| 1. |
- Shahsavari, Sima, 1976, et al.
(författare)
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A comparison between the transfer function of ABP to ICP and compensatory reserve index in TBI
- 2008
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Ingår i: Acta Neurochirurgica, Supplement. - Vienna : Springer Vienna. - 0065-1419. - 9783211855775 ; 102:102, s. 9-13
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The transfer functions which map the arterial blood pressure to the intracranial pressure and the compensatory reserve index have been investigated by various groups to evaluate the brain compliance of patients with traumatic brain injury. The focus of this study has been to assess the capability of both the above mentioned methods to monitor the intracranial compliance in patients suffering from brain swelling. MATERIALS AND METHODS: Clinical data was collected from sixteen traumatic brain injury patients and split into 4 min segments. For each segment, both the magnitude of the empirical transfer function at the fundamental cardiac frequency and the compensatory reserve index were extracted. FINDINGS: The mean values of the compensatory reserve index and the magnitude of the transfer function which scored higher than 0.7 and 0.1 respectively were recorded for all patients suffering from brain swelling. By comparing the histogram of the magnitude of the transfer function at the fundamental cardiac frequency with the histogram of the compensatory reserve index for all patients, a positive correlation between the mean values and a negative correlation among their variances were observed. The linear correlation between the mean values was estimated at r = 0.82 (p
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| 2. |
- Ansar, Saema, et al.
(författare)
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Elevated intracranial pressure or subarachnoid blood responsible for reduction in cerebral blood flow after SAH
- 2008
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Ingår i: Cerebral Vasospasm: New Strategies in Research and Treatment. - Vienna : Springer Vienna. - 0065-1419. - 9783211757178 ; 104, s. 231-233
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Konferensbidrag (refereegranskat)abstract
- Background. The pathogenesis of cerebral ischemia after subarachnoid hemorrhage (SAH) still remains elusive. The purpose of the present study was to examine whether it is the change in intracranial pressure (ICP) or the extravasated blood that is responsible for cerebral ischemia and cerebral vasoconstriction observed following SAH. Method. Three groups of animals were studied; (1) cisternal injection of 250 mu l blood (SAH), (2) injection of 250 mu l NaCl (saline) or (3) same procedure in every detail but no fluid injection (sham). Two days after the treatment, an autoradiographic technique was used to investigate the cerebral blood flow (CBF). Findings. Both SAH (blood+ ICP) and saline injection (ICP only) resulted in significantly reduced regional and global CBF after as compared to sham/control. Conclusions. This study revealed that both the elevation of ICP and A Subarachnoid blood per se contribute approximately equally to the SAH induced effects.
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| 3. |
- Ansar, Saema, et al.
(författare)
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Subarachnoid hemorrhage induces upregulation of vascular receptors and reduction in rCBF via an ERKI/2 mechanism
- 2008
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Ingår i: Cerebral Vasospasm: New Strategies in Research and Treatment. - Vienna : Springer Vienna. - 0065-1419. - 9783211757178 ; 104, s. 65-67
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Konferensbidrag (refereegranskat)abstract
- Previous studies have shown that endothelin type B (ETB) and 5-hydroxytryptamine type IB (5-HTIB) receptors are upregulated following subarachnoid hemorrhage (SAH). The purpose of the present study was to test whether extracellular signal-regulated kinase (ERKI/2) inhibition could alter the degree of SAH induced receptor upregulation in addition to prevent the cerebral blood flow (CBF) reduction. The ERKI/2 inhibitor SB386023-b was injected intra cisternally in conjunction with and after the induced SAH in rats. Two days after SAH cerebral arteries were harvested and the contractile response to endothelin-1 (ET-I) and 5-carboxamidotryptamine (5-CT) were investigated with a myograph. The contractile responses to ET-I and 5-CT were increased after SAH compared to sham. Administration of SB-386023-b prevented the upregulated contraction elicited by application of ET-I and 5-CT in cerebral arteries. Regional CBF evaluated by an autoradiographic technique, revealed a reduced CBF by 50% after SAH this was prevented by treatment with SB-386023-b. The results indicate that an ERKI/2 mechanism is involved in cerebral vasospasm and ischemia associated with SAH.
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| 4. |
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| 5. |
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| 6. |
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| 7. |
- Bjorkman, A, et al.
(författare)
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Cortical reintegration of a replanted hand and an osseointegrated thumb prosthesis
- 2007
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Ingår i: Acta Neurochirurgica. Supplementum. - 0065-1419. ; 100, s. 109-112
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Following a peripheral nerve repair the injured nerve has to re-innervate its original cortical area, a process, which is poorly understood. Errors in this cortical re-innervation have been suggested as one key reason for the generally poor clinical outcome following nerve injuries in the hand. METHOD: Functional magnetic resonance imaging (fMRI) was used to assess cortical reintegration following amputation and reattachment of bodyparts in two different situations: a patient with a hand amputation followed by immediate surgical replantation and a patient with an osseointegrated thumb prosthesis. FINDINGS: The primary motor cortex rapidly returns to a normal activation pattern after amputation followed by replantation or application of an osseointegrated prosthesis. The primary somatosenory cortex changes from an initial ipsilateral to a bilateral activation pattern. Sensory stimulation of an osseointegrated prosthesis also shows a bilateral activation pattern in the primary somatosenory cortex. CONCLUSIONS: The primary motor cortex shows a more normal activation pattern possibly because most muscles controlling the hand are proximal to the injury and can be activated after an amputation. The primary somatosensory cortex reorganises more and the activation pattern is more bilateral compared to a healthy hand. This bilateral activation pattern could represent a compensatory mechanism for the inferior tactile function in the replanted hand and the osseointegrated prosthesis.
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| 8. |
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| 9. |
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| 10. |
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| 11. |
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| 12. |
- Dahlin, Lars, et al.
(författare)
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Functional recovery and mechanisms in end-to-side nerve repair in rats
- 2007
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Ingår i: Acta Neurochirurgica. Supplementum. - Vienna : Springer Vienna. - 0065-1419. ; 100, s. 93-95
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: End-to-side nerve repair is attachment of a single distal nerve segment (recipient nerve) end-to-side to an intact donor nerve when there is a lack of proximal nerve segment after injury. The technique is currently used clinically but the mechanism(s) behind this technique are essentially unknown. METHODS: We have studied end-to-side nerve repair in the forelimb of rats, where a single distal radial nerve or an ulnar or a median, or both, nerves are attached end-to-side to an intact musculocutaneous nerve. We have studied functional recovery, origin of the regenerating axons and cell activation by the end-to-side nerve repair. FINDINGS: Functional recovery occurs after end-to-side nerve repair but is less sufficient than conventional end-to-end nerve repair or a nerve graft procedure. Sensory and motor axons grow from the musculocutaneous nerve out into the attached nerve segment(s). An injury is required to the musculocutaneous nerve to activate sensory and motor neurons as well as Schwann cells in the musculocutaneous nerve for initiation of regeneration. CONCLUSIONS: End-to-side nerve repair may be an alternative method in specific cases of complex nerve injuries to reconstruct nerve trunks when no other repair options are possible. Some functional recovery does occur but regeneration of sensory and motor axons require an injury to the neurons of the donor nerve.
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| 13. |
- Dahlin, Lars, et al.
(författare)
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Schwann cells, acutely dissociated from a predegenerated nerve trunk, can be applied into a matrix used to bridge nerve defects in rats
- 2007
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Ingår i: Acta Neurochirurgica. Supplementum. - 0065-1419. ; 100, s. 57-60
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The gold standard to reconstruct a nerve defect is a conventional autologous nerve graft. There may be a lack of such grafts in severe nerve injuries. Alternatives to autologous nerve grafts are needed. METHODS: We have developed a technique where mainly Schwann cells are acutely dissociated from the ends of the severed nerve trunk after nerve injury. The technique does not require long-term cell culture procedures. The obtained cells, which can be dissociated within a few hours, are applied to a silicone tube or a tendon autograft used to bridge a nerve defect. FINDINGS: Dissociated cells from the ends of the severed nerve ends consist of more than 85% of Schwann cells. The remaining cells are ED1 stained macrophages. The cells survive transfer to a silicone tube or a tendon autograft which bridge the nerve defect. Axons do grow through such a graft filled with dissociated cells. CONCLUSION: Our novel model to obtain mainly Schwann cells by dissociation of the cells from the severed nerve ends after injury and add them to a matrix, thereby creating an artificial nerve graft, may be a new technique with potential clinical application in nerve reconstruction.
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| 14. |
- de Dios, Eddie, et al.
(författare)
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Introduction to Deep Learning in Clinical Neuroscience
- 2022
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Ingår i: Acta Neurochirurgica, Supplement. - Cham : Springer International Publishing. - 2197-8395 .- 0065-1419. ; 134, s. 79-89
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- The use of deep learning (DL) is rapidly increasing in clinical neuroscience. The term denotes models with multiple sequential layers of learning algorithms, architecturally similar to neural networks of the brain. We provide examples of DL in analyzing MRI data and discuss potential applications and methodological caveats. Important aspects are data pre-processing, volumetric segmentation, and specific task-performing DL methods, such as CNNs and AEs. Additionally, GAN-expansion and domain mapping are useful DL techniques for generating artificial data and combining several smaller datasets. We present results of DL-based segmentation and accuracy in predicting glioma subtypes based on MRI features. Dice scores range from 0.77 to 0.89. In mixed glioma cohorts, IDH mutation can be predicted with a sensitivity of 0.98 and specificity of 0.97. Results in test cohorts have shown improvements of 5–7% in accuracy, following GAN-expansion of data and domain mapping of smaller datasets. The provided DL examples are promising, although not yet in clinical practice. DL has demonstrated usefulness in data augmentation and for overcoming data variability. DL methods should be further studied, developed, and validated for broader clinical use. Ultimately, DL models can serve as effective decision support systems, and are especially well-suited for time-consuming, detail-focused, and data-ample tasks.
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| 15. |
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| 16. |
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| 17. |
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| 18. |
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| 19. |
- Grabowski, Martin, et al.
(författare)
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Fetal neocortical grafts placed in brain infarcts do not improve paw-reaching deficits in adult spontaneously hypertensive rats
- 1996
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Ingår i: Acta Neurochirurgica. Supplementum. - 0065-1419. ; 66, s. 68-72
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Tidskriftsartikel (refereegranskat)abstract
- The aim was to study if neural grafts placed brain infarcts could improve functional recovery. The middle cerebral artery was occluded (MCAO) in 19 spontaneously hypertensive rats. Nine rats were sham operated. Twelve to 16 days after the ischemic insult, 9 of the MCAO rats received transplants of dissociated fetal neocortical tissue (MCAO-T) and 1, 3 and 6 months after transplantation surgery, the rats were behaviorally evaluated by a test for forelimb function. Infarct and transplant sizes were measured morphometrically. The remaining volume of the infarcted hemisphere was 66 +/- 7% (mean +/- SD) in the MCAO group and 71 +/- 9% in the MCAO-T group of the non-operated hemisphere. All grafted rats had surviving transplants. Contralateral to the lesion, paw-reaching was highly impaired in both infarcted groups compared with sham-operated controls with no significant difference between MCAO and MCAO-T. The lesion size correlated significantly with contralateral paw-reach performance at all test periods. We conclude that neocortical grafts did not alleviate the impaired forepaw function.
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| 20. |
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| 21. |
- Johansson, Barbro, et al.
(författare)
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Environmental influence on gene expression and recovery from cerebral ischemia
- 1999
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Ingår i: Acta Neurochirurgica. Supplementum. - 0065-1419. ; 73, s. 51-55
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Tidskriftsartikel (refereegranskat)abstract
- An emerging concept in neurobiology is that the adult brain retains a capacity for plasticity and functional reorganization throughout the life span. Experimental data from electrophysiological, morphological and behavioral studies have documented experience dependent plasticity in the intact and injured adult brain. Neuroimaging clinical studies indicate altered post stroke functional activation patterns, usually including activation of the intact hemisphere. However, there is some disagreement regarding their functional significance and longitudinal studies correlating outcome and activation pattern are needed to solve some controversies. Postoperative housing of rats in activity stimulating environment after ligation of the middle cerebral artery significantly enhances outcome. Gene expression for brain derived neurotrophic factor and Ca2+/calmodulin-dependent protein kinase II, two substances with potential role in brain plasticity, show different patterns in animals housed in standard and in enriched environment. The functional significance of altered gene expression needs to be evaluated.
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| 22. |
- Johansson, Barbro
(författare)
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Environmental influence on outcome after experiment brain infarction
- 1996
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Ingår i: Acta Neurochirurgica. Supplementum. - 0065-1419. ; 66, s. 63-67
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Tidskriftsartikel (refereegranskat)abstract
- After permanent ligation of the middle cerebral artery the motor function of rats housed in an enriched environment, i.e. cages with opportunities for various activities but not forcing the rats to do any particular task, is significantly better than in rats housed in individual cages. Rats kept in an enriched environment before and after MCA ligation improved sooner and slightly more than those placed in the enriched environment after ischemia but with no lasting significant difference except for climbing. Preliminary studies suggest that social stimulation is more important than physical activity. Rats with fetal neocortical grafts implanted into the infarct cavity performed better if exposed to enriched environment than grafted control rats housed in standard laboratory cages with 5 rats in each cage. However, they did not perform better than non-grafted rats housed in the same enriched environment. The infarct size did not differ between rats housed in an enriched environment and control rats. There was no correlation between infarct size and performance in rats exposed to an enriched environment. The improved motor function suggest that a rich environment may stimulate mechanisms that enhance brain plasticity.
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| 23. |
- Karki, A, et al.
(författare)
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Tirilazad reduces brain edema after middle cerebral artery ligation in hypertensive rats
- 1994
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Ingår i: Acta Neurochirurgica, Supplement. - 0065-1419. ; 60, s. 3-310
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Tidskriftsartikel (refereegranskat)abstract
- Tirilazad (3 mg/kg i.v.) or vehicle was given 10 min, 3 and 12 hours after ligation of the right middle cerebral artery in male spontaneously hypertensive rats (n = 12 in each group). Brain specific gravity was determined in 23 predetermined cortical regions covering the core and penumbra areas 24 hours after the occlusion. The specific gravity was significantly higher in tirilazad-treated rats than in controls (p < 0.0001). When individual regions of the two groups were compared, the difference was significant in 9 of the 23 samples predominantly, but not exclusively, in the penumbra zone.
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| 24. |
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| 25. |
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| 26. |
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| 27. |
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| 28. |
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| 29. |
- Lundborg, Göran, et al.
(författare)
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Enhanced sensory relearning after nerve repair by using repeated forearm anaesthesia: aspects on time dynamics of treatment
- 2007
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Ingår i: Acta Neurochirurgica. Supplementum. - 0065-1419. ; 100, s. 121-126
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: We describe a new principle for enhancing the effects of sensory re-education following nerve injury and repair. The outcome from nerve repair in adult patients is generally poor. One reason is the functional cortical reorganisation which always occurs because of axonal misdirection at the repair site. In healthy individuals selective anaesthesia of the forearm results in improved hand sensation. Here we hypothesised that this principle would be valid also after nerve injury and repair. METHOD: In a prospective, randomised, double blind study we studied the effects of cutaneous forearm anaesthesia combined with sensory reeducation on the outcome after median or ulnar nerve repair at wrist or distal forearm level. FINDINGS: EMLA-application four times over a two week period starting with beginning reinnervation of the fingers resulted in significantly improved sensory recovery (tactile gnosis) as compared to the placebo group and also at assessment four weeks after the last EMLA-session. However, at assessment 8-11 months after the first EMLA-treatment there was no difference between the groups. CONLUSIONS: Our findings indicate that repeated cutaneous forearm anaesthesia over a two week period can enhance the effects of sensory re-education at least over the four following weeks. However, the optimal time protocol for EMLA-treatment, aiming at a long-lasting or permanent effect on sensory recovery still has to be defined.
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| 30. |
- Mathiesen, T, et al.
(författare)
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Machine Learning and Ethics
- 2022
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Ingår i: Acta neurochirurgica. Supplement. - Cham : Springer International Publishing. - 0065-1419. ; 134, s. 251-256
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Tidskriftsartikel (refereegranskat)
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| 31. |
- Nilsson, O. G., et al.
(författare)
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Increased Levels of Glutamate in Patients with Subarachnoid Haemorrhage as Measured by Intracerebral Microdialysis
- 1996
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Ingår i: Clinical Aspects of Microdialysis. - Vienna : Springer Vienna. - 0065-1419. - 9783709174265 - 9783709168943 ; , s. 45-47
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Cerebral ischemia associated with subarachnoid haemorrhage (SAH) may have severe consequences for neuronal function leading to reversible or permanent neurological deficits. The excitatory amino acid neurotransmitters, such as glutamate, have been shown to be of particular importance for ischemic neuronal damage. In seven patients who underwent early surgery for a ruptured intracranial aneurysm, microdialysis of glutamate was performed in order to monitor local metabolic changes in the medial temporal (all patients) and subfrontal cortex (four patients). The preliminary results indicate that: (i) extracellular glutamate concentrations may rise to very high levels after SAH and aneurysm surgery, (ii) the increased levels of excitatory amino acids correlate with the clinical course, and (iii) a rise in extracellular glutamate in one region is not necessarily paralleled with a rise in the other, as seen by the simultaneous sampling from two different vascular territories.
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| 32. |
- Nordström, Carl-Henrik
(författare)
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The Lund concept: is this logical?
- 2005
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Ingår i: Acta Neurochirurgica. Supplementum. - 0065-1419. ; 95, s. 80-475
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Tidskriftsartikel (refereegranskat)
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| 33. |
- Povlishock, John T., et al.
(författare)
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Initiating mechanisms involved in the pathobiology of traumatically induced Axonal Injury and Interventions targeted at blunting their progression
- 1999
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Ingår i: Acta Neurochirurgica Supplementum. - Vienna : Springer. - 0065-1419. ; 73, s. 15-20
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Tidskriftsartikel (refereegranskat)abstract
- To gain better insight into the initiating factors involved in traumatically induced axonal injury cats and rats were subjected to various forms of traumatic brain injury. Following injury at intervals ranging from 10 min. to 3 hours, the animals were sacrificed and prepared in accordance with multiple immunocytochemical strategies capable of detecting focal changes in the axolemma, the subaxolemmal spectrin network, the underlying cytoskeleton as well as any related abnormalities in axoplasmic transport. Through these approaches it was recognized that the most severe forms of injury resulted in focal abnormalities of axonal permeability which were observed together with calpain-mediated spectrin proteolysis in the subaxolemmal network. These events were associated with compaction of the underlying neurofilaments and some microtubular loss which occurred without any direct evidence of overt axoplasmic proteolysis with the exception of the most severely injured fibers. In addition to these severely injured axonal profiles, other injured axons did not manifest overt changes in axolemmal permeability or early calpain-mediated spectrin proteolysis but demonstrated dramatic neurofilament and microtubular misalignment and impaired axoplasmic transport. Lastly, other small caliber axons showed another form of intraaxonal change manifested in the local pooling of organelles in the nodal and paranodal regions, with the suggestion that some of these changes may be reversible. In relation to these axonal responses the efficacy of various therapeutic investigations were assessed. The use of calcium chelators showed a trend for protection in those axons manifesting altered axolemmal permeability. However, the use of early and delayed hypothermia demonstrated dramatic protection resulting in significant reduction in the number of damaged axonal profiles. These studies illustrate the diversity and complexity of those axonal responses evoked by traumatic brain injury, suggesting that multiple forms of therapy may be needed to blunt these multifaceted forms of progression.
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| 34. |
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| 35. |
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| 36. |
- Sharma, Hari Shanker, et al.
(författare)
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Intracerebral administration of neuronal nitric oxide synthase antiserum attenuates traumatic brain injury-induced blood-brain barrier permeability, brain edema formation, and sensory motor disturbances in the rat
- 2006
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Ingår i: Acta neurochirurgica. Supplement. - 0065-1419. ; 96, s. 288-294
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Tidskriftsartikel (refereegranskat)abstract
- The role of nitric oxide (NO) in traumatic brain injury (TBI)-induced sensory motor function and brain pathology was examined using intracerebral administration of neuronal nitric oxide synthase (nNOS) antiserum in a rat model. TBI was produced by a making a longitudinal incision into the right parietal cerebral cortex limited to the dorsal surface of the hippocampus. Focal TBI induces profound edematous swelling, extravasation of Evans blue dye, and up-regulation of nNOS in the injured cerebral cortex and the underlying subcortical areas at 5 hours. The traumatized animals exhibited pronounced sensory motor deficit, as seen using Rota-Rod and grid-walking tests. Intracerebral administration of nNOS antiserum (1 : 20) 5 minutes and 1 hour after TBI significantly attenuated brain edema formation, Evans blue leakage, and nNOS expression in the injured cortex and the underlying subcortical regions. The nNOS antiserum-treated rats showed improved sensory motor functions. However, administration of nNOS antiserum 2 hours after TBI did not influence these parameters significantly. These novel observations suggest that NO participates in blood-brain barrier disruption, edema formation, and sensory motor disturbances in the early phase of TBI, and that nNOS antiserum has some potential therapeutic value requiring additional investigation.
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| 37. |
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| 38. |
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| 39. |
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| 40. |
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| 41. |
- Shaw, M, et al.
(författare)
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The brain monitoring with information technology (BrainIT) collaborative network : data validation results
- 2009
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Ingår i: Acta Neurochirurgica Supplements. - Vienna : Springer Vienna. - 9783211855775 - 9783211855782 ; , s. 217-221
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Background The BrainIT group works collaboratively on developing standards for collection and analyses of data from brain injured patients towards providing a more efficient infrastructure for assessing new health technology. Materials and methods Over a 2 year period, core dataset data (grouped by nine categories) were collected from 200 head-injured patients by local nursing staff. Data were uploaded by the BrainIT web and random samples of received data were selected automatically by computer for validation by data validation (DV) research nurse staff against gold standard sources held in the local centre. Validated data was compared with original data sent and percentage error rates calculated by data category. Findings Comparisons, 19,461, were made in proportion to the size of the data received with the largest number checked in laboratory data (5,667) and the least in the surgery data (567). Error rates were generally less than or equal to 6%, the exception being the surgery data class where an unacceptably high error rate of 34% was found. Conclusions The BrainIT core dataset (with the exception of the surgery classification) is feasible and accurate to collect. The surgery classification needs to be revised.
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| 42. |
- Siesjö, B K, et al.
(författare)
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Molecular mechanisms of acidosis-mediated damage
- 1996
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Ingår i: Acta Neurochirurgica, Supplement. - Vienna : Springer Vienna. - 0065-1419. ; 66, s. 8-14
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Forskningsöversikt (refereegranskat)abstract
- The present article is concerned with mechanisms which are responsible for the exaggerated brain damage observed in hyperglycemic animals subjected to transient global or forebrain ischemia. Since hyperglycemia enchances the production of lactate plus H+ during ischemia, it seems likely that aggravation of damage is due to exaggerated intra- and extracellular acidosis. This contention is supported by results showing a detrimental effect of extreme hypercapnia in normoglycemic rats subjected to transient ischemia or to hypoglycemic coma. Enhanced acidosis may exaggerate ischemic damage by one of three mechanisms: (i) accelerating free radical production via H(+)-dependent reactions, some of which are catalyzed by iron released from protein bindings by a lowering of pH, (ii) by perturbing the intracellular signal transduction pathway, leading to changes in gene expression or protein synthesis, or (iii) by activating endonucleases which cause DNA fragmentation. While activation of endonucleases must affect the nucleus, the targets of free radical attack are not known. Microvessels are considered likely targets of such attack in sustained ischemia and in trauma; however, enhanced acidosis is not known to aggravate microvascular dysfunction, or to induce inflammatory responses at the endothelial-blood interface. A more likely target is the mitochondrion. Thus, if the ischemia is of long duration (30 min) hyperglycemia triggers rapidly developing mitochondrial failure. It is speculated that this is because free radicals damage components of the respiratory chain, leading to a secondary deterioration of oxidative phosphorylation.
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| 43. |
- Sikström, Sverker
(författare)
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Computational Perspectives on Neuromodulation of Aging
- 2007
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Ingår i: Acta Neurochirurgica. Supplementum. - Vienna : Springer Vienna. - 0065-1419. ; 97, s. 513-518
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Forskningsöversikt (refereegranskat)abstract
- Cognitive functions, such as memory, attention, and perception, declines with age. Besides other neuroanatomical changes, the level of dopamine also attenuates during aging. We review how computational modeling can provide insights in how these lifetime changes in dopamine levels is expressed at the behavioral level yielding a bridge across different levels. Results indicate that attenuation of dopamine lowers the signal to noise ratio providing a less distinctive neural representation, and detrimental cognitive performance.
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| 44. |
- Uchino, Hiroyuki, et al.
(författare)
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Cyclophilin-D inhibition in neuroprotection : dawn of a new era of mitochondrial medicine
- 2013
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Ingår i: Acta Neurochirurgica. Supplementum. - Vienna : Springer Vienna. - 0065-1419. ; 118, s. 5-311
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Tidskriftsartikel (refereegranskat)abstract
- Traumatic brain injury and ischemia can result in marked neuronal degeneration and residual impairment of cerebral function. However, no effective pharmacological treatment directed at tissues of the central nervous system (CNS) for acute intervention has been developed. The detailed pathophysiological cascade leading to -neurodegeneration in these conditions has not been elucidated, but cellular calcium overload and mitochondrial dysfunction have been implicated in a wide range of animal models involving degeneration of the CNS. In particular, activation of the calcium-induced mitochondrial permeability transition (mPT) is considered to be a major cause of cell death inferred by the broad and potent neuroprotective effects of -pharmacological inhibitors of mPT, especially modulators of cyclophilin activity and, more specifically, genetic inactivation of the mitochondrial cyclophilin, cyclophilin D. Reviewed are evidence and challenges that could bring on the dawning of mitochondrial medicine aimed at safeguarding energy supply following acute injury to the CNS.
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| 45. |
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| 46. |
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| 47. |
- Zygmunt, S C, et al.
(författare)
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Realignment and surgical fixation of atlanto-axial and subaxial dislocations in rheumatoid arthritis (RA) patients
- 1988
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Ingår i: Acta Neurochirurgica. Supplementum. - 0065-1419. ; 43, s. 79-84
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Tidskriftsartikel (refereegranskat)abstract
- One hundred consecutive patients with atlanto-axial dislocation(s) were subjected to posterior occipito-cervical fusion and followed up to 16 1/2 years postoperatively (mean: 4 1/2 years). The mean age at surgery was 60.3 years. At the time of follow-up, 45 patients had died, mostly due to cardiopulmonary disease. Out of the 100 patients, 67% showed a major improvement and in an additional 14% there was a slight or moderate improvement. Some patients with a stable fusion later developed subaxial dislocation(s) necessitating an anterior fusion which in patients with RA is difficult due to poor bone quality. MRI revealed pannus formation around the odontoid peg in many patients, in several to such a degree that cord compression was evident. Following the posterior fixation, the pannus disappeared or was reduced which may at least partly explain the generally favourable operative outcome following the fixation procedure. Early occipito-cervical fusion appears to prevent further vertical dislocation or upwards migration of the odontoid which is a more severe condition, and does not appear to result in increased incidence of subsequent subaxial dislocation(s). Such luxation(s) pose a technically difficult problem since the quality of the patients' own bone usually does not permit a common anterior fusion procedure with autologous graft. In such cases with cord compression, acrylic cement may be used to obtain a normalized realignment.
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