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Biomedical subjects

N Vila

Publications and source records attributed to N Vila.

At least 19 recordsLinked to original sources
PubMed1998

[Plasma homocysteine levels in patients with ischemic cerebral infarction].

BACKGROUND: Moderate hyperhomocysteinemia is an independent risk factor for stroke. The relationship between homocysteinemia and stroke and its related factors are unknown in Spain. PATIENTS AND METHODS: We determined plasma homocysteine concentrations in 80 stroke patients and in 48 control subjects without vascular risk factors. Folate, vitamin B12 and creatinine concentrations were also measured in stroke patients. RESULTS: Total plasma homocysteine concentrations were higher in stroke patients compared to controls (11.2 [SD 3.2] mumol/l versus 8.1 [2.6] mumol/l; p < 0.001). Hyperhomocysteinemia was present in 20% of patients and in 2.2% of controls (odds ratio [OR] = 5.75; 95% CI = 1.24-53.4; p < 0.01). Homocysteine values were related to vitamin B12 (r = 0.28; p < 0.05) and creatinine concentrations (r = 0.24; p < 0.05). Multiple regression analysis showed that about 15% of the variation in plasma homocysteine concentrations could be predicted by the values of vitamin B12 (p < 0.001) and creatinine (p < 0.05). Homocysteine values were unrelated to age, sex, folate concentrations, atherosclerotic subtype or to the presence of vascular risk factors. CONCLUSIONS: Moderate hyperhomocysteinemia was present in about 20% of stroke patients in our series. Homocysteine plasma level was not related with other stroke risk factors or with the atherosclerotic subtype of stroke, but it was partially related with the renal function parameters and the serum levels of vitamin B12.

Brain Ischemia↗
PubMed1998

Sympathetic skin response in patients with lateral medullary syndrome.

We have carried out a prospective study of the sympathetic skin response (SSR) in 21 patients with lateral medullary syndrome (LMS), with the aim of identifying the most common pattern of SSR abnormalities and its possible correlation with clinical and radiological findings. The amplitude of the SSR recorded in the ipsilateral hand to the infarct was abnormally reduced in the patients as a group. However, using different stimulation and recording sites, and considering only the presence or absence of the response, we identified 5 different patterns of SSR abnormalities: 1. Normal responses; 2. Bilaterally absent responses to stimulation of the ipsilateral supraorbital nerve but not to other stimulation sites; 3. Absent responses in the side ipsilateral to the stroke, with normal responses in the contralateral side; 4. A combination of patterns 2 and 3; and 5. Absent responses to all stimuli. All patients with ipsilateral facial sensory loss had absent SSR to ipsilateral supraorbital nerve stimulation, while there was only a positive correlation between abnormal contralateral facial sensation and preservation of the SSR (Fisher's exact test P=0.003). No correlation was found between the pattern of SSR abnormalities and the infarct topography, assessed with the MRI. Our findings suggest that the damage to the SSR circuits of patients with LMS is not uniform, and follows an heterogeneous distribution independent from the MRI findings, and poorly related to the clinical sensory manifestations.

Adult↗
PubMed1998

Blood pressure and functional recovery in acute ischemic stroke.

BACKGROUND AND PURPOSE: The relevance of elevated blood pressure in acute ischemic stroke and its most appropriate management are unresolved. We aimed to evaluate the rate of functional recovery with relation to early blood pressure management in patients with ischemic stroke. METHODS: Four hundred eighty-one consecutive ischemic stroke patients were admitted to the Neurology Service within 20.9+/-10.5 hours of symptoms onset as part of the Barcelona Downtown Stroke Registry, including 235 patients who received oral antihypertensive agents within <24 hours after stroke onset. Demographic, clinical (Mathew scale), and CT scan findings were collected prospectively. Mean arterial pressure (MAP) was recorded before hospital arrival and at 7 AM on days 1, 2, and 7 of hospitalization. The primary end point was complete functional recovery at day 7 defined as a score of 0 to 1 on the modified Rankin scale. RESULTS: Two hundred fifty-two patients achieved complete recovery on day 7. Using logistic regression, independent predictors of complete recovery included mild impairment at stroke presentation, lack of history of hypertension, and absence of brain edema on CT scan. Also, a 20% to 30% drop in MAP on day 2 after stroke onset almost tripled the odds of full recovery (odds ratio, 2.9; 95% CI, 1.3 to 6.3). MAP tended to normalize after stroke in all subjects, more rapidly if hypotensive agents were administered. Brain edema was also less frequent in patients with a greater drop in blood pressure. Despite the fact that a drop in MAP >30% from baseline was observed in 49 patients, this preceded worsening stroke in only 4 patients. Conversely, worsening stroke occurred in 51 patients despite stable blood pressure. CONCLUSIONS: These results suggest that complete recovery in ischemic stroke is facilitated by a moderate blood pressure reduction when brain edema develops, most likely as the result of a more adequate cerebral perfusion pressure. Conversely, stroke worsening due to pharmacological hypoperfusion is exceptional.

Activities of Daily Living↗
PubMed1997

[Factors associated to aspirin failure for secondary stroke prevention].

BACKGROUND: It is not settled whether aspirin (ASA) failure may be predicted in stroke and transient ischemic attack (TIA) patients. The risk of ASA failure may be predicted by analyzing the epidemiological traits of patients with stroke or TIA. PATIENTS AND METHODS: We evaluated retrospectively 695 stroke or TIA patients admitted to the Downtown Barcelona Stroke Registry, including 54 patients who recurred while on 125-500 mg/day of ASA (group ASA failure), and 178 patients who showed a good clinical response to the same dose of ASA for at least one year of follow-up (group ASA sensitive). Vascular risk factors, stroke subtypes, and clinical and radiological findings were compared in both groups. RESULTS: On multivariate analysis ASA failure was independently correlated with history of myocardial infarction, nonvalvular atrial fibrillation or hypercholesterolemia. A trend toward age older than 65 was also correlated with ASA failure. On the contrary, periventricular lucencies were a protector factor. Stroke severity at clinical onset and at follow-up was unrelated to the intake of ASA at stroke onset. CONCLUSIONS: Males or females older than 65 years, with a history of coronary heart disease or atrial fibrillation, serum cholesterol level > 240 mg/dl, and a CT scan showing no evidence of small vessel disease are, respectively, the characteristics most frequently encountered in patients who suffer an ischemic stroke despite preventive treatment with 125-500 mg/day of ASA. Moreover, this treatment does not reduce initial and long-term stroke severity.

Aged↗
PubMed1997

Periventricular white matter lucencies in patients with lacunar stroke. A marker of too high or too low blood pressure?

BACKGROUND: Periventricular white matter lucencies (PWML) have been described in stroke patients with arterial hypertension, hypotensive episodes, or increased nocturnal fall of blood pressure (BP). As a result of these mixed factors, the relationship between PWML and BP remains unsettled and the appropriate management of arterial BP in stroke patients with PWML is unknown. OBJECTIVE: To clarify the relationship between PWML, arterial BP, and cerebral hemodynamics. DESIGN: Cohort study followed up 6 months after index stroke. SETTING: Referral center. PATIENTS: In 41 consecutive patients with first-ever lacunar infarction, the extent of PWML detected on brain magnetic resonance images was measured. Six months after stroke, BP values were monitored during a 24-hour period and transcranial Doppler examinations were performed at rest and following the administration of acetazolamide. MAIN OUTCOME MEASURES: Correlation of cerebral hemodynamics and BP values with the extent of PWML. RESULTS: The severity of PWML varied substantially among patients, suggesting that PWML and lacunar infarctions could be due to several different mechanisms. Older age, elevated awake systolic BP, increased cerebrovascular tone, and the interaction between history of heart disease and the lowest heart rate were the strongest independent predictors of the severity of PWML. Diastolic BP and the vasodilatory capacity of the resistance vessels did not predict the severity of PWML. CONCLUSIONS: Overall, PWML are markers of systolic damage in older lacunar stroke patients with stiffer arteries. In addition, hemodynamic failure may be relevant in patients with concomitant heart disease.

Aged↗
PubMed1997

Cervical and facial myoclonus associated with dolichoectasia of the left vertebral artery.

A 52-year-old man presented with rapid jerking movements of his head to the right and clonic involuntary twitches involving his left eyelid and cheek. Electromyographic (EMG) recordings were consistent with left sternocleidomastoid and facial asynchronous myoclonus. Magnetic resonance imaging showed the presence of a dolichoectatic left vertebral artery displacing the medulla. Facial involvement and the asynchronism between cervical and facial myoclonus did not support a medullary origin for the movements. A direct compression of the eleventh and seventh cranial nerves by the dolichoectatic left vertebral artery may be the mechanism responsible for myoclonus in our patient.

Cerebellopontine Angle↗
PubMed1997

Blink reflex in patients with Wallenberg's syndrome.

Knowledge of the neural circuits involved in Wallenberg's syndrome (WS) is incomplete. Study of the blink reflex (BR) in patients with WS can help in reaching a better understanding of the physiopathology underlying clinical symptoms and may help in the prediction of clinical outcome. We evaluated the BR in response to supraorbital nerve electrical stimuli in 20 patients with WS. All patients were studied within the 1st week after onset of symptoms, and 10 of them were also studied repeatedly during a follow-up period of 3-12 months. At the first examination the long latency bilateral responses (R2 and R2c) to stimulation of the supraorbital nerve of the affected side were absent in 11, delayed in 4, and normal in 5 patients. At follow-up, there was a normalization of the BR in all patients who had absent or delayed responses at the first examination except for one patient whose responses remained absent at the 9th month. Late responses elicited on the side of the lesion by stimulation of the non-affected supraorbital nerve were normal in all but one patient. This patient died from cardiorespiratory arrest within the 1st month of the illness. One patient with normal BR responses also died in the acute phase. The BR is abnormal in most patients with acute WS and tends to normalize in a mean period of 7 months. BR pattern is not a predictor of early fatal complications in patients with this syndrome.

Adult↗
PubMed1997

Ballistic movements due to ischemic infarcts after intravenous heroin overdose: report of two cases.

Stroke is an infrequent but recognized complication of heroin addiction. Two heroin addicts, aged 34 and 19 years, developed ballistic movements after intravenous heroin overdose. Patient 1 presented bilateral ballism 1 week after intravenous heroin injection. Magnetic resonance imaging (MRI) showed bilateral ischemic lesions of the globus pallidus, suggesting a generalized cerebral hypoxia during the comatose state as pathogenic mechanism. Patient 2 presented an acute left hemiballismus when consciousness was restored with naloxone. MRI demonstrated an ischemic infarct in the right striatum. An embolic mechanism of stroke was suspected in this patient, considering the normal results of blood analysis, echocardiogram and cerebral arteriograms. Ballistic movements ceased after administration of haloperidol; both patients remained without abnormal movements thereafter.

Adult↗
PubMed1997

[The effect of clinical trials on hospital admission for stroke].

OBJECTIVE: To analyze the contribution of clinical trials in the hospital treatment of acute ischaemic cerebrovascular disease. DEVELOPMENT: In recent studies many trials have been designed for the treatment of the acute phase of this illness. Based on experimental studies, the drugs used in the trial need to be given within a 'therapeutic window' of less than six hours from the onset of the illness. This time factor has led to a radical change in the organization of hospital services dealing with this illness. In order to run clinical trials the medical staff have had to be organized into functional stroke units for the swift protocolized diagnosis of the condition. Also information has to be given to health workers regarding the need for urgent specialized treatment. Several studies have shown that early, specialist treatment reduces morbi-mortality, time spent in hospital and financial cost in these patients. CONCLUSION: Clinical trials in acute cerebrovascular pathology have formed the basis for the creation of stroke units, led to the drawing up of protocols for the diagnosis and guidelines for treatment. It has also made the medical profession more aware of the importance of early diagnosis and specialized treatment in acute cerebral ischaemia.

Brain Ischemia↗
PubMed1996

Brain stem reflexes in patients with Wallenberg's syndrome: correlation with clinical and magnetic resonance imaging (MRI) findings.

In spite of the general clinical uniformity of Wallenberg's syndrome (WS), individual patients present with a slightly different clinical picture, and detailed studies with magnetic resonance imaging (MRI) show differences in the topography of the brain stem lesion. Neurophysiological characterization of the lesion in WS has been known for a long time, but there are no studies on the possible correlation between lesion topography and neurophysiological deficit. Assuming that afferents from the three branches of the trigeminal nerve reach different parts of the trigeminal nuclei, we examined the possible correlation between the lesion topography assessed by the MRI and the neurophysiological deficit, assessed by studying the brain stem reflexes in patients with WS within 2 weeks after stroke. Neurophysiological abnormalities were always located in the afferent branch of the reflexes examined, but not all patients exhibited abnormalities in all responses. The ophthalmic branch was involved in 92.8% of patients, and the mandibular branch in 57.1% of patients. The patients with MRI lesions located in the lower medulla had normal responses with infraorbital or mental nerve stimulation. The results of this neurophysiological study confirm the heterogeneity of WS. Whether the neurophysiological identification of different subgoups of patients is relevant for clinical outcome needs further studies.

Action Potentials↗
PubMed1996

Contribution of arterial blood pressure to the clinical expression of lacunar infarction.

BACKGROUND AND PURPOSE: The relation between symptomatic lacunar infarction, silent stroke, and arterial hypertension is controversial. METHODS: From 500 patients with ischemic or hemorrhagic stroke admitted to the Downtown Barcelona Stroke Registry between July 1992 and December 1994, we evaluated prospectively the prevalence of silent infarction in 249 patients who had a brain MRI. The association of risk factors with silent infarction was investigated with the use of logistic regression analysis. In a selected group of 43 patients with symptomatic lacunes, we performed at stroke follow-up transcranial Doppler sonography and 24-hour continuous blood pressure monitoring to evaluate whether blood pressure, cerebrovascular tone, and cerebral blood flow at rest and after the administration of 1 g acetazolamide correlated with silent infarction. RESULTS: A total of 147 silent infarctions were observed in 83 patients (33%). Most silent infarctions corresponded to small deep lesions in the territory of the lenticulostriate arteries. Patients with silent infarctions had higher systolic and diastolic blood pressure at stroke onset. However, on multivariate analysis, age greater than 60 years was the only risk factor associated with silent infarction. In a subgroup of 43 patients with symptomatic lacunes and patent extracranial vessels, systolic and diastolic pressure at stroke onset and diastolic pressure and vascular resistance at stroke follow-up were higher when silent infarctions co-existed. However, cerebral blood flow at rest and after acetazolamide injection were unrelated to silent infarction. CONCLUSIONS: Silent ischemia in patients with symptomatic lacunar and nonlacunar stroke was only associated with aging. However, a history of arterial hypertension was perhaps unrecognized, since hemodynamic testing and continuous blood pressure monitoring in patients with lacunar stroke suggested that the coexistence of silent lesions indicated a more generalized cerebral arteriolosclerosis.

Acetazolamide↗
PubMed1995

Early prediction of stroke severity. Role of the erythrocyte sedimentation rate.

BACKGROUND AND PURPOSE: Early predictors of functional outcome after stroke are necessary for better planning of treatment and care. METHODS: We evaluated prospectively early clinical predictors of short-term functional outcome in a group of patients with ischemic cerebral infarction and explored whether the intensity of the acute-phase response provided further information concerning the short-term functional outcome. We evaluated a group of 208 ischemic stroke patients using the Mathew scale at entry. All patients had neuroimaging studies and routine blood tests, including erythrocyte sedimentation rate (ESR), within 72 hours from clinical onset. At discharge, functional outcome was graded according to a Stroke Outcome Scale. RESULTS: Larger infarcts, more embolic infarcts, and fewer lacunar infarcts were observed in the poor-outcome group. Vascular risk factors, radiological findings not related to the index stroke, time to admission, and treatment were similar in the two outcome groups. Variables with statistically significant differences between outcome groups included the following: age > 65 years, female sex, admission Mathew score < 75, worsening at clinical presentation, infarct volume > 6 cm3, complicating infections, fasting glucose > 110 mg, nonfasting glucose > 130 mg, and elevated ESR. With stepwise logistic regression analysis, Mathew score on admission, infarct volume, mode of clinical presentation, and ESR remained in the predictive model of stroke outcome, with a sensitivity and specificity of 89.91% and 85.71%, respectively. After removing the computed tomographic information from the model the same variables remained, with a sensitivity and specificity of 83.05% and 94.29%, respectively. CONCLUSIONS: Infarct size and clinical severity on admission are the stronger predictors of short-term functional outcome. Mode of clinical presentation, clinical evolution during the first day of stroke, and ESR are also independent predictors of short-term stroke outcome. These findings might be indicative of an inadequate collateral profile and/or a more pronounced prothrombotic state.

Adult↗
PubMed1995

Early anticoagulation after large cerebral embolic infarction: a safety study.

OBJECTIVE: To assess whether hemorrhage after early anticoagulation in nonseptic embolic infarction is related to clinical severity and infarction size. BACKGROUND: Explicit clinical criteria and timing of anticoagulation after large embolic infarctions are unknown. METHODS: Out of 171 patients receiving anticoagulation between July 1992 and December 1993, 83 patients with hemispheric embolisms received heparin within 72 hours from onset (activated partial thromboplastin time [aPTT] 1.5 times control value). Stratified by age and sex, a "high-risk" group (46 patients) was defined as those having stroke symptoms involving three or more CNS domains, Mathew Scale score < or = 74, or hemorrhagic infarction on initial CT, and a "low-risk" group (37 patients) as those having stroke symptoms involving fewer than three cortical domains, or Mathew Scale score > 74, and CT showing no blood. Loss of consciousness, seizures, or history of bleeding were exclusion criteria. Repeated CTs (100%) and MRIs (36%) detailed infarctions according to standard maps and evaluated all unexplained clinical worsening. RESULTS: Prior to therapy, high-risk patients had more severe clinical deficits (p < 0.01), larger infarctions on CT (p < 0.01), and more mass effect (p < 0.01). Hemorrhagic conversion (26% in the high-risk group versus 22% in the low-risk group) and hemorrhagic worsening (4% in the high-risk group versus 13% in the low-risk group) were unrelated to admission clinical severity or infarction size, but they were related to an excessive prolongation of the aPTT (p < 0.01). CONCLUSIONS: Infarction size and clinical severity in alert patients with nonseptic embolic stroke carries no additional bleeding complications after early anticoagulation. If anticoagulants are deemed necessary, treatment delay seems unjustified. However, rigorous monitoring of the aPTT is strongly advised to keep the level at 1.5 to 2 times control values.

Aged↗