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Barz S, Friedemann M, Voigt S, Melloh M, Barz T. Epidural pressure measurement using a fiber-optic sensor (proof-of-principle in vivo animal trial). Animal Model Exp Med 2024. [PMID: 38981680 DOI: 10.1002/ame2.12469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2024] [Accepted: 06/14/2024] [Indexed: 07/11/2024] Open
Abstract
BACKGROUND An increase in epidural pressure around the stenosis has been observed in patients with lumbar spinal stenosis (LSS) with positive signs of sedimentation or redundant nerve roots. Further analysis of the pressure conditions in the stenotic area would be of great interest. We hypothesized that it would be possible to determine the physiological parameters of the epidural pulse wave and its course in pathological stenosis as a basis for objective identification of LSS based on pressure using a new measuring method with continuous spatial and temporal resolution. METHODS We performed a single-case proof-of-principle in vivo animal trial and used a newly developed hybrid pressure-measurement probe with a fiber-tip Fabry-Pérot interferometer and several fiber Bragg gratings (FBG). RESULTS With reproducible precision, we determined the mean epidural pressure to be 7.5 mmHg and the peak-to-peak value to be 4-5 mmHg. When analyzing the pressure measured by an FBG array, both the heart and respiratory rates can be precisely determined. This study was the first to measure the pulse wave velocity of the cerebrospinal fluid pressure wave as 0.97 m/s using the newly developed pressure probe. A simulated LSS was detected in real time and located exactly. CONCLUSIONS The developed fiber-optic pressure sensor probe enables a new objective measurement of epidural pressure. We confirmed our hypothesis that physiological parameters of the epidural pulse wave can be determined and that it is possible to identify an LSS.
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Affiliation(s)
- Susanne Barz
- Department of Anaesthesiology, Intensive Care Medicine and Pain Therapy, Rostock University Medical Center, Universitätsmedizin Rostock, Rostock, Germany
| | | | | | - Markus Melloh
- School of Public Health and Social Work, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Thomas Barz
- Orthopedic Department, University of Greifswald, Greifswald, Germany
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Bessen MA, Gayen CD, Quarrington RD, Walls AC, Leonard AV, Kurtcuoglu V, Jones CF. Characterising spinal cerebrospinal fluid flow in the pig with phase-contrast magnetic resonance imaging. Fluids Barriers CNS 2023; 20:5. [PMID: 36653870 PMCID: PMC9850564 DOI: 10.1186/s12987-022-00401-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 12/13/2022] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Detecting changes in pulsatile cerebrospinal fluid (CSF) flow may assist clinical management decisions, but spinal CSF flow is relatively understudied. Traumatic spinal cord injuries (SCI) often cause spinal cord swelling and subarachnoid space (SAS) obstruction, potentially causing pulsatile CSF flow changes. Pigs are emerging as a favoured large animal SCI model; therefore, the aim of this study was to characterise CSF flow along the healthy pig spine. METHODS Phase-contrast magnetic resonance images (PC-MRI), retrospectively cardiac gated, were acquired for fourteen laterally recumbent, anaesthetised and ventilated, female domestic pigs (22-29 kg). Axial images were obtained at C2/C3, T8/T9, T11/T12 and L1/L2. Dorsal and ventral SAS regions of interest (ROI) were manually segmented. CSF flow and velocity were determined throughout a cardiac cycle. Linear mixed-effects models, with post-hoc comparisons, were used to identify differences in peak systolic/diastolic flow, and maximum velocity (cranial/caudal), across spinal levels and dorsal/ventral SAS. Velocity wave speed from C2/C3 to L1/L2 was calculated. RESULTS PC-MRI data were obtained for 11/14 animals. Pulsatile CSF flow was observed at all spinal levels. Peak systolic flow was greater at C2/C3 (dorsal: - 0.32 ± 0.14 mL/s, ventral: - 0.15 ± 0.13 mL/s) than T8/T9 dorsally (- 0.04 ± 0.03 mL/s; p < 0.001), but not different ventrally (- 0.08 ± 0.08 mL/s; p = 0.275), and no difference between thoracolumbar levels (p > 0.05). Peak diastolic flow was greater at C2/C3 (0.29 ± 0.08 mL/s) compared to T8/T9 (0.03 ± 0.03 mL/s, p < 0.001) dorsally, but not different ventrally (p = 1.000). Cranial and caudal maximum velocity at C2/C3 were greater than thoracolumbar levels dorsally (p < 0.001), and T8/T9 and L1/L2 ventrally (p = 0.022). Diastolic velocity wave speed was 1.41 ± 0.39 m/s dorsally and 1.22 ± 0.21 m/s ventrally, and systolic velocity wave speed was 1.02 ± 0.25 m/s dorsally and 0.91 ± 0.22 m/s ventrally. CONCLUSIONS In anaesthetised and ventilated domestic pigs, spinal CSF has lower pulsatile flow and slower velocity wave propagation, compared to humans. This study provides baseline CSF flow at spinal levels relevant for future SCI research in this animal model.
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Affiliation(s)
- Madeleine Amy Bessen
- grid.1010.00000 0004 1936 7304Adelaide Spinal Research Group and Centre for Orthopaedics and Trauma Research, Adelaide Medical School, The University of Adelaide, Level 7, Adelaide Health and Medical Sciences Building, The University of Adelaide, North Terrace, Adelaide, SA 5005 Australia
| | - Christine Diana Gayen
- grid.1010.00000 0004 1936 7304Adelaide Spinal Research Group and Centre for Orthopaedics and Trauma Research, Adelaide Medical School, The University of Adelaide, Level 7, Adelaide Health and Medical Sciences Building, The University of Adelaide, North Terrace, Adelaide, SA 5005 Australia ,grid.1010.00000 0004 1936 7304Translational Neuropathology Laboratory, School of Biomedicine, The University of Adelaide, Level 2, Helen Mayo North Building, The University of Adelaide, Frome Road, Adelaide, SA 5005 Australia
| | - Ryan David Quarrington
- grid.1010.00000 0004 1936 7304Adelaide Spinal Research Group and Centre for Orthopaedics and Trauma Research, Adelaide Medical School, The University of Adelaide, Level 7, Adelaide Health and Medical Sciences Building, The University of Adelaide, North Terrace, Adelaide, SA 5005 Australia ,grid.1010.00000 0004 1936 7304School of Electrical and Mechanical Engineering, The University of Adelaide, North Terrace, Adelaide, SA 5005 Australia
| | - Angela Catherine Walls
- grid.430453.50000 0004 0565 2606Clinical and Research Imaging Centre, South Australian Health and Medical Research Institute, National Imaging Facility, Northern Pod, SAHMRI, North Terrace, Adelaide, SA 5000 Australia
| | - Anna Victoria Leonard
- grid.1010.00000 0004 1936 7304Translational Neuropathology Laboratory, School of Biomedicine, The University of Adelaide, Level 2, Helen Mayo North Building, The University of Adelaide, Frome Road, Adelaide, SA 5005 Australia
| | - Vartan Kurtcuoglu
- grid.7400.30000 0004 1937 0650Institute of Physiology, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland ,grid.7400.30000 0004 1937 0650Zurich Center for Integrative Human Physiology, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland ,grid.7400.30000 0004 1937 0650Neuroscience Center Zurich, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Claire Frances Jones
- grid.1010.00000 0004 1936 7304Adelaide Spinal Research Group and Centre for Orthopaedics and Trauma Research, Adelaide Medical School, The University of Adelaide, Level 7, Adelaide Health and Medical Sciences Building, The University of Adelaide, North Terrace, Adelaide, SA 5005 Australia ,grid.1010.00000 0004 1936 7304School of Electrical and Mechanical Engineering, The University of Adelaide, North Terrace, Adelaide, SA 5005 Australia ,grid.416075.10000 0004 0367 1221Department of Orthopaedics, Royal Adelaide Hospital, Adelaide, SA 5000 Australia
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The Water Transport System in Astrocytes–Aquaporins. Cells 2022; 11:cells11162564. [PMID: 36010640 PMCID: PMC9406552 DOI: 10.3390/cells11162564] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 07/26/2022] [Accepted: 08/08/2022] [Indexed: 11/16/2022] Open
Abstract
Highlights (AQPs) are transmembrane proteins responsible for fast water movement across cell membranes, including those of astrocytes. The expression and subcellular localization of AQPs in astrocytes are highly dynamic under physiological and pathological conditions. Besides their primary function in water homeostasis, AQPs participate in many ancillary functions including glutamate clearance in tripartite synapses and cell migration.
Abstract Astrocytes have distinctive morphological and functional characteristics, and are found throughout the central nervous system. Astrocytes are now known to be far more than just housekeeping cells in the brain. Their functions include contributing to the formation of the blood–brain barrier, physically and metabolically supporting and communicating with neurons, regulating the formation and functions of synapses, and maintaining water homeostasis and the microenvironment in the brain. Aquaporins (AQPs) are transmembrane proteins responsible for fast water movement across cell membranes. Various subtypes of AQPs (AQP1, AQP3, AQP4, AQP5, AQP8 and AQP9) have been reported to be expressed in astrocytes, and the expressions and subcellular localizations of AQPs in astrocytes are highly correlated with both their physiological and pathophysiological functions. This review describes and summarizes the recent advances in our understanding of astrocytes and AQPs in regard to controlling water homeostasis in the brain. Findings regarding the features of different AQP subtypes, such as their expression, subcellular localization, physiological functions, and the pathophysiological roles of astrocytes are presented, with brain edema and glioma serving as two representative AQP-associated pathological conditions. The aim is to provide a better insight into the elaborate “water distribution” system in cells, exemplified by astrocytes, under normal and pathological conditions.
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De Andres J, Hayek S, Perruchoud C, Lawrence MM, Reina MA, De Andres-Serrano C, Rubio-Haro R, Hunt M, Yaksh TL. Intrathecal Drug Delivery: Advances and Applications in the Management of Chronic Pain Patient. FRONTIERS IN PAIN RESEARCH 2022; 3:900566. [PMID: 35782225 PMCID: PMC9246706 DOI: 10.3389/fpain.2022.900566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Accepted: 05/02/2022] [Indexed: 11/19/2022] Open
Abstract
Advances in our understanding of the biology of spinal systems in organizing and defining the content of exteroceptive information upon which higher centers define the state of the organism and its role in the regulation of somatic and automatic output, defining the motor response of the organism, along with the unique biology and spatial organization of this space, have resulted in an increased focus on therapeutics targeted at this extracranial neuraxial space. Intrathecal (IT) drug delivery systems (IDDS) are well-established as an effective therapeutic approach to patients with chronic non-malignant or malignant pain and as a tool for management of patients with severe spasticity and to deliver therapeutics that address a myriad of spinal pathologies. The risk to benefit ratio of IDD makes it a useful interventional approach. While not without risks, this approach has a significant therapeutic safety margin when employed using drugs with a validated safety profile and by skilled practioners. The present review addresses current advances in our understanding of the biology and dynamics of the intrathecal space, therapeutic platforms, novel therapeutics, delivery technology, issues of safety and rational implementation of its therapy, with a particular emphasis upon the management of pain.
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Affiliation(s)
- Jose De Andres
- Surgical Specialties Department, Valencia University Medical School, Valencia, Spain
- Anesthesia Critical Care and Pain Management Department, Valencia, Spain
- *Correspondence: Jose De Andres
| | - Salim Hayek
- Department of Anesthesiology, University Hospitals Cleveland Medical Center, Cleveland, OH, United States
| | - Christophe Perruchoud
- Pain Center and Department of Anesthesia, La Tour Hospital, Geneva, Switzerland
- Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Melinda M. Lawrence
- Department of Anesthesiology, University Hospitals Cleveland Medical Center, Cleveland, OH, United States
| | - Miguel Angel Reina
- Department of Anesthesiology, Montepríncipe University Hospital, Madrid, Spain
- CEU-San-Pablo University School of Medicine, Madrid, Spain
- Department of Anesthesiology, University of Florida College of Medicine, Gainesville, FL, United States
- Facultad de Ciencias de la Salud Universidad Francisco de Vitoria, Madrid, Spain
| | | | - Ruben Rubio-Haro
- Anesthesia and Pain Management Department, Provincial Hospital, Castellon, Spain
- Multidisciplinary Pain Clinic, Vithas Virgen del Consuelo Hospital, Valencia, Spain
| | - Mathew Hunt
- Department of Physiology, Karolinska Institute, Stockholm, Sweden
| | - Tony L. Yaksh
- Departments of Anesthesiology and Pharmacology, University of California, San Diego, San Diego, CA, United States
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Morphometrics of the Spinal Cord and Surrounding Structures in Alligator mississippiensis. BIOLOGY 2022; 11:biology11040514. [PMID: 35453713 PMCID: PMC9024830 DOI: 10.3390/biology11040514] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 03/22/2022] [Accepted: 03/24/2022] [Indexed: 02/04/2023]
Abstract
Simple Summary Morphometric analysis of the spinal cord and surrounding tissue of the American alligator (Alligator mississippiensis) reveals that there are four significantly discrete regions; cervical, thoracic, lumbar, and caudal. Crocodylians, unlike mammals, have a caudal spinal cord that extends throughout the length of their tail (which accounts for roughly 50% of their total body length). Alligator mississippiensis has one of the largest ranges of body sizes among terrestrial vertebrates, this study documents how the different spinal structures change with increasing body size. Though most of the structures exhibit slightly positive allometry, a few exhibit slightly negative allometry; these differences mean that there are significant relational changes as hatchlings grow into large adults. This study provides the first documentation that A. mississippiensis has an expansive subdural space, a lumbar cistern, at the pelvis. Abstract Understanding the fluid dynamics of the cerebrospinal fluid requires a quantitative description of the spaces in which it flows, including the spinal cord and surrounding meninges. The morphometrics of the spinal cord and surrounding tissues were studied in specimens of the American alligator (Alligator mississippiensis) ranging from hatchlings through adults. Within any size class of alligators (i.e., hatchlings), along the axial length there are significant differences in the size of the spinal cord, meninges, and vertebral canal; these differences can be used to define discrete cervical, thoracic, lumbar and caudal regions. When compared across the range of body sizes in Alligator, every structure in each spinal region had a distinctive growth rate; thus, the physical arrangements between the structures changed as the alligator grew. The combination of regional differentiation and differential growth rates was particularly apparent in the lumbar meninges where a unique form of lumbar cistern could be identified and shown to decrease in relative size as the alligator ages. This analysis of the spinal cord and surrounding tissues was undertaken to develop a data set that could be used for computational flow dynamics of the crocodilian cerebrospinal fluid, and also to assist in the analysis of fossil archosaurs.
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Coccoluto A, Capogna G, Camorcia M, Hochman M, Velardo M. Analysis of Epidural Waveform to Determine Correct Epidural Catheter Placement After CSE Labor Analgesia. Local Reg Anesth 2021; 14:103-108. [PMID: 34168495 PMCID: PMC8216732 DOI: 10.2147/lra.s312194] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 06/09/2021] [Indexed: 11/25/2022] Open
Abstract
Background The epidural pressure is pulsatile and synchronized with arterial pulsations. Monitoring the epidural waveform has been suggested as a technique to reliably confirm the appropriate localization of the epidural catheter. Objective The aim of this study was to evaluate the sensitivity and specificity of the Computer Controlled Drug Delivery System with continuous pressure and waveform sensing technology (CCDDS) (CompuFlo® CathCheck™) as an instrument to assess the correct placement of the catheter in the epidural space in parturients who have received combined spinal-epidural technique (CSE) for labor analgesia. Methods We enrolled 40 consecutive healthy patients undergoing CSE labor analgesia with successful analgesia. All the cases in which pulsatile waveforms in synchrony with heart rate were detected were considered to be true positives; all the cases in which there was the absence of pulsatile waves were followed up. If these patients had to eventually relocate or manipulate the epidural catheter, they were considered to be true negative. If the absence of pulse waves was observed in the presence of successful analgesia during labor, the patients were considered to be false negatives. Results Pulsatile waveforms synchronous with heart rate were observed in 33 cases associated with adequate analgesia. In 5 cases, the pulsatile waveforms were absent due to unilateral analgesia or catheter occlusion (true negatives). In 2 cases, the patients had effective analgesia but we were not able to observe a distinct pulsatile waveform. The pressure waveform analysis through the epidural catheter had a sensitivity of 95%, a positive predictive value of 100%, a specificity of 100% and a negative predictive value of 60%. Conclusion Pulsatile pressure waveform recording with CCDDS through the epidural catheter resulted in high sensitivity and positive predictive value which can help the proper placement of the epidural catheter.
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Affiliation(s)
| | | | - Michela Camorcia
- Department of Anesthesiology, Città di Roma Hospital, Roma, Italy
| | | | - Matteo Velardo
- Department of Anesthesiology, Policlinico Casilino, Roma, Italy
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The Need for Head Space: Brachycephaly and Cerebrospinal Fluid Disorders. Life (Basel) 2021; 11:life11020139. [PMID: 33673129 PMCID: PMC7918167 DOI: 10.3390/life11020139] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 02/06/2021] [Accepted: 02/08/2021] [Indexed: 12/12/2022] Open
Abstract
Brachycephalic dogs remain popular, despite the knowledge that this head conformation is associated with health problems, including airway compromise, ocular disorders, neurological disease, and other co-morbidities. There is increasing evidence that brachycephaly disrupts cerebrospinal fluid movement and absorption, predisposing ventriculomegaly, hydrocephalus, quadrigeminal cistern expansion, Chiari-like malformation, and syringomyelia. In this review, we focus on cerebrospinal fluid physiology and how this is impacted by brachycephaly, airorhynchy, and associated craniosynostosis.
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