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Biomedical subjects

P Canhão

Publications and source records attributed to P Canhão.

17 recordsLinked to original sources
PubMed2004

Thrombolysis for cerebral vein and dural sinus thrombosis.

BACKGROUND: Treatment of cerebral sinus thrombosis with thrombolytics has been reported in cases with a deteriorating clinical course despite anticoagulant therapy. The rationale of this treatment is to promote rapid recanalisation of the occluded sinus. OBJECTIVES: To review the available evidence on the efficacy and safety of thrombolysis in confirmed cerebral sinus thrombosis. SEARCH STRATEGY: We searched the Cochrane Stroke Group trials register (March 2003), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 1, 2003), MEDLINE (1966 to March 2003), EMBASE (1980 to March 2003), and reference lists of all relevant publications. SELECTION CRITERIA: We aimed to analyse separately unconfounded randomised controlled trials comparing thrombolytic agent with placebo, or thrombolytic agent with antithrombotic therapy, or thrombolytic agent and antithrombotic with antithrombotic alone, in patients with dural sinus thrombosis (confirmed by MR venography, intra-arterial venography or CT venography). DATA COLLECTION AND ANALYSIS: Two groups of reviewers independently applied the inclusion criteria. MAIN RESULTS: No randomised controlled trials were found. REVIEWER'S CONCLUSIONS: There is currently no available evidence from randomised controlled trials regarding the efficacy or safety of thrombolytic therapy in dural sinus thrombosis. A randomised controlled trial is justified to test this therapy especially in patients predicted to have a poor prognosis.

Cerebral Veins↗
PubMed2000

Cognitive and emotional consequences of perimesencephalic subarachnoid hemorrhage.

Little is known about the long-term cognitive-functional outcome of patients with perimesencephalic subarachnoid haemorrhage (PM SAH). We investigated the neurological, cognitive and emotional consequences of perimesencephalic subarachnoid haemorrhage in eighteen PM SAH patients admitted between November 1990 and July 1997 to the Neurology/Neurosurgery services of a University Hospital. The follow-up study consisted of a face-to-face interview, a neurological examination, an headache questionnaire, a neuropsychological evaluation (Mini-Mental State and a complementary battery to assess specific cognitive domains), the Hamilton Depression Rating Scale (HDRS) and the Blessed Dementia Scale. Thirteen patients performed below the 10th percentile in at least one cognitive domain. Six patients scored more than 12 points on the HDRS. Mini-Mental State and HDRS scores were moderately correlated (r = 0.55). Only three patients left their previous occupation. Minor cognitive deficits and high scores on a depression scale were frequent findings in this cohort of PM SAH patients. Reassurance and treatment of depressive symptoms could be important to improve the long-term outcome of PM SAH patients.

Adult↗
PubMed1999

Vascular risk factors for perimesencephalic nonaneurysmal subarachnoid hemorrhage.

No data have been published on the role of vascular risk factors for perimesencephalic nonaneurysmal subarachnoid hemorrhage (PMSAH). In a case-control study we compared the prevalence of vascular risk factors in 40 consecutive patients who suffered a perimesencephalic subarachnoid hemorrhage with that in two controls groups: (a) 120 subjects registered with a general practitioner (GP: matched at a 3:1 ratio for age and sex) and (b) 81 proxies of patients of a hospital outpatient clinic. A conditional multivariate logistic regression model was performed taking into account the matched design. Hypertension was more frequent among PMSAH patients than among the two control group subjects for men and women. Among women, smoking was more common in PMSAH than in the GP control group. The conditional multivariate logistic regression model confirmed that hypertension was an independent risk factor for PMSAH (P = 0.036) Hypertension is a preventable risk factor of PMSAH.

Adult↗
PubMed1998

Venous transcranial Doppler in acute dural sinus thrombosis.

The value of conventional transcranial Doppler ultrasound in the diagnosis and monitoring of cerebral vein thrombosis is unclear. Previous studies have suggested the usefulness of this method in two cases with superior sagittal sinus thrombosis that showed increased velocities of deep cerebral veins. The purpose of the present study was to evaluate the deep intracranial venous circulation in patients with that pathology. Venous transcranial Doppler ultrasound was performed with a range-gated 2 MHz transducer in 17 healthy volunteers and in six cases of proven acute superior sagittal sinus thrombosis. Peak systolic, end diastolic and mean blood flow velocities were measured in the basal vein of Rosenthal (BVR) and deep middle cerebral vein (DMCV) through a posterior temporal window. In 16 controls and in one patient, the straight sinus was also studied through an occipital approach. Sex distribution and mean age of controls and patients were similar. Mean blood flow velocities in controls were as follows (mean, SD): DMCV, 10.4, 1.4 cm/s; BVR, 11.3, 1.8 cm/s; straight sinus, 29.5, 9.9 cm/s. Three of the patients with superior sagittal sinus thrombosis showed increased velocities either in the DMCV, the BVR or the straight sinus. One patient showed slightly increased velocities in the BVR, and the other two showed normal venous velocity values. This study confirms the usefulness of conventional transcranial Doppler ultrasound in detecting superior sagittal sinus thrombosis. However, a normal examination does not exclude this diagnosis.

Adult↗
PubMed1998

Diagnosis of stroke by the nonneurologist. A validation study.

BACKGROUND AND PURPOSE: The first medical contact of an acute stroke victim is often a nonneurologist. Validation of stroke diagnosis made by these medical doctors is poorly known. The present study seeks to validate the stroke diagnoses made by general practitioners (GPs) and hospital emergency service physicians (ESPs). METHODS: Validation through direct interview and examination by a neurologist was performed for diagnoses of stroke made by GPs in patients under their care and doctors working at the emergency departments of 3 hospitals. RESULTS: Validation of the GP diagnosis was confirmed in 44 cases (85%); 3 patients (6%) had transient ischemic attacks and 5 (9%) suffered from noncerebrovascular disorders. Validation of the ESP diagnosis was confirmed in 169 patients (91%); 16 (9%) had a noncerebrovascular diagnosis. Overall, the most frequent conditions misdiagnosed as stroke were neurological in nature (cerebral tumor, 3; subdural hematoma, 1; seizure, 1; benign paroxysmal postural vertigo, 1; peripheral facial palsy, 2; psychiatric condition, 6; and other medical disorders, 7). CONCLUSIONS: In the majority of cases, nonneurologists (either GPs or ESPs) can make a correct diagnosis of acute stroke. Treatment of acute stroke with drugs that do not cause serious side effects can be started before evaluation by a neurologist and CT scan.

Adult↗
PubMed1996

Diagnosis of transient ischemic attack by the nonneurologist. A validation study.

BACKGROUND AND PURPOSE: Interobserver reliability of the diagnosis of transient ischemic attack (TIA) is low, and diagnosis of TIA made by nonneurologists is often erroneous. We sought to validate the diagnosis of TIA made by general practitioners (GPs) and by hospital emergency service physicians (emergency MDs). METHODS: A list of 20 neurological symptoms was distributed to 20 GPs and 22 neurologists who graded the compatibility of each symptom with the TIA diagnosis. At least two neurologists validated TIA diagnoses made by GPs for patients under their care or by emergency MDs. RESULTS: Compared with neurologists, GPs considered "confusion" and "unexplained fall" more often compatible with TIA and "lower facial palsy" and "monocular blindness" less often compatible with TIA. Validation of diagnosis by GP was confirmed in 10 patients (19%); 26 patients had strokes, and 16 (31%) had a noncerebrovascular disorder. Validation of diagnosis by emergency MD was confirmed in 4 patients (13%); 10 patients had strokes, and 17 (55%) had noncerebrovascular disorders. The most frequent conditions misdiagnosed as TIAs were transient disturbances of consciousness, mental status, and balance. CONCLUSIONS: The TIA concept is understood differently by neurologists and nonneurologists. GPs and emergency MDs often label minor strokes and several nonvascular transient neurological disturbances as TIAs. Until this misconception of TIA is changed, the term TIA should probably be avoided in the communication between referring physicians and neurologists. If not referred to a neurologist, one third to one half of patients labeled with a diagnosis of TIA will be inappropriately managed.

Cerebrovascular Disorders↗
PubMed1996

Carotid stenosis associated with atrial fibrillation.

PURPOSE AND SETTING: To describe the prevalence and risk factors for carotid stenosis in TIA/stroke patients with non valvular atrial fibrillation (AF) and to compare clinical and CT characteristics of TIA/stroke in AF patients with and without carotid stenosis. SUBJECTS: 50 TIA/stroke patients with AF who had ultrasound investigation of the extracranial vessels, included in a prospective hospitalar registry. RESULTS: Twenty-two patients had some degree of carotid stenosis, but only 5 had more than 50% stenosis, including one with occlusion. Stenosis was neither more frequent nor more severe on the symptomatic side. Smokers were significantly more frequent in AF patients with > 50% stenosis. Clinical and CT features were quite similar in patients with and without carotid stenosis. CONCLUSION: The association in a TIA/Stroke patient of AF and severe carotid stenosis on the symptomatic side is exceptional. TIA/strokes related to carotid stenosis cannot be identified by their clinical/CT characteristics. Management of these patients must be decided by stratification of risk of recurrence for AF and from carotid stenosis and balance of these risks with that of endarterectomy.

Aged↗
PubMed1995

Perimesencephalic and nonperimesencephalic subarachnoid haemorrhages with negative angiograms.

BACKGROUND: van Gijn and co-workers identified "Perimesencephalic haemorrhage" (PM) as distinct, benign, non-aneurysmal subarachnoid haemorrhage. However, there is only one retrospective series of this entity outside the Netherlands. PURPOSE: to confirm (or not) the benign nature of perimesencephalic subarachnoid haemorrhage by evaluating its clinical course and long-term follow-up in a consecutive series of patients admitted to a University Hospital. METHODS: Patients with subarachnoid haemorrhage and negative cerebral angiography admitted between January 1985 and April 1992 were classified according to the distribution of blood on a CT scan performed within 72 hours after onset, in perimesencephalic and non-perimesencephalic haemorrhages. Demographic and clinical data (collected consecutively), complications and long-term follow-up (obtained by chart review and follow-up by mail) were compared in the two groups. RESULTS: Seventy one cases, 36 perimesencephalic and 35 nonperimesencephalic were included. Sex and age distribution were similar in the two groups. A normal examination on admission was the rule in the perimesencephalic group. Only one patient with perimesencephalic haemorrhage had a complication--transient neurological signs during angiography--and there were no deaths or morbidity during follow-up. In the non-perimesencephalic group three patients rebleed, four developed hydrocephalus and two had delayed cerebral ischaemia. Mean duration of follow-up was 27.6 months for the perimesencephalic and 30.8 months for the non-perimesencephalic group. After discharge there was a fatal rebleed in the latter group. Fifteen percent of the subjects (11% of the perimesencephalic group and 20% of the non-perimesencephalic group) retired from work during the follow-up period. Headaches and depression were found in similar percentages (22-25%) in both groups. CONCLUSIONS: This study confirms that perimesencephalic haemorrhage is a distinct entity within the larger group of subarachnoid haemorrhage with negative angiograms, with a good short term and long-term prognosis, and no need for repeated angiographic investigation.

Adult↗
PubMed1995

A multivariate study of headache associated with ischemic stroke.

Thirty-four percent of 182 ischemic stroke patients registered during 1 year in a prospective hospital stroke data base complained of headache within a 72-hour interval of stroke onset. Headache was more common in patients under 70 years of age, in nonsmokers, in those with a past history of migraine, and in subjects presenting transient loss of consciousness, nausea/vomiting, or visual field defects. Headache was more frequent in vertebrobasilar (57%) than in carotid (20%) territory strokes, more so in posterior cerebral artery (90%) and cerebellar infarcts (80%), and was infrequent in subcortical infarcts (7%) and lacunes due to single perforator disease (9%). In multiple regression analysis, vertebrobasilar stroke (odds ratio 6.9), lacuanr stroke (odds ratio 0.06), and past history of migraine (odds ratio 6.7) were significant independent predictors of headache, suggesting that ischemic stroke location is the major determinant of stroke-associated headache, most probably related to activation of the trigeminovascular system, whose threshold may be modified by individual susceptibility.

Aged↗
PubMed1995

Headache associated with transient ischemic attacks.

Sixty (29%) of 205 consecutive patients with transient ischemic attacks registered in a hospital stroke data base had headache within 72 hours of onset. Headache was significantly more common in nonsmokers (odds ratio = 2.8; 95% confidence interval = 6.7 to 1.2). Headache was infrequent in patients with amaurosis fugax, and was not significantly associated with any other particular clinical presentation of transient ischemic attack. Headache was more common in vertebrobasilar (33%) than in carotid distribution (24%) episodes, and was not rare in transient ischemic attacks presenting as lacunar syndromes (29%). Headache was less frequent in patients whose computerized tomograms showed an infarct appropriate to the symptoms (odds ratio = 0.2; 95% confidence interval = 0.02 to 1.4). A diffuse headache was more common in patients with lacunar events than in patients with cortical attacks (odds ratio = 3.0; 95% confidence interval = 13 to 0.07). No other association was found between headache location and the presumed involved vascular territory. Headache in patients with transient ischemic attacks is poorly related/explained by the clinical characteristics of the ischemic event.

Aged↗
PubMed1994

1,3-Dipropyl-8-cyclopentylxanthine attenuates the NMDA response to hypoxia in the rat hippocampus.

Excitatory amino acids may cause neuronal damage and death in cerebral hypoxia and ischemia, through the activation of different subtypes of glutamate receptors, in particular of the N-methyl-D-aspartate (NMDA) receptor. In the present work, the effect of hypoxia on the component of the field excitatory postsynaptic potential (fepsp) mediated by the NMDA receptor was studied in the hippocampal CA1 area of the rat. A period of 15 min of hypoxia induced virtual abolition of the NMDA receptor-mediated fepsp and a 94.8 +/- 0.7% maximal decrease in the fepsp. A period of 3 min of hypoxia induced a 89.3 +/- 12.3% maximal decrease in the NMDA receptor-mediated component of the fepsp and only a 50.8 +/- 11.5% maximal decrease in the fepsp. Both periods of hypoxia thus induced a more pronounced depression of the NMDA receptor-mediated component of the fepsp than of the fepsp. We found that 48.5 +/- 9.1% decrease (about half of the total decrease) in the NMDA receptor-mediated fepsp, and 51.6 +/- 19.6% decrease (approximately all decrease) in the fepsp induced by hypoxia (3 min) were reversed in the presence of the selective adenosine A1 receptor antagonist, 1,3-dipropyl-8- cyclopentylxanthine (DPCPX) (50 nM), and thus likely to be mediated by endogenous adenosine, through the activation of adenosine A1 receptors.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Smoking and aneurysmal subarachnoid haemorrhage: a case-control study.

BACKGROUND: Despite recent advances in the management of subarachnoid haemorrhage, the mortality rate associated with the condition remains high. The identification of risk factors for subarachnoid haemorrhage may lead to the development of interventions aimed at its prevention. METHODS: We compared the prevalence of vascular risk factors using a case-control design in 141 consecutively admitted patients who had suffered a subarachnoid haemorrhage with that in age- and sex-matched subjects registered with a general practitioner in a western suburb of Lisbon. RESULTS: The prevalence of diabetes and hyperlipidaemia did not differ between the groups. Hypertension was 8.3 times more frequent among patients with subarachnoid haemorrhage (95% confidence interval 4.6-16.7) than in the control group, and smoking was four times more frequent (95% confidence interval 2.0-8.6). The association between smoking and subarachnoid haemorrhage persisted after controlling for the presence of hypertension (odds ratio for hypertensive participants = 10.5, 95% confidence interval 1.9-56.4; odds ratio for normotensive participants = 3.7, 95% confidence interval 1.6-10.1) and was independent of both age and sex. CONCLUSION: These results indicate that hypertension and smoking are both involved in the growth or rupture of cerebral aneurysms.

Adult↗
PubMed1993

How often is a perimesencephalic subarachnoid haemorrhage CT pattern caused by ruptured aneurysms?

BACKGROUND: Angiography is usually recommended in perimesencephalic subarachnoid haemorrhage (PM SAH) to rule out a basilar artery aneurysm. However it is not known how often aneurysms are found among patients with a CT pattern of PM haemorrhage or the frequency of this CT pattern after rupture of posterior circulation aneurysms. METHOD: CTs of all SAH caused by posterior circulation aneurysms admitted from 1/85 to 12/92 where reviewed by two examiners. Late (> 72h) examinations were excluded. The remaining CTs were classified in perimesencephalic (PM) or non PM. RESULTS: 81 posterior circulation aneurysms were collected. Only one PM-like CT pattern was found, due to ruptured posterior communicating artery aneurysm (1.3%; 95% Cl (confidence intervals) = .03-6.7%). During the same period 37 PM SAH with negative angiographic results were admitted. The likelihood of finding an aneurysm in a patient with an early CT showing a PM distribution of haematic densities was 2.7% (95% Cl = .07-.14%). CONCLUSIONS: Although the probability of finding an aneurysm in a SAH patient with a PM CT pattern is low, a complete 4-vessel angiogram must be obtained.

Aneurysm, Ruptured↗
PubMed1992

[Neurologic manifestations of Behçet disease. Review of the caseload of the Neurology and Dermatology services at the Santa Maria Hospital].

Neurological involvement in a series of patients with Behçet's disease, evaluated at the Departments of Neurology and Dermatology, St. Maria Hospital is reported. Meningoencephalytic or encephalytic were the most common clinical forms, while headache, cerebellar and pyramidal signs were the most prevalent symptoms/signs. On follow-up (range 2-13 years) the majority of the patients had either a progressive or a remitting-progressive course. Magnetic ressonance imaging was the most valuable method of detecting central nervous system lesions.

Adult↗
PubMed1992

[Perimesencephalic hemorrhage].

Among 293 subarachnoid hemorrhages admitted to the Neurology and Neurosurgery departments of Sta Maria Hospital, 108 patients had a normal cerebral angiography. Twenty-three meet the radiological criteria for perimesencephalic hemorrhage (center of the hemorrhage located in front of the mesencephalon, without blood in the interhemispheric and lateral sylvian fissures, nor significant intraventricular hemorrhage). The clinical picture was one of sudden, severe headache with meningeal signs, without focal signs or decreased alertness. Evolution was benign: there was no intrahospital mortality, morbidity or rebleeds on follow-up (3.5 years). In this subgroup of subarachnoid hemorrhage there is no need for a repeated angiogram if the first angiography is considered normal.

Female↗
PubMedDate not supplied

[Nimodipine in subarachnoid hemorrhage].

The efficacy of nimodipine in decreasing mortality and morbidity of subarachnoid haemorrhage (HSA) is evaluated in 51 patients admitted to the Neurological and Neurosurgery Departments of the Santa Maria Hospital. Reductions of 2 x (0.65, 6.39) of the incidence of ischemia in the total group and of 2.1 x (0.58, 7.79) of mortality in the sub-group with initial severity of less than 4 points of the Hunt score were observed relatively to a comparable group of patients previously admitted who did not receive nimodipine. Randomized clinical trials that tested the effect of nimodipine in the context of HSA are reviewed.

Adolescent↗