Spatial distribution of human arachnoid trabeculae

Benko, Nikolaus; Luke, Emma; Alsanea, Yousef; Coats, Brittany

doi:10.1111/joa.13186

Cited by 19 publications

(12 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To our knowledge, human PAC biomechanical properties have not been documented, and therefore a direct comparison with our results is not possible. While studies using human tissues are limited, the volume fraction in post-mortem human SAT was found to be 5 to 10% greater in frontal regions of the brain compared to other regions [27]. In principle, these differences in volume fraction could lead to relatively small regional differences in mechanical properties, but these relatively small regional differences were not possible to confirm in the present study.…”

Section: Comparison Of Biomechanical Results To Previous Studiescontrasting

confidence: 65%

“…Scanning electron microscopy and transmission electron microscopy showed that the structural morphology of human (post-mortem) SAT consisted of pillars, columns, sheets, branched fibrils, and other complex structures with fibril diameters that varied from 0.5-3 µm [3]. Optical coherence tomography was utilized to show that SAT fiber diameter varies from 19.2-45.5 µm [27]. Fiber diameter in the human (post-mortem) bulbar subarachnoid space was also found to be between 0.2-1 µm [39].…”

Section: Structural Morphologymentioning

confidence: 99%

See 1 more Smart Citation

Ex-vivo quantification of ovine pia arachnoid complex biomechanical properties under uniaxial tension

Natividad

Theodossiou

Schiele

et al. 2020

Fluids Barriers CNS

View full text Add to dashboard Cite

Background The pia arachnoid complex (PAC) is a cerebrospinal fluid-filled tissue conglomerate that surrounds the brain and spinal cord. Pia mater adheres directly to the surface of the brain while the arachnoid mater adheres to the deep surface of the dura mater. Collagen fibers, known as subarachnoid trabeculae (SAT) fibers, and microvascular structure lie intermediately to the pia and arachnoid meninges. Due to its structural role, alterations to the biomechanical properties of the PAC may change surface stress loading in traumatic brain injury (TBI) caused by sub-concussive hits. The aim of this study was to quantify the mechanical and morphological properties of ovine PAC. Methods Ovine brain samples (n = 10) were removed from the skull and tissue was harvested within 30 min post-mortem. To access the PAC, ovine skulls were split medially from the occipital region down the nasal bone on the superior and inferior aspects of the skull. A template was used to remove arachnoid samples from the left and right sides of the frontal and occipital regions of the brain. 10 ex-vivo samples were tested with uniaxial tension at 2 mm s−1, average strain rate of 0.59 s−1, until failure at < 5 h post extraction. The force and displacement data were acquired at 100 Hz. PAC tissue collagen fiber microstructure was characterized using second-harmonic generation (SHG) imaging on a subset of n = 4 stained tissue samples. To differentiate transverse blood vessels from SAT by visualization of cell nuclei and endothelial cells, samples were stained with DAPI and anti-von Willebrand Factor, respectively. The Mooney-Rivlin model for average stress–strain curve fit was used to model PAC material properties. Results The elastic modulus, ultimate stress, and ultimate strain were found to be 7.7 ± 3.0, 2.7 ± 0.76 MPa, and 0.60 ± 0.13, respectively. No statistical significance was found across brain dissection locations in terms of biomechanical properties. SHG images were post-processed to obtain average SAT fiber intersection density, concentration, porosity, tortuosity, segment length, orientation, radial counts, and diameter as 0.23, 26.14, 73.86%, 1.07 ± 0.28, 17.33 ± 15.25 µm, 84.66 ± 49.18°, 8.15%, 3.46 ± 1.62 µm, respectively. Conclusion For the sizes, strain, and strain rates tested, our results suggest that ovine PAC mechanical behavior is isotropic, and that the Mooney-Rivlin model is an appropriate curve-fitting constitutive equation for obtaining material parameters of PAC tissues.

show abstract

Section: Comparison Of Biomechanical Results To Previous Studiescontrasting

confidence: 65%

Section: Structural Morphologymentioning

confidence: 99%

Ex-vivo quantification of ovine pia arachnoid complex biomechanical properties under uniaxial tension

Natividad

Theodossiou

Schiele

et al. 2020

Fluids Barriers CNS

View full text Add to dashboard Cite

show abstract

“…45 Analysis of postmortem human subjects identified a mean volume fraction of arachnoid trabeculae of ≈25%. 46 The random fibril organisation within the trabeculae is thought to allow for stress redistribution under supraphysiological loading. 45 The arachnoid trabeculae are the main load bearing component of the PAC in normal traction loading but are thought to function primarily in resisting tensile stress, as they buckle under small magnitudes of compressive load.…”

Section: Pia-arachnoid Complex (Pac) Structural Composition and Alignmentmentioning

confidence: 99%

Mechanical Properties of the Cranial Meninges: A Systematic Review

Walsh

Zhou

et al. 2021

Journal of Neurotrauma

View full text Add to dashboard Cite

The meninges are membranous tissues which are pivotal in maintaining homeostasis of the central nervous system. Despite the importance of the cranial meninges in nervous system physiology and in head injury mechanics, our knowledge of the tissues' mechanical behaviour and structural composition is limited. This systematic review analyses the existing literature on the mechanical properties of the meningeal tissues. Publications were identified from a search of Scopus, Academic Search Complete and Web of Science and screened for eligibility according to PRISMA guidelines. The review details the wide range of testing techniques employed to date and the significant variability in the observed experimental findings. Our findings identify many gaps in the current literature which can serve as a guide for future work for meningeal mechanics investigators. The review identifies no peer-reviewed mechanical data on the falx and tentorium tissues, both of which have been identified as key structures in influencing brain injury mechanics. A dearth of mechanical data for the pia-arachnoid complex was also identified (no experimental mechanics studies on the human pia-arachnoid complex were identified), which is desirable for biofidelic modelling of human head injuries. Finally, this review provides recommendations on how experiments can be conducted to allow for standardisation of test methodologies, enabling simplified comparisons and conclusions on meningeal mechanics.

show abstract

“…SAT consisted of pillars, columns, sheets, branched fibrils, and other complex structures with fibril diameters that varied from 0.5-3 µm [3]. Optical coherence tomography was utilized to show that SAT fiber diameter varies from 19.2-45.5 µm [27]. Fiber diameter in the human (post-mortem)…”

Section: Structural Morphologymentioning

confidence: 99%

Ex-vivo Quantification of Ovine Pia Arachnoid Complex Biomechanical Properties Under Uniaxial Tension

Natividad

Theodossiou

Schiele

et al. 2020

Preprint

View full text Add to dashboard Cite

The pia arachnoid complex (PAC) is a cerebrospinal fluid-filled tissue conglomerate that surrounds the brain and spinal cord. Pia mater adheres directly to the surface of the brain while the arachnoid mater adheres to the inferior side of the dura mater. Collagen fibers, known as subarachnoid trabeculae (SAT) fibers, and microvascular structure lie intermediately to the pia and arachnoid meninges. Due to its structural role, alterations to the biomechanical properties of the PAC may change surface stress loading in traumatic brain injury (TBI) caused by sub-concussive hits. The aim of this study was to quantify the mechanical and morphological properties of ovine PAC. Ovine brain samples (n = 10) were removed from the skull and tissue was harvested within 30 minutes post-mortem. To access the PAC, ovine skulls were split medially from the occipital region down the nasal bone on the superior and inferior aspects of the skull. A template was used to remove arachnoid samples from the left and right sides of the frontal occipital regions of the brain. 10 ex-vivo samples were tested with uniaxial tension at 2 mm/s, average strain rate of 0.59 s− 1, until failure at < 5 hours post extraction. The force and displacement data were acquired at 100 Hz using LabVIEW. PAC tissue collagen fiber microstructure was characterized using second-harmonic generation (SHG) imaging on a subset of n = 4 stained tissue samples. Samples were stained with DAPI and anti-von Willebrand Factor to visualize cell nuclei and epithelial cells, respectively. The Mooney-Rivlin model for average stress-strain curve fit was used to model PAC material properties. The elastic modulus, ultimate stress, and ultimate strain were found to be 7.7 ± 3.0 MPa, 2.7 ± 0.76 MPa, and 0.60 ± 0.13, respectively. No statistical significance was found across brain dissection locations in terms of biomechanical properties. SHG images were post-processed to obtain average SAT fiber intersection density, concentration, porosity, tortuosity, segment length, orientation, radial counts, and diameter as 0.23%, 26.14%, 73.86%, 1.07 ± 0.28, 17.33 ± 15.25 µm, 84.66 ± 49.18º, 8.15%, 3.46 ± 1.62 µm, respectively. For the sizes, strain, and strain rates tested, our results suggest that ovine PAC mechanical behavior is isotropic, and that the Mooney-Rivlin model is an appropriate curve-fitting constitutive equation for obtaining material parameters of PAC tissues.

show abstract

Spatial distribution of human arachnoid trabeculae

Abstract: This is the author manuscript accepted for publication and has undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as

Cited by 19 publications

References 31 publications

Ex-vivo quantification of ovine pia arachnoid complex biomechanical properties under uniaxial tension

Ex-vivo quantification of ovine pia arachnoid complex biomechanical properties under uniaxial tension

Mechanical Properties of the Cranial Meninges: A Systematic Review

Ex-vivo Quantification of Ovine Pia Arachnoid Complex Biomechanical Properties Under Uniaxial Tension

Contact Info

Product

Resources

About