Anatomy of the supraventricular portion of the pyramidal tract

Zolal, Amir; Vachata, Petr; Hejčl, Aleš; Bartoš, Robert; Malucelli, Alberto; Nováková, Martina; Derner, Milouš; Sameš, Martin

doi:10.1007/s00701-012-1326-0

Cited by 6 publications

(6 citation statements)

References 12 publications

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“…However, the reversibility of symptoms after shunt surgery even after a long period suggests that irreversible axonal damage is unlikely to be the sole cause of gait disturbance [4]. The “compression hypothesis” is also supported by the fact that the fibers of the legs are closest in proximity to the lateral ventricles [37]–[39]; this explains why gait disturbance is the most prominent neurological feature in iNPH. Moreover, a detailed tract-specific analysis of the CST demonstrated that the increase in FA was limited to areas near the lateral ventricle [15], an observation consistent with CST compression by the ventricular enlargement.…”

Section: Discussionmentioning

confidence: 99%

Axon Diameter and Intra-Axonal Volume Fraction of the Corticospinal Tract in Idiopathic Normal Pressure Hydrocephalus Measured by Q-Space Imaging

et al. 2014

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PurposePrevious studies suggest that compression and stretching of the corticospinal tract (CST) potentially cause treatable gait disturbance in patients with idiopathic normal pressure hydrocephalus (iNPH). Measurement of axon diameter with diffusion MRI has recently been used to investigate microstructural alterations in neurological diseases. In this study, we investigated alterations in the axon diameter and intra-axonal fraction of the CST in iNPH by q-space imaging (QSI) analysis.MethodsNineteen patients with iNPH and 10 age-matched controls were recruited. QSI data were obtained with a 3-T system by using a single-shot echo planar imaging sequence with the diffusion gradient applied parallel to the antero-posterior axis. By using a two-component low-q fit model, the root mean square displacements of intra-axonal space ( = axon diameter) and intra-axonal volume fraction of the CST were calculated at the levels of the internal capsule and body of the lateral ventricle, respectively.ResultsWilcoxon's rank-sum test revealed a significant increase in CST intra-axonal volume fraction at the paraventricular level in patients (p<0.001), whereas no significant difference was observed in the axon diameter. At the level of the internal capsule, neither axon diameter nor intra-axonal volume fraction differed significantly between the two groups.ConclusionOur results suggest that in patients with iNPH, the CST does not undergo irreversible axonal damage but is rather compressed and/or stretched owing to pressure from the enlarged ventricle. These analyses of axon diameter and intra-axonal fraction yield insights into microstructural alterations of the CST in iNPH.

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Section: Discussionmentioning

confidence: 99%

Axon Diameter and Intra-Axonal Volume Fraction of the Corticospinal Tract in Idiopathic Normal Pressure Hydrocephalus Measured by Q-Space Imaging

et al. 2014

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“…This observation is likely to result from the use of the CSD-PFT algorithm (Girard et al, 2014), but especially with the weighting of the fODF based on a PyT template, which allowed a better tracking of PyT streamlines in the centrum semiovale (Rheault et al, 2017). These ventro-lateral projections represent a significant improvement compared to previous CST/PyT extracted using individual tractography (Kumar et al, 2009;Zolal et al, 2012;Groisser et al, 2014;Angstmann et al, 2016;Bigourdan et al, 2016) and also compared to the different previous probabilistic CST/PyT atlases (Zhang et al, 2010;Thiebaut de Schotten et al, 2011;Rojkova et al, 2016;Archer et al, 2018).…”

Section: Pyt Cortical Projectionsmentioning

confidence: 99%

A population-based atlas of the human pyramidal tract in 410 healthy participants

Chenot

Tzourio‐Mazoyer

Rheault

et al. 2018

Preprint

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With the advances in diffusion MRI and tractography, numerous atlases of the human pyramidal tract (PyT) have been proposed but the inherent limitation of tractography to resolve crisscrossed bundles within the centrum semiovale have so far prevented the complete description of the most lateral PyT projections. Here, we combined a precise manual positioning of individual subcortical regions of interest along the descending pathway of the PyT with a new bundle-specific tractography algorithm. This later is based on anatomical priors to improve streamlines tracking in crossing areas. We then extracted both left and right PyT in a large cohort of 410 healthy participants and built a probabilistic atlas of the whole-fanning PyT with a complete description of its most cortico-lateral projections.Clinical applications are envisaged, the whole-fanning probabilistic PyT atlas being likely a better marker of corticospinal integrity metrics than those currently used within the frame of prediction of post-stroke motor recovery. The present probabilistic PyT, freely available, provides an interesting tool for clinical applications in order to locate specific PyT damage and its impact to the short and long-term motor recovery after stroke.

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Section: Pyt Cortical Projectionsmentioning

confidence: 99%

A population-based atlas of the human pyramidal tract in 410 healthy participants

et al. 2018

View full text Add to dashboard Cite

With the advances in diffusion MRI and tractography, numerous atlases of the human pyramidal tract (PyT) have been proposed but the inherent limitation of tractography to resolve crisscrossed bundles within the centrum semiovale have so far prevented the complete description of the most lateral PyT projections. Here, we combined a precise manual positioning of individual subcortical regions of interest along the descending pathway of the PyT with a new bundle-specific tractography algorithm. This later is based on anatomical priors to improve streamlines tracking in crossing areas. We then extracted both left and right PyT in a large cohort of 410 healthy participants and built a probabilistic atlas of the whole-fanning PyT with a complete description of its most cortico-lateral projections. Clinical applications are envisaged, the whole-fanning probabilistic PyT atlas being likely a better marker of corticospinal integrity metrics than those currently used within the frame of prediction of post-stroke motor recovery. The present probabilistic PyT, freely available, provides an interesting tool for clinical applications in order to locate specific PyT damage and its impact to the short and long-term motor recovery after stroke.

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Anatomy of the supraventricular portion of the pyramidal tract

Abstract: The pyramidal tract undergoes a large part of its rotation from mediolateral to posteroanterior configuration during its course in the supraventricular white matter, although interindividual differences exist.

Cited by 6 publications

References 12 publications

Axon Diameter and Intra-Axonal Volume Fraction of the Corticospinal Tract in Idiopathic Normal Pressure Hydrocephalus Measured by Q-Space Imaging

Axon Diameter and Intra-Axonal Volume Fraction of the Corticospinal Tract in Idiopathic Normal Pressure Hydrocephalus Measured by Q-Space Imaging

A population-based atlas of the human pyramidal tract in 410 healthy participants

A population-based atlas of the human pyramidal tract in 410 healthy participants

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