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D d'Avella

Publications and source records attributed to D d'Avella.

At least 19 recordsLinked to original sources
PubMed2003

Traumatic acute subdural haematomas of the posterior fossa: clinicoradiological analysis of 24 patients.

BACKGROUND: We report 24 patients with a traumatic acute subdural haematoma of the posterior fossa managed between 1997 and 1999 at 8 Italian neurosurgical centres. METHOD: Each centre provided data about patients' clinico-radiological findings, management, and outcomes, which were retrospectively reviewed. FINDINGS: A poor result occurred in 14 patients (58.3%). Ten patients (41.7%) had favourable results. Patients were divided into two groups according to their admission Glasgow Coma Scale (GCS) scores. In Group 1 (12/24 cases; GCS score, > or =8), the outcome was favourable in 75% of cases. In Group 2 (12/12 cases; GCS score, <8), the outcome was poor in 91.6% of cases. Nineteen patients underwent posterior fossa surgery. Factors correlating to outcome were GCS score, status of the basal cisterns and the fourth ventricle, and the presence of supratentorial hydrocephalus. Multivariate analysis showed significant independent prognostic effect only for GCS score (P<0.05). INTERPRETATION: acute posterior fossa subdural haematomas can be divided into two distinct groups: those patients admitted in a comatose state and those with a moderate/mild head injury on admission. Comatose patients present usually with signs of posterior fossa mass effect and have a high percentage of bad outcomes. On the contrary, patients admitted with a GCS of 8 or higher are expected to recover. In these patients the thickness of the haematoma (<1 cm) seems to be a guide to indicate surgical evacuation of the haematoma.

Adolescent↗
PubMed2003

Large sphenocavernous meningiomas: is there still a role for the intradural approach via the pterional-transsylvian route?

BACKGROUND: Large-sized sphenocavernous meningiomas represent a surgical challenge. Although the role of skull base techniques with combined extra- and intradural steps has been recently emphasized, pure intradural resection tactics via the pterional route constitute the traditional microsurgical approach for resection of such tumours. METHOD: We report the application of the pterional-transsylvian approach in 13 patients with sphenocavernous meningiomas. This series is unique because it includes only patients with tumours exceeding 5 cm in their greatest dimension. FINDINGS: A gross total resection was accomplished in 10 patients (77%). Eight patients had a good outcome, one had a persistent mild hemiparesis, and one died. No recurrences occurred in this group. Three patients (23%) had subtotal resections owing to invasion of the cavernous sinus in one instance and encasement of the middle cerebral artery in the others. Two had a good outcome and one died. In these patients minimal asymptomatic tumour progression was seen 3 and 6 years after surgery. The overall surgical outcome was good in 10 patients (77%), fair in one, and death in two. INTERPRETATION: In our experience, large sphenocavernous meningiomas may be operated on adopting pure intradural resection tactics via the pterional-transsylvian route with rates of gross total removal and surgical complications related to brain retraction or vascular manipulation comparable to those of extensive skull base approaches. The traditional intradural pterional transsylvian approach continues to have a place in the treatment of these lesions.

Adult↗
PubMed2000

Effects of the radical scavenger AVS on behavioral and BBB changes after experimental subarachnoid hemorrhage.

Free radicals are important contributors to the global brain dysfunction that follows subarachnoid hemorrhage (SAH). We evaluated the effects of hydroxyl radical scavenger AVS [(+/-)-N,N'-propylenedinicotinamide; Nicaraven] after experimental SAH on rodent behavioral deficits (employing a battery of well-characterized assessment tasks over a 2-day observation period) and blood-brain barrier (BBB) permeability changes two days after SAH (quantifying the microvascular alterations according to the extravasation of protein-bound Evans Blue using a spectrophotofluorimetric technique) in dose-response and time-window experiments. Groups of 10 rats were injected with 400 microl of autologous blood into the cisterna magna, and followed by intravenous continuous infusion of saline or 0.1, 03 or 1 mg/kg/min of AVS beginning within 5 minutes or 6 or 12 hours after SAH. The results were compared with sham-operated saline-treated and with SAH saline-treated animals. AVS significantly ameliorated performances on Beam Balance (p < 0.01) and decreased BBB permeability changes in frontal, temporal, parietal, occipital and cerebellar cortices and subcortical and cerebellar nuclei and brainstem (p < 0.01), but did not significantly affect changes in Beam Walking. This study demonstrates the neuroprotective effects of AVS when administered after experimental SAH in rats. These effects were dose-dependent and, moreover, were evident within the therapeutic window of 6-12 hours after SAH. These results reinforce the concept of a participation of reactive oxygen intermediates in the cerebral dysfunction following SAH.

Animals↗
PubMed2000

Time-course of blood-brain barrier permeability changes after experimental subarachnoid haemorrhage.

An increase in blood-brain barrier (BBB) permeability after subarachnoid haemorrhage (SAH) has been described in humans and has been correlated with delayed cerebral ischemia and poor clinical outcome. Few studies examined in the laboratory the relationship between SAH and BBB, with contrasting results due to limitations in experimental probes adopted and in timing of observation. The aim of this study was to quantify the time-course of BBB changes after experimental SAH. Groups of eight rats received injections of 400 microl of autologous arterial blood into the cisterna magna. BBB was assessed 6, 12, 24, 36, 48, 60, and 72 hours after SAH and in sham-operated animals separately for cerebral cortex, i.e. frontal, temporal, parietal, occipital, subcortical gray matter (Caudate-Putamen-Thalamus), cerebellar cortex and nuclei, and brain stem by a spectrophotofluorimetric evaluation of Evans Blue dye extravasation. As compared to sham-operated controls, SAH determined a significant BBB permeability change beginning 36 hours after SAH, peaking at 48 hours, and normalizing on day 3. This study provides a quantitative description of the temporal progression and recovery of BBB dysfunction after SAH. These results have implications for the management of aneurysm patients and for assessing the rationale and the therapeutic window of new pharmacological approaches.

Animals↗
PubMed2000

Novel characteristics of glutamate-induced cell death in primary septohippocampal cultures: relationship to calpain and caspase-3 protease activation.

Studies examined the phenotypic characteristics of glutamate-induced cell death and their relationship to calpain and caspase-3 activation. Cell viability was assessed by fluorescein diacetate and propidium iodide staining and lactate dehydrogenase release. Calpain and caspase-3 activity was inferred from signature proteolytic fragmentation of alpha-spectrin. Characterization of cell death phenotypes was assessed by Hoechst 33258 and DNA fragmentation assays. Exposure of septohippocampal cultures to 1.0, 2.0, and 4.0 mmol/L glutamate induced a dose-dependent cell death with an LD50 of 2.0 mmol/L glutamate after 24 hours of incubation. Glutamate treatment induced cell death in neurons and astroglia and produced morphological alterations that differed from necrotic or apoptotic changes observed after maitotoxin or staurosporine exposure, respectively. After glutamate treatment, cell nuclei were enlarged and eccentrically shaped, and aggregated chromatin appeared in a diffusely speckled pattern. Furthermore, no dose of glutamate produced evidence of internucleosomal DNA fragmentation. Incubation with varying doses of glutamate produced calpain and caspase-3 activation. Calpain inhibitor II (N-acetyl-Leu-Leu-methionyl) provided protection only with a narrow dose range, whereas carbobenzoxy-Asp-CH2-OC(O)-2,6-dichlorobenzene (Z-D-DCB; pan-caspase inhibitor) and MK-801 (N-methyl-D-aspartate receptor antagonist) were potently effective across a wider dose range. Cycloheximide did not reduce cell death or protease activation.

Animals↗
PubMed1999

Giant olfactory meningiomas: the pterional approach and its relevance for minimizing surgical morbidity.

Olfactory groove meningiomas may attain surprisingly large size. The subfrontal approach is currently the route preferred by most neurosurgeons for their excision. The pterional-transsylvian route represents an alternate exposure for microsurgery of frontobasal tumors. Although this approach has been already described for olfactory meningiomas, tumors of giant size were not specifically addressed in the literature. We report the application of the pterional-transsylvian approach in six patients with giant olfactory meningiomas. This series is unique because it includes only patients with tumors exceeding 6 cm in diameter with bilateral symmetrical development. A radical removal was achieved in all patients and all of them made a full recovery. To investigate the relevance of the pterional-transsylvian approach for minimizing surgical morbidity, a magnetic resonance imaging protocol was designed to characterize even subtle postoperative frontal lobe structural changes. These changes, limited to the frontal lobe ipsilateral to exposure and localized in specific anatomical domains of the prefrontal area, included cystic degenerative alterations, parenchymal gliosis, and associated persistent white matter edema. Results from the present series strengthen the usefulness of the pterional-transsylvian approach as a safe surgical route for lesions affecting the anterior skull base, even with huge bilateral symmetrical expansion, such as giant olfactory meningiomas.

Journal Article↗
PubMed1999

Does lamina terminalis fenestration reduce the incidence of chronic hydrocephalus after subarachnoid hemorrhage?

OBJECTIVE: The incidence of chronic hydrocephalus requiring cerebrospinal fluid shunting was analyzed for a prospective series of 52 consecutive patients with ruptured cerebral aneurysms who underwent fenestration of the lamina terminalis during early microsurgical aneurysm repair. We hypothesized that, by creating an anterior ventriculocisternostomy, fenestration of the lamina terminalis would facilitate cerebrospinal fluid dynamics and decrease the risk of subsequent hydrocephalus. METHODS: Patients were enrolled according to the following criteria: 1) age more than 40 years; 2) admission Hunt and Hess Grade 2 to 4; 3) initial subarachnoid hemorrhage severity of Fisher Grade 3 or 4; and 4) early microsurgical repair of an anterior circulation aneurysm. RESULTS: The mortality rate in this series was 9.6%. Of the 47 surviving patients, 32 (68%) were discharged with a Glasgow Outcome Scale score of 5, 10 (21%) with a Glasgow Outcome Scale score of 4, and 5 (11%) with a Glasgow Outcome Scale score of 3. The follow-up period ranged from 12 to 60 months. Chronic hydrocephalus was radiographically and clinically evident in 3.8% of the total population. Shunt surgery was performed for two patients who exhibited symptoms resulting from hydrocephalus, corresponding to 4.2% of the surviving patients. CONCLUSION: Estimates from the most recently published studies indicate that an incidence of chronic post-subarachnoid hemorrhage hydrocephalus (requiring shunt surgery) of 15 to 20% is representative for an average contemporary population of patients with aneurysmal subarachnoid hemorrhage. The lower incidence of chronic hydrocephalus observed in this series possibly reflects the favorable effect of lamina terminalis fenestration on cerebrospinal fluid dynamics.

Adult↗
PubMed1999

Magnetic resonance imaging-monitored conservative management of traumatic spinal epidural hematomas. Report of four cases.

Spinal epidural hematomas (SEHs) are uncommon complications of traumatic injury to the spine. Emergency surgical evacuation is the standard treatment. Although it is recognized in the literature, the possibility of nonsurgical treatment of traumatic SEH is far from being codified. The authors report excellent outcomes in four conservatively managed patients who had sustained a severe spine injury with fracture of the lumbar vertebral body and in whom traumatic SEHs were diagnosed by magnetic resonance imaging. Although in the authors' experience a good spontaneous outcome in this subgroup of minimally symptomatic patients harboring moderate-sized SEHs has been achieved, further studies are necessary to understand the real spectrum of nonsurgical treatment of such lesions.

Adult↗
PubMed1998

Radiation-induced blood-brain barrier changes: pathophysiological mechanisms and clinical implications.

The pathophysiology of whole-brain radiation (WBR) toxicity remains incompletely understood. The possibility of a primary change in blood-brain barrier (BBB) associated with microvascular damage was investigated. Rats were exposed to conventional fractionation in radiation (200 +/- cGy/d, 5d/wk; total dose, 4,000 cGy). BBB changes were assessed by means of the quantitative 14C-alpha-aminoisobutyric acid (AIB) technique coupled with standard electron microscopy (EM) and morphometric techniques as well as studies of the transcapillary passage of horseradish peroxidase (HRP). At 15 days after WBR, AIB transport across BBB increased significantly in cerebral cortex. EM disclosed vesicular transport of HRP across the intact endothelium without opening of the tight junctions. Ninety days after WBR, well-defined alterations of the microvasculature were observed. The main feature of cortical microvessels was their collapsed aspect, associated with perivascular edema containing cell debris. Data suggest a possible association between damage of the microvascular/glial unit of tissue injury and development of radiation-induced brain cerebral dysfunction. We hypothesize the following sequence of pathophysiological events: WBR causes an early increase in BBB permeability, which produces perivascular edema and microvascular collapse. The interference with microcirculation affects blood flow and energy supply to the tissue, resulting in structural damage on an ischemic/dysmetabolic basis.

Animals↗
PubMed1998

Antivasospastic and brain-protective effects of a hydroxyl radical scavenger (AVS) after experimental subarachnoid hemorrhage.

OBJECT: The radical scavenger (+/-)-N,N'-propylenedinicotinamide (AVS) was shown recently to ameliorate delayed neurological deficits resulting from ischemia in patients who have had an aneurysmal subarachnoid hemorrhage (SAH). The aim of this study was to evaluate the effect of AVS administration after experimental SAH on 1) behavioral deficits; 2) angiographically confirmed basilar artery (BA) spasm; and 3) blood-brain barrier (BBB) permeability changes. METHODS: These parameters were measured by 1) using a battery of well-characterized chronic assessment tasks over a 5-day observation period; 2) assessing in vivo the mean vessel diameter 2 days after SAH; and 3) evaluating the extravasation of protein-bound Evans Blue dye by using a spectrophotofluorimetric technique 2 days after SAH. Groups of eight to 10 rats received injections of 400 microl of autologous blood into the cisterna magna. Within 5 minutes after the surgical procedures were completed the rats were treated with an intravenously administered continuous infusion of saline (Group III) or AVS (1 mg/kg/minutes, Group IV). Results were compared with those in sham-operated animals treated with intravenously administered saline (Group I) or AVS (Group II). The AVS-treated rats had significantly improved balance beam scores on Days 1 to 2 (p < 0.05), shorter beam traverse times on Day 1 (p < 0.05), and better beam walking performance on Days 1 to 4 (p < 0.01), but no significant effect was seen in terms of SAH-related changes in body weight. Treatment with AVS also attenuated the SAH-induced BA spasm (p < 0.05) and decreased BBB permeability changes in frontal, temporal, parietal, occipital, and cerebellar cortices, and in the subcortical and cerebellar gray matter and brainstem (p < 0.01). CONCLUSIONS: These results demonstrate useful antivasospastic and brain-protective actions of AVS after induction of experimental SAH and provide support for observations of beneficial effects of AVS made in the clinical setting.

Animals↗
PubMed1997

Chronic encapsulated intracerebral hematoma: contribution of thallium-201 single photon emission computed tomography in preoperative diagnosis: case report.

OBJECTIVE AND IMPORTANCE: Chronic encapsulated intracerebral hematoma is a fairly rare clinical entity. This unique lesion is peculiar for its clinical onset, formation of a capsule, and progressive enlargement. The mechanism for capsule formation and self-perpetuating expansion still remains uncertain, as well as the causal relationship with vascular malformations. Because of their pseudotumoral course and misleading neuroradiological features, these lesions can be misdiagnosed preoperatively as cerebral neoplasms. CLINICAL PRESENTATIONS: A 62-year-old man was referred with a 2-month history of generalized tonicoclonic seizures. There was no history of head injury or arterial hypertension. The results of a neurological examination were normal. Computed tomographic scans revealed a slightly hyperdense roundish area in the right parietotemporal region with ring-like enhancement after contrast medium injection, moderate mass effect, and perifocal low attenuation. With the provisional diagnosis of astrocytoma, the patient was admitted for a craniotomy. Before surgery, a thallium-201 single photon emission computed tomographic study was performed, which showed no abnormal uptake of the tracer, raising significant doubt regarding the presumptive diagnosis of a tumor. INTERVENTION: Intraoperative findings revealed a hematoma, with a well-demarcated, thick, fibrous-elastic capsule. There was evidence of repeated intracapsular hemorrhages. The lesion was totally removed, and the patient recovered fully. No other pathological findings, including vascular malformations, were noted. CONCLUSION: Chronic encapsulated intracerebral hematomas probably occur more frequently than the limited number of reported cases would indicate. This case represents a realistic clinical problem-solving setting in with thallium-201 single photon emission computed tomography was used because of its capacity for functional tumor detection and differential diagnosis.

Cerebral Hemorrhage↗
PubMed1997

Microsurgical excision of a primary isolated hypothalamic eosinophilic granuloma. Case report.

Solitary focal eosinophilic granuloma (EG) is one element in the spectrum of diseases associated with Langerhans' cell histiocytosis (LCH). This report documents the occurrence of a primary isolated hypothalamic EG in a man who presented with diabetes insipidus and panhypopituitarism. His treatment consisted of complete microsurgical excision of the lesion. After a 13-month follow-up period, no residual tumor was evident on magnetic resonance imaging and no other lesions were present in peripheral tissues. This case is unique in several respects: 1) it is the third documented case of a primary isolated hypothalamic LCH granuloma diagnosed in a living patient; 2) it is the only known example of complete microsurgical excision of such a lesion in the hypothalamic region; and 3) it demonstrates the efficacy of direct surgery in this scenario, as compared with other treatment modalities such as biopsy and irradiation, suggesting that complete surgical excision may represent the treatment of choice for isolated intracerebral LCH granulomas, being curative in most instances. Also, the literature is reviewed for information about the diagnosis and treatment of this particular type of unifocal brain lesion.

Eosinophilic Granuloma↗
PubMed1996

Brain energy metabolism in the acute stage of experimental subarachnoid haemorrhage: local changes in cerebral glucose utilization.

An experimental model was used to investigate acute alterations of cerebral metabolic activity in rats subjected to subarachnoid haemorrhage (SAH). Haemorrhages were produced in anaesthetized animals by injecting 0.3 ml of autologous, arterial nonheparinized blood into the cisterna magna. Control rats received subarachnoid injections of mock-cerebrospinal fluid to study the effect of sudden raised intracranial pressure, or underwent sham operation. Three hours after SAH rats were given an intravenous injection of [14C]-2-deoxyglucose. Experiments were terminated by decapitation, and the brains were removed and frozen. Regional brain metabolic activity was studied by quantitative autoradiography. In comparison with sham-operated controls, cerebral metabolic activity was diffusely decreased after SAH. Statistically significant decreases in metabolic rate were observed in 23 of 27 brain regions studied. Subarachnoid injections of mock-cerebrospinal fluid also produced depression of cerebral metabolic activity, but quantitatively these changes were not as pronounced and diffuse as in SAH rats. The present study shows that a widespread depression of brain metabolism occurs in the acute stage after experimental SAH and is probably secondary to the subarachnoid presence of blood itself and/or blood products.

Animals↗
PubMed1996

Time-related ultrastructural changes in an experimental model of whole brain irradiation.

To stimulate therapeutic irradiation, we exposed rats to conventional fractionation (200 +/- 4 cGy/d, 5 d/wk; total dose, 4000 cGy). The effects of this regimen were assessed by electron microscopic examinations of brain microvascular and parenchymal cells 15 and 90 days after irradiation. Studies of the transendothelial passage of horseradish peroxidase provided information about the functional status of the blood-brain barrier. At 15 days after irradiation, there was an increased vesicular transport of horseradish peroxidase across the intact endothelium without opening of the tight junctions, and without evidence of structural alterations of neuropil, neuronal bodies, and astrocytes. Ninety days after irradiation, well-defined ultrastructural alterations were observed, involving the microvasculature, the neuropil, the neuronal bodies, and astrocytes. The main ultrastructural feature of cortical microvessels was their collapsed aspect, associated with perivascular edema containing cell debris. Altered neurons and reactive activated astrocytes were also noticeable. These data suggest a possible association, not necessarily causal, between damage of the microvascular/glial unit of tissue injury and development of radiation-induced brain toxicity.

Animals↗
PubMed1994

Behavioral deficits following experimental subarachnoid hemorrhage in the rat.

To characterize some of the short-term and long-term functional consequences of subarachnoid hemorrhage (SAH) in rats, we employed a battery of well-characterized tests for assessment of acute and chronic behavioral and neurologic performances. Three groups of 10 rats (blood injected, mock CSF injected and sham-operated controls) were studied. During the acute stage, simple nonpostural somatomotor reflexes (pinna and corneal reflexes), simple postural responses (paw flexion, tail flexion, and head support), startle response, and postural functions (righting reflex) did not differ significantly between the experimental groups. Assessments of body weight, beam walking ability, and beam balancing revealed significant disturbances in blood-injected rats. This work demonstrates that this single-hemorrhage rodent model of SAH is associated with the induction of enduring neurologic and behavioral deficits. Because of the significant interspecies difference, a direct extrapolation of our results to humans may not be appropriate. However, we suggest that the observed behavioral and neurologic changes may parallel those seen in humans after SAH. Results reported here further confirm the rat model of SAH as a viable laboratory instrument for the study of the pathophysiology of SAH and provide normative values for the evaluation of new treatment modalities.

Acute Disease↗
PubMed1994

Spinal cord compression in homozygous beta-thalassemia intermedia.

Symptomatic spinal cord compression caused by an epidural mass of extramedullary hematopoietic tissue in patients with beta-thalassemia is a rare occurrence, that becomes exceptional in childhood and adolescence. The literature is not uniform about the optimal treatment of these patients and different modes of therapy have been proposed so far, including surgical excision or decompressing laminectomy followed by local irradiation and/or hypertransfusional regimens. We report the successful treatment of such a complication in an adolescent with homozygous beta-thalassemia by surgery followed by repeated blood transfusions aimed at maintaining hematocrit at normal levels.

Adolescent↗
PubMed1994

Progressive perturbations in cerebral energy metabolism after experimental whole-brain radiation in the therapeutic range.

Basic mechanisms underlying the tolerance and reaction of the central nervous system to ionizing radiation have not been fully elucidated in the literature. The authors employed the [14C]-2-deoxy-D-glucose autoradiography method to investigate the effect of whole-brain x-irradiation on local cerebral glucose utilization in the rat brain. The animals were exposed to conventional fractionation (200 +/- 4 cGy/day, 5 days/week for a total dose of 4000 cGy), and the effects of this regimen were assessed at 2 weeks and 3 months postirradiation. In rats evaluated 2 weeks after treatment, statistically significant decreases in cerebral metabolic activity were found in 13 of the 27 regions studied, compared to control animals. In rats studied 3 months after treatment, additional metabolic suppression and statistically significant decreases in cerebral metabolic activity were found in 11 of the 27 regions, compared to rats studied 2 weeks after treatment. A weighted-average rate for the brain as a whole was approximately 15% and approximately 25% below that of control animals 2 weeks and 3 months after exposure, respectively. Although the difference in species is significant enough so that direct extrapolation to humans may not be appropriate, the data reported here may have potential clinical implications for the evaluation of the risk-benefit ratio for radiotherapy. This model can be used reproducibly for further investigations, including evaluation of therapies that may reduce irradiation-induced brain injury.

Animals↗