Diss. (sammanfattning) Stockholm : Karolinska institutet, 2009. / Härtill 5 uppsatser.

Thesis (Ph. D.)--University of Washington, 2002. / Vita. Includes bibliographical references (leaves 120-128).

Source: Masters Abstracts International, Volume: 47-06, page: 3500. Adviser: Lu-Yu Hwang. Includes bibliographical references.

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Σκοπός: Πρόκειται για μια προοπτική μελέτη που αφορά στη χειρουργική θεραπεία ασθενών που έπασχαν από εκφυλιστική σπονδυλική στένωση της ΟΜΣΣ σε πολλαπλά επίπεδα (δύο ή περισσότερα). Αποσκοπεί στο να διερευνήσει εάν η συγκεκριμένη χειρουργική τεχνική βελτιώνει τα συμπτώματα των ασθενών και κατά πόσον αυτή η βελτίωση διατηρείται στο χρόνο. Υλικό-Μέθοδος: Σαράντα-ένας ασθενείς συμμετείχαν στην μελέτη, που έλαβε χώρα στην Ορθοπαιδική Κλινική του Πανεπιστημίου Πατρών, από το 1997 έως το 2004. Οι ασθενείς είχαν συμπληρώσει τουλάχιστον 1 έτος μετεγχειρητικής παρακολούθησης. Ο μ.ο. ηλικίας των ασθενών ήταν 61,02 +_ 9,62 έτη (κυμαινόμενη από 33 έως 79 έτη). Οι ασθενείς προεγχειρητικά υποβάλλονταν σε λεπτομερή ακτινολογικό και κλινικό έλεγχο. Ο ακτινολογικός έλεγχος περιελάμβανε απλές και δυναμικές ακτινογραφίες, αξονική τομογραφία (CT), μαγνητική τομογραφία (MRI) και/ή μυελογραφία με μυελο-CT. Ο κλινικός έλεγχος περιελάμβανε τη συμπλήρωση του ερωτηματολογίου της Oswestry Disability Index (ODI) και της Visual Analog Scale (VAS). Βάσει του προεγχειρητικού ελέγχου 23 ασθενείς έπασχαν από εκφυλιστική στένωση σε 2 σπονδυλικά επίπεδα (περιελάμβανε 3 σπονδύλους), σε 16 ασθενείς είχαν προσβληθεί 3 επίπεδα και 2 ασθενείς είχαν προσβληθεί 4 επίπεδα. Επιπλέον αναδείχθηκε ότι 12 ασθενείς έπασχαν από σκολίωση, 18 ασθενείς από σπονδυλολίσθηση 1ου βαθμού, ενώ 9 ασθενείς από τμηματική αστάθεια. Η κλινική εικόνα των ασθενών περιελάμβανε κυρίως άλγος στην οσφύ και στα κάτω άκρα και/ή νευρογενή διαλείπουσα χωλότητα. Επιπλέον 6 ασθενείς παρουσίαζαν σταδιακά επιδεινούμενη νευρολογική σημειολογία. Η χειρουργική τεχνική περιελάμβανε ευρεία οπίσθια αποσυμπίεση των οστικών και συνδεσμικών δομών. Περιελάμβανε αφαίρεση της ακανθώδους απόφυσης του σπονδυλικού πετάλου και του ωχρού συνδέσμου, ώστε να υπάρξει απελευθέρωση του σπονδυλικού καναλιού οπισθίως. Η αποσυμπίεση εκτείνονταν από το έξω όριο του ενός καναλιού των ριζών έως το έξω όριο του άλλου και αφορούσε όλα τα στενωτικά επίπεδα που εκ των προτέρων είχαν καθοριστεί μέσω, του προεγχειρητικού ελέγχου. Η σταθερότητα της Σ.Σ. επιτυγχανόταν με την τοποθέτηση διαυχενικού συστήματος σπονδυλοδεσίας, που εκτείνονταν ένα σπονδυλικό επίπεδο εκατέρωθεν των επιπέδων αποσυμπίεσης. Το τελικό στάδιο της τεχνικής περιελάμβανε τοποθέτηση μοσχευμάτων για την επίτευξη αρθρόδεσης, τα οποία τοποθετούνταν μεταξύ των εγκαρσίων αποφύσεων. Ο μέσος χειρουργικός χρόνος ήταν 228min (από 120min έως 420min). Η παρακολούθηση των ασθενών μετεγχειρητικά γίνονταν σε ετήσια βάση και περιελάμβανε τη συμπλήρωση της ODI και VAS όσον αφορά στο κλινικό σκέλος και απλές και δυναμικές ακτινογραφίες όσον αφορά στο ακτινολογικό σκέλος. Αποτελέσματα: Ο μέσος χρόνος παρακολούθησης των ασθενών ήταν 3,71 +_ 1,54 έτη (κυμαινόμενος από 1 έτος έως 6 έτη). Η συνολική ποιότητα ζωής των ασθενών, όπως εκτιμάται με την ODI, παρουσίασε στατιστικά σημαντική βελτίωση μετεγχειρητικά, που διατηρήθηκε για όλα τα έτη παρακολούθησης. Συγκεκριμένα από 61,06% προεγχειρητικά, βελτιώθηκε στο 16,30% το 4ο μετεγχειρητικό έτος. Στατιστικά σημαντική βελτίωση παρουσίασε και ο πόνος όπως εκτιμήθηκε με τη VAS. Συγκεκριμένα από 7,88 προεγχειρητικά, βελτιώθηκε σε 2,35 το 4ο μετεγχειρητικό έτος. Εκτιμώντας τις επιμέρους παραμέτρους της ODI, διαπιστώνεται πως η μεγαλύτερη βελτίωση επιτεύχθηκε στο άλγος, στην προσωπική φροντίδα, στην ικανότητα καθίσματος, στην ικανότητα ύπνου και στην ικανότητα για ταξίδι. Στις παραπάνω δραστηριότητες ποσοστό ασθενών μεγαλύτερο από 90% παρουσίαζε φυσιολογική ή σχεδόν φυσιολογική δραστηριότητα, με βαθμολογία ‘0’ ή ‘1’ το 4ο μετεγχειρητικό έτος στην 6βάθμια κλίμακα. Η ακτινολογική παρακολούθηση μετεγχειρητικά ανέδειξε αστάθεια σε παρακείμενο επίπεδο σε 2 ασθενείς (4,87%), θραύση μιας βίδας στον Ι1 σπόνδυλο σε 1 ασθενή (2,43%) και χαλάρωση μιας βίδας σε 1 ασθενή (2,43%). Όλοι οι ανωτέρω ασθενείς υποβλήθηκαν σε νέα επέμβαση. Η πιθανότητα συνεπώς για τους ασθενείς της μελέτης να μην υποβληθούν σε νέα επέμβαση λόγω μηχανικής αποτυχίας της αρχικής επέμβασης, ήταν 90,24%. Οι υπόλοιποι ασθενείς παρουσίασαν στον ακτινολογικό έλεγχο πλήρη πώρωση με συνεχή οστική γεφύρωση μεταξύ των εγκαρσίων αποφύσεων άμφω και σταθερότητα σε παρακείμενα επίπεδα. Τέλος οι 39 ασθενείς (95,12%) δήλωσαν ικανοποιημένοι με το αποτέλεσμα της επέμβασης και ότι θα την επαναλάμβαναν κάτω από τις ίδιες συνθήκες. Συμπέρασμα: Η ευρεία οπίσθια αποσυμπίεση συνοδευόμενη από οπισθοπλάγια σπονδυλοδεσία με χρήση υλικών, προσφέρει ικανοποιητικά και αναπαραγόμενα κλινικά και ακτινολογικά αποτελέσματα σε ασθενείς που υποφέρουν από πολυεπίπεδη σπονδυλική στένωση και αστάθεια (εκφυλιστική σκολίωση και/ή εκφυλιστική σπονδυλολίσθηση). Με την παραπάνω τεχνική αποφεύγεται η υποτροπή της στένωσης λόγω άναρχης οστικής αναδόμησης (bone regrowth). Όταν η τεχνική εφαρμόζεται σε προσεκτικά επιλεγμένους ασθενείς οδηγεί σε μικρό ποσοστό επιπλοκών, αποτελώντας μια αξιόπιστη λύση στο πρόβλημα της σημαντικής παθολογίας της σπονδυλικής στήλης. / Aim: This is a prospective study on the surgical treatment of patients who suffered from degenerative spinal stenosis of lumbar spine in multiple levels (2 or more). Our goal was to show if our technique improves substantially patient’s symptoms and if the improvement is long lasting. Patients and Method: Between 1997 and 2004, 41 patients were participated in this study, which took place at the Orthopaedic Department of Patras University Hospital. All patients had completed 1-year postoperative follow up. Mean age was 61 years (range 33 – 79 years). All patients underwent preoperatively detailed radiological and clinical evaluation. Radiological aproach included face, profile and dynamic x-rays, computer tomography (CT), magnetic resorance (MRI) and/or myelography with myelo-CT. Clinical evaluation was done using Oswestry Disability Index (ODI) and Visual Analog Scale (VAS). Twenty-three patients suffered from degenerative stenosis in 2 levels (included 3 vertebral bodies), in 16 patients were involved 3 levels and in 2 patients were involved 4 levels. Furthermore 12 patients suffered from concomitant scoliosis, 18 patients from concomitant spondylolisthesis (1st grade), 9 patients from segmental instability and 2 patients from scoliosis and spondylolisthesis. Patients’ symptoms were low back pain, sciatica and/or neurologic intermittent claudication. In 6 patients neurologic deterioration was observed. Surgical technique was wide posterior decompression. This included removal of spinous process, vertebral lamina and ligamentum flavum, and lead to fully posterior exposure of the spinal canal. Decompression was taken place in all the stenotic segments and was extended from one to another root canal in each segment. In order to achieve stability of the spine we used transpedicular screw fixation system, which extended one segment above and one below the decompressed area. Finally we used osseous graft and allograft between transverse processes. Mean surgical time was 228 (120-420) min. Patients’ follow up was done once per year and included the completion of ODI and VAS and face profile and dynamic x-rays for clinical and radiological assessment respectively. Results: Mean follow up was 3,7 (1-6) years. The quality of patients’ life, as is estimated with ODI, showed substantial improvement, which lasted all years. In specific from 61% preoperatively, improved to 16% the 4th postoperative year. Pain also presented statistical significant improvement, as is estimated with VAS. In specific from 7,9 preoperatively improved to 2,3 the 4th postoperative year. Evaluation of ODI’s parameters showed that the greater improvement was achieved in pain, personal care, sitting, sleeping and traveling. More than 90% of the patients had normal or nearly normal activity in these aforementioned parameters, the 4th postoperative year. Two patients had instability in an adjacent level (4,9%). Also one screw breakage in 1 patient (2,4%) and one screw loosening in another one (2,4%), both in S1 vertebral, was observed. These 4 patients underwent second surgical intervention due to instability. Finally there was possibility 90,2% for the patients not to underwent second operation due to mechanical failure. The rest of the patients presented with solid fusion, confluent osseous bridging between the transverse processes and stable adjacent vertebral levels. Conclusions: Wide posterior decompression combined with posterolateralinstrumented fusion, lead to satisfactory and reproducible clinical and radiological results to patients who suffer from degenerative lumbar spinal stenosis in multiple levels with concomitant instability (degenerative scoliosis and/or degenerative spondylolisthesis). The aforementioned technique avoids substantial bone regrowth and stenosis recurrence. Proper use in carefully selected patients has low complication rate, giving us a good and long-lasting result.

There are about 250 new spinal cord injury cases in Lithuania each year. Usually, young people of a „working age” are getting injured. Men are getting spinal cord injuries four times often than women. Researches were made in Wellness center of Vilkpėde in year 2004 and year 2005, in Vilnius (rehabilitation takes 35 days). In this supportive rehabilitation participated 24 patients who have experienced cord injuries in a past 2 years. There were 32 – 45 years old, both sex patients (79,2 % males, 20,8 % females). Participants were divided into two groups. There were 12 patients with spinal cord injuries participating in each group (paraplegics). In the first (control) group researched patients were treated only with kinesitherapy, and the second group was experimental where patients were treated using K.Nyshi method. There were made 40 procedures for the patients in each group. Purpose of this research is – the influence of K. Nyshi method for the patients with spinal cord injures. Goal of this work is – to compare the efficiency of K. Nyshi method and kinesitherapy; to evaluate patient’s functional independence; shoulder joint flexibility. During this research the following evaluation tests were used – functional independence, spinal muscle strength, waist muscular strength balance, shoulder joint flexibility, waist flexibility. Chances of bedsores were evaluated by scale of Norton. After spinal cord injuries, in period after traumas or when disease was irascible and heavy... [to full text]

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Access to and subsequent control of spinal cord function are critical considerations for design of optimal therapeutic strategies for SCI patients. Electrical stimulation of the spinal cord is capable of activating behaviorally-relevant populations of neurons for recovery of function, and is therefore an attractive target for potential devices. A promising method for accessing these spinal circuits is through their axons, which are organized as longitudinal columns of white matter funiculi along the cord exterior. For this thesis, I hypothesized that these funiculi can be selectively recruited via electrodes appropriately placed on the surface of the spinal cord, for functional activation of relevant motor circuitry in a chronically-transected spinal cord. My tandem design goal was to fabricate and implement a conformable multi-electrode array (MEA) that would enable this selective stimulation. To accomplish this design goal, I participated in the design, fabrication, and electromechanical testing of a conformable MEA for surface stimulation of spinal tracts. I then assessed the fundamental capability of this MEA technology to stimulate white matter tracts in a precise, controlled, and functionally-relevant manner. This was accomplished via in vitro experiments that explored the ability of this MEA to locally activate axons via single- and dual-site surface stimulation. The results from these evaluation studies suggest that spinal-cord surface stimulation with this novel MEA technology can provide discrete, minimally-damaging activation of spinal systems via their white matter tracts. To test my hypothesis that surface stimulation can be used to recruit distinct populations in the spinal cord, I performed studies that stimulated lateral funiculi in both chronically-transected and intact in vitro spinal cords. Results from these studies reveal that selective surface stimulation of white matter tracts in the ventrolateral funiculus (VLF) elicit motor outputs not elicited in intact cords. In addition, I was able to demonstrate that the spinal systems activated by this surface stimulation involve synaptic components and are responsive to spatial, temporal, and pharmacologic facilitation. Corresponding labeling of the axonal tracts projecting through the T12 VLF indicate that, after chronic transection, the remaining spinal neurons whose axons travel through the VLF include those with cell bodies in both the intermediate region and dorsal horn. These electrophysiological results show that surface-stimulating technologies used to control motor function after injury should include focal activation of interneuronal systems with axons in the ventrolateral funiculus. As a whole, these studies provide essential starting points for further use of conformable MEAs to effectively activate and control spinal cord function from the surface of the spinal cord.

Doctor of Philosophy / The general aim of this current work was to examine spinal cord injury (SCI), and in particular to examine the pathology of injury as it relates to changes in sensory transmission. Due to the limited possibilities for experimentation in humans, a range of animal models of SCI have been developed and are reviewed here. The weight drop SCI model is the most similar to the clinical presentation of SCI in humans and has been widely used in the rat. It was selected for the series of experiments reported in this thesis. Many of the functional deficits produced by SCI result from a cascade of biochemical events set into motion by the injury. Included amongst these is the activation of the enzyme nitric oxide synthase which produces the gaseous neuromodulator, nitric oxide (NO). NO is amongst the most widely distributed and widely utilised molecule in virtually all living organisms, and it is an important signalling molecule in the nervous system. One of the major functions performed by NO appears to relate to sensory transmission, and thus alterations in sensory transmission observed as a result of SCI may involve alterations to NO synthesis. One of the principal aims of this thesis was to examine the effect of SCI on the NO producing cells of the spinal cord and to consider what any changes in NO synthesis may suggest in regards to sensation. NO producing cells were examined using NADPH diaphorase (NADPH-d) histochemistry. As the symptoms of SCI such as motor loss and changes in sensory processing are functional changes, it was also useful to examine changes in neuronal function as a result of SCI. Widespread neuronal function was examined via immunohistochemical detection of the gene product of the immediate early gene, c-fos. It is not known how extensive the biochemical changes resulting from SCI may be, thus another of the aims of the present thesis was to examine the effects of SCI on NO synthesis not only at the level of injury, but also distant to the injury. Findings of the present thesis indicated that traumatic SCI resulted in a decrease in the number of NADPH-d positive cells from the superficial dorsal horn (SDH) of the spinal cord, while the number of these cells are increased in the ventral horn. These changes were restricted to spinal segments adjacent to the injury. Fos expression was also altered by injury and was found to decrease. The most profound changes were found to occur in lamina III, although the other laminae also demonstrated similar changes. Changes in fos expression however were notably more widespread than those for NADPH-d and were not restricted to the level of the injury, occurring at all levels of the spinal cord examined. It was interpreted that alterations in NO synthesis appear to be modulated by the local injury-induced environment while fos expression may be altered by widespread changes to the global level of activity within the central nervous system. Having observed that the number of NADPH-d positive cells of the SDH is reduced following injury, it was of interest to determine whether these cells were in fact killed, or whether they were still present but with reduced NADPH-d activity. Cell counts suggested that the NADPH-d positive cells, which were likely to represent a population of inhibitory interneurons, were not killed following injury, but rather are disrupted such that their normal biochemistry is altered. Since these cells were likely to be inhibitory and were located in laminae involved in sensory transmission, the question arose how disruption of these cells may relate to the neuropathic pain observed to develop following SCI. Thus both NADPH-d and fos expression were again examined, but this time in conjunction with the sensory function of the rats. Sensory thresholds to pain-like behaviour were determined prior to and after injury using Von Frey filaments. Rats that demonstrated a decrease in sensory threshold of at least two Von Frey filament gradations (>70%) were classed as allodynic, while those with a less than a 70% decrease in threshold were classed as non-allodynic. A subpopulation of each of the groups of rats (uninjured, non-allodynic and allodynic) underwent a somatic stimulation paradigm. It was found that stimulation resulted in an increase in the number of NO producing cells but only in the allodynic group of animals. Since this group of animals by definition would perceive this stimulation as noxious, it is likely that the noxious nature of the stimulation resulted in the increased number of NO producing cells observed. This effect occurred only in segments adjacent to the injury. When fos expression was examined in the uninjured animals it was noted that somatic stimulation resulted in a decrease in fos expression, almost exclusively in lamina III. Following injury, there was no change in fos expression in lamina III observed. Instead the only change observed was an increase in fos expression in the deep dorsal horn (DDH, lamina IV and V). This occurred most profoundly in the allodynic group. These results suggested that SCI may lead to misprocessing of sensory signals such that non-noxious somatic stimuli are processed in the DDH rather than lamina III following SCI. It is proposed here that this change in laminae processing may be responsible for the perception of pain towards a non-noxious stimulus, and that the reported injury-induced loss of NO producing inhibitory interneurons in the SDH may be responsible for this alteration in sensory processing following SCI. Sensation is also processed by a number of supraspinal structures and a number of these have been implicated in the development of neuropathic pain states. The effects of SCI on neuronal activity as well as NO synthesis were examined in the periaqueductal grey region of the mid brain (PAG). SCI was shown to result in reduced neuronal activity in the PAG. This reduction in activity did not follow the somatotopy of the lateral column of the PAG (lPAG). It was suggested the reduced activity may not be solely caused by reduced spinal input as a result of SCI. Reduced neuronal activity in the PAG may indicate reduced PAG function, which includes descending modulation of spinal sensory transmission. Injury was not found to alter NADPH-d expression in the PAG. The effect of traumatic lumbar SCI on the parietal (sensorimotor) cortex of the rat was also examined, as loss of inputs following SCI have been shown to result in a profound reorganisation of the cortex. Results indicated that SCI results in a virtual cessation of neuronal activity in areas 1 and 2 of the parietal cortex, likely as a result of lost afferent drive. Theories of cortical plasticity suggest that while the primary inputs via the lumbar spinal cord may be lost following SCI, other less dominants input will remain and become more dominant. It has been proposed previously that cortical reorganisation involves a rapid reorganisation of the entire sensory system. It was interpreted that a similar process may explain the system-wide reduction in neuronal activity observed in the present series of studies.

Thesis (M.S.)--University of Regina, 2004. / Includes bibliographical references (leaves 127-135). Also available online (PDF file) by a subscription to the set or by purchasing the individual file.