Fingolimod treatment modulates PPARγ and CD36 gene expression in women with multiple sclerosis

Fingolimod is an oral immunomodulatory drug used in the treatment of multiple sclerosis (MS) that may change lipid metabolism. Peroxisome proliferator-activated receptors (PPAR) are transcription factors that regulate lipoprotein metabolism and immune functions and have been implicated in the pathophysiology of MS. CD36 is a scavenger receptor whose transcription is PPAR regulated. The objective of this study was to evaluate whether fingolimod treatment modifies PPAR and CD36 gene expression as part of its action mechanisms. Serum lipoprotein profiles and PPAR and CD36 gene expression levels in peripheral leukocytes were analysed in 17 female MS patients before and at 6 and 12 months after fingolimod treatment initiation. Clinical data during the follow-up period of treatment were obtained. We found that fingolimod treatment increased HDL-Cholesterol and Apolipoprotein E levels and leukocyte PPARγ and CD36 gene expression. No correlations were found between lipid levels and variations in PPARγ and CD36 gene expression. PPARγ and CD36 variations were significantly correlated during therapy and in patients free of relapse and stable disease. Our results suggest that PPARγ and CD36-mediated processes may contribute to the mechanisms of action of fingolimod in MS. Further studies are required to explore the relation of the PPARγ/CD36 pathway to the clinical efficacy of the drug and its involvement in the pathogenesis of the disease.

Ensaios Clínicos: História e Atualidade

Embora haja referências prévias na Bíblia, no Cânone de Medicina de Avicenna e na obra do médico-cirurgião francês Ambroise Parré datada de 1537, considera-se que o primeiro ensaio clínico da era moderna foi realizado por James Lind em 1747, quando foi descoberto o efeito terapêutico do consumo de citrinos no tratamento do escorbuto. Passados cerca de cem anos, em 1863, Austin Flint realizou o primeiro ensaio com um grupo placebo em doentes com reumatismo. Em 1943 surge pela primeira vez um estudo duplamente cego com aleatorização alternada em doentes com síndrome gripal. Três anos depois é realizado o primeiro ensaio com processo de aleatorização, tal como definido hoje em dia, com dupla ocultação em doentes com tuberculose, em que o efeito da estreptomicina foi comparado com tratamento de repouso apenas. Trata-se também do primeiro ensaio em que a avaliação dos “endpoints”, neste caso o resultado da radiografia do tórax foi avaliado, por médicos independentes, que desconheciam o braço a que pertenciam os doentes. Foi na segunda metade do século XX, sobretudo no rescaldo da II Guerra Mundial, que a maioria dos avanços de natureza ética na condução de ensaios clínicos foram realizados, tendo em vista a proteção dos indivíduos que participavam em ensaios clínicos. Em 1947 o código de Nuremberga estipula a necessidade de participação voluntária e da necessidade de existência de consentimento informado. Quase em simultâneo, em 1948, a Declaração dos Direitos Humanos, proíbe a participação de seres humanos em tratamentos considerados prejudiciais. [...] Recebido: 10/08/2016 – Aceite: 22/08/2016

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.

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.

Long-term prognosis of first-ever lacunar strokes. A hospital-based study

BACKGROUND AND PURPOSE

Information concerning the long-term prognosis of lacunar strokes is still limited and has shown different results. The aim of this study was to investigate the long-term prognosis of first-ever lacunar strokes and the possible role of clinical prognostic factors and different pathogenic mechanisms.

METHODS

Between March 1990 and November 1993, a cohort of consecutive patients presenting with first-ever lacunar infarcts was prospectively evaluated after stroke onset at day 0 to 3 and/or day 7, every 3 months up to 1 year, and every 6 months thereafter. All patients were studied according to a protocol that included demographic and clinical data, neurological examination, Toronto Stroke Scale, Barthel Index, Rankin Scale, CT scan, routine laboratory workup, electrocardiogram, carotid duplex scanning, and echocardiogram. More recently, patients have also been evaluated with transcranial Doppler ultrasonography. Recurrent strokes, myocardial infarction, and death were registered through direct observation, chart review, or interviews with the attending physician or family members.

RESULTS

One hundred forty-five patients-94 (65%) with pure hemiparesis, 33 (23%) with sensorimotor stroke, 11 (8%) with ataxic hemiparesis, 5 (3%) with pure sensory stroke, and 2(1%) with dysarthria-clumsy hand syndrome-were followed for a median period of 39 months. During follow-up ther were 17 deaths (3 vascular), 30 recurrent strokes (1 fatal), and 4 myocardial infarctions. Five-year survival rate free of recurrent stroke was 63% (95% confidence interval [CI], 52% to 73%), while 5-year survival rate was 86% (95% CI, 78% to 91%). Cox proportional hazards analysis showed that age (p=.02) was the only significant predictor of survival free of recurrent stroke. Age (P<.001) and the degree of neurological dysfunction and functional disability at 7 days after the index stroke measured by the Toronto Stroke Scale (P=.05) and a Barthel Index score <40 (P=.04) were the only significant predictors of death. The 5-year probability rate of stroke-free recurrence was 72% (95% CI, 60% to 81%). Sixty-three percent of the first recurrent strokes were lacunar infarcts. When clinical, laboratory, and CT data as well as possible etiopathogenic mechanisms of lacunar strokes were considered, Cox proportional hazards analysis could not identify any predictor of stroke recurrence.

CONCLUSIONS

Our study confirms that lacunar infarcts are associated with low stroke recurrence and mortality rates. In our series, the majority of first recurrent strokes were also lacunar infarcts. Age, degree of neurological dysfunction, and functional disability at day 7 after the index stroke were significant predictors of death.

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.

Headache in lacunar stroke

The presence of headache within a 72-h interval of stroke onset was investigated in a cohort of 145 lacunar infarcts. Fourteen (10%) experienced diffuse or bilateral headache. Hypertension was less frequent (43 vs 76%; 95% CI: 6 to 60%) and of shorter duration (2.4 vs 7.8 years; t = 2.29; p = 0.02) among patients with headache. Leukoaraiosis was less frequent (40% vs 71%; 95% CI: -57 to -7%) and severe (7 vs 24%; 95% CI: -33 to -2%) in patients with headache. Age, sex, stroke risk factors, type of lacunar stroke, mode of onset, stroke severity, ultrasound and other CT findings were similar in patients with and without headache. No differences in the sixth month neurological or functional outcome were detected between lacunar patients with and without headache. Headache in lacunar stroke cannot be predicted by the clinical characteristics of the stroke and is not due to coexisting cardiembolism, intra or extracranial disease. Hypertensive small-vessel disease is less common and severe in lacunar strokes with associated headache.

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.

Lacunar stroke associated headache is not related to intracranial large vessel disease

It was recently suggested that lacunar strokes presenting with headache may be due to large intracranial artery disease. From the stroke database of the Neurology department, Hospital Sta Maria, we retrieved all lacunar strokes who had investigations of the intracranial circulation. Forty seven of the 208 lacunar strokes registered had either angiography (5 cases) or transcranial doppler (42 cases). Twelve subjects noticed headache during stroke onset, but all had normal investigations of the intracranial circulation. In five patients transcranial Doppler showed ipsilesional increased peak systolic velocities and another subject had a middle cerebral artery branch occlusion. None of them reported headache. Headache associated with lacunar strokes is not related to intracranial artery disease.

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.

Isovolumic hemodilution with dextran 40 in the rat: effect on the development of peripheral edema and various physiologic parameters

Low molecular weight dextran 40 (D40), 40,000 daltons, is a potential therapeutic agent for cerebral ischemia because it increases local cerebral blood flow. However, the evaluation of D40 in the rat has been difficult due to systemic effects. We evaluated the effects of isovolumic hemodilution with D40 on the development of peripheral edema, mean arterial pressure, hematocrit (Hct) and total blood volume in 18 rats, during 30 min or 4 hr i.v. infusions, in animals with and without previous challenge with D40. Reduction of Hct without peripheral edema to a mean of approximately 31% was only achieved in the animals challenged with i.p. D40 24 hr before hemodilution and who received D40 over a period of 4 hr. Infusion of D40 over a period of 30 min was associated with shorter survival time, compared to the 4-hr infusion group (P less than .005). In the pretreated, rapidly infused group, total blood volume per body weight decreased significantly over time (P less than .005) and the mean arterial blood pressure dropped, but not significantly (P less than .07), whereas no change in Hct was detected and there was a trend toward increased peripheral edema, relative to the slowly infused groups. We conclude that reduction of Hct can be achieved successfully with i.p. administration of D40 24 hr before the study combined with infusion of the agent during a 4-hr period, without significant peripheral edema and early hypotension. This procedure should be used to avoid allergic reactions when evaluating hemodilution with D40 in rats.

Bimodal treatment with nimodipine and low-molecular-weight dextran for focal cerebral ischemia in the rat

We compared the effects of intravenous treatment with combined low-molecular-weight dextran and nimodipine (n = 9), or placebo (n = 10), on local cerebral blood flow after occlusion of the left middle cerebral and common carotid artery in the rat. Treatment for a total of 4 hours with low-molecular-weight dextran (5 mg/kg/min) and nimodipine (0.25 microgram/kg/min) produced a decrease in hematocrit from 46 +/- 1 to 33 +/- 1% at the end of the study and a statistically significant increase in local cerebral blood flow, when compared to the control group, in 6 regions of interest: the territories of the right middle (p = 0.01), right anterior (p = 0.007), and left anterior cerebral arteries (p = 0.001); the superior (p = 0.03) and inferior border zone (p = 0.003); and white matter in the right hemisphere (p = 0.04). The ischemic volume, defined as brain volume with a cerebral blood flow of less than the critical level of 25 ml/min/100 gm was determined as a percentage of total brain volume for the control and treatment groups. The group treated with low-molecular-weight dextran and nimodipine showed a 31% decrease in ischemic volume (p = 0.03). These results indicate that a bimodal approach with low-molecular-weight dextran and nimodipine can be safely used in a model of acute stroke and has a beneficial effect on local cerebral blood flow and ischemic volume when compared with control subjects. After 4 hours, the potential exists that this treatment is therapeutic, assuming that the ischemic volume progresses to infarction.

Neurologic complications of endocarditis: a 12-year experience

We reviewed the neurologic complications in 113 patients with native and 62 patients with prosthetic valve endocarditis. Neurologic complications occurred with the same frequency (35.3% vs 38.7%) and distribution among the two groups. Death occurred in 20.6% of patients with neurologic complications and in 13.6% of patients without neurologic complications (p = 0.23). Staphylococcus aureus endocarditis correlated statistically with the development of neurologic complications (p less than 0.01) and death (p less than 0.01). Among 50 patients discharged from the hospital after receiving only medical treatment for native valve endocarditis, and followed for a mean period of 48 months, there was one patient with mitral valve prolapse and stroke. We conclude that (1) neurologic complications occur with the same frequency in native and prosthetic valve endocarditis, (2) S aureus endocarditis increases the risk of neurologic complications and death, (3) mortality is not significantly increased in patients with neurologic complications, and (4) an episode of treated native valve endocarditis does not increase the natural history of stroke in valvular disease.

Mycotic aneurysm, subarachnoid hemorrhage, and indications for cerebral angiography in infective endocarditis

We compared the clinical course of 68 patients with infective endocarditis and mycotic aneurysm and 147 patients with infective endocarditis but no mycotic aneurysm. Among the patients with mycotic aneurysm, 57% had subarachnoid hemorrhage without warning. Forty-three percent had a neurologic prodrome 2 days to 18 months (median 17 days) prior to discovery of the mycotic aneurysm. A focal deficit consistent with embolism was the most common prodrome (23%). However, there was no significant difference in the frequency of neurologic symptoms between patients with and without mycotic aneurysm. During an average follow-up of 40 months, there were no instances of subarachnoid hemorrhage/mycotic aneurysm among 121 patients discharged after a full course of antibiotic therapy. Therefore, the risk of rupture of an unsuspected mycotic aneurysm following a full course of antibiotics is low. When a prodrome does precede a mycotic aneurysm, it most often is a focal deficit consistent with embolism. We favor angiography in all patients with infective endocarditis who experience a focal deficit with good recovery. The timing and other indications for angiography in infective endocarditis are discussed.