Effects of compressive lesions on intraoperative human spinal cord elasticity

2021 ◽  
pp. 1-10
Author(s):  
Amro Al-Habib ◽  
Wajda Alhothali ◽  
Abdulrahman Albakr ◽  
Sherif Elwatidy ◽  
Ghaida Alawaji ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Dura Mater ◽  
Shear Wave Elastography ◽  
Conus Medullaris ◽  
Tissue Elasticity ◽  
External Compression ◽  
Human Spinal Cord ◽  
Bone Removal ◽  
The Impact

OBJECTIVE Although evaluating tissue elasticity has various clinical applications, spinal cord elasticity (SCE) in humans has never been well documented. In this study, the authors aimed to evaluate the impact of compression on human SCE in vivo. METHODS The authors prospectively assessed SCE using intraoperative shear wave elastography (SWE). All consecutive patients undergoing spinal cord (SC) decompression (laminectomy or corpectomy) between June 2018 and June 2019 were included. After intraoperative exposure of the patient’s dura mater, at least three SWE measurements of the SC and its coverings were performed. Intraoperative neurological monitoring in the form of motor and somatosensory evoked potentials was utilized. Cases were divided into two groups based on the state of SC compression following bone removal (laminectomy or corpectomy): patients with adequate decompression (the decompressed SC group [DCG]) following bone removal and patients with remining compression, e.g., compressing tumor or instability (the compressed SC group [COG]). RESULTS A total of 25 patients were included (8 females and 17 males) with a mean age of 48.28 ± 21.47 years. Most cases were degenerative diseases (10 cases) followed by tumors (6 cases), and the compression was observed at cervical (n = 14), thoracic (n = 9), and conus medullaris (n = 2) levels. The COG (6 cases) expressed significantly higher elasticity values, i.e., greater stiffness (median 93.84, IQR 75.27–121.75 kPa) than the decompressed SC in DCG (median 9.35, IQR 6.95–11.22 kPa, p < 0.001). Similarly, the compressed dura mater in the COG was significantly stiffer (mean ± SD 121.83 ± 70.63 kPa) than that in the DCG (29.78 ± 18.31 kPa, p = 0.042). Following SC decompression in COG, SCE values were significantly reduced (p = 0.006; adjusted for multiple comparisons). Intraoperative monitoring demonstrated no worsening from the baseline. CONCLUSIONS The current study is to the authors’ knowledge the first to quantitatively demonstrate increased stiffness (i.e., elasticity value) of the human SC and dura mater in response to external compression in vivo. It appears that SCE is a dynamic phenomenon and is reduced following decompression. Moreover, the evaluation of human SCE using the SWE technique is feasible and safe. Information from future studies aiming to further define SCE could be valuable in the early and accurate diagnosis of the compressed SC.

scholarly journals In vivo assessment of spinal cord elasticity using shear wave ultrasound in dogs

2018 ◽  
Vol 29 (4) ◽  
pp. 461-469 ◽  
Author(s):  
Amro Al-Habib ◽  
Abdulrahman Albakr ◽  
Abdullah Al Towim ◽  
Metab Alkubeyyer ◽  
Abdullah Abu Jamea ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Shear Wave ◽  
Dura Mater ◽  
Ex Vivo ◽  
Shear Wave Elastography ◽  
Biomechanical Properties ◽  
Tissue Elasticity ◽  
Pia Mater ◽  
Balloon Compression

OBJECTIVEEvaluation of living tissue elasticity has wide applications in disease characterization and prognosis prediction. Few previous ex vivo attempts have been made to characterize spinal cord elasticity (SCE). Recently, tissue elasticity assessment has been clinically feasible using ultrasound shear wave elastography (SWE). The current study aims to characterize SCE in healthy dogs, in vivo, utilizing SWE, and to address SCE changes during compression.METHODSTen Greyhound dogs (mean age 14 months; mean weight 14.3 kg) were anesthetized and tracheally intubated, with hemodynamic and neurological monitoring. A 3-level, midcervical laminectomy was performed. SCE was assessed at baseline. Next, 8- and 13-mm balloon compressions were sequentially applied ventral to the spinal cord.RESULTSThe mean SCE was 18.5 ± 7 kPa. Elasticity of the central canal, pia mater, and dura mater were 21.7 ± 9.6 kPa, 26.1 ± 14.8 kPa, and 63.2 ± 11.5 kPa, respectively. As expected, the spinal cord demonstrated less elasticity than the dura mater (p < 0.0001) and pia mater (trend toward significance p = 0.08). Notably, the 13-mm balloon compression resulted in a stiffer spinal cord than at baseline (233 ± 73 kPa versus 18.5 ± 7 kPa, p < 0.0001) and 8-mm balloon compression (233 ± 73 kPa versus 185 ± 68 kPa, p < 0.048).CONCLUSIONSIn vivo SCE evaluation using SWE is feasible and comparable to earlier reports, as demonstrated by physical sectioning of the spinal cord. The compressed spinal cord is stiffer than a free spinal cord, with a linear increase in SCE with increasing mechanical compression. Knowledge of the biomechanical properties of the spinal cord including SCE has potential implications for disease management and prognosis.

Surgical treatment of the retethered spinal cord after repair of lipomyelomeningocele

1991 ◽  
Vol 74 (5) ◽  
pp. 709-714 ◽  
Author(s):  
Hiroaki Sakamoto ◽  
Akira Hakuba ◽  
Ken Fujitani ◽  
Shuro Nishimura
Keyword(s):  
Spinal Cord ◽  
Dura Mater ◽  
Conus Medullaris ◽  
Posterior Arch ◽  
Pia Mater ◽  
Dense Adhesion ◽  
Content Type ◽  
Dural Sac ◽  
Long Term Observation

✓ In a series of 75 patients with surgically treated lipomyelomeningoceles, the neurological condition of six patients deteriorated 6 months to 14 years after the operation due to repeat tethering of the spinal cord. The tethering resulted from postoperative dense adhesion between the cord and the overlying dura mater. Two of the six patients underwent conventional repeat untethering procedures, and the remaining four were successfully treated with a new surgical technique developed by the authors to prevent such dural adhesion. For this procedure, after complete untethering of the spinal cord, the lumbosacral cord is retained in the center of the dural sac by fine stay sutures between the pia mater of the conus medullaris and the ventral dura mater. In addition, the dura mater is tacked to the posterior arch which is reconstructed with bone grafts at one or two bifid vertebral levels. During a postoperative follow-up period of 1 to 3 years, no further deterioration has been observed and magnetic resonance studies have demonstrated a space filled with cerebrospinal fluid (CSF) around the lumbosacral cord. The authors conclude that long-term observation, both neurological and radiological, is essential even after successful repair of a lipomyelomeningocele. This new surgical procedure can maintain a CSF bath around the lumbosacral cord, thus preventing dural adhesion. Application of this technique will hopefully be beneficial in lipomyelomeningocele patients with a high risk of cord retethering after initial repair.

Diffusion restriction in the human spinal cord characterized in vivo with high b-value STEAM diffusion imaging

NeuroImage ◽  
2013 ◽  
Vol 82 ◽  
pp. 416-425 ◽  
Author(s):  
Novena A. Rangwala ◽  
David B. Hackney ◽  
Weiying Dai ◽  
David C. Alsop
Keyword(s):  
Spinal Cord ◽  
Diffusion Imaging ◽  
B Value ◽  
Diffusion Restriction ◽  
Human Spinal Cord ◽  
High B Value

High-resolution myelin water imaging in post-mortem multiple sclerosis spinal cord: A case report

2016 ◽  
Vol 22 (11) ◽  
pp. 1485-1489 ◽  
Author(s):  
Cornelia Laule ◽  
Andrew Yung ◽  
Vlady Pavolva ◽  
Barry Bohnet ◽  
Piotr Kozlowski ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Spinal Cord ◽  
Cross Sections ◽  
Anatomical Variation ◽  
Conus Medullaris ◽  
Entire Length ◽  
Post Mortem ◽  
Water Fraction ◽  
Formalin Fixed

Background: Loss of myelin in the spinal cord in multiple sclerosis (MS) is likely an important, and early, contributor to atrophy and associated disability. In vivo measurement of myelin is possible using myelin water fraction (MWF) imaging, but MWF has never been assessed in MS along the entire length of the spinal cord in vivo or in post-mortem tissue. Objective: To assess the feasibility of measuring the distribution of MWF along the entire length of the spinal cord in post-mortem MS tissue using high-field MRI. Methods: One formalin-fixed spinal cord from a female with secondary progressive MS (age: 78 years, disease duration: 25 years) was cut into 104 5-mm-thick cross sections along the entire length of the spinal cord from the cervico-medullary junction to the conus medullaris and imaged using a 64 echo T2 relaxation experiment at 7T. Results: Myelin water maps showed cord anatomy in superb detail, white matter demonstrating a higher MWF than the grey matter. Anatomical variation in myelin distribution along cervical, thoracic and lumbar regions was observed. Lesions demonstrated myelin loss. Conclusion: Post-mortem myelin water imaging of formalin-fixed MS spinal cord is feasible.

In vivo diffusion tensor imaging of chronic spinal cord compression: a rat model with special attention to the conus medullaris

2016 ◽  
Vol 57 (12) ◽  
pp. 1531-1539 ◽  
Author(s):  
Peng Zhao ◽  
Chao Kong ◽  
Xueming Chen ◽  
Hua Guan ◽  
Zhenshan Yu ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Diffusion Tensor Imaging ◽  
Spinal Cord Compression ◽  
Rat Model ◽  
Diffusion Tensor ◽  
Cord Compression ◽  
Conus Medullaris

Anatomy of the human spinal cord arachnoid cisterns: applications for spinal cord surgery

2019 ◽  
Vol 31 (5) ◽  
pp. 756-763 ◽  
Author(s):  
Corentin Dauleac ◽  
Timothée Jacquesson ◽  
Patrick Mertens
Keyword(s):  
Spinal Cord ◽  
Cauda Equina ◽  
Ventral Surface ◽  
Conus Medullaris ◽  
Pia Mater ◽  
Axial Section ◽  
Human Spinal Cord ◽  
Spinal Subarachnoid Space ◽  
Subarachnoid Spaces ◽  
Arachnoid Mater

OBJECTIVEThe goal in this study was to describe the overall organization of the spinal arachnoid mater and spinal subarachnoid space (SSAS) as well as its relationship with surrounding structures, in order to highlight spinal cord arachnoid cisterns.METHODSFifteen spinal cords were extracted from embalmed adult cadavers. The organization of the spinal cord arachnoid and SSAS was described via macroscopic observations, optical microscopic views, and scanning electron microscope (SEM) studies. Gelatin injections were also performed to study separated dorsal subarachnoid compartments.RESULTSCompartmentalization of SSAS was studied on 3 levels of axial sections. On an axial section passing through the tips of the denticulate ligament anchored to the dura, 3 subarachnoid cisterns were observed: 2 dorsolateral and 1 ventral. On an axial section passing through dural exit/entrance of rootlets, 5 subarachnoid cisterns were observed: 2 dorsolateral, 2 lateral formed by dorsal and ventral rootlets, and 1 ventral. On an axial section passing between the two previous ones, only 1 subarachnoid cistern was observed around the spinal cord. This compartmentalization resulted in the anatomical description of 3 elements: the median dorsal septum, the arachnoid anchorage to the tip of the denticulate ligament, and the arachnoid anchorage to the dural exit/entrance of rootlets. The median dorsal septum already separated dorsal left and right subarachnoid spaces and was described from C1 level to 3 cm above the conus medullaris. This septum was anchored to the dorsal septal vein. No discontinuation was observed in the median dorsal arachnoid septum. At the entrance point of dorsal rootlets in the spinal cord, arachnoid trabeculations were described. Using the SEM, numerous arachnoid adhesions between the ventral surface of the dorsal rootlets and the pia mater over the spinal cord were observed. At the ventral part of the SSAS, no septum was found, but some arachnoid trabeculations between the arachnoid and the pia mater were present and more frequent than in the dorsal part. Laterally, arachnoid was firmly anchored to the denticulate ligaments’ fixation at dural points, and dural exit/entrance of rootlets made a fibrous ring of arachnoidodural adhesions. At the level of the cauda equina, the arachnoid mater surrounded all rootlets together—as a sac and not individually.CONCLUSIONSArachnoid cisterns are organized on each side of a median dorsal septum and compartmentalized in relation with the attachments of denticulate ligament and exit/entrance of rootlets.

Clinico-pathological evidence that axonal loss underlies disability in progressive multiple sclerosis

2010 ◽  
Vol 16 (4) ◽  
pp. 406-411 ◽  
Author(s):  
Emma C Tallantyre ◽  
Lars Bø ◽  
Omar Al-Rawashdeh ◽  
Trudy Owens ◽  
Chris H Polman ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Spinal Cord ◽  
Progressive Multiple Sclerosis ◽  
Axonal Loss ◽  
Motor Disability ◽  
Human Spinal Cord ◽  
Axonal Pathology ◽  
Motor Tracts ◽  
First Time

Growing evidence suggests that axonal degeneration rather than demyelination is the pathological substrate underlying chronic, irreversible disability in multiple sclerosis. However, direct evidence linking clinical disability measured in vivo with corresponding post-mortem measures of axonal pathology is lacking. Our objective in this study was to investigate the relationship between motor disability accumulated by patients with multiple sclerosis during life and the degree of axonal loss observed in their descending motor tracts after death. Human spinal cord derived at autopsy from 45 patients with multiple sclerosis was investigated. The medical records of each patient were reviewed by a multiple sclerosis neurologist to determine the degree of motor disability reached before death. Spinal cord sections were stained immunohistochemically. The degree of demyelination and the number of surviving corticospinal tract axons were measured in each patient. Patients who had accumulated higher levels of motor disability prior to death demonstrated fewer surviving corticospinal axons. Motor disability did not correlate with degree of demyelination. This study provides for the first time, direct clinico-pathological evidence that axonal loss is the pathological substrate of established disability in multiple sclerosis.

Vascular configurations of anastomotic basket of conus medullaris in human spinal cord

2017 ◽  
Vol 31 (3) ◽  
pp. 441-448 ◽  
Author(s):  
Santiago Rojas ◽  
Marisa Ortega ◽  
Alfonso Rodríguez‐Baeza
Keyword(s):  
Spinal Cord ◽  
Conus Medullaris ◽  
Human Spinal Cord
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