Trattamento endovascolare con spirali degli aneurismi cerebrali

Dal maggio 93 al giugno 95 sono stati trattati per via endovascolare 48 aneurismi in 47 pazienti, utilizzando fibered coils nei primi 6 casi e GDC in 42. In 26 casi il trattamento è stato effettua-to in acuto dopo emorragia subaracnoidea; di questi 14 presentavano condizioni cliniche scadenti ed erano stati giudicati inoperabili. 6 aneurismi erano localizzati a livello del circolo posteriore, 42 a livello del circolo anteriore.

Una occlusione completa è stata ottenuta in 30 casi su 48 (62% circa), un occlusione subtotale (>70%) e parziale (<70%) rispettivamente in 12 (25, 5%) e 2 (4%) casi. Per motivi tecnici non fu possibile trattare 4 pazienti (8, 5%). Si sono verificate 2 perforazioni della sacca durante il trattamento (4%): in entrambi i casi si ottenne l'occlusione dell'aneurisma con arresto dell'emorragia senza aggravamento clinico.

Nonostante l'eparinizzazione sistemica si sono verificati deficit neurologici da probabile tromboem-bolia in 8 casi: in 4 (8%) il recupero clinico è stato rapido e completo, in 2 (4%) è residuato un modesto deficit, 2 pazienti infine (4%), in gravissime condizioni cliniche, sono deceduti nei giorni successivi.

Role of Nitric Oxide in Glioblastoma Therapy: Another Step to Resolve the Terrible Puzzle ?

Glioblastoma Multiforme, the most common and aggressive primary brain tumor, remains incurable despite of the advent of modern surgical and medical treatments. This poor prognosis depends by the recurrence after surgery and intrinsic or acquired resistance to chemotherapy and radiotherapy. Nitric oxide is a small molecule that plays a key roles in glioma pathophysiology. Many researches showing that NO is involved in induction of apoptosis, radiosensitization and chemosensitization. Therefore, NO role, if clarified, may improve the knowledge about this unsolved puzzle called GBM.

Different quantification algorithms may lead to different results: a comparison using proton MRS lipid signals

Proton magnetic resonance spectroscopy (MRS) is a sensitive method for investigating the biochemical compounds in a tissue. The interpretation of the data relies on the quantification algorithms applied to MR spectra. Each of these algorithms has certain underlying assumptions and may allow one to incorporate prior knowledge, which could influence the quality of the fit. The most commonly considered types of prior knowledge include the line-shape model (Lorentzian, Gaussian, Voigt), knowledge of the resonating frequencies, modeling of the baseline, constraints on the damping factors and phase, etc. In this article, we study whether the statistical outcome of a biological investigation can be influenced by the quantification method used. We chose to study lipid signals because of their emerging role in the investigation of metabolic disorders. Lipid spectra, in particular, are characterized by peaks that are in most cases not Lorentzian, because measurements are often performed in difficult body locations, e.g. in visceral fats close to peristaltic movements in humans or very small areas close to different tissues in animals. This leads to spectra with several peak distortions. Linear combination of Model spectra (LCModel), Advanced Method for Accurate Robust and Efficient Spectral fitting (AMARES), quantitation based on QUantum ESTimation (QUEST), Automated Quantification of Short Echo-time MRS (AQSES)-Lineshape and Integration were applied to simulated spectra, and area under the curve (AUC) values, which are proportional to the quantity of the resonating molecules in the tissue, were compared with true values. A comparison between techniques was also carried out on lipid signals from obese and lean Zucker rats, for which the polyunsaturation value expressed in white adipose tissue should be statistically different, as confirmed by high-resolution NMR measurements (considered the gold standard) on the same animals. LCModel, AQSES-Lineshape, QUEST and Integration gave the best results in at least one of the considered groups of simulated or in vivo lipid signals. These outcomes highlight the fact that quantification methods can influence the final result and its statistical significance.

New strategies for repairing the injured spinal cord: the role of stem cells

Thanks to advances in the stem cell biology of the central nervous system, the previously unconceivable regeneration of the damaged spinal cord is approaching reality. A number of potential strategies aim to optimize functional recovery after spinal cord injury. They include minimizing the progression of secondary injury, manipulating the inhibitory environment of the spinal cord, replacing lost tissue with transplanted cells or peripheral nerve grafts, remyelinating denuded axons and maximizing the intrinsic regenerative potential of endogenous progenitor cells. We review the application of stem cell transplantation to the spinal cord, emphasizing the use of embryonic stem cells for remyelinating damaged axons. Recent advancements in neural injury and repair, and the progress towards development of neuroprotective and regenerative interventions are discussed.

Stem cells based therapy in high grade glioma: why the intraventricular route should be preferred?

AIM

Mesenchymal stem cells (MSCs) migrate in response to chemokines and possess extensive tropism for experimental glioma. Antitumor effects have been reported following intracranial and intravenous administration of gene-modified MSCs. Among the different routes for cell transplant, the intraventricular (IV) approach found very little employment in comparison with intraparenchymal, intratumoral and intravenous administration protocols. Nevertheless, IV transplantation offers advantages in terms of cells viability and distribution toward target sites, opening interesting opportunities for its clinical application.

METHODS

Using a rat glioma model, we investigated migratory capacity, tumor tropism, distribution and differentiation of MSCs following IV administration.

RESULTS

Transplanted MSCs create niches of viable cells in the subventricular zone and can be stimulated to migrate to sites of tumor infiltration. MSCs seemed not to be involved in tumor growth and angiogenesis.

CONCLUSION

We speculate that the IV route can be used to achieve a kind of reservoir of self-renewal cells, potentially active against the spread of cancer cells. Further studies are needed to shed light on MSCs distribution close to the ventricular wall, in order to define their lifespan and their capacity to migrate towards new-enhancing foci time after implantation.

Recent therapeutic strategies for spinal cord injury treatment: possible role of stem cells

Spinal cord injury (SCI) often results in significant dysfunction and disability. A series of treatments have been proposed to prevent and overcome the formation of the glial scar and inhibitory factors to axon regrowth. In the last decade, cell therapy has emerged as a new tool for several diseases of the nervous system. Stem cells act as minipumps providing trophic and immunomodulatory factors to enhance axonal growth, to modulate the environment, and to reduce neuroinflammation. This capability can be boosted by genetical manipulation to deliver trophic molecules. Different types of stem cells have been tested, according to their properties and the therapeutic aims. They differ from each other for origin, developmental stage, stage of differentiation, and fate lineage. Related to this, stem cells differentiating into neurons could be used for cell replacement, even though the feasibility that stem cells after transplantation in the adult lesioned spinal cord can differentiate into neurons, integrate within neural circuits, and emit axons reaching the muscle is quite remote. The timing of cell therapy has been variable, and may be summarized in the acute and chronic phases of disease, when stem cells interact with a completely different environment. Even though further experimental studies are needed to elucidate the mechanisms of action, the therapeutic, and the side effects of cell therapy, several clinical protocols have been tested or are under trial. Here, we report the state-of-the-art of cell therapy in SCI, in terms of feasibility, outcome, and side effects.

Luminescence and fluorescence of essential oils. Fluorescence imaging in vivo of wild chamomile oil

Essential oils are currently of great importance to pharmaceutical companies, cosmetics producers and manufacturers of veterinary products. They are found in perfumes, creams, bath products, and household cleaning substances, and are used for flavouring food and drinks. It is well known that some of them act on the respiratory apparatus. The increasing interest in optical imaging techniques and the development of related technologies have made possible the investigation of the optical properties of several compounds. Luminescent properties of essential oils have not been extensively investigated. We evaluated the luminescent and fluorescent emissions of several essential oils, in order to detect them in living organisms by exploiting their optical properties. Some fluorescent emission data were high enough to be detected in dermal treatments. Consequently, we demonstrated how the fluorescent signal can be monitored for at least three hours on the skin of living mice treated with wild chamomile oil. The results encourage development of this technique to investigate the properties of drugs and cosmetics containing essential oils.

Fast and minimally invasive determination of the unsaturation index of white fat depots by micro-Raman spectroscopy

In the last 20 years increasing interest has been devoted to the investigation of white adipose tissue (WAT) because hypo- or hyperfunction of WAT is involved in the pathogenesis of obesity and other pathologies. The investigation and discrimination of different characteristics in adipose tissues by means of spectroscopic techniques appears as a topic of current interest, also in view of possible medical-technological applications. The aim of this work was to establish micro-Raman spectroscopy as a tool for the characterization of mammals fat tissue. After preliminary tests aimed at defining a suitable sample preparation protocol, Raman spectra of WAT specimens excised from mice of different ages were recorded in the energy range 750-3,350 cm⁻¹. Quantitative values of the unsaturation index were obtained through the calibration with HR-NMR spectra of lipid extracts. Raman spectroscopy detected a sharp increase in the unsaturation index between 22 and 30 days of age in close correspondence with the weaning of mice (21 days). The present results show that Raman spectroscopy is an inexpensive, fast and robust technique to analyze the unsaturation index of mammals fat tissues that could be routinely used in bioptic samples.

Interleukin 6 gene polymorphisms are not associated with aneurysmal subarachnoid haemorrhage in an Italian population

OBJECTIVE

Several lines of evidence indicate a role for inflammatory processes in the development of cerebral aneurysms. Recently, polymorphisms in the promoter region of the interleukin 6 (IL6) gene were shown to be associated with intracranial aneurysmal disease. The purpose of this study was to verify the association of two functionally active polymorphisms (-174 G>C and -572 G>C) in the promoter region of the IL6 gene with the risk and clinical features of aneurysmal subarachnoid haemorrhage (SAH) in an Italian population.

METHODS

A total of 179 consecutive aneurysmal SAH patients and 156 healthy controls were involved in the study. Cases and controls were genotyped for the -174 G<C and the -572 G<C biallelic polymorphisms of the IL6 gene. The frequencies of different promoter haplotypes were compared between cases and controls.

RESULTS

Allelic and genotypic frequencies of the examined polymorphism were not significantly different between cases and controls. Inferred haplotypes were not significantly different in both groups. Finally, the different IL6 genotypes did not seem to significantly modify the main clinical features of the disease.

CONCLUSIONS

Our study did not confirm the association between functionally active polymorphisms in the IL6 gene and the risk of aneurysmal SAH in an Italian population. Additional studies in different populations are warranted to clarify the role of the IL6 gene in the pathogenesis of aneurysmal SAH.

Periprocedural morbidity and mortality by endovascular treatment of cerebral aneurysms with GDC: a retrospective 12-year experience of a single center

Despite increasing experience and improved material, endovascular treatment of cerebral aneurysms still has risks linked to the technique itself and to the specificity of the pathology treated. The purpose of this report is to examine procedural technical and clinical negative events, even minimal ones, occurring in this type of treatment. We considered 557 procedures carried out from January 1994 to December 2005 in 533 patients harboring 550 aneurysms. Of the patients, 448 presented with SAH and 85 with unruptured aneurysms. All procedures were performed under general anesthesia. The GDC-10 system was routinely used. Additional devices like the balloon remodeling technique, Trispan and stents were also occasionally used. Every procedural complication occurring during or soon after treatment was registered. Endovascular treatment was completed in 539 out of 557 procedures. There were 18 failures (3.3%). Occlusion of the aneurysm was judged complete in 343 (64%), near complete in 184 (34%) and incomplete in 12 (2%). Procedural complications occurred in 72 (13%) of the cases. The most frequent negative events were thromboembolisms (6.6%) and ruptures (3.9%). Other types (coil migration, transient occlusions of the parent vessel, dissections and early rebleeding) were rarer (2.5%). In the majority of cases there were no clinical consequences. Procedural morbidity and mortality were 1.1 and 1.8%, respectively. Considering the 449 procedures performed in ruptured and the 90 in the unruptured aneurysms separately, morbidity and mortality were 1.1 and 2.2% in the former group and 1.1 and 0% in the latter. Many factors influence the risk of complications. Being progressively aware of this and with increasing experience, the frequency can be limited. Negative events linked to the procedure have more significant serious clinical consequences in patients admitted in a critical clinical condition after SAH, because of the already present changes involving the brain parenchyma and cerebral circulation.

Presence of Shiga toxin-producing Escherichia coli O157:H7 in living layer hens

AIMS

To evaluate the presence of Shiga toxin-producing strains of Escherichia coli (STEC) of the O157:H7 serotype in living layer hens so as to analyse the role of this avian species as potential reservoir.

METHODS AND RESULTS

Cloacal swabs were collected between November 2004 and November 2005 from four intensive management layer hen farms and analysed for STEC O157:H7 by immunomagnetic separation methods and multiplex polymerase chain reaction for stx1 and/or stx2, the E. coli attaching and effacing (eae) and hly genes. STEC was detected in 26 of the 720 samples.

CONCLUSIONS

The layer hens analysed were shown to carry STEC O157:H7. The presence of this bacterium in living layer hen farms investigated did not result in any detectable increase in gastrointestinal disease in this species.

SIGNIFICANCE AND IMPACT OF THE STUDY

Living layer hens are a novel potential reservoir of E. coli O157:H7.

Endovascular treatment of cerebral aneurysms in elderly patients

We report our experience in the endovascular treatment with detachable platinum coils of ruptured or symptomatic unruptured cerebral aneurysms in 61 patients aged 70-82 years. Complete occlusion was achieved in 38, subtotal in 17 and partial in one. The treatment failed in five patients. Clinical follow-up was performed in all patients for 8 months to 8 years. No bleeding occurred during the follow-up period. Outcome was favourable in 63% of the patients. When we compared the outcome of elderly patients with those of younger age endovascularly treated in the same period of time, we found a significantly higher frequency of poorer outcome in the elderly group (chi(2) = 9.084; P = 0.011). The frequency of favourable outcome in the elderly was significantly lower than in the younger group for H-H IV-V (chi(2) = 9.299; P = 0.010). The most important factor influencing the outcome was not age itself, but primary clinical condition on admission. The therapy of symptomatic aneurysms in elderly patients should not be purely conservative--a direct approach of the aneurysm should be considered. Endovascular treatment whenever possible seems to be a good alternative to surgery.

Neuropsychological assessment after microsurgical clipping or endovascular treatment for anterior communicating artery aneurysm

BACKGROUND

After open surgery for ruptured ACoA aneurysms, several patients who have achieved a favourable neurological outcome still exhibit significant cognitive deficits. The aim of this study was to investigate the cognitive performances in patients with ACoA aneurysms submitted to different therapeutic options such as endovascular treatment and surgical clipping.

METHODS

We evaluated 37 consecutive patients in WFNS grade I or II, who underwent an early treatment (within 48 hours) of a bleeding ACoA aneurysm: 20 out of 37 were surgically clipped (group A) and 17 were treated with endovascular coiling (group B). These two groups were compared with 16 patients (group C) with subarachnoid haemorrhage and negative cerebral panangiography and with 18 volunteers (group D) without neurological or psychiatric disorders. All patients were neurologically intact at discharge and were in Glasgow Outcome Scale 1 at 6 months follow-up after SAH. All subjects were tested to assess selective attention, verbal, spatial and logical memory, frontal lobe executive functions, language and intelligence. Depressive symptoms and anxiety were also examined.

FINDINGS

Selective attention, verbal and spatial memory, and intelligence tests didn't show any significant difference between the patients and the controls. Surgically treated patients showed a significant worse performance on the logical memory and on the frontal lobe executive functions compared to controls, while the endovascular group and the group C (not treated) showed a significant decrease only in the literal fluency score.Moreover, the surgical group showed a significant impairment in using grammatical and syntactical rules to produce sentences. No significant difference was found between the group B, C and controls. Treated patients were not significantly more depressive or anxious than controls.

INTERPRETATION

Investigation of neuropsychological deficits can show an impairment, even in patients classified as good outcome by Glasgow Outcome Scale (GOS). The frontal lobe functions and language are impaired especially in surgically treated in comparison with controls, but no significant difference was found respect to the endovascular and no treated patients (group C).

Nitric oxide synthase and cytochrome c oxidase changes in the tumoural and peritumoural cerebral cortex

BACKGROUND

We analysed changes in nitric oxide synthase (NOS) and cytochrome oxidase (CO) activities in the tumoural and peritumoural cerebral cortex in order to investigate: a) the role of NO in tumourigenesis, in TBF regulation, and in vasogenetic PBE; b) the metabolic changes caused by the neoplasm in the surrounding tissues.

METHOD

Intra-operative samples of cerebral cortex were studied by means of immunohistochemistry for nNOS and iNOS, and by histochemistry for NADPH-diaphorase (NADPH-d) and CO.

FINDINGS

In contrast with normal cortex, reactive glial cells and the endothelium of small blood vessels displayed strong NADPH-d and iNOS activities in oedematous peritumoural tissue. In the tumoural cortex, NADPH-d and nNOS-positive neurones were reduced in number and their dendrites were thin and interrupted, and infiltrates of NADPH-d and iNOS-positive tumoural cells were frequent. CO activity was decreased in the deep layers of peritumoural cortex, and it was almost absent in the tumoural cortex.

INTERPRETATION

In peritumoural and tumoural cortex changes in NOS and CO activities suggest that the coupling between neuronal activity and blood flow is impaired in the damaged cerebral cortex, and that the increase in NOS activity may play a role in tumour vascularization and progression.

Sudden presentation of intracranial meningioma after elective general anesthesia

A case of "silent" intracranial meningioma unmasked by narcosis is described. The diagnosis was made because of the patient's failure to wake up after elective general anesthesia for orthopaedic surgery. Factors leading to this complication and its management are discussed. Early computed tomography scan and antiedema therapy are strongly suggested for these patients.

[Pharmacologic therapy of subarachnoid hemorrhage]

Medical treatment of subarachnoid haemorrhage, is focused on the prevention of rebleeding and vasospasm, of damages of oxitading products, and on the improvement of general conditions of the patient. Some authors consider use of antifibrinolytic usefull to reduce the risk of rebleeding, but the percentage of hydrocephalus and ischemia are increased. In our Centre combination of nimodipine-cloricromene and hemodilution is used for the prevention of vasospasm. We report conclusions about 216 patients in I-II-III grade of Hunt-Hess scale, treated before 48 hours from SAH. We obtained only 8% postspasm ischemias, with no neurological deficit, and only 23% of increased cerebral blood flow revealed by transcranial Doppler. Cloricromene is used only after aneurysm is occlused. It presents different action mechanisms. It is an inhibitor of platelet activation and aggregation, of cyclooxygenase and lipooxygenase activity, so reducing thromboxanes ratio. Phospholipase A2 inhibition it's possible but not demonstrated. It also interferes with phosphoinositoles path and so with proteinkinase C activity, and reduces hemostatic thrombotic balance activation and leukocyte endothelial adhesion and activation. It reduces, finally, the release of free radicals, cytokines inflammation amplyfing. The reduced damage to the endothelium allows the releasing of vasodilatatory agents like NO.

[Therapeutic decisions and grading of subarachnoid hemorrhage]

Early admission and medical treatment can improve prognosis in patients with subarachnoid hemorrhage (SAH). In our Centre in 10 years, 595 patients with SAH have been treated: 422 were admitted within 24 hours (71%) and 498 (84%) within 72 hours. 374 underwent surgical treatment: 283 within 48 hours and 91 underwent late surgery. Thirty-three patients underwent emergency surgery for intracranial hematomas, with a mortality rate of 30%. One hundred eighty-one patients in Hunt-Hess grade I-II underwent early surgery. Mortality rate was 7%. Mortality rate for rebleeding, when surgery was delayed was more than 10%. Patients in Hunt-Hess grade III underwent early surgery in the majority of cases (68 out of 111). Only in 52% of cases surgical result was good. Thirty-four out of 108 in grade IV-V underwent early surgery, with a mortality rate of 45%. The analysis of general results shows that early surgery improves prognosis in Hunt-Hess grade III patients. Also patients in Hunt-Hess grade III-IV-V can take advantage of early surgery. Old age, arterial hypertension and angiographical vasospasm do not worsen prognosis even in patients operated on early. Endovascular treatment even in acute phase has improved results especially in cases of certain aneurysms types such as posterior circulation aneurysms.

False-negative angiograms in subarachnoid haemorrhage due to intracranial aneurysms

Of 440 patients with spontaneous subarachnoid haemorrhage in whom an aneurysm was suspected, 60 had a negative angiogram. A second angiogram performed 1-4 weeks later revealed an aneurysm in 5 of 40 cases. Of these patients, 3 had a second haemorrhage. In all cases, diffuse bleeding, with involvement of the anteroinferior interhemispheric fissure, was present on CT. There were three aneurysms of the anterior communicating artery and two of the carotid siphon. The reasons for the false-negative angiograms and the usefulness of repeated angiography are discussed.