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Biomedical subjects

F Signorelli

Publications and source records attributed to F Signorelli.

At least 19 recordsLinked to original sources
PubMed2005

[Usefulness of direct electrical stimulations during surgery for gliomas located within eloquent brain regions].

Glioma surgery in functional areas has undergone a dramatic development these last few years, thanks to improvements in both intraoperative functional imaging and direct electrical stimulation of cortical areas or association pathways. The goal of these techniques to achieve complete as possible surgical removal of tumors located in eloquent areas (sensitive, motor and language areas) with minimal risk of permanent sequelae. To be reliable, a rigorous methodology is required. Current cortical mapping is very easy to achieve, whereas mapping of association pathways will require much more experience. In case of tumors located in somatosensorial or language areas, the difficulties related to accurate sub cortical localization are combined with these of local anesthesia and the best task choice to evaluate the integrity of cognitive functions. These functional techniques allow total or sub total removal in 52% to 76.2% of patients. Transient worsening is observed in 13% to 80% of the patients; the rate of permanent sequelae averages 4%.

Brain Mapping↗
PubMed2003

One-trocar laparoscopy: a valid procedure to treat abdominal complications in children with peritoneal shunt for hydrocephalus.

BACKGROUND: The aim of this paper is to show the efficacy of laparoscopy using only one umbilical trocar to treat abdominal complications of hydrocephalic children with ventriculoperitoneal shunts (VPS). MATERIALS AND METHODS: In a 15-year period, 14 laparoscopies were performed on as many children with VPS complications: in the last 4 patients only one trocar was used to solve the complications, and this subgroup will be the object of the present study. Concerning the indication for surgery, the patients presented one catheter lost in the abdominal cavity; one cerebrospinal fluid pseudocysts; one bowel obstruction; and one malfunctioning peritoneal limbs of the catheter. We used the one-trocar laparoscopic approach in all the 4 patients, and the 10-mm trocar was always introduced through the umbilical orifice in open laparoscopy. RESULTS: The laparoscopic technique was curative in all four cases and permitted the solution of the complication. CONCLUSIONS: One-trocar laparoscopic surgery can be considered as the ideal procedure in case of abdominal complications of VPS in children with hydrocephalus.

Abdominal Cavity↗
PubMed2003

Technical refinements for validating functional MRI-based neuronavigation data by electrical stimulation during cortical language mapping.

Preoperative functional neuroimaging techniques represent an appealing method to localize language areas in tumor surgery, but their reliability still needs to be confirmed by accurate comparison with more invasive but validated mapping techniques like intraoperative electrical cortical stimulation. Two patients harboring a glioma involving speech areas underwent mapping of language function by preoperative functional magnetic resonance imaging (fMRI), whose results were integrated into the neuronavigation device, and by intraoperative electrical stimulation mapping (ESM). The utilization of neuronavigation allowed us to estimate the degree of spatial correspondence between language areas detected by the two techniques. Language areas identified by functional magnetic resonance imaging on the cerebral cortex exposed during surgery corresponded to those identified by invasive mapping in both patients. It was possible to achieve a gross total tumor removal while respecting language areas in both cases, with no permanent postoperative phasic aggravation. The concordance of results between pre- and intraoperative mapping techniques in our patients indicates that preoperative fMRI language mapping may prove useful when planning the resection of intracerebral lesions in language areas. However, accurate neurofunctional imaging protocols and image analysis are crucial to obtain a preoperative language mapping that is in agreement with ESM findings.

Brain Mapping↗
PubMed2003

Effects of Ginko Biloba and caspase inhibitors on brain ischemia in the Mongolian Gerbil.

AIM: Data reported in previous studies and our own previous experience have led us to explore the mechanism of and the degree of protection afforded by Ginko Biloba in a model of cerebral ischemia in the Mongolian Gerbil evaluating histological and neurological effects in this rodent. METHODS: Mongolian Gerbils were divided into experimental groups: Group A consisted of animals subjected only to experimental ischemia; 5 minutes occlusion of the carotid arteries. Group B consisted of animals subjected to experimental ischemia and to a dose of Ginko Biloba, given intraperitoneally immediately before the surgical procedure. Group C consisted of animals subjected to experimental ischemia and to a dose of Ginko Biloba, given intraperitoneally immediately after the surgical procedure. Group D consisted of animals subjected to experimental ischemia and to a dose of the caspase inhibitors z-VAD.FMK and z-DEVD.FMK injected intracerebroventricularly through the right hemisphere before the surgical procedure. Group E consisted of animals subjected to experimental ischemia and to a dose of caspase inhibitors injected after the surgical procedure. Group F consisted of Sham-operated animals. Histological controls were done by H and E and the TUNEL method in the frontal cortex and caudate-putamen. RESULTS: The percentage of normal cells was not statistically significant at analysis with H and E, whereas the TUNEL method showed good protection with Ginko Biloba and caspase inhibitors, when the latter is given in the reperfusion phase. These data were in agreement with data obtained at neurological examination. CONCLUSION: We could say that cellular morphology is in itself an untrustworthy tool for judging the effects of ischemia and protective drugs; the TUNEL method may add important information about the different components of cellular death; the reperfusion phase may be critical for apoptotic phenomena; Ginko Biloba might protect neurons of the frontal cortex from both necrotic and apoptotic death in this model of ischemia.

Amino Acid Chloromethyl Ketones↗
PubMed2002

Intracranial ependymomas in adult patients: analyses of prognostic factors.

OBJECTIVE: The goal of our study is to identify significant prognostic factors for a series of intracranial ependymomas in an adult population. Age, location, histology, preoperative clinical status, extent of resection and radiotherapy were examined. METHODS: Our series includes 34 patients. Ten tumors were located in the brain parenchyma, 5 in the lateral ventricle, 8 in the third and 11 in the fourth ventricle. Seventeen ependymomas were grades 2 and 17 were anaplastic. Surgical resection was gross-total in 27 patients and partial in 7. RESULTS: At a mean follow-up of 9 years (+/- 1 year) 16 patients died and, among the 18 survivors 14 are in complete remission and 4 present a local recurrence. The 5- and 10-year overall survival rates were respectively 62% and 43%. The 5- and 10-year progression-free survivals were 47% and 43%. Univariate analysis revealed that location in the brain parenchyma and anaplasia are the only statistically significant predictors of poor outcome. CONCLUSION: We can make out three groups of patients from our series: the first encompasses patients operated on for an intraparenchymal tumor, in all our cases an anaplastic ependymoma, with a 5-year rate of tumor-related deaths of 100%. The second group includes fourth ventricle ependymomas, which are mostly grade 2 tumors. They display a 10-year survival rate of 90%. Last group entails lateral and third ventricle ependymomas, of both low and high grade, with a 10-year survival rate of 60% for lateral ventricle and 35% for third ventricle tumors.

Adult↗
PubMed2001

Differential expression of somatostatin receptors in ependymoma: implications for diagnosis.

Somatostatin receptors (SSts) have been found in a variety of brain tumors, e.g., meningiomas, medulloblastomas and astrocytomas. Our aim was to investigate their expression in ependymomas. Using RT-PCR, expression of mRNA for the different SSt subtypes was analyzed and quantified in 28 ependymomas and correlated with different variables (age, tumor location, histological grade, recurrence and survival). In addition, in 8 cases, protein expression was studied in vitro, using immunohistochemistry, and in vivo, by somatostatin scintigraphy. mRNAs for all 5 subtypes were variably expressed in each ependymoma. The Southern blotting signal obtained after SSt(1) and SSt(2) amplification was higher than that for the other receptor subtypes. No significant correlation was seen between the level of SSt(1) and SSt(2) mRNA expression and age, location, histological grading, recurrence or survival. In the 8 cases, SSt(1) staining was negative in 3 and low in 5. Staining for SSt(2A) was positive but low in every specimen analyzed. SSt(1) and SSt(2) immunoreactivity was seen only in the cytoplasm of tumoral cells. Somatostatin scintigraphy showed clear uptake, which agreed with MRI data in the majority of cases. However, no correlation was seen between tracer uptake intensity and histological grade, SSt(1) and SSt(2) mRNA expression or immunostaining intensity. This evidence for the expression of SSt(2) receptors in ependymomas opens interesting prospects for their follow-up.

Adolescent↗
PubMed2001

The value of cortical stimulation applied to the surgery of malignant gliomas in language areas.

This study analyzes the utility of peroperative cortical language mapping applied to the surgery of high-grade gliomas situated within or in close vicinity to speech areas. Fifteen consecutive patients harboring high-grade gliomas located in the dominant hemisphere, causing regressive or minor language troubles, underwent awake craniotomy in our institution between June 1998 and April 2000. The technique of cortical stimulation under local anesthesia for language mapping, initially described by Ojemann and colleagues, was applied with some modifications. All patients tolerated awake craniotomy except one, who was intubated after the mapping procedure. Mapping results confirmed a high variability in location of language sites. It was possible to achieve a gross total tumor removal in all cases. Nine patients (60%) exhibited a transient postoperative aggravation. Two patients (13%) presented permanent phasic aggravation. One patient died 16 days after surgery from pulmonary embolism. Five patients died for tumor progression, with a mean survival time of 16.4 months and a median high-quality survival period of 14.2 months. With a mean follow-up of 9.9 months (range, 18-6 months), the 9 survivors are recurrence-free and reveal no significant change in linguistic abilities. This technique is well tolerated and consents to maximize the extent of surgical removal while minimizing the risks of permanent postoperative deficits. This results in an improvement of survival and quality of life.

Adult↗
PubMed2001

Differential expression of somatostatin receptors in medulloblastoma.

OBJECT: Somatostatin receptors have been found on a variety of tumours like neuroendocrine breast or brain tumours. Their detection opens new diagnostic and therapeutic paths. The aim of this work was to investigate their expression in medulloblastomas. METHODS: Using both techniques, reverse transcriptase-polymerase chain reaction and immunohistochemistry, we analysed mRNA of different subtypes of somatostatin receptors in 15 medulloblastomas and the localisation of the subtype SSTR2 receptor at the cellular level in 13 medulloblastomas. All five subtypes mRNA were variably expressed in each medulloblastoma. The signal obtained after Southern blotting for SSTR2 receptor amplification was the highest as compared to the signal obtained for the other receptor subtypes. Immunostaining for SSTR2A receptor was present in every tumour specimen and was specifically located to the cellular membrane of neoplastic cells. No staining was identified at the level of peritumoral veins. CONCLUSION: The evidence of predominant expression of SSTR2 receptors in medulloblastomas opens interesting prospects for their diagnosis and therapy.

Cerebellar Neoplasms↗
PubMed2001

[Perioperative cortical stimulation of language fields under local anesthesia in preparation to excision of tumors of the dominant hemisphere].

OBJECTIVES: The aim of this study is to demonstrate the accuracy of direct cortical stimulation of language areas preparatory to the removal of infiltrating tumors of dominant hemisphere. MATERIAL AND METHODS: From June 1998 to March 2000 we included in our study 15 patients, aged from 30 to 75 years, harboring gliomas (14 high grades and 1 low grade) close to language-specific cortex. All patients had slight inaugural phasic troubles. They underwent craniotomy under local anesthesia for cortical stimulation language mapping, in conjunction with electrocorticography to identify the after-discharge threshold. Stimulation mapping covered the entire macroscopically tumor involved area, extending up to 3 cm away from the margins of the lesion, without searching to identify systematically the language areas. Therefore, the lesion was removed as completely as possible, respecting a security margin of at least 1 cm from the recognized language sites. RESULTS: We identified from 1 to 6 language sites for 14 of our patients, in different locations. A radical removal was achieved for all high grade gliomas, while the low grade was only partially removed. A patient died on the 16th postoperative day from pulmonary embolism; 2 patients deteriorated from peri- or immediate postoperative complications; 9 showed a transient neurological worsening that receded by the 2nd postoperative month, while 3 did not present any postoperative aggravation. At a follow-up of 1 month to 2 years (mean 8 months), 6 patients died and the 9 survivors maintain a good life quality. CONCLUSIONS: Cortical stimulation for language mapping is an accurate technique that allows the surgical morbidity of lesions in proximity to language areas to decrease and become comparable to the surgical morbidity for lesions in non eloquent areas.

Adult↗
PubMed2000

Tentorial meningiomas. Report on twenty-seven cases.

OBJECTIVE: Report our experience with 27 tentorial meningiomas (TM) surgically treated between 1985 and 1998. METHODS: The records of 27 patients with TMs were retrospectively reviewed for clinical presentation, neuroradiological evaluation, surgical treatment and long-term outcome. The extent of tumor resection was scored according to the Simpson's grading for tumor removal. Long-term results were evaluated according to the Glasgow Outcome Score (GOS). RESULTS: The average age was 53 years. Female predominance was 74%. The most common complaints at presentation were headaches (51%), gait ataxia (33%), memory disturbances (30%) and hypoacousia (30%). A classification of TMs into 5 subgroups according to tumor site is proposed on the basis of imaging studies. A cerebrospinal fluid shunt was established prior to direct approach in 7 patients and as the sole procedure in one inoperable patient. Twenty-seven direct approaches were undertaken in 26 patients, including 17 infratentorial and 10 supratentorial approaches. Total tumor removal was achieved in 20 patients (77%) and subtotal removal in 6 (23%). Fifteen patients (55%) experienced 22 postoperative complications. One patient died three months after a subtotal resection (mortality = 3.7%). With a mean follow-up of 54 months, all 26 survivors are currently alive with 23 having resumed their normal activities and 3 needing assistance. Five of 6 patients with subtotal resection survived and were followed for a period ranging from 72 to 132 months: none showed residual tumor progression and no re-operation was considered. An additional patient experienced a ( ) recurrence 6 years after total removal, with no tumor progression 2 years after his recurrence was recognized. DISCUSSION: The best surgical approach to TMs is still a controversial matter. The advantages and drawbacks of conventional versus transbasal approaches are reviewed. Our experience suggests that subtotal removal can be associated with long recurrence-free intervals and preserved quality of life. TMs located at the tentorial edge carried a definitely worse prognosis than peripheral forms.

Adult↗
PubMed1999

Ischaemic pre-conditioning in organotypic hippocampal slice cultures is inversely correlated to the induction of the 72 kDa heat shock protein (HSP72).

In vivo, preconditioning with a sublethal insult can confer resistance to normally lethal episodes of cerebral ischaemia. This phenomenon has been linked with the induction of the 72 kDa heat shock protein (HSP72), but this has not been clearly demonstrated in vitro. We have used organotypic hippocampal slice cultures to investigate whether tolerance to lethal ischaemia is dependent on HSP72. Cultures were maintained in vitro for 14 days, and neuronal damage assessed using propidium iodide fluorescence. Prolonged neuronal HSP72 upregulation occurred following exposure to 30 min ischaemia, 45 min hypoxia and 1 microM kainate, but not 1 microM NMDA or 20 min ischaemia, all sublethal insults. Preconditioning with ischaemia, kainate or hypoxia 24 h prior to lethal ischaemia (45 min) was not protective, and when the delay was increased to 48 h, damage in the CA3 pyramidal cell region was significantly increased compared to cultures exposed to 45 min ischaemia alone. Preconditioning with 20 min ischaemia had no effect on the severity of ischaemic damage. Preconditioning with 1 microM NMDA significantly reduced neuronal damage produced by either 45 or 60 min ischaemia when the delay between insults was 48 h. NMDA pre-treatment also prevented neurotoxicity produced by glutamate (5-10 mM) but not NMDA (10-30 microM). These data suggest that in vitro, the increased expression of HSP72 following some sublethal insults should be considered as a marker of cell stress prejudicial to the survival of neurones subsequently exposed to ischaemia, while tolerance can be produced through mechanisms independent of HSP72 induction.

Animals↗
PubMed1999

Endoscopic surgery for monoventricular hydrocephalus.

BACKGROUND: Monoventricular hydrocephalus is usually treated with extrathecal shunting. However, today endoscopic fenestration of the septum pellucidum seems to be a very useful and less invasive technique. METHODS: Five patients with monoventricular hydrocephalus have been treated with neuroendoscopic techniques. In three cases with an excluded lateral ventricle due to contralateral shunt overdrainage, the normal-sized ventricle was first cannulated and fenestration of the septum pellucidum from the normal to the enlarged lateral ventricle was performed. RESULTS: Complete remission of intracranial hypertension symptoms and decrease in size of the enlarged ventricle were observed in all five patients. CONCLUSIONS: Endoscopic fenestration of the septum pellucidum is the technique of choice for treating monoventricular hydrocephalus. We advise first cannulating the normal lateral ventricle and then performing a septostomy from it to the enlarged ventricle. This approach allows one to easily recognize the protruding septum pellucidum and perform fenestration without difficulty using a direct trajectory. In exceptional cases of choroid plexus cyst obstructing one foramen of Monro, fenestration of the cyst wall is sufficient.

Adolescent↗
PubMed1997

Symptomatic subependymomas of the lateral ventricles. Report of eight cases.

Subependymomas are rare, slow-growing, benign intraventricular tumors, which often are asymptomatic and are discovered incidentally. The review of the literature shows more than 100 symptomatic cases, less than half located in the lateral ventricles. Here we report 8 cases of symptomatic subependymomas of the lateral ventricles, studied by CT and/or MR and treated by direct surgical approach. The suspicion of a subependymoma should arise when a patient older than 10-15 years with long clinical history presents an intraventricular tumor isodense on CT and isointense in T1 and hyperintense in T2 on MR, with scarce or discrete contrast enhancement. Surgical treatment is indicated in symptomatic subependymomas of the lateral ventricles and usually allows complete tumor removal. The prognosis is usually good, also without postoperative irradiation.

Adolescent↗
PubMed1996

Acquired immune deficiency syndrome (AIDS) and cerebral astrocytoma.

The presence of cerebral lesions in patients affected by the acquired immune deficiency syndrome (AIDS) has been estimated to be around 10%, with the majority being infective lesions or primary central nervous system lymphomas. The co-occurrence of a cerebral glioma in such patients is rare. The aim of this report is to present four more cases, discussing their clinical and neuroradiological features, as well as the outcome and the possible pathogenesis.

Acquired Immunodeficiency Syndrome↗