baudry S, Balériaux D. Diffusion tensor imaging (DTI) and tractography of the cerebellar projections to prefrontal and posterior parietal cortices: a study at 3T. J Neuroradiol 2008;35:42-50.
Naidich TP, Duvernoy HM, Delman BN, Sorensen AG, Kollias SS, Haacke EM. Duvernoy's atlas of the human brain stem and cerebellum: high-field MRI, surface anatomy, internal structure, vascularization and 3D sectional anatomy. Wien: Springer-Verlag; 2009:876.
Park JK, Kim BS, Choi G, Kim SH, Choi JC, Khang H. Evaluation of the somatotopic organization of corticospinal tracts in the internal capsule and cerebral peduncle: results of diffusion-tensor MR tractography. Korean J Radiol 2008;9:191-195.
Ramnani N, Behrens TEJ, Johansen-Berg H, et al. The evolution of prefrontal inputs to the cortico-pontine system: diffusion imaging evidence from macaque monkeys and humans. Cerebral Cortex 2006;16:811-818.
Salamon N, Sicotte N, Alger J, et al. Analysis of the brain-stem white-matter tracts with diffusion tensor imaging Neuroradiology 2005;47:895-902.
Stieltjes B, Kaufmann WE, van Zijl PCM, et al. Diffusion tensor imaging and axonal tracking in the human brainstem. NeuroImage 2001;14:723-735.
Stoodley CJ, Schmahmann JD. Evidence for topographic organization in the cerebellum of motor control versus cognitive and affective processing. Cortex 2010; 46:831-844.
Conturo TE, Lori NF, Cull TS, et al. Tracking neuronal fiber pathways in the living human brain. PNAS 1999;96:10422-10427.
Engelhardt E, Moreira DM. O cerebelo e suas principais conexões: estudo com tensor de difusão. Rev Bras Neurol 2009;45:17-32.
Salamon N, Sicotte N, Drain A, et al. White matter fiber tractography and color mapping of the normal human cerebellum with diffusion tensor imaging. J Neuroradiol 2007;34: 115-128.
Schmahmann JD, Pandya DN. Fiber pathways of the brain. Oxford: Oxford University Press; 2006:654.
Engelhardt E, Moreira DM. Cerebrocerebellar system - Arnold's bundle tractography. Preliminary results, (abstr). Sixth International Congress on Vascular Dementia. Barcelona, 2009.
Mukherjee P, Chung SW, Berman JI, Hess CP, Henry RG. Diffusion tensor MR imaging and fiber tractography: technical considerations. AJNR 2008;29:843-852.
Hagmann P, Thiran JP, Jonasson L, et al. DTI mapping of human brain connectivity: statistical fibre tracking and virtual dissection. Neuroimage 2003;19:545-554.
Brett M. Finding commissures [Internet]. lastly edited on 2006-07-31. Retrieved in: 2010 ago. Available from: Available from: http://ccn.ucla.edu/wiki/index.php/Find_the_AC-PC_line
» http://ccn.ucla.edu/wiki/index.php/Find_the_AC-PC_line
Nakayama N, Okumura A, Shinoda J, Nakashima T, Iwama T. Relationship between regional cerebral metabolism and consciousness disturbance in traumatic diffuse brain injury without large focal lesions: an FDG-PET study with statistical parametric mapping analysis. J Neurol Neurosurg Psychiatry 2006;77:856-862.
Nii Y, Uematsu S, Lesser RP, Gordon B. Does the central sulcus divide motor and sensory functions? Cortical mapping of human hand areas as revealed by electrical stimulation through subdural grid electrodes. Neurology 1996;46:360-367.
Vorobiev V, Govoni P, Rizzolatti G, Matelli M, Luppino G. Parcellation of human mesial area 6: cytoarchitectonic evidence for three separate areas. Eur J Neurosci 1998;10:2199-2203.
Yamada K, Kizu O, Mori S, et al. Brain fiber tracking with clinically feasible diffusion-tensor MR imaging: initial experience. Radiology 2003;227:295-301.
Catani M, Thiebaut de Schotten M. A diffusion tensor imaging tractography atlas for virtual in vivo dissections. Cortex 2008;44:1105-1132.
Hagmann P, Thiran JP, Jonasson L, et al. DTI mapping of human brain connectivity: statistical fibre tracking and virtual dissection NeuroImage 2003;19:545-554.
Wakana S, Jiang H, Nagae-Poetscher LM, van Zijl PCM, Mori S. Fiber tract-based atlas of human white matter anatomy. Radiology 2004;230:77-87.
Ramnani N. The primate cortico-cerebellar system: anatomy and function. Nature Rev Neurosci 2006;7:511-522.
Bürgel U, Amunts K, Hoemke L, Mohlberg H, Gilsbach JM, Zilles K. White matter fiber tracts of the human brain: three-dimensional mapping at microscopic resolution, topography and intersubject variability. NeuroImage 2006;29:1092-1105.
Ciccarelli O, Toosy AT, Parker GJM, et al. Diffusion tractography based group mapping of major white-matter pathways in the human brain. NeuroImage 2003;19:1545-1555.
Catani M, Mesulam M. The arcuate fasciculus and the disconnection theme in language and aphasia: history and current state. Cortex 2008; 44:953-961.

Publication Dates

Publication in this collection
Oct-Dec 2010

History

Received
10 Sept 2010
Accepted
11 Nov 2010

This is an open-access article distributed under the terms of the Creative Commons Attribution License

[1] Barlow JS. The cerebellum and adaptive control [Internet]. Cambridge: Cambridge University Press, 2002:3-5. Retrieved in: 2009. Available from: Available from: http://books.google.com.br/books
» http://books.google.com.br/books

[2] Glickstein M, Voogd J. Lodewijk Bolk and the comparative anatomy of the cerebellum. Trends Neurosci 1995;18:206-210.

[3] Schmahmann JD. Rediscovery of an early concept. In: Schmahmann JD (Editor), The cerebellum and cognition. San Diego: Academic Press; 1997:4-30.

[4] Leiner HC, Leiner AL, Dow RS. Does the cerebellum contribute to mental skills? Behav Neurosci 1986;100:443-454.

[5] Rapoport M, van Reekum R, Mayberg H. The role of the cerebellum in cognition and behavior: a selective review. J Neuropsychiatry Clin Neurosci 2000;12:193-198.

[6] Schmahmann JD, Caplan D. Cognition, emotion and the cerebellum. Brain 2006;129:290-292.

[7] Watson PJ. Nonmotor functions of the cerebellum. Psychol Bull 1978;85:944-967.

[8] Baldaçara L, Borgio JGF, Lacerda ALT, Jackowski AP. Cerebellum and psychiatric disorders. Rev Bras Psiquiatr 2008;30: 281-289.

[9] Middleton FA, Strick PL. Basal ganglia and cerebellar loops: motor and cognitive circuits. Brain Res Brain Res Rev 2000; 31:236-250.

[10] Schmahmann JD, Pandya DN. The cerebrocerebellar system. Int Rev Neurobiol 1997a;41:31-60

[11] Axer H, Keyserlingk DG. Mapping of fiber orientation in human internal capsule by means of polarized light and confocal scanning laser microscopy. J Neurosci Methods 2000;94:165-175.

[12] Beck E. The origin, course and termination of the prefronto-pontine tract in the human brain. Brain 1950;73:368-391.

[13] Dejerine J. Anatomie des centres nerveux. Paris: J Rueff Ed., 1901:1-586.

[14] Gebbink TB. Structure and connections of the basal ganglia in man. Thesis Leiden. Assen: Van Gorcum & Comp., 1967.

[15] Marin OSM, Angevine Jr JB, Locke S. Topgrtaphical organization of the lateral segmento f the basis pedunculi in man. J Comp Neurol 1962;118:165-183.

[16] Probst M. Zur Kenntniss des Binderarms, der Haubenstrhalung und des Regio Subthalamica. Mschr Psychiat Neurol 1901;10:288-309

[17] Voogd J. Cerebellum and precerebellar nuclei. In: Paxinos G, Mai JK (Editors), The human nervous system. 2nd ed. Amasterdam: Elsevier; 2004:321-392.

[18] Schmahmann JD, Pandya DN. Fiber pathways of the brain. Oxford: Oxford University Press, 2006:654.

[19] Smith MC. Histological findings after hemicerebellectomy in man: anterograde, retrograde and transneuronal degeneration. Brain Res 1975;95:423-442.

[20] Arnold F. Handbuch der anatomie des menschen. v. 2, 5th Book: Vom Nervensystem. Freiburg im Breisgau: Herder'sche Verlagshandlung, 1851:636-740.

[21] Armand J. The origin, course and terminations of corticospinal fibers in various mammals. In: Kuypers GJM, Martin GF (Editors). Anatomy of descending pathways to the spinal cord. v.57, Amsterdam: Elsevier Progress in Brain Research 1982:329-360.

[22] Clark DL, Boutros NN, Mendez MF. The Brain and behavior: an introduction to behavioral neuroanatomy. 3rd ed. Cambridge: Cambridge University Press ; 2010:325.

[23] Ebeling U, Reulen HJ. Subcortical topography and proportions of the pyramidal tract. Acta Neurochir (Wien) 1992;118: 164-171.

[24] Iragui VJ, McCutchen CB. Capsular ataxic hemiparesis. Arch Neurol 1982;39:528-529.

[25] Kumar A, Juhasz C, Asano E, et al. Diffusion tensor imaging study of the cortical origin and course of the corticospinal tract in healthy children. Am J Neuroradiol 2009;30:1963-1970.

[26] Lassek A. The human pyramidal tract: VII. A critical review of its origin. J Nerv Ment Dis 1944;99:22-28.

[27] Martin JH. Neuroanatomy: text and atlas. 3rd ed. New York: McGraw-Hill, 2003:532.

[28] Penfield W, Boldrey E. Somatic motor and sensory representation in the cerebral cortex of man as studied by electrical stimulation. Brain 1937;60:389-443.

[29] Sunderland S. The projection of the cerebral cortex on the pons and cerebellum in the macaque monkey. J Anat 1940;74: 201-226.

[30] Schmahmann JD, Pandya DN. Anatomic organization of the basilar pontine projections from prefrontal cortices in Rhesus monkey. J Neurosci 1997b;17:438-458.

[31] Türe U, Yasargil MG, Friedman AH, Al-Mefty O. Fiber dissection technique: lateral aspect of the brain. Neurosurgery 2000;47:417-427.

[32] Lassek AM. The pyramidal tract: its status in medicine. Springfiel: Charles C Thomas, 1954:166.

[33] Mendoza J, Foundas AL. Clinical neuroanatomy: a neurobehavioral approach. New York: Springer Science, 2008:704.

[34] Crosby EC, Huphrey T, Lauer EW. Correlative anatomy of the nervous system. New York: MacMillan Co, 1962:188-220.

[35] Gray H. Anatomy of the human body [Internet]. Philadelphia: Lea & Febiger, 1918:788-796. Retrieved in: 2009. Available from: Available from: http://www.bartleby.com/107/
» http://www.bartleby.com/107/

[36] Nieuwenhuys R, Voogd J, van Huijzen C. The human central nervous system. Berlin: Springer Verlag, 1980.

[37] Ross ED. Localization of the pyramidal tract in the internal capsule by whole brain dissection. Neurology 1980;30:59-64.

[38] Jissendi P, Baudry S, Balériaux D. Diffusion tensor imaging (DTI) and tractography of the cerebellar projections to prefrontal and posterior parietal cortices: a study at 3T. J Neuroradiol 2008;35:42-50.

[39] Naidich TP, Duvernoy HM, Delman BN, Sorensen AG, Kollias SS, Haacke EM. Duvernoy's atlas of the human brain stem and cerebellum: high-field MRI, surface anatomy, internal structure, vascularization and 3D sectional anatomy. Wien: Springer-Verlag; 2009:876.

[40] Park JK, Kim BS, Choi G, Kim SH, Choi JC, Khang H. Evaluation of the somatotopic organization of corticospinal tracts in the internal capsule and cerebral peduncle: results of diffusion-tensor MR tractography. Korean J Radiol 2008;9:191-195.

[41] Ramnani N, Behrens TEJ, Johansen-Berg H, et al. The evolution of prefrontal inputs to the cortico-pontine system: diffusion imaging evidence from macaque monkeys and humans. Cerebral Cortex 2006;16:811-818.

[42] Salamon N, Sicotte N, Alger J, et al. Analysis of the brain-stem white-matter tracts with diffusion tensor imaging Neuroradiology 2005;47:895-902.

[43] Stieltjes B, Kaufmann WE, van Zijl PCM, et al. Diffusion tensor imaging and axonal tracking in the human brainstem. NeuroImage 2001;14:723-735.

[44] Stoodley CJ, Schmahmann JD. Evidence for topographic organization in the cerebellum of motor control versus cognitive and affective processing. Cortex 2010; 46:831-844.

[45] Conturo TE, Lori NF, Cull TS, et al. Tracking neuronal fiber pathways in the living human brain. PNAS 1999;96:10422-10427.

[46] Engelhardt E, Moreira DM. O cerebelo e suas principais conexões: estudo com tensor de difusão. Rev Bras Neurol 2009;45:17-32.

[47] Salamon N, Sicotte N, Drain A, et al. White matter fiber tractography and color mapping of the normal human cerebellum with diffusion tensor imaging. J Neuroradiol 2007;34: 115-128.

[48] Schmahmann JD, Pandya DN. Fiber pathways of the brain. Oxford: Oxford University Press; 2006:654.

[49] Engelhardt E, Moreira DM. Cerebrocerebellar system - Arnold's bundle tractography. Preliminary results, (abstr). Sixth International Congress on Vascular Dementia. Barcelona, 2009.

[50] Mukherjee P, Chung SW, Berman JI, Hess CP, Henry RG. Diffusion tensor MR imaging and fiber tractography: technical considerations. AJNR 2008;29:843-852.

[51] Hagmann P, Thiran JP, Jonasson L, et al. DTI mapping of human brain connectivity: statistical fibre tracking and virtual dissection. Neuroimage 2003;19:545-554.

[52] Brett M. Finding commissures [Internet]. lastly edited on 2006-07-31. Retrieved in: 2010 ago. Available from: Available from: http://ccn.ucla.edu/wiki/index.php/Find_the_AC-PC_line
» http://ccn.ucla.edu/wiki/index.php/Find_the_AC-PC_line

[53] Nakayama N, Okumura A, Shinoda J, Nakashima T, Iwama T. Relationship between regional cerebral metabolism and consciousness disturbance in traumatic diffuse brain injury without large focal lesions: an FDG-PET study with statistical parametric mapping analysis. J Neurol Neurosurg Psychiatry 2006;77:856-862.

[54] Nii Y, Uematsu S, Lesser RP, Gordon B. Does the central sulcus divide motor and sensory functions? Cortical mapping of human hand areas as revealed by electrical stimulation through subdural grid electrodes. Neurology 1996;46:360-367.

[55] Vorobiev V, Govoni P, Rizzolatti G, Matelli M, Luppino G. Parcellation of human mesial area 6: cytoarchitectonic evidence for three separate areas. Eur J Neurosci 1998;10:2199-2203.

[56] Yamada K, Kizu O, Mori S, et al. Brain fiber tracking with clinically feasible diffusion-tensor MR imaging: initial experience. Radiology 2003;227:295-301.

[57] Catani M, Thiebaut de Schotten M. A diffusion tensor imaging tractography atlas for virtual in vivo dissections. Cortex 2008;44:1105-1132.

[58] Hagmann P, Thiran JP, Jonasson L, et al. DTI mapping of human brain connectivity: statistical fibre tracking and virtual dissection NeuroImage 2003;19:545-554.

[59] Wakana S, Jiang H, Nagae-Poetscher LM, van Zijl PCM, Mori S. Fiber tract-based atlas of human white matter anatomy. Radiology 2004;230:77-87.

[60] Ramnani N. The primate cortico-cerebellar system: anatomy and function. Nature Rev Neurosci 2006;7:511-522.

[61] Bürgel U, Amunts K, Hoemke L, Mohlberg H, Gilsbach JM, Zilles K. White matter fiber tracts of the human brain: three-dimensional mapping at microscopic resolution, topography and intersubject variability. NeuroImage 2006;29:1092-1105.

[62] Ciccarelli O, Toosy AT, Parker GJM, et al. Diffusion tractography based group mapping of major white-matter pathways in the human brain. NeuroImage 2003;19:1545-1555.

[63] Catani M, Mesulam M. The arcuate fasciculus and the disconnection theme in language and aphasia: history and current state. Cortex 2008; 44:953-961.

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