scholarly journals DI-5-Cuffs: Lumbar Intervertebral Disc Proteoglycan and Water Content Changes in Humans after Five Days of Dry Immersion to Simulate Microgravity

2020 ◽  
Vol 21 (11) ◽  
pp. 3748
Author(s):  
Loïc Treffel ◽  
Nastassia Navasiolava ◽  
Karen Mkhitaryan ◽  
Emmanuelle Jouan ◽  
Kathryn Zuj ◽  
...  
Keyword(s):  
Intervertebral Disc ◽  
Water Content ◽  
T2 Mapping ◽  
Lumbar Region ◽  
Gravitational Unloading ◽  
Lumbar Intervertebral Disc ◽  
Dry Immersion ◽  
Disc Herniations ◽  
Proteoglycan Content ◽  
Underlying Mechanisms

Most astronauts experience back pain after spaceflight, primarily located in the lumbar region. Intervertebral disc herniations have been observed after real and simulated microgravity. Spinal deconditioning after exposure to microgravity has been described, but the underlying mechanisms are not well understood. The dry immersion (DI) model of microgravity was used with eighteen male volunteers. Half of the participants wore thigh cuffs as a potential countermeasure. The spinal changes and intervertebral disc (IVD) content changes were investigated using magnetic resonance imaging (MRI) analyses with T1-T2 mapping sequences. IVD water content was estimated by the apparent diffusion coefficient (ADC), with proteoglycan content measured using MRI T1-mapping sequences centered in the nucleus pulposus. The use of thigh cuffs had no effect on any of the spinal variables measured. There was significant spinal lengthening for all of the subjects. The ADC and IVD proteoglycan content both increased significantly with DI (7.34 ± 2.23% and 10.09 ± 1.39%, respectively; mean ± standard deviation), p < 0.05). The ADC changes suggest dynamic and rapid water diffusion inside IVDs, linked to gravitational unloading. Further investigation is needed to determine whether similar changes occur in the cervical IVDs. A better understanding of the mechanisms involved in spinal deconditioning with spaceflight would assist in the development of alternative countermeasures to prevent IVD herniation.

Lumbar intervertebral disc abnormalities: comparison of quantitative T2 mapping with conventional MR at 3.0 T

2010 ◽  
Vol 20 (11) ◽  
pp. 2715-2722 ◽  
Author(s):  
Siegfried Trattnig ◽  
David Stelzeneder ◽  
Sabine Goed ◽  
Michael Reissegger ◽  
Tallal C. Mamisch ◽  
...  
Keyword(s):  
Intervertebral Disc ◽  
T2 Mapping ◽  
Lumbar Intervertebral Disc ◽  
3.0 T

scholarly journals Evaluation of Lumbar Intervertebral Disc Degeneration Using T1ρ and T2 Magnetic Resonance Imaging in a Rabbit Disc Injury Model

2018 ◽  
Vol 12 (2) ◽  
pp. 317-324 ◽  
Author(s):  
Tetsuhiro Ishikawa ◽  
Atsuya Watanabe ◽  
Hiroto Kamoda ◽  
Masayuki Miyagi ◽  
Gen Inoue ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Intervertebral Disc ◽  
T2 Mapping ◽  
Quantitative Mri ◽  
Resonance Imaging ◽  
Lumbar Intervertebral Disc ◽  
T1ρ Mapping ◽  
Grade 3 ◽  
Ivd Degeneration

<sec><title>Study Design</title><p>An <italic>in vivo</italic> histologic and magnetic resonance imaging (MRI) study of lumbar intervertebral disc (IVD) degeneration was conducted.</p></sec><sec><title>Purpose</title><p>To clarify the sensitivity and efficacy of T1ρ/T2 mapping for IVD degeneration, the correlation between T1ρ/T2 mapping and degenerative grades and histological findings in the lumbar IVD were investigated.</p></sec><sec><title>Overview of Literature</title><p>The early signs of IVD degeneration are proteoglycan loss, dehydration, and collagen degradation. Recently, several quantitative MRI techniques have been developed; T2 mapping can be used to evaluate hydration and collagen fiber integrity within cartilaginous tissue, and T1ρ mapping can be used to evaluate hydration and proteoglycan content.</p></sec><sec><title>Methods</title><p>Using New Zealand White rabbits, annular punctures of the IVD were made 10 times at L2/3, 5 times at L3/4, and one time at L4/5 using an 18-gauge needle (n=6) or a 21-gauge needle (n=6). At 4 and 8 weeks post-surgery, MRI was performed including T1ρ and T2 mapping. The degree of IVD degeneration was macroscopically assessed using the Thompson grading system. All specimens were cut for hematoxylin and eosin, safranin-O, and toluidine blue staining.</p></sec><sec><title>Results</title><p>Disc degeneration became more severe as the number of punctures increased and when the larger needle was used. T1ρ and T2 values were significantly different between grade 1 and grade 3 IVDs, grade 1 and grade 4 IVDs, grade 2 and grade 3 IVDs, and grade 2 and grade 4 IVDs (<italic>p</italic>&lt;0.05). There was a significant difference between grade 1 and grade 2 IVDs only in terms of T1ρ values (<italic>p</italic>&lt;0.05).</p></sec><sec><title>Conclusions</title><p>T1ρ and T2 quantitative MRI could detect these small differences. Our results suggest that T1ρ and T2 mapping are sensitive to degenerative changes of lumbar IVDs and that T1ρ mapping can be used as a clinical tool to identify early IVD degeneration.</p></sec>

scholarly journals NAIAD-2020: Characteristics of Motor Evoked Potentials After 3-Day Exposure to Dry Immersion in Women

2021 ◽  
Vol 15 ◽  
Author(s):  
Inna Nosikova ◽  
Alexandra Riabova ◽  
Liubov Amirova ◽  
Vladimir Kitov ◽  
Elena Tomilovskaya
Keyword(s):  
Menstrual Cycle ◽  
Evoked Potentials ◽  
Motor Evoked Potentials ◽  
Recovery Period ◽  
Microgravity Environment ◽  
Conduction Time ◽  
Gravitational Unloading ◽  
Dry Immersion ◽  
Small Group Size ◽  
Underlying Mechanisms

As female astronauts participate in space flight more and more frequently, there is a demand for research on how the female body adapts to the microgravity environment. In particular, there is very little research on how the neuromuscular system reacts to gravitational unloading in women. We aimed to estimate changes in motor evoked potentials (MEPs) in the lower leg muscles in women after 3-day exposure to Dry Immersion (DI), which is one of the most widely used ground models of microgravity. Six healthy female volunteers (mean age 30.17 ± 5.5 years) with a natural menstrual cycle participated in this experiment. MEPs were recorded from the gastrocnemius and soleus muscles twice before DI, on the day of DI completion, and 3 days after DI, during the recovery period. To evoke motor responses, transcranial and trans-spinal magnetic stimulation was applied. We showed that changes in MEP characteristics after DI exposure were different depending on the stimulation site, but were similar for both muscles. For trans-spinal stimulation, MEP thresholds decreased compared to baseline values, and amplitudes, on the contrary, increased, resembling the phenomenon of hypogravitational hyperreflexia. This finding is in line with data observed in other experiments on both male and female participants. MEPs to transcranial stimulation had an opposing dynamic, which may have resulted from the small group size and large inter-subject variability, or from hormonal fluctuations during the menstrual cycle. Central motor conduction time remained unchanged, suggesting that pyramidal tract conductibility was not affected by DI exposure. More research is needed to explore the underlying mechanisms.

scholarly journals Cranially migrated lumbar intervertebral disc herniations: A multicenter analysis with long-term outcome

2019 ◽  
Vol 10 (1) ◽  
pp. 57
Author(s):  
Sait Ozturk ◽  
Hakan Cakin ◽  
Fatih Demir ◽  
Serdal Albayrak ◽  
Bekir Akgun ◽  
...  
Keyword(s):  
Intervertebral Disc ◽  
Term Outcome ◽  
Lumbar Intervertebral Disc ◽  
Long Term Outcome ◽  
Disc Herniations ◽  
Multicenter Analysis

scholarly journals Intervertebral Disc Swelling Demonstrated by 3D and Water Content Magnetic Resonance Analyses after a 3-Day Dry Immersion Simulating Microgravity

2016 ◽  
Vol 7 ◽  
Author(s):  
Loïc Treffel ◽  
Karen Mkhitaryan ◽  
Stéphane Gellee ◽  
Guillemette Gauquelin-Koch ◽  
Claude Gharib ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Intervertebral Disc ◽  
Water Content ◽  
Dry Immersion

Effect of Annular Micro Tear on Lumbar Intervertebral Disc Biomechanics

2010 ◽  
Author(s):  
Raghu N. Natarajan ◽  
Mohammed Qasim ◽  
Howard An ◽  
Gunnar B. J. Andersson
Keyword(s):  
Intervertebral Disc ◽  
Tissue Structure ◽  
Age Group ◽  
Human Cadaver ◽  
Lumbar Intervertebral Disc ◽  
Structural Alterations ◽  
Disc Herniations ◽  
Probability Of Presence ◽  
Cadaver Studies ◽  
Annular Tear

Structural alterations of the disc are accompanied by changes in disc tissue structure and composition during degeneration processes. Human cadaver studies have shown that the probability of presence of annular tear is 0.6 in the age group 30 to 34 which increases to 0.85 in the 60 year age group. Among different phenomena that occur during disc degeneration, annular radial tears are commonly associated with disc herniations. The effect of increase in size of radial micro tear in the lumbar discs on the change in biomechanics of the disc is an area where there is very little information currently in the literature.

Sign in / Sign up

Export Citation Format

Share Document