Morphometric analysis of peripheral nerves in people with spinal cord injury

Abstract The morphology of peripheral nerves sampled at the time of nerve transfer surgery was directly assessed in participants within 15 months of their SCI. Fresh nerve samples were fixed in glutaraldehyde, processed and embedded in Araldite Epon. Light and electron microscopy was used to conduct...

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Main Authors: Aurora Messina, Mary P. Galea
Format: Article
Language:English
Published: Nature Portfolio 2025-07-01
Series:Scientific Reports
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Online Access:https://doi.org/10.1038/s41598-025-07809-6
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author Aurora Messina
Mary P. Galea
author_facet Aurora Messina
Mary P. Galea
author_sort Aurora Messina
collection DOAJ
description Abstract The morphology of peripheral nerves sampled at the time of nerve transfer surgery was directly assessed in participants within 15 months of their SCI. Fresh nerve samples were fixed in glutaraldehyde, processed and embedded in Araldite Epon. Light and electron microscopy was used to conduct a qualitative analysis of morphology and a quantitative morphometric analysis of axon, fibre and myelin areas and diameters and g-ratios. Over two-thirds of both donor and recipient nerves showed abnormalities that differed in appearance and aetiology. These included myelin thickening and folding (tomacula), demyelination, reduced density of large, myelinated axons, oedematous endoneurium, evidence of compression, and thickened epineurium and perineurium. Morphometric analysis showed differences in axon density and myelination in the sampled nerves, with substantial nerve fibre loss in teres minor and posterior axillary nerves, and increased myelin area in the other sampled nerves. Mean (SD) myelin area ranged from 26.23 (13.86) to 66.02 (32.14) µm2 in donor nerves, and from 54.58 (25.29) to 74.04 (31.72) µm2 in recipient nerves. The g-ratio was affected by the degree of myelin thickening and ranged from 0.6 to 0.7 to values below 0.25 in fibres where the myelin was thickened. The morphological findings show evidence of widespread peripheral nerve pathology after spinal cord injury. The loss of nerve fibres in teres minor and posterior axillary nerves may be related to compression. Myelin abnormalities are probably associated with loss of neural traffic after injury and may be reversible.
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spelling doaj-art-1a4f9cfcbf384903a910fccf351cc4dd2025-08-20T03:03:40ZengNature PortfolioScientific Reports2045-23222025-07-0115111110.1038/s41598-025-07809-6Morphometric analysis of peripheral nerves in people with spinal cord injuryAurora Messina0Mary P. Galea1Department of Medicine (Royal Melbourne Hospital), The University of MelbourneDepartment of Medicine (Royal Melbourne Hospital), The University of MelbourneAbstract The morphology of peripheral nerves sampled at the time of nerve transfer surgery was directly assessed in participants within 15 months of their SCI. Fresh nerve samples were fixed in glutaraldehyde, processed and embedded in Araldite Epon. Light and electron microscopy was used to conduct a qualitative analysis of morphology and a quantitative morphometric analysis of axon, fibre and myelin areas and diameters and g-ratios. Over two-thirds of both donor and recipient nerves showed abnormalities that differed in appearance and aetiology. These included myelin thickening and folding (tomacula), demyelination, reduced density of large, myelinated axons, oedematous endoneurium, evidence of compression, and thickened epineurium and perineurium. Morphometric analysis showed differences in axon density and myelination in the sampled nerves, with substantial nerve fibre loss in teres minor and posterior axillary nerves, and increased myelin area in the other sampled nerves. Mean (SD) myelin area ranged from 26.23 (13.86) to 66.02 (32.14) µm2 in donor nerves, and from 54.58 (25.29) to 74.04 (31.72) µm2 in recipient nerves. The g-ratio was affected by the degree of myelin thickening and ranged from 0.6 to 0.7 to values below 0.25 in fibres where the myelin was thickened. The morphological findings show evidence of widespread peripheral nerve pathology after spinal cord injury. The loss of nerve fibres in teres minor and posterior axillary nerves may be related to compression. Myelin abnormalities are probably associated with loss of neural traffic after injury and may be reversible.https://doi.org/10.1038/s41598-025-07809-6Spinal cord injuryPeripheral nerveMorphologyMorphometryMyelin abnormalitiesg-ratio
spellingShingle Aurora Messina
Mary P. Galea
Morphometric analysis of peripheral nerves in people with spinal cord injury
Scientific Reports
Spinal cord injury
Peripheral nerve
Morphology
Morphometry
Myelin abnormalities
g-ratio
title Morphometric analysis of peripheral nerves in people with spinal cord injury
title_full Morphometric analysis of peripheral nerves in people with spinal cord injury
title_fullStr Morphometric analysis of peripheral nerves in people with spinal cord injury
title_full_unstemmed Morphometric analysis of peripheral nerves in people with spinal cord injury
title_short Morphometric analysis of peripheral nerves in people with spinal cord injury
title_sort morphometric analysis of peripheral nerves in people with spinal cord injury
topic Spinal cord injury
Peripheral nerve
Morphology
Morphometry
Myelin abnormalities
g-ratio
url https://doi.org/10.1038/s41598-025-07809-6
work_keys_str_mv AT auroramessina morphometricanalysisofperipheralnervesinpeoplewithspinalcordinjury
AT marypgalea morphometricanalysisofperipheralnervesinpeoplewithspinalcordinjury