| 1. |
- Asplund, Pär, 1974-
(författare)
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Percutaneous Balloon Compression for the Treatment of Trigeminal Neuralgia
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background. Trigeminal neuralgia (TN) is a paroxysmal unilateral facial pain condition. That it is rather rare is of little comfort to those who are affected, as TN is often described as one of the worst pains known to mankind. Advanced age and multiple sclerosis (MS) are risk factors for developing TN. The first line of treatment is medical, primarily with carbamazepine. When medical treatment fails, as it does in many patients, there are several surgical options. One of the minimally invasive options, suitable for patients with comorbidity, is percutaneous balloon compression (PBC). Despite its introduction in the early 1980s, PBC is arguably the least well studied of the minimally invasive procedures for the treatment of TN.Aims. The aim of this thesis was to evaluate the efficacy of PBC, both overall and in MS-TN patients specifically. Further, it intended to identify and evaluate pre- and intraoperative parameters associated with the efficacy of PBC. It also investigated changes in sensory function after PBC, and identified side effects and complications associated with PBC. Finally, it sought to evaluate how efficacy, side effects and complications differed between PBC and another minimally invasive technique; percutaneous retrogasserian glycerol rhizotomy (PRGR).Methods. Cohorts of patients treated with PBC in Umeå and Stockholm, and with PRGR in Umeå, were followed retrospectively. Data from an existing database was combined with data from medical records, radiographs and telephone interviews.Results. After PBC, 90 % of the patients were completely pain free without medication for TN. The median time to recurrence of pain was 28 months. In patients with concurrent MS, the initial success rate was 67 % and the median time to recurrence was 8 months. In patients without MS, who had not previously been treated surgically, the initial success rate was 91 % and the median time to recurrence was 48 months. The procedure could, however, be repeated with good results. A good compression, indicated by a pear-shaped balloon as seen on intraoperative lateral radiograph, was crucial to achieve good pain relief. Postoperative hypoesthesia was present in the majority of patients, but after 3-6 months, sensibility was partly or fully normalized in most patients. Severe complications were rare, but included transient cardiac arrest, meningitis and dysesthesia. The side effects profile was favorable to that of percutaneous retrogasserian glycerol rhizotomy, in that the latter produced more cases of dysesthesia and decreased corneal sensibility. The efficacy of the two treatments were, however, not significantly different.Conclusions. PBC is an effective and relatively safe treatment option for patients with TN refractory to medical treatment. It deserves its place among the standard treatments for TN, and could be considered for those patients eligible for surgery for which open surgery is a less suitable option.
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| 2. |
- Bergman, Joakim, 1989-
(författare)
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Studies of the Biology of Intrathecal Treatment in Progressive MS
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Multiple Sclerosis (MS) is a chronic, inflammatory, autoimmune disease, affecting the central nervous system (CNS). About 85% of afflicted present with a relapsing-remitting form of the disease (RRMS), for which a breakthrough in treatment was made in 2008 with rituximab, an antibody directed towards CD20, a surface antigen on B-cells. These findings also contributed to cementing the importance of the B-cell’s role in MS pathophysiology. However, MS also exist as a progressive phenotype, affecting most MS patients either from onset or after a transition from RRMS, and for progressive MS the same treatment effect of anti-CD20 has not been observed. Still, studies have found follicle-like structures containing B-cells in meninges and subarachnoid space of the cortex in progressive MS brains, supporting the involvement of B-cells. Evidence also support the existence of a chronic, low-grade inflammatory process compartmentalised within the CNS that correlates with the progressive phase of MS, which may present a treatment barrier towards anti-CD20. Peripherally administrated therapeutic antibodies cross the intact blood-brain barrier with low efficiency with only 0.1-0.5% of the plasma concentration occurring in the cerebrospinal fluid (CSF). Intrathecal (IT) administration circumvents the blood-brain barrier, presenting an opportunity to better target the CNS B-cells.Aims: To evaluate the safety and feasibility of intrathecal anti-CD20 therapy with rituximab in progressive MS, its effect on disease progression through clinical parameters, and impact on biomarkers in CSF. Furthermore, this thesis aimed to evaluate the effect on biomarkers representative of cell injury related to insertion of a ventricular catheter for drug administration and to examine the interstitial milieu in the brain through microdialysis (MD).Methods: The thesis is based on the open-label, phase IIb, multicentre clinical trial Intrathecal Treatment Trial in Progressive Multiple Sclerosis (ITT-PMS; EudraCT 2008-002626-11), in which 23 participants received IT treatment with rituximab, and the extended follow-up study, ITT-PMS extension (EudraCT 2012-000721-53). All participants received a ventricular catheter and an Ommaya reservoir for drug administration through a neurosurgical procedure, and 10 participants received a MD catheter in parallel to the ventricular catheter for 10 days. The treatment effect was evaluated by regular clinical evaluations and analyses of CSF. The clinical outcome was evaluated through walking and upper-limb function tests, and by clinical evaluation scales. Levels of selected CSF biomarkers were analysed from the same time-points as the clinical evaluations.Results: After the completion of the extension trial, one clinical parameter (cognitive performance) showed improvement but could most likely be explained by a learning effect. Worsening of walking speed was observed, while the remaining clinical parameters showed no change. Two severe adverse events occurred in the form of low-virulent bacterial meningitis caused by Propionibacterium, but both were treated effectively with antibiotics without residual symptoms. A ‘spike’ was noticed in the level of lumbar CSF neurofilament light (NFL) following surgery but returned to pre-surgery baseline within 6-12 months. No change was observed for any of the other lumbar CSF biomarkers. No meaningful correlation of protein levels was observed when comparing MD samples, ventricular CSF, and lumbar CSF.Conclusions: Intrathecal treatment through intraventricular administration was well tolerated but not without risks. A continued progression was observed in gait impairment. The insertion of the ventricular catheter caused white matter injury, measured through an increase in NFL in lumbar CSF, in direct association with the surgical procedure. No impact was observed on other CSF biomarkers. There was a poor correlation between different CNS compartments regarding protein levels, arguing for caution in drawing conclusions about brain pathophysiology from lumbar CSF samples.
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| 3. |
- Johansson, Mikael, et al.
(författare)
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Tumor blood flow and the cytotoxic effects of estramustine and its constituents in a rat glioma model
- 1997
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Ingår i: Neurosurgery. - : Oxford University Press. - 0148-396X .- 1524-4040. ; 41:1, s. 237-244
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Estramustine (EaM) is a conjugate of nor-nitrogen mustard (NNM) and 17 beta-estradiol (E2) that has cytotoxic and radiosensitizing effects on experimental malignant glioma. Its mechanism of action is only partly understood. To further investigate the mechanism in vivo, the effects on tumor blood flow (TBF) and tumor growth were analyzed.METHODS: TBF was measured by radioactive microspheres, and tumor growth was measured by weight. Apoptosis was evaluated by in situ end labeling and gel electrophoresis. The effects of the constituents NNM and E2 were also evaluated.RESULTS: EaM increased TBF to 153.8 ml/100 g/min after 3 days and to 153.9 ml/100 g/min after 10 days of treatment, compared with 94.0 ml/100 g/min in untreated controls. Cerebral blood flow did not change after EaM treatment. NNM increased TBF but also showed a tendency to increase cerebral blood flow. E2 increased TBF, whereas cerebral blood flow was unchanged. EaM resulted in a rapid reduction in tumor weight from 230 mg in untreated animals to 146 mg after 3 days of treatment. EaM induced an early transient fragmentation of deoxyribonucleic acid in glioma but not in the normal brain. Neither NNM nor E2 affected tumor weight.CONCLUSION: EaM increases TBF in the BT4C rat glioma model with a concomitant rapid antitumoral effect. The increase in TBF could partially be induced by an estrogen-like action of EaM, but the rapid cytotoxic effect of the drug is obviously attributed to the intact EaM compound. This cytotoxic effect might be attributable to the induction of programmed cell death.
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| 4. |
- Tabatabaei, Pedram, 1978-
(författare)
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Stereotactic microdialysis for metabolic assessment and experimental treatment of malignant glioma
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Glioblastoma multiforme, the most common primary brain tumor, has a dire prognosis despite multimodal treatments that include surgery and radio-chemotherapy. To improve the outcome of this destructive disease, we need to improve our understanding of its tumor biology. Furthermore, the development of new treatment strategies will improve with a better understanding of the interplay between malignant cells and their direct surrounding microenvironment.This thesis aims to increase the understanding of the processes within high-grade glioma and its microenvironment during normal conditions as well as during the distress associated with treatment. Specifically, we have investigated the metabolic response to radiotherapy (study I and II), the immunologic response to radiotherapy (study II), and the metabolic response pattern to loco-regional treatment with cisplatin (study III and IV). Using microdialysis, we collected samples from the extracellular space in both normal brain and tumor tissue during radiotherapy (study I and II) and loco-regional cisplatin treatment (study III and IV). Theses samples were analyzed for glucose metabolites, glycerol, and glutamate (study I, II, and III) and for cytokines (study II). In addition, we analyzed the global metabolism with mass spectrometry to identify and assess the response pattern of malignant glioma cells to loco-regional cisplatin treatment (study IV).In study I and II, we found that malignant glioma cells used glucose at a higher rate than normal cells and preferred glycolysis for glucose metabolism. The given radiation dose (2 Gray (Gy) daily for five days) did not significantly affect glucose metabolism, glycerol levels, or glutamate levels in tumor tissue or the microenvironment. However, in study II, we observed an induced inflammatory effect due to the given radiation dose as several of the cytokines investigated showed significantly increased levels during radiotherapy. In study IV, we observed a complex and strong metabolic response to the loco-regional cisplatin therapy. At baseline, we found a metabolic pattern corresponding well with highly proliferating tumor tissue–i.e., high levels of amino acids, their metabolites, and other metabolic end products and low levels of sugar derivatives, antioxidants, and nucleotides. During the loco-regional therapy, we observed a clearly localized cytotoxic effect within the tumor and a metabolic response pattern corresponding with cisplatin’s complex mechanism of action, affecting several metabolic pathways within the malignant cell. Glutamate and glycerol also increased in tumor tissue following loco-regional treatment, a finding that further supported the observation of local toxicity.In study III, we investigated microdialysis as a method to assess the microenvironment in high-grade glioma and as a method for drug delivery (retrograde microdialysis). All studies demonstrated the usefulness of microdialysis as a tool for in vivo real-time assessment of molecular events in malignant glioma tissue. Although the method is invasive, no complications related to the surgical procedure or assessment were noted. In study III, we also demonstrated that retrograde microdialysis is a feasible method for locally delivering clinically significant doses of drugs such as cisplatin to tumor tissue in the brain. However, in addition to having a cytotoxic effect on tumor cells, cisplatin may induce clinically significant edema.
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| 5. |
- Wibom, Carl, 1977-
(författare)
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Multivariate analyses of proteomic and metabolomic patterns in brain tumors
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Glioblastoma multiforme (GBM) is the most common primary brain tumor. Given the current standard of care, the prognosis for patients diagnosed with this disease is still poor. There consequently exists a need to improve current treatments, as well as to develop new ones. Many obstacles however need to be overcome to facilitate this effort and one of these involves the development of improved methods to monitor treatment effects. At present, the effects of treatment are typically assessed by radiological means several months after its initiation, which is unsatisfactory for a fast growing tumor like GBM. It is however likely that treatment effects can be detected on a molecular level long before radiological response, especially considering many of the targeted therapies that are currently being developed. Biomarkers for treatment efficacy may be of great importance in the future individualization of brain tumor treatment. The work presented herein was primarily focused on detecting early effects of GBM treatment. To this end, we designed experiments in the BT4C rat glioma model in which we studied effects of both conventional radiotherapy and an experimental angiogenesis inhibitor, vandetanib. Brain tissue samples were analyzed using a high throughput mass spectrometry (MS) based screening, known as Surface Enhanced Laser Desorption/Ionization - Time of Flight - Mass Spectrometry (SELDI-TOF-MS). The vast amounts of data generated were subsequently analyzed by established multivariate statistical methods, such as Principal Component Analysis (PCA), Partial Least Squares (PLS), and Orthogonal Partial Least Squares (OPLS), developed for analysis of large and complex datasets. In the radiotherapy study we detected a protein spectrum pattern clearly related to tumor progression. We notably observed how this progression pattern was hampered by radiotherapy. The vandetanib study also revealed significant alterations of protein expression following treatment of different durations, both in tumor tissue and in normal brain contralateral to the tumor. In an effort to further elucidate the pathophysiology of GBM, particularly in relation to treatment, we collected extracellular fluid (ECF) samples from 11 patients diagnosed with inoperable GBM. The samples were collected by means of stereotactic microdialysis, both from within the contrast enhancing tumor and the brain adjacent to tumor (BAT). Samples were collected longitudinally from each patient in a time span of up to two weeks, during which the patient received the first five fractions of radiotherapy. The ECF samples were then analyzed by Gas Chromatography Mass Spectrometry (GC-MS) to screen them with respect to concentrations of low molecular weight compounds (metabolites). Suitable multivariate analysis strategies enabled us to extract patterns of varying metabolite concentrations distinguishing between samples collected at different locations in the brain as well as between samples collected at different time points in relation to treatment. In a separate study, we also applied SELDI-TOF-MS and multivariate statistical methods to unravel possible differences in protein spectra between invasive and non-invasive WHO grade I meningiomas. This type of tumor can usually be cured by surgical resection however sometimes it grows invasively into the bone, ultimately causing clinical problems. This study revealed the possibility to differentiate between invasive and non-invasive benign meningioma based on the expression pattern of a few proteins. Our approach, which includes sample analysis and data handling, is applicable to a wide range of screening studies. In this work we demonstrated that the combination of MS screening and multivariate analyses is a powerful tool in the search for patterns related to treatment effects and diagnostics in brain tumors.
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