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Michael R. Ruggieri - One of the best experts on this subject based on the ideXlab platform.
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Acute bladder decentralization in hound dogs: Preliminary results of effects on hypogastric nerve electroneurograms and detrusor pressure responses to Spinal Root and hypogastric nerve stimulation
2019Co-Authors: Ekta Tiwari, Danielle M. Salvadeo, Luke V. Musser, Matthew W. Wood, Alan S. Braverman, Mary F. Barbe, Michael Mazzei, Michel A. Lemay, Zdenka J. Delalic, Michael R. RuggieriAbstract:ObjectiveWe aimed to refine electroneurogram techniques for monitoring hypogastric nerve activity during bladder filling, and then examined nerve activity in normal intact versus acutely decentralized bladders.MethodsEffects of electrical stimulation of hypogastric nerves or lumbar ventral Roots on detrusor pressure were examined, as were effects of isoflurane versus propofol anesthetics on hypogastric nerve stimulation evoked pressure. Hypogastric nerve activity was then recorded using custom-made bipolar cuff electrodes during bladder filling before and after its transection between the Spinal cord and electrode to eliminate efferent nerve signals.ResultsElectrical stimulation of hypogastric nerves evoked low amplitude detrusor pressures that did not differ between the two anesthetics. Upper lumbar (L2) ventral Root stimulation evoked detrusor pressures were suppressed, yet not eliminated, after transection of hypogastric nerves and all Spinal Roots below L5. Afferent and efferent hypogastric nerve activity did not change with bladder filling in neuronally intact bladders yet decreased in decentralized bladders. No change in afferent activity was observed during bladder filling in either intact or decentralized bladders.ConclusionsThese findings indicate that a more complete decentralized bladder model should include transection of lumbosacral Spinal Roots innervating the bladder as well as hypogastric nerves. These refined electroneurogram recording methods may be suitable for evaluating the effectiveness of nerve transfer surgeries for bladder reinnervation by monitoring sensory activity in the transferred nerve.
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determining integrity of bladder innervation and smooth muscle function 1 year after lower Spinal Root transection in canines
Neurourology and Urodynamics, 2018Co-Authors: Danielle M. Salvadeo, Ekta Tiwari, Alan S. Braverman, Mary F. Barbe, Michael Mazzei, Nagat Frara, Justin C Brown, Michael R. RuggieriAbstract:Aims To assess bladder smooth muscle function and innervation after long-term lower Spinal Root transection in canines. Methods Thirteen female mixed-breed hound dogs underwent bladder decentralization, which included transection of all sacral dorsal and ventral Roots caudal to L7 and hypogastric nerves, bilaterally (n = 3); all sacral Roots and hypogastric nerves plus transection of L7 dorsal Roots, bilaterally (n = 4); or a sham operation (n = 6). At a year after initial surgery, bladder function was assessed in vivo by stimulation of the pelvic plexus. The bladder tissue was harvested for ex vivo smooth muscle contractility studies. Remaining bladder was evaluated for nerve morphology immunohistochemically using neuronal marker PGP9.5, apoptotic activity using terminal deoxynucleotidyl transferase dUTP nick end labeling, and histopathology using a hematoxylin and eosin stain. Results Sacral Root decentralization did not reduce maximum strength of pelvic plexus stimulation-induced bladder contraction, although long-term sacral dorsal and ventral Root plus L7 dorsal Root transection significantly decreased contraction strength. Electric field stimulation-induced contractions of the detrusor from all decentralized animals were preserved, compared to controls. Viable nerves and intramural ganglia were visualized in the bladder wall, regardless of group. There was no difference in amount of apoptosis in bladder smooth muscle between groups. Conclusion Bladder smooth muscle cells maintain their function after long-term bladder decentralization. While pelvic plexus-induced bladder contractions were less robust at 1 year after lower Spinal Root transection, the absence of atrophy and preservation of at least some nerve activity may allow for successful surgical reinnervation after long-term injury.
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neuromuscular nicotinic receptors mediate bladder contractions following bladder reinnervation with somatic to autonomic nerve transfer after decentralization by Spinal Root transection
The Journal of Urology, 2015Co-Authors: Sandra M Gomezamaya, Alan S. Braverman, Mary F. Barbe, Justin C Brown, Neil S. Lamarre, Michael R. RuggieriAbstract:Purpose: We investigated whether the reinnervated neuronal pathway mediates contraction via the same neurotransmitter and receptor mechanisms as the original pathway.Materials and Methods: After decentralizing the bladder by transecting the sacral Roots in dogs we performed peripheral nerve transfer, including bilateral genitofemoral to pelvic nerve transfer and unilateral left femoral nerve to bilateral pelvic nerve transfer. Reinnervation was assessed 7.5 months postoperatively by monitoring bladder pressure during electrical stimulation of the transferred nerves, Spinal ventral Roots and Spinal cord.Results: Of the 17 dogs with genitofemoral to pelvic nerve transfer 14 (82%) demonstrated functional bladder reinnervation as evidenced by increased bladder pressure during stimulation of the transferred genitofemoral nerve, or L3 or L4 Spinal ventral Roots. Lumbar Spinal cord stimulation caused increased bladder pressure in 9 of 10 dogs (90%) with unilateral left femoral nerve to bilateral pelvic nerve tra...
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neural reconstruction methods of restoring bladder function
Nature Reviews Urology, 2015Co-Authors: Sandra M Gomezamaya, Alan S. Braverman, Mary F. Barbe, Justin C Brown, William C De Groat, Gerald F Tuite, Jacques Corcos, Susan B Fecho, Michael R. RuggieriAbstract:During the past century, diverse surgical techniques to restore function of a decentralized bladder after Spinal cord or Spinal Root injury have been investigated. Gomez-Amaya et al. describe the tested nerve transfer strategies, discuss their strengths and limitations and indicate appropriate patient populations for each procedure.
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neural reconstruction methods of restoring bladder function a critical review
Nerves and Nerve Injuries#R##N#Vol 2: Pain Treatment Injury Disease and Future Directions, 2015Co-Authors: Sandra M Gomezamaya, Mary F. Barbe, Michael R. Ruggieri, Justin C Brown, William C De Groat, Gerald F Tuite, Jacques Corcos, Susan B FechoAbstract:During the last century, diverse studies have focused on the development of surgical strategies for restoration of function of a decentralized bladder after Spinal cord or Spinal Root injury via repair of the original Roots or by transferring in new axon sources. These techniques have included end-to-end sacral Root repairs, transfer of Roots from other segments to sacral Roots, transfer of intercostal nerves to sacral Roots, transfer of various somatic nerves to the pelvic or pudendal nerve, direct neurotization of the detrusor muscle, and creation of an artificial “skin-CNS-bladder” reflex pathway. We have comprehensively reviewed these surgical techniques, the strengths and limitations of each, and have discussed the most appropriate patient population for each procedure. Our purpose is to critically assess the potential efficacy of nerve transfer techniques as options for restoring urinary function after bladder decentralization.
Shin'ichi Takeda - One of the best experts on this subject based on the ideXlab platform.
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schwann cell myelination occurred without basal lamina formation in laminin alpha2 chain null mutant dy3k dy3k mice
Glia, 2001Co-Authors: Masahiro Nakagawa, Ikuya Nonaka, Koji Ikezoe, Yuhei Miyata, Kiyonori Harii, Yuko Miyagoesuzuki, Shin'ichi TakedaAbstract:The laminin α2 chain is a major component of basal lamina in both skeletal muscle and the peripheral nervous system. Laminin α2 chain deficiency causes merosin-deficient congenital muscular dystrophy, which affects not only skeletal muscles, but also the peripheral and central nervous systems. It has been reported that the formation of basal lamina is required for myelination in the peripheral nervous system. In fact, the Spinal Root of dystrophic mice (dy/dy mice), whose laminin α2 chain expression is greatly reduced, shows lack of basal lamina and clusters of naked axons. To investigate the role of laminin α2 chain and basal lamina in vivo, we examined the peripheral nervous system of dy3K/dy3Kmice, which are null mutants of laminin α2 chain. The results indicate the presence of myelination although Schwann cells lacked basal lamina in the Spinal Roots of dy3K/dy3K mice, suggesting that basal lamina is not an absolute requirement for myelination in vivo. Immunohistochemically, the expression of laminin α4 chain was increased and laminin α5 chain was preserved in the endoneurium of the Spinal Root. Laminin α4 and α5 chains may play the critical role in myelination instead of laminin α2 chain in dy3K/dy3Kmice. In addition, the motor conduction velocity of the sciatic nerve was significantly reduced compared with that of wild-type littermate. This reduction in conduction velocity may be due to small axon diameter, thin myelin sheath and the patchy disruption of the basal lamina of the nodes of Ranvier in dy3K/dy3Kmice. GLIA 35:101–110, 2001. © 2001 Wiley-Liss, Inc.
P Anand - One of the best experts on this subject based on the ideXlab platform.
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restoration of sensory function and lack of long term chronic pain syndromes after brachial plexus injury in human neonates
Brain, 2002Co-Authors: P Anand, R BirchAbstract:Obstetric complications are a common cause of brachial plexus injuries in neonates. Failure to restore sensation leads to trophic injuries and poor limb function. It is not known whether the infant suffers chronic neuropathic or Spinal cord Root avulsion pain; in adults, chronic pain is usual after Spinal Root avulsion injuries, and this is often intractable. The plexus is repaired surgically in severe neonatal injures; if no spontaneous recovery has occurred by 3 months, and if neurophysiological investigations point to poor prognosis, then nerve trunk injures are grafted, while Spinal cord Root avulsion injuries are treated by transferring an intact neighbouring nerve (e.g. intercostal) to the distal stump of the damaged nerve, in an attempt to restore sensorimotor function. Using a range of non-invasive quantitative measures validated in adults, including mechanical, thermal and vibration perception thresholds, we have assessed for the first time sensory and cholinergic sympathetic function in 24 patients aged between 3 and 23 years, who had suffered severe brachial plexus injury at birth. While recovery of function after Spinal Root avulsion was related demonstrably to surgery, there were remarkable differences from adults, including excellent restoration of sensory function (to normal limits in all dermatomes for at least one modality in 16 out of 20 operated cases), and evidence of exquisite CNS plasticity, i.e. perfect localization of restored sensation in avulsed Spinal Root dermatomes, now presumably routed via nerves that had been transferred from a distant Spinal region. Sensory recovery exceeded motor or cholinergic sympathetic recovery. There was no evidence of chronic pain behaviour or neuropathic syndromes, although pain was reported normally to external stimuli in unaffected regions. We propose that differences in neonates are related to later maturation of injured fibres, and that CNS plasticity may account for their lack of long-term chronic pain after Spinal Root avulsion injury.
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Spinal nerve Root repair and reimplantation of avulsed ventral Roots into the Spinal cord after brachial plexus injury
Journal of Neurosurgery, 2000Co-Authors: Thomas Carlstedt, P Anand, Rolf G Hallin, Peter Misra, Georg Noren, Thanos SeferlisAbstract:Object. The authors review the first series of 10 cases in which injured intraSpinal brachial plexus were surgically repaired. They describe the technique of Spinal cord implantation or repair of ruptured nerve Roots, as well as patient outcome. Methods. Spinal Root repair/implantation was performed from 10 days to 9 months postinjury. There were nine male patients and one female patient. Postoperatively in most cases, regeneration of motor neurons from the Spinal cord to denervated muscles could be demonstrated. The first signs of regeneration were noted approximately 9 to 12 months postoperatively. Useful function with muscle power of at least Medical Research Council Grade 3 occurred in three of 10 cases. Magnetic brain stimulation studies revealed a normal amplitude and latency from the cortex to reinnervated muscles on surgically treated and control sides. A certain degree of cocontraction between antagonistic muscles (for example, biceps—triceps) compromised function. With time there was a reduction...
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pain following human brachial plexus injury with Spinal cord Root avulsion and the effect of surgery
Pain, 1998Co-Authors: Jonathan S Berman, R Birch, P AnandAbstract:Brachial plexus injury leading to Spinal cord Root avulsion in humans produces a characteristic constant crushing and intermittent shooting pain, which is often intractable. Preliminary observations suggested that this pain might be alleviated after successful nerve transfers to restore limb function. We therefore studied a group of 14 patients prospectively, to establish the validity of this observation, and to elucidate the underlying mechanisms. We found a strong correlation and temporal relationship between reduction in pain and successful nerve repair. All five patients with motor recovery experienced significant relief of de-afferentation pain, while in the seven patients with persistent pain, none had motor recovery. There was no correlation between pain relief and the minimal recovery of sensation in some cases, and no case had any return of sensory or sympathetic cutaneous axon-reflexes. While skin sympathetic axon-reflexes were reduced with T1 Root lesions, there was no relationship between T1 Root damage and pain. It was concluded that nerve repair can reduce pain from Spinal Root avulsions and that the mechanism may involve successful regeneration, and/or restoration of peripheral connections prior to their function, possibly in muscle.
Mary F. Barbe - One of the best experts on this subject based on the ideXlab platform.
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Acute bladder decentralization in hound dogs: Preliminary results of effects on hypogastric nerve electroneurograms and detrusor pressure responses to Spinal Root and hypogastric nerve stimulation
2019Co-Authors: Ekta Tiwari, Danielle M. Salvadeo, Luke V. Musser, Matthew W. Wood, Alan S. Braverman, Mary F. Barbe, Michael Mazzei, Michel A. Lemay, Zdenka J. Delalic, Michael R. RuggieriAbstract:ObjectiveWe aimed to refine electroneurogram techniques for monitoring hypogastric nerve activity during bladder filling, and then examined nerve activity in normal intact versus acutely decentralized bladders.MethodsEffects of electrical stimulation of hypogastric nerves or lumbar ventral Roots on detrusor pressure were examined, as were effects of isoflurane versus propofol anesthetics on hypogastric nerve stimulation evoked pressure. Hypogastric nerve activity was then recorded using custom-made bipolar cuff electrodes during bladder filling before and after its transection between the Spinal cord and electrode to eliminate efferent nerve signals.ResultsElectrical stimulation of hypogastric nerves evoked low amplitude detrusor pressures that did not differ between the two anesthetics. Upper lumbar (L2) ventral Root stimulation evoked detrusor pressures were suppressed, yet not eliminated, after transection of hypogastric nerves and all Spinal Roots below L5. Afferent and efferent hypogastric nerve activity did not change with bladder filling in neuronally intact bladders yet decreased in decentralized bladders. No change in afferent activity was observed during bladder filling in either intact or decentralized bladders.ConclusionsThese findings indicate that a more complete decentralized bladder model should include transection of lumbosacral Spinal Roots innervating the bladder as well as hypogastric nerves. These refined electroneurogram recording methods may be suitable for evaluating the effectiveness of nerve transfer surgeries for bladder reinnervation by monitoring sensory activity in the transferred nerve.
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determining integrity of bladder innervation and smooth muscle function 1 year after lower Spinal Root transection in canines
Neurourology and Urodynamics, 2018Co-Authors: Danielle M. Salvadeo, Ekta Tiwari, Alan S. Braverman, Mary F. Barbe, Michael Mazzei, Nagat Frara, Justin C Brown, Michael R. RuggieriAbstract:Aims To assess bladder smooth muscle function and innervation after long-term lower Spinal Root transection in canines. Methods Thirteen female mixed-breed hound dogs underwent bladder decentralization, which included transection of all sacral dorsal and ventral Roots caudal to L7 and hypogastric nerves, bilaterally (n = 3); all sacral Roots and hypogastric nerves plus transection of L7 dorsal Roots, bilaterally (n = 4); or a sham operation (n = 6). At a year after initial surgery, bladder function was assessed in vivo by stimulation of the pelvic plexus. The bladder tissue was harvested for ex vivo smooth muscle contractility studies. Remaining bladder was evaluated for nerve morphology immunohistochemically using neuronal marker PGP9.5, apoptotic activity using terminal deoxynucleotidyl transferase dUTP nick end labeling, and histopathology using a hematoxylin and eosin stain. Results Sacral Root decentralization did not reduce maximum strength of pelvic plexus stimulation-induced bladder contraction, although long-term sacral dorsal and ventral Root plus L7 dorsal Root transection significantly decreased contraction strength. Electric field stimulation-induced contractions of the detrusor from all decentralized animals were preserved, compared to controls. Viable nerves and intramural ganglia were visualized in the bladder wall, regardless of group. There was no difference in amount of apoptosis in bladder smooth muscle between groups. Conclusion Bladder smooth muscle cells maintain their function after long-term bladder decentralization. While pelvic plexus-induced bladder contractions were less robust at 1 year after lower Spinal Root transection, the absence of atrophy and preservation of at least some nerve activity may allow for successful surgical reinnervation after long-term injury.
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neuromuscular nicotinic receptors mediate bladder contractions following bladder reinnervation with somatic to autonomic nerve transfer after decentralization by Spinal Root transection
The Journal of Urology, 2015Co-Authors: Sandra M Gomezamaya, Alan S. Braverman, Mary F. Barbe, Justin C Brown, Neil S. Lamarre, Michael R. RuggieriAbstract:Purpose: We investigated whether the reinnervated neuronal pathway mediates contraction via the same neurotransmitter and receptor mechanisms as the original pathway.Materials and Methods: After decentralizing the bladder by transecting the sacral Roots in dogs we performed peripheral nerve transfer, including bilateral genitofemoral to pelvic nerve transfer and unilateral left femoral nerve to bilateral pelvic nerve transfer. Reinnervation was assessed 7.5 months postoperatively by monitoring bladder pressure during electrical stimulation of the transferred nerves, Spinal ventral Roots and Spinal cord.Results: Of the 17 dogs with genitofemoral to pelvic nerve transfer 14 (82%) demonstrated functional bladder reinnervation as evidenced by increased bladder pressure during stimulation of the transferred genitofemoral nerve, or L3 or L4 Spinal ventral Roots. Lumbar Spinal cord stimulation caused increased bladder pressure in 9 of 10 dogs (90%) with unilateral left femoral nerve to bilateral pelvic nerve tra...
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neural reconstruction methods of restoring bladder function
Nature Reviews Urology, 2015Co-Authors: Sandra M Gomezamaya, Alan S. Braverman, Mary F. Barbe, Justin C Brown, William C De Groat, Gerald F Tuite, Jacques Corcos, Susan B Fecho, Michael R. RuggieriAbstract:During the past century, diverse surgical techniques to restore function of a decentralized bladder after Spinal cord or Spinal Root injury have been investigated. Gomez-Amaya et al. describe the tested nerve transfer strategies, discuss their strengths and limitations and indicate appropriate patient populations for each procedure.
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neural reconstruction methods of restoring bladder function a critical review
Nerves and Nerve Injuries#R##N#Vol 2: Pain Treatment Injury Disease and Future Directions, 2015Co-Authors: Sandra M Gomezamaya, Mary F. Barbe, Michael R. Ruggieri, Justin C Brown, William C De Groat, Gerald F Tuite, Jacques Corcos, Susan B FechoAbstract:During the last century, diverse studies have focused on the development of surgical strategies for restoration of function of a decentralized bladder after Spinal cord or Spinal Root injury via repair of the original Roots or by transferring in new axon sources. These techniques have included end-to-end sacral Root repairs, transfer of Roots from other segments to sacral Roots, transfer of intercostal nerves to sacral Roots, transfer of various somatic nerves to the pelvic or pudendal nerve, direct neurotization of the detrusor muscle, and creation of an artificial “skin-CNS-bladder” reflex pathway. We have comprehensively reviewed these surgical techniques, the strengths and limitations of each, and have discussed the most appropriate patient population for each procedure. Our purpose is to critically assess the potential efficacy of nerve transfer techniques as options for restoring urinary function after bladder decentralization.
Joost Verhaagen - One of the best experts on this subject based on the ideXlab platform.
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Clinical and neurobiological advances in promoting regeneration of the ventral Root avulsion lesion.
The European journal of neuroscience, 2015Co-Authors: Ruben Eggers, Martijn R. Tannemaat, Fred De Winter, Martijn J. A. Malessy, Joost VerhaagenAbstract:Root avulsions due to traction to the brachial plexus causes complete and permanent loss of function. Until fairly recent, such lesions were considered impossible to repair. Here we review clinical repair strategies and current progress in experimental ventral Root avulsion lesions. The current gold standard in patients with a Root avulsion is nerve transfer, whereas reimplantation of the avulsed Root into the Spinal cord has been performed in a limited number of cases. These neurosurgical repair strategies have significant benefit for the patient but functional recovery remains incomplete. Developing new ways to improve the functional outcome of neurosurgical repair is therefore essential. In the laboratory, the molecular and cellular changes following ventral Root avulsion and the efficacy of intervention strategies have been studied at the level of Spinal motoneurons, the ventral Spinal Root and peripheral nerve, and the skeletal muscle. We present an overview of cell-based pharmacological and neurotrophic factor treatment approaches that have been applied in combination with surgical reimplantation. These interventions all demonstrate neuroprotective effects on avulsed motoneurons, often accompanied with various degrees of axonal regeneration. However, effects on survival are usually transient and robust axon regeneration over long distances has as yet not been achieved. Key future areas of research include finding ways to further extend the post-lesion survival period of motoneurons, the identification of neuron-intrinsic factors which can promote persistent and long-distance axon regeneration, and finally prolonging the pro-regenerative state of Schwann cells in the distal nerve.
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nt 3 delivered by an adenoviral vector induces injured dorsal Root axons to regenerate into the Spinal cord of adult rats
Journal of Neuroscience Research, 1998Co-Authors: Yi Zhang, Paul A Dijkhuizen, P N Anderson, Robert A Lieberman, Joost VerhaagenAbstract:Sensory axons interrupted in the dorsal Roots of adult mammals are normally unable to regenerate into the Spinal cord. We have investigated whether the introduction of a neurotrophin gene into the Spinal cord might offer an approach to otherwise intractable Spinal Root injuries. The dorsal Roots of the 4th, 5th, and 6th lumbar Spinal nerves of adult rats were severed and reanastomosed. Fourteen to nineteen days later, adenoviral vectors containing either the LacZ or NT-3 genes were injected into the ventral horn of the lumbar Spinal cord, resulting in strong expression of the transgenes in glial cells and motor neurons between 4 and 40 days after injection. When dorsal Root axons were transganglionically labelled with HRP conjugated to cholera toxin subunit B, 16 to 37 days after dorsal Root injury, large numbers of labelled axons could be seen to have regenerated into the cord, but only in those animals injected with vector carrying the NT-3 gene. The regenerated axons were found at the injection site, mainly in the grey matter, and had penetrated as deep as lamina V. Gene therapy with adenoviral vectors encoding a neurotrophin has therefore been shown to be capable of enhancing and directing the regeneration of a subpopulation of dorsal Root axons (probably myelinated A fibres), into and through the CNS environment.