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P S Dias

Publications and source records attributed to P S Dias.

17 recordsLinked to original sources
PubMed2005

Stereotactic radiosurgery and vestibular schwannoma: hydrocephalus associated with the development of a secondary arachnoid cyst: a report of two cases and review of the literature.

Stereotactic radiosurgery for vesibular schwannoma requires long-term follow-up with complete MR imaging. We report two cases of a large secondary arachnoid cyst developing in the cerebellopontine angle following stereotactic radiosurgery. In one case this was associated with progressive ventriculomegaly and the onset of symptomatic hydrocephalus requiring emergency treatment. The second patient had ventriculomegaly at diagnosis, but developed an arachnoid cyst following treatment. Although both arachnoid cysts and hydrocephalus may also occur spontaneously in patients with vestibular schwanomma, the incidence is higher after stereotactic radiosurgery. As both complications may be associated with sudden clinical deterioration, follow-up with full cranial T1 and T2 weighted MR imaging is required to reveal these complications, in addition to assessing tumour response.

Aged↗
PubMed1998

Compound anterior cranial base fractures: classification using computerized tomography scanning as a basis for selection of patients for dural repair.

OBJECT: A classification is proposed to organize anterior cranial base fractures systematically according to their location and size. The goal of this study was to determine whether these two variables, irrespective of cerebrospinal fluid (CSF) rhinorrhea, are related to the long-term risk of posttraumatic meningitis and, hence, to standardize decision making concerning surgical repair of associated CSF fistulas. METHODS: With the aid of high-resolution thin-section coronal computerized tomography (CT) scanning, anterior cranial base fractures were classified into the following four major types: I, cribriform; II, frontoethmoidal; III, lateral frontal; and IV, complex (any combination of the other three types). Fractures with a maximum bone displacement that extended farther than 1 cm in any plane were classified as "large" and those less than 1 cm as "small." The authors used this classification in a study of 48 patients who were treated by conservative (20 patients) or surgical (28 patients) means. The results showed a gradation of risk: the fracture most likely to develop infection was a large cribriform (Type I) and the least likely was a small lateral frontal (Type II). Statistical analysis showed that the trend for an increased infection rate was related to the cumulative effect of three variables in the following order: 1) prolonged duration of rhinorrhea (analysis of variance [ANOVA], p = 0.017); 2) large size of fracture displacement (ANOVA, p = 0.079); and 3) fracture's proximity to the midline (ANOVA, p = 0.015). CONCLUSIONS: In this series, microsurgical repair was accompanied by a minimum complication rate. Hence, the authors recommend that patients with fractures that combine the aforementioned variables should be considered to have a high long-term risk of infection and their injury should be surgically repaired as soon as the posttraumatic edema has subsided. This applies to the following fractures: large cribriform (Type I) with transient rhinorrhea lasting 5 to 8 days and large frontoethmoidal (Type II) with prolonged rhinorrhea lasting longer than 8 days. Furthermore, the authors conclude that this classification can improve the management of posttraumatic CSF fistulas of the anterior cranial base and may provide insights into the mechanisms underlying their spontaneous repair and susceptibility to meningitis.

Adolescent↗
PubMed1995

Identification of polymorphism at the glutathione S-transferase, GSTM3 locus: evidence for linkage with GSTM1*A.

Allelism in the glutathione S-transferase, GSTM3 gene has been identified using PCR with specific primers to exon 6/exon 7. Sequencing showed the mutant GSTM3*B allele to have a three-base deletion in intron 6 with a frequency of 0.158. The mutation generates a recognition sequence, 5'-AAGATA-3', for the negative transcription factor YY1. GSTM3*B was significantly associated with GSTM1*A.

Base Sequence↗
PubMed1995

Susceptibility to astrocytoma and meningioma: influence of allelism at glutathione S-transferase (GSTT1 and GSTM1) and cytochrome P-450 (CYP2D6) loci.

We describe a case-control study to identify associations between polymorphism at the cytochrome P-450 (CYP2D6) and glutathione S-transferase (GSTT1 and GSTM1) loci and susceptibility to astrocytoma and meningioma. Accordingly, genotype frequencies in 112 astrocytoma and 50 meningioma patients were compared with frequencies in 577 controls. GSTM1 genotype frequencies in these groups were not different. Logistic regression analysis showed GSTT1 null and CYP2D6 poor metabolizer were risk factors in astrocytoma (odds ratio = 2.67 P = 0.0005 and odds ratio = 4.17 P = 0.0043, respectively) and meningioma (odds ratio = 4.52, P = 0.0001 and odds ratio = 4.90, P = 0.0132, respectively) when corrected for the other variables. No interactive effects between genotypes were identified. The data suggest polymorphism at loci encoding carcinogen-metabolizing enzymes influences susceptibility to astrocytoma and meningioma, possibly by determining effectiveness in the detoxification of environmental carcinogens.

Adult↗
PubMed1995

Cognitive outcome after aneurysm rupture: relationship to aneurysm site and perioperative complications.

We evaluated cognitive outcome in a group of 37 patients who had undergone surgery for rupture and repair of a single intracranial aneurysm at least 6 months previously. We compared outcome--assessed by tests of intelligence, attention, executive functions sensitive to frontal lobe lesions, memory, neglect, and mood, as well as by a specially devised questionnaire--between a group of 20 patients who had aneurysms of the anterior communicating artery and 17 patients who had aneurysms located on other branches of the internal carotid artery. There were no differences in cognitive outcome between patients with anterior communicating artery aneurysms and those with aneurysms on other branches of the internal carotid artery. The patient group as a whole, however, showed impairment in executive functions and some aspects of memory in comparison with normative data. Overall, 65% of the patients were impaired in at least one cognitive domain, with 19% showing executive impairments alone, 14% showing memory impairments alone, and 32% showing deficits in both domains. Cognitive outcome was most strongly predicted by postoperative neurologic events, although clipping of an anterior cerebral artery was associated with a higher impairment rating on a symptom profile completed by patients' relatives, and although preoperative rebleeding of aneurysms predicted impairment of executive function.

Adult↗
PubMed1992

Spinal epidermoid cyst and cauda equina syndrome in a teenage girl.

A sixteen year old girl presented with a four year history of hip pain followed subsequently by back pain radiating down her left leg, progressive urgency of micturition, urinary incontinence, a feeling of bladder fullness and incomplete bladder emptying, faecal impaction and finally, numbness in both of her buttocks. A diagnosis of Cauda Equina Syndrome was suspected on the history and the clinical examination. A plain X-ray of her lumbar spine revealed evidence of a slow growing mass within the vertebral canal at the level of L3. A Magnetic Resonance Imaging (MRI) scan confirmed an intradural space occupying lesion at the same level. This lesion was surgically removed and histological examination revealed a benign epidermoid cyst.

Adolescent↗
PubMed1992

Untoward clinical effects after stereotactic radiosurgery for intracranial arteriovenous malformations.

Stereotactic radiosurgery has become one of the most acceptable means of treating deep-seated intracranial arteriovenous malformations, as well as being a useful adjunct in a number of other pathologies. One hundred and sixty patients are discussed, having follow-up of at least 2 years. Radionecrosis occurred in six patients and haemorrhage in the latent period prior to thrombo-obliteration in a further six. Successful thrombo-obliteration was ultimately achieved in 76% of patients. As a bonus, epilepsy was improved in 29 of 48 patients presenting with seizures and worsened transiently in only three of these.

Adolescent↗
PubMed1989

Results of stereotactic radiosurgery of arteriovenous malformations: an analysis of 52 cases.

The stereotactic radiosurgery unit in Sheffield became operational in September 1985 and over 180 patients harbouring AVMs have been treated. The first 52 patients underwent one year follow up angiography and comprise the material for this study. At one year 26 patients (50%) already had a favourable outcome (16 complete and 10 almost complete obliteration). The results were the same in the two sexes. There was a better response in younger patients: under 20 years 75% favourable, between 20 and 40 years 45% favourable and above 40 years about 25% favourable. Malformations in a lateral position appeared to respond better than those in the midline. Lesions fed by vessels from more than one large vessel territory had less chance of complete obliteration at one year than those gaining blood from only one main supply. There was no difference in outcome between small malformations (less than 2 cm3) medium (2-3 cm3) or large (greater than 3 cm3). No immediate morbidity or late side effects were encountered in these patients. Stereotactic radiosurgery is a safe and effective method in the treatment of arteriovenous malformations but there is a relatively long latency. The number of malformations obliterated is expected to be much higher when two years have elapsed after treatment.

Adolescent↗
PubMed1989

Giant epidermoid cysts of the skull.

The authors describe two cases of giant intradiploic epidermoid cysts of the cranial vault and a case of a large epidermoid arising from the frontal sinus and extending intracranially. The aetiology of epithelial cysts is reviewed. The characteristic radiological and CT scan appearances of diploic epidermoid cysts are described, their clinical presentation and surgical management briefly discussed.

Adult↗
PubMed1989

Management of cerebrovascular malformations.

More and more cerebrovascular malformations are being recognized during life as a result of improved imaging techniques. The nature of the different varieties of malformation and their clinical significance are discussed and a brief account given of the relative merits of surgical excision, thrombo-obliteration by stereotactic radiosurgery, and occlusion by endovascular embolization as compared with conservative management.

Embolization, Therapeutic↗
PubMed1988

Cerebral medullary venous malformations. Report of four cases and review of the literature.

Each type of cerebral vascular malformation has its own unique clinical, radiological and pathological features, and a different pattern of natural evolution. With greater awareness and advances in neuroimaging, there is increasing recognition of Cerebral Medullary Venous Malformations (MVM), angiographically characterised by an 'Umbrella' or 'Caput Medusae' appearance. The clinical and radiological features of four patients with angiographically demonstrable features of cerebral medullary venous malformations, seen in our departments are presented to illustrate the features of cerebral MVMs. Three patients have been managed conservatively and one has been treated with stereotactic radiosurgery. The literature on cerebral MVMs has been reviewed and presented in this paper. It appears that most are benign and even in those cases where there has been a haemorrhage the outcome seems to be much better than with arteriovenous malformations. The rationale behind radiosurgical treatment is discussed. Before embarking upon any form of interventional therapy the natural course of these lesions should be considered.

Adolescent↗
PubMed1988

CT scanning in the management of intracranial abscess: a review of 100 cases.

One hundred cases of brain abscess presenting between 1974 and 1984 are reviewed. The overall mortality was 20%, 98 cases were actively treated with a peroperative mortality of 14%. The results are compared to Garfield's 1969 series, drawn from similar clinical material. Changes in presentation and outcome are described. A significant improvement in survival (p less than 0.001) has occurred following the introduction of computerised tomography (CT Scan) which permits the rapid diagnosis and accurate localisation of intracranial sepsis. As the basic therapeutic regime remains unchanged (burr hole aspiration and appropriate antibiotic treatment), other aspects of management have been examined, leading to the suggestion that CT Scanning has made a major contribution to the reduction in mortality.

Adolescent↗
PubMed1987

Management of subdural empyema: a series of 24 cases.

Twenty four cases of subdural empyema are reviewed. The overall mortality was 17%, 18 patients were managed by burr hole and five by craniotomy or craniectomy. Antibiotic therapy was commenced once pus had been evacuated. Infection of the paranasal and mastoid sinuses was the commonest aetiological factor. Aspiration of pus through burr holes is the recommended surgical procedure with low mortality and morbidity, when combined with early diagnosis and aggressive chemotherapy.

Adult↗
PubMed1986

Spontaneous subarachnoid hemorrhage and negative cerebral panangiography. Review of 140 cases.

One hundred and forty consecutive patients who sustained proven spontaneous subarachnoid hemorrhage (SAH) with negative cerebral panangiography were studied retrospectively. Attention was directed to the presence, amount, and distribution of subarachnoid blood on computerized tomography (CT) scans. It was determined that the finding of blood on CT had a significant association with clinical grade, loss of consciousness, ventricular ratio, fixed ischemic deficit, and total of all complications, but not with epilepsy, hypertension (previously known or detected on admission), treated hydrocephalus, rebleeding, angiographic spasm, and eventual outcome (which was generally excellent on follow-up examination). The distribution of blood, predominantly around the basal cisterns, suggests leakage from ventriculostriate and thalamoperforating vessels as the cause of SAH, and closer study of these vessels is suggested.

Adolescent↗