Biomedical subjects

A Ducati

Publications and source records attributed to A Ducati.

At least 19 recordsLinked to original sources

PubMed2007

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.

Adult↗

PubMed2006

Complications of vagal nerve stimulation for epilepsy in children.

Vagal nerve stimulation (VNS) is a surgical option to treat drug-resistant epilepsy. A few side effects have been described, mainly as anecdotal reports. We analysed our material concerning a juvenile population to identify the most common and most important complications, discussing them with the literature. Thirty-six patients were studied (18 months-18 years old). The children were assessed before the VNS implant and 3, 6, 12, 24 and 36 months after surgery. The mean follow-up was 30 months. Four patients required a second surgery: two for changing the device 3 years after implant; one for revision of an imperfect implant; one for removing a non-functioning device. In one patient a transient vocal cord paralysis was observed. Hoarseness was the main complaint (38.8%). More infrequent was mild sleep apnoea (8.3%), sternocleidomastoid muscle spasm, drooling and snoring in one patient each. Skin scars were reported with a different frequency according to the surgical technique. At variance with the literature reports, we did not observe infections. Side effects of VNS can be minimised, but not avoided completely, with a correct technical procedure, which in turn depends upon a thorough knowledge of vagus nerve anatomy.

Adolescent↗

PubMed2006

Clinical and neuroimaging features of severely brain-injured patients treated in a neurosurgical unit compared with patients treated in peripheral non-neurosurgical hospitals.

Most European TBI patients are managed in peripheral hospitals without benefit of guidelines for transfer of such patients to neurosurgical units as needed. This report compares clinical features and outcomes in two series of severe TBI patients: those admitted to a neurosurgical centre or to a general hospital, all in the Piedmont Region of Italy. Of 630 patients with a GCS of 3-8, 351 were admitted to a centralized neurosurgical unit, and 279 were admitted and treated at a peripheral hospital. All patients had a CT scan read by a neurosurgeon on duty and were classified using the Marshall criteria as having a diffuse injury or non-surgical mass lesions. Outcomes were assessed between 6 months and 6 years using either the GOS Extended or the GOS. Independent variables were age, sex, GCS score and Marshall classification. All the examined factors were significantly different between the two groups (p<0.001). For patients admitted to the neurosurgical centre, age, Marshall classification of the CT and GCS were predictors of a favourable outcome, while for patients treated in general hospitals, Marshall classification of the CT, gender and age were predictors of a favourable outcome. Patients admitted to neurosurgical centres are different from those treated in general hospitals not having these specialized facilities and personnel. The absence of guidelines for the transfer of these patients for more advanced care are lacking and should be the focus of new studies on patient referral.

Adolescent↗

PubMed2006

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.

Animals↗

PubMed2005

Anterior cervical fusion with polyetheretherketone (PEEK) cages in the treatment of degenerative disc disease. Preliminary observations in 36 consecutive cases with a minimum 12-month follow-up.

STUDY DESIGN: Retrospective analysis of 36 cases of degenerative disc disease treated by interbody fusion with polyetheretherketone (PEEK) cages. OBJECTIVE: To determine the safety and efficiency of PEEK cages for anterior cervical fusion (ACF). SUMMARY OF BACKGROUND DATA: ACF with autologous bone has been reported since over 50 years ago. The recent development of cages housing materials inducing osteogenesis simplifies the technique of interbody fusion. The main purposes of bone substitutes for ACF are immediate biomechanical support, osteo-integration of the graft, and elimination of local side effects at the donor site. This report shows our results using PEEK cages. MATERIALS AND METHODS: During an 18-month period, 36 consecutive patients had cervical fusions at 43 levels between C3 and C7. All operations involved one or two disc spaces for degenerative disc disease. We implanted all disc spaces with PEEK cages (Stryker Corporation, Kalamazoo, MI) containing granulated coralline hydroxylapatite (Pro-Osteon 200, Interpore Cross International, Irvine, CA) or deantigenated pig bone in a gel solution (Gen-Os, Tecnoss, Torino, Italy). RESULTS: About 97% of patients had a good to excellent outcome; the result in one myelopathic patient was fair. The cervical fusion rate was 16.7% at 3 months, 61.1% at 6 months, and 100% at one year. CONCLUSIONS: PEEK cages appear to be safe and efficient for ACF. In order to confirm our preliminary impressions studies on larger series with long term follow-up are warranted.

Adult↗

PubMed2005

Retrosigmoid approach for vestibular neurectomy in Meniere's disease.

BACKGROUND: Vestibular nerve section is considered to be the most effective surgical procedure to control intractable symptoms secondary to Meniere's disease (MD). This study was developed to analyze the adequacy of retrosigmoid vestibular neurectomy in terms of vertigo control, hearing preservation and clinical complications of this procedure. METHODS: A retrospective review was carried out on 14 patients affected by definite unilateral MD who underwent vestibular neurectomy via the retrosigmoid approach. FINDINGS: One patient was lost from follow-up; another one had only a short postoperative observation. At follow-up performed on 12 cases, no patients reported any crisis of acute vertigo. Four patients were free from any vestibular symptoms, while 8 reported some slight gait disturbances. Hearing function was preserved in 10 patients and improved in 2. 1 year postoperative vestibular function was absent at the side operated on and unchanged on the other side in all the cases. CONCLUSIONS: Vestibular neurectomy via the retrosigmoid approach can be considered a safe and effective procedure in relieving medically refractory vertigo in Meniere's disease, while preserving hearing.

Adult↗

PubMed2001

Multicentric glioma with unusual clinical presentation.

Multiple glioma is a well-recognized but uncommon entity. They are grouped in two categories: multifocal and multicentric gliomas. Multifocal gliomas grow through dissemination along an established route, spreading through commissural pathways, CSF channels, or the blood or by local extension through satellite formation; at the opposite end of the spectrum, multicentric gliomas are widely separated lesions whose simultaneous presence cannot be attributed to any of the above pathways. Reports in the literature refer to single cases or small series of multicentric gliomas, almost always in adult patients, their occurrence in children being even less frequent. We report the case of a 12-year-old boy with multicentric glioma, atypical acute clinical onset and fast growth of three other tumors in 8 months, and then discuss the problems of diagnosis and therapy.

Brain Neoplasms↗

PubMed1999

Neuronal and glial localization of NR1 and NR2A/B subunits of the NMDA receptor in the human cerebral cortex.

N-Methyl-D-aspartate (NMDA) receptors play a critical role in many cortical functions and are implicated in several neuropsychiatric diseases. In this study, the cellular expression of the NMDAR1 (NR1) and NMDAR2A and B (NR2A and B) subunits was investigated in the human cerebral cortex by immunocytochemistry with antibodies that recognize the NR1 or the NR2A and B subunits of the NMDA receptor. In frontal (areas 10 and 46) and temporal (area 21) association cortices and the cingulofrontal transition cortex (area 32), NR1 and NR2A/B immunoreactivity (ir) were similar and were localized to numerous neurons in all cortical layers. NR1- and NR2A/B-positive neurons were mostly pyramidal cells, but some nonpyramidal neurons were also labeled. Electron-microscopic observations showed that NR1 and NR2A/B ir were similar. In all cases, labeling of dendrites and dendritic spines was intense. In addition, both NR1 and NR2A/B were consistently found in the axoplasm of some axon terminals and in distal astrocytic processes. This investigation revealed that numerous NMDA receptors are localized to dendritic spines, and that they are also localized to axon terminals and astrocytic processes. These findings suggest that the effects of cortical NMDA activation in the human cortex do not depend exclusively on the opening of NMDA channels located at postsynaptic sites, and that the localization of NMDA receptors is similar in a variety of mammalian species.

Adult↗

PubMed1998

Neuronal and glial localization of GAT-1, a high-affinity gamma-aminobutyric acid plasma membrane transporter, in human cerebral cortex: with a note on its distribution in monkey cortex.

High-affinity gamma-aminobutyric (GABA) plasma membrane transporters (GATs) influence the action of GABA, the main inhibitory neurotransmitter in the human cerebral cortex. In this study, the cellular expression of GAT-1, the main cortical GABA transporter, was investigated in the human cerebral cortex by using immunocytochemistry with affinity-purified polyclonal antibodies directed to the C-terminus of rat GAT-1. In temporal and prefrontal association cortex (Brodmann's areas 21 and 46) and in cingulofrontal transition cortex (area 32), specific GAT-1 immunoreactivity (ir) was localized to numerous puncta and fibers in all cortical layers. GAT-1+ puncta were distributed homogeneously in all cortical layers, although they were slightly more numerous in layers II-IV, and appeared to have a preferential relationship to the somata and proximal dendrites of unlabeled pyramidal cells, even though, in many cases, they were also observed around nonpyramidal cells. Electron microscopic observations showed that GAT-1+ puncta were axon terminals that formed exclusively symmetric synapses. In addition, some distal astrocytic processes also contained immunoreaction product. Analysis of the patterns of GAT-1 labeling in temporal and prefrontal association areas (21 and 46), in cingulofrontal transition areas (32), and in somatic sensory and motor areas (1 and 4) of the monkey cortex revealed that its distribution varies according to the type of cortex examined and indicated that the distribution of GAT-1 is similar in anatomically corresponding areas of different species. The present study demonstrates that, in the human homotypical cortex, GAT-1 is expressed by both inhibitory axon terminals and astrocytic processes. This localization of GAT-1 is compatible with a major role for this transporter in GABA uptake at GABAergic synapses and suggests that GAT-1 may contribute to determining GABA levels in the extracellular space.

Animals↗

PubMed1998

Tuberculous spondylitis: a retrospective study on a series of 12 patients operated on in a 25-year period.

BACKGROUND: The incidence of tuberculous spondylitis, which had declined steadily for over 40 years in our countries, started increasing again in the eighties, paralleling the resurgence of pulmonary tuberculosis. Therefore it has become a matter of discussion in contemporary literature, because it can be a diagnostic challenge and, in spite of its severe neurological complications, it is a potentially curable illness. METHODS: In this retrospective study the authors report their experience concerning 12 patients operated on in a 25-year period because of serious cord compression from thoracic (9 cases) and cervical (1 case) tuberculous spondylitis or from thoracic tubercular epidural lesion (2 cases). Surgical techniques were selected on the basis of the cause of cord compression. Fusion with autologous bone and metallic osteosynthesis was performed in the cervical case (1986); no other patient received spinal instrumentation, and this can be explained with the consideration that all but one cases of Pott's paraplegia were treated in the years 1968-1977. In all of these cases fusion was achieved by means of plaster jackets and prolonged bed rest. Prolonged chemotherapy was systematically administered. RESULTS: Follow-up data collected in 1995 show good and long-lasting results. CONCLUSIONS: They conclude that surgical treatment is required in case of cord compression and results can be excellent even in presence of severe neurological impairment; spinal instrumentation available in our era should be now considered in order to make rehabilitation earlier and morphologic results more satisfactory.

Adult↗

PubMed1998

Transcranial Doppler sonographic monitoring during cerebral aneurysm embolization: a preliminary report.

BACKGROUND AND PURPOSE: The wide application of embolization in the treatment of aneurysms has created the need for an intraprocedural means to anticipate a poor outcome by monitoring hemodynamic changes in the brain. METHODS: Transcranial Doppler sonography was used to monitor flow velocity in the middle cerebral artery (MCA) in 23 patients undergoing embolization with Guglielmi detachable coils (GDCs) of either incidental or symptomatic intracranial aneurysms. Sonographic values were recorded from the ipsilateral MCA at the beginning, middle, and end of the interventional procedure and 24 hours afterward. RESULTS: No complications occurred in 15 patients. In these cases, sonography showed an average decrease in MCA flow velocity of 2.7% after GDC application, returning to baseline at the end of treatment and then increasing by about 17% 24 hours later. In four patients with vasospasm on posttreatment angiograms, MCA flow velocity increased to values higher than 120 cm/s after GDC application, returning to baseline after 24 hours. In four patients with ischemic complications (two transient ischemic attacks, one stroke, one vascular death), MCA flow velocity decreased more than 30% and did not return to preoperative values within 24 hours. CONCLUSION: The application of transcranial Doppler sonographic monitoring during endovascular treatment may help to identify patients at risk for posttreatment cerebral ischemia.

Adult↗

PubMed1998

[The clinical grading of subarachnoid hemorrhage].

Clinical grading scales for subarachnoid haemorrhages are exposed and discussed. These have been introduced by Botterell, in the middle fifties, to allow a better clinical evaluation, a more correct prognosis and, as a consequence, a more effective therapy. The most popular grading scale is, up to now, the one proposed by Hunt and Hess in 1968. The H-H scale divides patients in 5 groups or levels, whose severity is progressively increasing. A clinical study based on the H-H scale demonstrated that low grade patients (I-II) take advantage from early surgery; at the opposite, high grade patients (III-IV-V) achieve better results when treated with late surgery. To leave behind several difficulties in interpreting the clinical signs and therefore in using the H-H scale, in 1988 Drake, on behalf of the World Federation of Neuro-logical Surgeons, published an "universal" grading scale for subarachnoid haemorrhage, based upon the well known Glasgow Come Scale score and on the finding of a motor focal deficit. The WFNS Scale is nowadays recommended for universal use, being easy and compatible with formerly employed scales.

Humans↗

PubMed1998

Effect of age on synaptic size in human brain tissue proximal to tumor masses.

OBJECTIVE: To measure the effect of age on synaptic morphologic rearrangements in human brain tissue peripheral to space-occupying lesions. STUDY DESIGN: Synaptic length (L) was measured interactively by computer-assisted image analysis in brain tissue samples from adult (mean age, 39 years) and old (mean age, 67.2 years) patients. Each group consisted of five subjects. RESULTS: L was reduced by 9% in the old vs. adult group of patients. A percent distribution of the data showed that junctional areas smaller than 0.25 micron accounted for 47.2% in old patients and 31% in the adults. CONCLUSION: The present findings are in contrast with current literature data documenting a significant increase in the percent of enlarged contact zones in the senile brain. We interpret these results in terms of synaptic dynamic morphology and suggest that they may reflect alterations of neuronal adaptive capabilities due both to the pathologic condition and age of the patients.

Adult↗

PubMed1996

Alpha6 beta4 and alpha6 beta1 integrins in astrocytomas and other CNS tumors.

Laminin may alter the biological behavior of gliomas. Therefore, we investigated the expression of two laminin receptors, alpha6 beta1 and alpha6 beta4 integrins in normal brain, astrogliotic brain, and astrocytomas as compared to other central nervous system (CNS) tumors. In most CNS tumors, the expression of these integrins was unchanged in neoplastic as compared to normal counterpart cells. In contrast, increased numbers of reactive and neoplastic astrocytes expressed beta4 integrin as compared to normal astrocytes, whereas alpha6 and beta1 integrin expression did not change. Conversely, lower numbers of astrocytoma blood vessels expressed beta4, whereas all blood vessels in normal brain expressed beta4. These data suggest that the profile of laminin receptors changes in neoplastic astrocytes and in astrocytoma blood vessels; this change may play an important role in astrocytoma pathogenesis.

Astrocytoma↗

PubMed1990

Morphology and neurophysiology of focal axonal injury experimentally induced in the guinea pig optic nerve.

A new model of focal axonal injury was reproduced by rapid and controlled elongation (uniaxial stretch) of the guinea pig optic nerve. Light microscopy study of optic nerve specimens after horseradish peroxidase injection into the vitreous of the animal's eye showed that axonal lesions were identical to those seen in human and primate post-traumatic diffuse axonal injury (DAI). The lesions were characterized by the formation of terminal clubs in severed axons and focal axonal enlargements in those axons that were lesioned-in-continuity. Visual-evoked potentials upon flash stimulation were recorded before and after injury. Mean amplitude and mean latency of occipital peaks were significantly elongated in the acute post-traumatic phase. Electron microscopy examination showed that the main axonal changes observed in this model were cytoskeleton disorganization, accumulation of axoplasm membrane-bound bodies at the site of terminal balls and dilatations-in-continuity and detachment of the axolemma from the myelin sheath. Such axonal alterations were similar to those found in many other biological models of central and peripheral axonal injuries in which the lesion was produced by invasive methods. This model is unique since it reproduces the same mechanism of injury and the identical lesions that have been demonstrated in humans and primates with post-traumatic (DAI).

Animals↗

PubMed1990

Multimodality evoked potentials in HIV infected subjects: a longitudinal study.

18 subjects with symptomless HIV infection were investigated with multimodal evoked potentials for possible CNS involvement and again after an 8-12 month interval. 13 subjects showed neuropsychological changes, which were confirmed at the second examination. The 5 subjects found normal remained so at the second examination. On WAIS assessment the only patient to earn pathological scores was the one with the greatest evoked potentials changes. Thus the evoked potentials procedure proved capable of identifying early CNS involvement by HIV infection.

Adult↗

PubMed1988

Monitoring of brain function by means of evoked potentials in cerebral aneurysm surgery.

Deliberate arterial hypotension is currently used to operate upon cerebral aneurysms. However, it is not ascertained whether this practice is really safe for all patients, especially those presenting with preoperative vasospasm. 50 patients, requiring surgical treatment for cerebral aneurysm, have been submitted, during surgery, to the recording of Somatosensory Evoked Potentials (SEPs) on median nerve stimulation. This technique allows the functional evaluation of neural pathways mediating the somatosensory stimuli and of primary somatosensory cortex; it is known that a decrease of cerebral perfusion may affect the SEP waveforms in terms of reduced subcortical conduction velocity (i.e., increased central conduction time, CCT) and of reduced cortical response amplitude. These changes may be apparent before a permanent neurological damage is produced. Preoperative SEP recording demonstrated a prolonged CCT, possibly related to vasospasm, in 9 patients, a normal clinical evaluation notwithstanding (grade I and II). During intraoperative deliberate hypotension, a SEP change has always been produced. No postoperative damage has been observed, however, as long as the CCT did not exceed 9 msec for 10 minutes (maximum normal CCT value is 6.7 msec) and as the cortical response had been visible throughout the whole surgical procedure. The critical value of CCT has been reached at a mean arterial pressure (MAP) lower than 60 Torr in patients with a normal preoperative SEP recording; at the opposite, in patients presenting with a prolonged preoperative CCT, the value of 9 msec was arrived at with a MAP value that is generally accepted as safe for all patients (75 Torr).(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia↗

PubMed1988

Pattern reversal visual evoked potentials in phenylketonuria.

The pathogenesis of brain dysfunction in phenylketonuria (PKU) is still under investigation. Hyperphenylalaninaemia results in increased turnover of myelin. In order to demonstrate the derangement of myelinization in PKU we studied the visual evoked potentials (VEP) in 14 PKU patients and in 20 normal subjects. VEP findings were correlated with the metabolic control of the disease and with the electroencephalographic findings. VEP were more sensitive than the EEG in detecting a neurological dysfunction. VEP are influenced by dietary control and are normal only in children with good metabolic control.

Adolescent↗