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A Lagares

Publications and source records attributed to A Lagares.

At least 37 records · Page 2Linked to original sources
PubMed2002

[Parasplenial arteriovenous malformations. Report of 15 surgically treated cases].

INTRODUCTION: Yasargil called paraesplenial those AVMs located at the confluence of the hippocampus, the isthmus of the cingulate girus and the girus occipitotemporalis medialis. Large AVMs at this location are among the most difficult to delineate and to treat. OBJECTIVE: Analyze the clinical presentation, the findings in the imaging studies, the surgical management and the final outcome in 15 patients with paraesplenial AVMs treated with embolization (the last 4 cases), and microsurgical removal. RESULTS: Nine patients (60%) were female and 6 males of ages between 15 and 39 years (mean = 24 yrs). Eleven (75%) presented with hemorrhage, (intraventricular in most cases) and the remaining with epilepsy. The Spetzler-Martin grade was II in one Case, III in 5 cases, IV in 8 cases and V in one case. Preoperative embolization clearly improved surgical management. All the patients had complete resection of the lesion, 13 in a single stage and 2 in two stages. The final outcome was good but four patients developed defects of the visual field not seen preoperatively. CONCLUSIONS: The authors comment the peculiarities of paraesplenial AVMs which can be safely and completely removed with microsurgery and the aid of preoperative embolization.

Adolescent↗
PubMed2001

Traumatic cervical central cord syndrome due to intramedullary hemorrhage studied with MRI: case presentation.

Cervical central cord syndrome is characterized by disproportionately greater motor impairment of the upper than the lower extremities, predominantly distal motor dysfunction, varying degrees of sensory abnormalities, and bladder dysfunction. Although the original description stated that intramedullary hemorrhage is a possible cause of traumatic cervical central cord syndrome, recent studies have not demonstrated its presence on the basis of magnetic resonance imaging (MRI) or pathological evidence. The authors describe and discuss a case of traumatic central cervical cord syndrome studied with MRI, which presented intramedullary hemorrhage. This supports hemorrhage as a possible cause of traumatic cervical central cord syndrome.

Aged↗
PubMed2001

Prognostic factors on hospital admission after spontaneous subarachnoid haemorrhage.

BACKGROUND AND OBJECTIVE: Factors related to prognosis after subarachnoid haemorrhage (SAH) have been mainly extracted from surgical series, and only few authors have considered these factors in total management or population series. Though the level of consciousness is a major determinant of outcome after subarachnoid haemorrhage, there is not a consensus about which classification should be used to define it. The objective of this study was twofold. Firstly to find which factors recorded on hospital admission relate to outcome determining their relative importance in a non-selected series of patients suffering from aneurysmal SAH admitted to our centre, and secondly to assess the validity of the WFNS clinical scale for predicting the final result. METHODS: A series of 294 patients consecutively admitted to Hospital 12 de Octubre Madrid between January 1990 and June 2000 with the diagnosis of aneurysmal SAH were retrospectively reviewed. All factors possibly related to prognosis were recorded on hospital admission. Outcome was measured by means of the Glasgow Outcome Scale measured one month after hospital discharge. Relationship between factors and outcome was evaluated by univariate and logistic regression multivariate analysis. RESULTS: Although several factors, appeared related to prognosis in the univariate analysis, only the age. the level of consciousness defined by the WFNS scale and the presence of global brain hypodensity on the initial CT scan had a significant prognostic influence in the logistic regression model. Global brain hypodensity was strongly related to mortality. Since a number of factors associated with poor outcome in the univariate analysis are related to age, their influence could be explained by the difficulty of recovery of the ageing brain. The WFNS grading scale failed to predict significant differences in outcome between some of its grades. CONCLUSIONS: Age and clinical grade on admission are the most important factors influencing the final outcome of patients suffering aneurysmal SAH. A reappraisal of the WFNS grading scale should be considered as no significant differences in outcome were found between some of its grades.

Adolescent↗
PubMed2001

Intracranial hemangiopericytoma: study of 12 cases.

Most hemangiopericytomas (HPCs) are located in the musculoskeletal system and the skin, while the intracranial location is rare. They represent 2 to 4% in large series of meningeal tumours, thus accounting for less than 1% of all intracranial tumours. Many authors have argued about the true origin of this tumour. The current World Health Organization classification of Central Nervous System tumours distinguishes HPC as an entity of its own, and classified it into the group of "mesenchymal, non-meningothelial tumours". Radical surgery is the treatment of choice, but must be completed with postoperative radiotherapy, which has proved to be the therapy most strongly related to the final prognosis. HPCs have a relentless tendency for local recurrence and metastases outside the central nervous system which can appear even many years after diagnosis and adequate treatment of the primary tumour. Twelve patients with intracranial HPC were treated at our Unit between 1978 and 1999. There were 10 women and 2 men. Ten tumours were supratentorial and most located at frontoparietal parasagittal level. The most common manner of presentation was a focal motor deficit. All tumours were hyperdense in the basal Computed Tomography scans and most enhanced homogeneously following intravenous contrast injection. In 50% of cases, tumour margins were irregular or lobulated. Seven tumours were studied with Magnetic Resonance Imaging, being six of them iso-intense with the cortical gray matter on T1-weighted and T2-weighted images. Twenty operations were performed in the 12 patients. In 10 cases radical excision could be achieved with no operative mortality. Total recurrence rate was 33.3%. Eight patients were treated with external radiotherapy at some time through the course of their disease. Eight out of the 12 patients in this series are disease-free (Glasgow Outcome Scale categories 1 and 2) after a mean follow up of 52 months.

Adolescent↗
PubMed2001

Ganglioglioma of the brainstem: report of three cases and review of the literature.

BACKGROUND: Brainstem gangliogliomas are rare low-grade tumors that usually have a long clinical history. However, they may cause sudden death. There are only 31 cases of brainstem ganglioglioma reported in the literature, and only one has been studied with magnetic resonance (MR). We present three new cases of brainstem ganglion cell tumor studied with computed tomography (CT) (3 cases) and MR (2 cases) and discuss the clinical presentation, diagnostic imaging and treatment of these tumors. CASE DESCRIPTION: Age at presentation ranged from 19 to 59 years old. Two patients were female and 1 male. Duration of symptoms before diagnosis ranged from 1 year to nearly 14 years. Presenting complaints included syncope spells, cranial nerve deficits, headache, and gait instability. Imaging studies revealed well-circumscribed lesions involving the brainstem; the lesion was cystic in one case and calcified in one. They were iso- or hyperdense on CT scan, isodense on T1-weighted and hyperdense on T2-weighted MRI and frequently showed contrast enhancement. All tumors were operated through a posterior fossa craniectomy. Using microsurgical techniques only partial resection could be achieved, as there was no sharp delineation from the surrounding tissue in any case. Two of our patients had increased neurological deficits after surgery. Radiotherapy was not given. Follow-up of tumoral remnants has not shown clear tumor growth after 1, 3.5, and 10 years. CONCLUSIONS: Imaging characteristics of brainstem gangliogliomas do not seem to differ from those in other locations and are not specific. Radical surgery is rarely if ever possible, nor is it advisable because of the risk of functional deterioration. However, because of their benign histology, partial resection seems to carry a similar prognosis as tumors in other locations that are amenable to complete resection.

Adult↗
PubMed2001

[Subarachnoid hemorrhage secondary to dissecting aneurysms of the vertebral artery. Description of 2 cases and review of the literature].

UNLABELLED: OBJECTIVES AND INTRODUCTION: The pathogenesis and natural history of intracranial vertebral artery dissection remain uncertain up to now due in part to its relative rarity. In this article we review the state of the art of this process and remark the good outcome obtained with embolization using Guglielmi detachable coiling (GDC). METHODS: Two cases with subarachnoid hemorrhage secondary to rupture of a vertebral dissection aneurysms are described. The first patient initially suffered brain stem infarction, followed by a subarachnoid hemorrhage a year later. The second patient who had a severe subarachnoid hemorrhage with two early rebleedings was successfully treated with embolization using GDC. CONCLUSIONS: Subarachnoid hemorrhage due to rupture of vertebral dissecting aneurysm is a relatively unknown disease with some important aspects that should be known. The high incidence of early rebleeding (up to 60%), makes early diagnosis and treatment important goals. Classically the preferred treatment has been proximal vertebral artery occlusion. However, the recent introduction of embolization with GDC has made possible the occlusion of the dissection with very good final outcome.

Aged↗
PubMed2001

Parosteal osteosarcoma of the skull.

Parosteal osteosarcoma of the skull is a distinct surface bone tumor, with a better prognosis than conventional osteosarcoma. The most common location is on the surface of the distal femur which accounts for 46-66% of the cases. The presentation in the skull is uncommon and there are few cases reported in the literature. We describe the case of a man who developed a parosteal osteosarcoma arising from the occipital bone with extension to the parietal bone. The patient was operated and had a complete tumor resection.

Cerebral Angiography↗
PubMed2001

[Meningioma of the olfactory groove: review of a series of 27 cases].

OBJECTIVE: To describe our experience with olfactory groove meningiomas, analysing their clinical and radiological form of presentation and their surgical treatment. METHODS: The clinical records of 27 patients diagnosed of olfactory groove meningioma, extracted from the series of meningiomas operated on in our department since 1973, were retrospectively reviewed. Demographical data, the clinical presentation and duration of the symptoms before diagnosis were collected. Several radiological characteristics were also reviewed such as the tumour size, associated brain edema, type of contrast enhancement, presence of endostosis and invasion of the cranial base. The surgical resection grade, the histological type and the presence of recurrences in the follow-up were also analysed. RESULTS: The average age at presentation was 59 years. Average duration of symptoms prior to diagnosis was 39 months. The most frequent symptom at presentation was higher function impairment (52%), The average maximum tumoral diameter was 6.2 cm. 61% of the patients presented moderate or severe brain edema, which was quite frequently bilateral (74%). Radiological endostosis was present in 37% of the cases, but there were no signs of bone invasion in any case. The approach used was the basal frontal, uni or bilateral. In all cases the grade of resection was Simpson II. The majority of the cases presented a typical histology. Over 80% of the cases presented a good recovery at discharge. None of the patients presented with a tumoral recurrence after an average radiological follow-up of 74 months. CONCLUSIONS: The olfactory groove is an infrequent location for intracranial meningiomas, accounting for only 4.5% of all meningiomas in our experience. These tumours reach a big size due to the delay in diagnosis. Drilling of the cranial base does not seem necessary for preventing tumoral recurrence.

Adult↗
PubMed2001

Posterior fossa decompression and clot evacuation for fourth ventricle hemorrhage after aneurysmal rupture: case report.

OBJECTIVE AND IMPORTANCE: Massive intraventricular hemorrhage due to aneurysmal rupture is associated with a dismal prognosis. An intraventricular clot causing fourth ventricle dilation can cause compression to the brainstem similar to other posterior fossa masses such as cerebellar hemorrhage or infarction. The presence of fourth ventricle dilation carries a very high risk of death within 48 hours. Neither ventricular drainage nor fibrinolytic infusion has been successful in eliminating clots of the fourth ventricle. Posterior fossa decompression and direct evacuation of the clot could have good results in relieving brainstem compression caused by the clot. CLINICAL PRESENTATION: A 45-year-old woman was admitted to our intensive care unit after experiencing an aneurysmal subarachnoid hemorrhage. The neurological examination at admission revealed that she was in Grade V according to the World Federation of Neurological Surgeons grading system, but brainstem reflexes were present. Computed tomographic scanning revealed a massive intraventricular hemorrhage, with fourth ventricle dilation caused by an intraventricular clot. Bilateral external ventricular drains were placed to relieve elevated intracranial pressure. Cerebral angiography revealed a 1-cm basilar tip aneurysm, which was embolized with Guglielmi detachable coils (Boston Scientific, Boston, MA) during the same procedure. INTERVENTION: Given the patient's poor neurological condition, it was decided that brainstem compression should be relieved. A posterior fossa decompressive craniectomy was performed immediately after coil therapy, with direct evacuation of the intraventricular clot. The patient experienced a clear improvement in the level of consciousness and has achieved a good neurological result at early follow-up. CONCLUSION: Dilation of the fourth ventricle by an intraventricular clot is a sign of brainstem compression that can be relieved by posterior fossa decompression and direct clot evacuation.

Aneurysm, Ruptured↗
PubMed2001

Genetic characterization of a Sinorhizobium meliloti chromosomal region in lipopolysaccharide biosynthesis.

The genetic characterization of a 5.5-kb chromosomal region of Sinorhizobium meliloti 2011 that contains lpsB, a gene required for the normal development of symbiosis with Medicago spp., is presented. The nucleotide sequence of this DNA fragment revealed the presence of six genes: greA and lpsB, transcribed in the forward direction; and lpsE, lpsD, lpsC, and lrp, transcribed in the reverse direction. Except for lpsB, none of the lps genes were relevant for nodulation and nitrogen fixation. Analysis of the transcriptional organization of lpsB showed that greA and lpsB are part of separate transcriptional units, which is in agreement with the finding of a DNA stretch homologous to a "nonnitrogen" promoter consensus sequence between greA and lpsB. The opposite orientation of lpsB with respect to its first downstream coding sequence, lpsE, indicated that the altered LPS and the defective symbiosis of lpsB mutants are both consequences of a primary nonpolar defect in a single gene. Global sequence comparisons revealed that the greA-lpsB and lrp genes of S. meliloti have a genetic organization similar to that of their homologous loci in R. leguminosarum bv. viciae. In particular, high sequence similarity was found between the translation product of lpsB and a core-related biosynthetic mannosyltransferase of R. leguminosarum bv. viciae encoded by the lpcC gene. The functional relationship between these two genes was demonstrated in genetic complementation experiments in which the S. meliloti lpsB gene restored the wild-type LPS phenotype when introduced into lpcC mutants of R. leguminosarum. These results support the view that S. meliloti lpsB also encodes a mannosyltransferase that participates in the biosynthesis of the LPS core. Evidence is provided for the presence of other lpsB-homologous sequences in several members of the family Rhizobiaceae.

Bacterial Proteins↗
PubMed2001

Basal ganglia hematomas in severely head injured patients: clinicoradiological analysis of 37 cases.

OBJECT: The authors analyzed the clinicoradiological presentation of traumatic basal ganglia hematomas (TBGHs) in severely head injured (SHI) patients. METHODS: The records of 37 patients (28 male and nine female patients with a mean age of 28 years) in whom computerized tomography (CT) scans revealed TBGHs 2 ml or more in volume were retrospectively reviewed. These cases represented 2.4% of the total series of 1526 SHI patients admitted to the authors' institution between 1979 and 1998. Thirty-five patients (94%) were involved in traffic accidents and only two exhibited a period of lucidity. Associated extracranial injuries were seen in 21 patients (57%) and coagulation disorders in 32 (86%). Skull fracture was present in 10 (43%) of the 23 patients in whom skull x-ray films were obtained. Computerized tomography findings indicated diffuse axonal injury in 27 patients (73%), intraventricular hemorrhage in 22 patients (59%), and subarachnoid hemorrhage in 16 patients (43%). In all but two patients, the TBGHs were visible on the initial CT scan, and in 28 cases (76%) these hematomas were contralateral to the side of impact. Hematoma enlargement over the first few posttraumatic days was noted in 65% of the patients in whom control CT scans had been obtained (22 of 34 patients). Four patients (11%) underwent surgery to remove their TBGHs. Final outcomes were poor: 22 patients (59%) died, two (5%) became vegetative, seven (19%) experienced severe disabilities, and only six patients (16%) made a favorable recovery. CONCLUSIONS: Traumatic basal ganglia hematomas are dynamic lesions that tend to enlarge during the acute posttraumatic period. The overall prognosis in this series was poor. Patients in whom the volume of the hematoma was larger than 25 ml and those in whom hematoma volume enlargement or raised intracranial pressure occurred had the worst outcomes, perhaps indicating the need for a more aggressive surgical treatment.

Adolescent↗
PubMed2001

[Tentorial meningiomas. A study of 14 surgically verified cases].

OBJECTIVE: Complete surgical resection is considered to be the elective treatment for tentorial meningiomas. The objective of this work is to describe the clinical and radiological characteristics of these tumours, the best surgical approach, complications related to surgery and long term outcome of patients harbouring a meningioma at this location. MATERIALS AND METHODS: A series of 14 patients with tentorial meningiomas consecutively operated at our department between 1977 and 1999 is analyzed. Twelve patients were studied with CT and the last 8 with MR. Arteriography or angio-MR were performed in some patients when dural sinuses involvement was suspected. Tumoral resection was evaluated by means of Simpson Scale and final outcome according to the Glasgow Outcome Scale (GOS). RESULTS: Nine patients were female and 5 male. Mean age was 64 years (41-82). The average duration of presenting symptoms was 17 months. Headache was the most frequent presenting symptom. The tumour was implanted at the tentorial free edge in 4 cases, at the lateral region in 9 and at the falcotentorial region in 1 case. Complete surgical resection (Simpson I-II) was achieved in 10 cases. Final outcome was good recovery in 9 cases, moderate disability in 1, severe disability in 2 and two patients died. CONCLUSIONS: Surgery is the elective treatment for tentorial meningiomas. In most cases, complete surgical resection should be the objective. Subtotal resection may be considered when the tumour invades a patent dural sinus or the cavernous sinus or when the tumour is closely adherent to the brain stem. In these cases a close follow up is needed and reoperation or radiosurgical treatment may be contemplated if residual tumour growth occurs.

Adult↗
PubMed2000

Lateral asymmetries in the trigeminal ganglion of the male rat.

We have applied stereological methods to estimate the number and perikaryal size of primary sensory neurons in celloidin-embedded trigeminal ganglia of male albino rats, specifically looking for inter-individual and side variability. The mean total number of neurons per ganglion was 35,300, with a moderate variability among ganglia. On average, 66% of the neurons were classified as A-type and 34% as B-type. Although for individual cases there could be notable side differences in the number of neurons of each type, on a population basis these differences were not significant. Mean neuronal volume was four times larger for A- than for B-cells, and both populations exhibited a moderate variability among individuals. High intra-animal side differences were found for A-cells, which were on average a significant 23.5% larger in the right ganglia. B-cells did not show significant side differences. The distribution of individual volumes around the mean value was consistently skewed to the right, particularly in the case of A-cells, which partially overlapped with the largest B-cells. In the right ganglion the distribution of A-cells, but not of B-cells, showed a rightward bias, revealing the increase in bigger neurons. The existence of larger A-type neurons in the right trigeminal ganglion may provide a structural substrate for some somesthetically based complex behaviors which are best performed by rats using their right vibrissae.

Animals↗
PubMed2000

Spinal cord ependymoma presenting with acute paraplegia due to tumoral bleeding.

Acute paraplegia is a rare presentation for a spinal cord ependymoma Among spinal cord tumors ependymomas are most commonly associated with subarachnoid hemorrhage and there is evidence that some have had intratumoral hemorrhage, but most of these bleedings pass without symptoms. In this report, a case of spinal cord ependymoma debutting with acute neurological deterioration due to tumoral bleeding is presented. We discuss the clinical and neuroradiological findings and review the literature related to this unusual presentation.

Adult↗
PubMed1999

Release of outer membrane vesicles from Bordetella pertussis.

The aim of the study reported here was to investigate the production of Bordetella pertussis outer membrane vesicles (OMVs). Numerous vesicles released from cells grown in Stainer-Scholte liquid medium were observed. The formation of similar vesicle-like structures could also be artificially induced by sonication of concentrated bacterial suspensions. Immunoblot analysis showed that OMVs contain adenylate cyclase-hemolysin (AC-Hly), among other polypeptides, as well as the lipopolysaccharide (LPS). Experiments carried out employing purified AC-Hly and OMVs isolated from B. pertussis AC-Hly- showed that AC-Hly is an integral component of the vesicles. OMVs reported here contain several protective immunogens and might be considered a possible basic material for the development of acellular pertussis vaccines.

Adenylate Cyclase Toxin↗