Multiple Transient Ischemic Attacks Research Articles

PAW17 Recurrent transient ischaemic attack, capsular warning syndrome, ABCD2 score and early risk of stroke: a population-based study

BackgroundMany guidelines recommend urgent intervention for patients with 2 or more transient ischaemic attacks (TIAs) within 7 days irrespective of ABCD2 score, perhaps in recognition of capsular warning syndrome (CWS)....

Neuron specific metabolic adaptations following multi-day exposures to oxygen glucose deprivation

Prior exposure to sub toxic insults can induce a powerful endogenous neuroprotective program known as ischemic preconditioning. Current models typically rely on a single stress episode to induce neuroprotection whereas the clinical reality is that patients may experience multiple transient ischemic attacks (TIAs) prior to suffering a stroke. We sought to develop a neuron-enriched preconditioning model using multiple oxygen glucose deprivation (OGD) episodes to assess the endogenous protective mechanisms neurons implement at the metabolic and cellular level. We found that neurons exposed to a five minute period of glucose deprivation recovered oxygen utilization and lactate production using novel microphysiometry techniques. Using the non-toxic and energetically favorable five minute exposure, we developed a preconditioning paradigm where neurons are exposed to this brief OGD for three consecutive days. These cells experienced a 45% greater survival following an otherwise lethal event and exhibited a longer lasting window of protection in comparison to our previous in vitro preconditioning model using a single stress. As in other models, preconditioned cells exhibited mild caspase activation, an increase in oxidized proteins and a requirement for reactive oxygen species for neuroprotection. Heat shock protein 70 was upregulated during preconditioning, yet the majority of this protein was released extracellularly. We believe coupling this neuron-enriched multi-day model with microphysiometry will allow us to assess neuronal specific real-time metabolic adaptations necessary for preconditioning.

Brain imaging in transient ischemic attack – redefining TIA

Transient ischemic attack (TIA) has recently been redefined to incorporate the latest clinical and neuroimaging information that has shed new light on TIA pathophysiology. Patients suffering from TIA are at a substantial risk of subsequent stroke, but quantifying this risk is difficult as TIA patients are a heterogeneous population and there are multiple TIA mimics. Clinical scores for prediction of stroke risk are principally based on patient history and potentially understate actual risk. Magnetic resonance imaging (MRI), in particular diffusion-weighted imaging (DWI) performed in the first days following TIA, reveals relevant focal ischemic abnormalities in 21-68% of patients. These lesions predict stroke recurrence, functional dependence and subsequent vascular events. Adding imaging information to clinical scores improves prediction of stroke risk following TIA. Alongside clinical judgement, use of MRI has the potential to change the management of TIA patients and is the imaging modality of choice for this condition.

Intraoperative use of somatosensory-evoked potentials: is general anaesthesia comparable to awake condition?

Editor, We have read with great interest the article by Fielmuth and Uhlig [1] on the role of somatosensory-evoked potentials (SSEPs) in detecting cerebral ischaemia during carotid endarterectomy. The authors made an assessment of the validity of SSEP monitoring during carotid endarterectomy in awake patients under locoregional anaesthesia. They correctly reported the current substantial variety of SSEP parameters and thresholds related to these SSEP parameters used to detect critical deterioration in cerebral blood flow (CBF). Their study was designed to compare SSEP tracings with the objective clinical–neurological examination in order to evaluate the reliability of the different SSEP-generated criteria. They referred to Shapiro and Aidinis [2], who developed a model, which can be seen as the methodological basis for current neuromonitoring during carotid surgery. This model correlates neuronal integrity and electrical activity with CBF. Using this approach to interpret changes in SSEP tracing as a perfusion-dependent neuronal metabolic situation, different parameters and values have been established to detect a relevant reduction in CBF.

Wagging the dog‐moving closer to features defined by basic scientists, the protection of prodromal transient ischaemic attacks reveals itself

Wagging the dog‐moving closer to features defined by basic scientists, the protection of prodromal transient ischaemic attacks reveals itself

Incidence and prognosis of >=50% symptomatic vertebral or basilar artery stenosis: prospective population-based study

The higher risk of early recurrent stroke after posterior circulation transient ischaemic attack or minor stroke versus after carotid territory events could be due to a greater prevalence of large artery stenosis, but there have been few imaging studies, and the prognostic significance of such stenoses is uncertain. Reliable data are necessary to determine the feasibility of trials of angioplasty and stenting and to inform imaging strategies. In the first-ever population-based study, we determined the prevalence of > or = 50% apparently symptomatic vertebral and basilar stenosis using contrast-enhanced MRA in consecutive patients, irrespective of age, presenting with posterior circulation transient ischaemic attack or minor ischaemic stroke in the Oxford Vascular Study and related this to the 90-day risk of recurrent transient ischaemic attack and stroke. For comparison, we also determined the prevalence of > or = 50% apparently symptomatic carotid stenosis on ultrasound imaging in consecutive patients with carotid territory events. Of 538 consecutive patients, 141/151 (93%) had posterior circulation events and had vertebral and basilar imaging, of whom 37 (26.2%) had > or = 50% vertebral and basilar stenosis, compared with 41 (11.5%) patients with > or = 50% ipsilateral carotid stenosis in 357/387 (92%) patients with carotid events who had carotid imaging (OR = 2.74; 95% CI = 1.67-4.51; P = 0.002). Presence of > or = 50% vertebral and basilar stenosis was unrelated to age, sex or vascular risk factors and, in contrast to > or = 50% carotid stenosis was not associated with evidence of coronary/peripheral atherosclerosis. In patients with posterior circulation events, > or = 50% vertebral and basilar stenosis was associated multiple transient ischaemic attacks at presentation (22% versus 3%; OR = 9.29; 95% CI = 2.31-37.27; P < 0.001) and with a significantly higher 90-day risk of recurrent events (OR = 3.2; 95% CI = 1.4-7.0; P = 0.006), reaching 22% for stroke and 46% for transient ischaemic attack and stroke. The prevalence of > or = 50% vertebral and basilar stenosis in posterior circulation transient ischaemic attack or minor stroke is greater than the prevalence of > or = 50% carotid stenosis in carotid territory events, and is associated with multiple transient ischaemic attacks at presentation and a high early risk of recurrent stroke. Trials of interventional treatment are therefore likely to be feasible, but more data are required on the long-term risk of stroke on best medical treatment.

The Frequency of Symptoms in Transient Ischaemic Attack: Analysis of Nanjing Stroke Register Program Data

The clinical characteristics of 172 patients experiencing single or multiple (two or more) transient ischaemic attacks (TIAs) were investigated. Risk factors, clinical manifestations and vascular examinations were compared. Intracranial and extra-cranial large-artery disease (stenosis > or = 50%) occurred more frequently in multiple-TIA patients than in single-TIA patients, and weakness and atrial fibrillation were observed more frequently in single TIA than in multiple TIA patients. The type of aetiological examination performed in TIA patients should depend on the frequency of attacks.

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Response

Use of intravenous heparin by North American neurologists: do the data matter?

Our aim was to determine current usage patterns of intravenous heparin for patients with acute ischemic stroke. A survey was undertaken of 280 neurologists from the United States and 270 neurologists from Canada. Brief vignettes were presented for the following 5 scenarios: stroke in evolution, atrial fibrillation-related stroke (A FIB), vertebrobasilar stroke, carotid territory stroke, and multiple transient ischemic attacks. The effect of medicolegal factors was also ascertained. Statistical comparisons were done with chi-squared testing. US neurologists were significantly more likely than Canadian neurologists to use intravenous heparin for patients with stroke in evolution (51% versus 33%, P<0.001), vertebrobasilar stroke (30% versus 8%, P<0.001), carotid territory stroke (31% versus 4%, P<0.001), and multiple transient ischemic attacks (47% versus 9%, P<0.001). The vast majority of US and Canadian neurologists would use intravenous heparin for acute stroke patients with A FIB (88% and 84%, respectively). US neurologists more often cited medicolegal factors as a potential influence on the decision-making process than Canadian neurologists (33% versus 10%, P<0.001). In several clinical scenarios, US neurologists were significantly more likely than Canadian neurologists to use intravenous heparin. Fears regarding medicolegal consequences may partially explain the treatment disparity. Despite the publication of 4 clinical trials, which have not shown any long-term benefit for patients with acute stroke and A FIB (International Stroke Trial, Heparin in Acute Embolic Stroke Trial) or cardioembolic stroke (Trial of Org 10172 in Acute Stroke Treatment, the Tinzaparin in Acute Ischemic Stroke Trial), both US and Canadian neurologists would use intravenous heparin in large numbers for this condition. Further studies are warranted to investigate the lack of impact of "negative" studies on clinician behavior.

On the pathogenesis of headache following TIA.

Twelve out of 49 patients with single or multiple transient ischemic attacks (TIAs) had TIA-related headaches, mostly in close temporal relation to the ischemic onset. Headache predominated in patients taking vasodilators when TIA occurred or with orthostatic hypotension at the first clinical examination, but atrial hypertension or a personal history of migraine were not more frequent in patients with headache. The site of the pain did not correlate with the presumed territory of cerebral ischemia. Pain during TIA is conceivably due to an interaction between cerebral vessels and the surrounding nervous system. Blood vessels have a sturdy physiological role concerning blood flow regulation, with receptors and signaling molecules potentially involved with pain production. Reflex mechanisms should justify pain in other areas.

Pattern and frequency of recurrent transient ischemic attacks

Objectives. Natural history studies and stroke prevention trials in patients with transient ischemic attacks (TIAs) have focused primarily on stroke or death outcomes and not recurrent TIA, yet treatment decisions are often based on recurrences. This study was undertaken to evaluate the frequency and pattern of recurrent TIAs in patients presenting with their first TIA. Methods. We monitored TIA recurrence for an average of 16 months in 47 consecutive patients hospitalized in a tertiary care center within 3 weeks of their first TIA. Treatment in 22 patients was aspirin or ticlopidine alone, and 12 underwent endarterectomy. Remaining patients received warfarin, dipyridamole, or pentoxifylline alone or with aspirin, including two who underwent endarterectomy. Treatment was changed in only four patients during the follow-up period. Results. Thirty-four patients (72%) had more than one TIA; 23 of these (68%) had two to five recurrences and 11 (32%) had more than five TIAs. Nineteen of the 34 patients with multiple TIAs had recurrences within 1 month of the initial TIA. Only four patients (12%) had recurrent TIAs throughout the follow-up period. Stroke occurred in five patients (11%); one patient had a single prior TIA, and the rest had multiple TIAs. No risk factors or treatments predicted which patients had single or multiple TIAs. Conclusions. Most patients have few recurrent TIAs, and recurrences usually occur within the first month of the initial TIA. The patterns of TIA recurrence identified should aid in treating patient and in devising appropriate outcome measures in treatment trials in which TIA is an endpoint.

Recurrent Ischemic Events and Diffuse White Matter Disease in Patients with Pseudoxanthoma Elasticum

Pseudoxanthoma elasticum (PXE) is a rare hereditary disorder of elastic tissue with prominent dermatologic, ocular, and vascular manifestations. Although PXE has been associated with ischemic stroke, the clinical and radiologic features have not been fully characterized. We describe two women with PXE, hypertension, and progressive motor and intellectual deterioration related to multiple strokes and transient ischemic attacks beginning at ages 50 and 56. Magnetic resonance imaging in both patients showed widespread and multiple punctate ischemic vascular lesions with diffuse white matter involvement. Although brain infarction in PXE may result from a variety of mechanisms, our patients show the association of this disorder with severe, predominantly small-vessel occlusive disease.

The Intra-Aortic Balloon Pump, a Novel Addition to Staged Repair of Combined Symptomatic Cerebrovascular and Coronary Artery Disease

Five patients with severe symptomatic carotid and coronary artery disease were treated with staged carotid endarterectomy and coronary artery bypass grafting (CABG) under the protection of an intra-aortic balloon pump (IABP) over a 56-month period. All patients presented with unstable angina and multiple ipsilateral transient ischemic attacks. Two of the four patients had four previous myocardial infarctions. Arteriography demonstrated three-vessel coronary artery disease and 80% to 95% stenosis of the ipsilateral internal carotid artery in all patients. An IABP was placed prior to uneventful carotid endarterectomy performed with vein patch angioplasty (three patients) or primary closure (two patients) under general anesthesia. All five patients had remarkably stable blood pressure and cardiac outputs while on the IABP. Twenty-four hours after carotid endarterectomy the patients underwent uneventful CABG of three or more vessels. No complications occurred with either surgical procedure. One patient required femoral embolectomy and repair of a small false femoral aneurysm following removal of the IABP. All patients were discharged home 7 to 13 days after CABG. This initial report suggests that IABP can be used safely in staged operations for carefully selected patients with unstable angina and severe symptomatic carotid artery disease.

Predictors of cerebral infarction following transient ischemic attack

Transient ischemic attack (TIA) is a warning sign for impending cerebral infarction, mainly within several months following the attack. To determine if any clinical characteristics could prognosticate cerebral infarction following a TIA, we studied and followed 68 consecutive patients who presented with a TIA. We determined the vascular risk factors, frequency, duration, vascular territory involved, and presumed etiology of the attacks. Diagnostic tests and treatment were individualized. Follow-up ranged from 1 day to 36 months (mean, 19 months). Four patients died from non-neurologic causes without having had a stroke. Cerebral infarction occurred in five patients (7%), 6 hours, 1 day, 10 days, 5 months, and 14 months after the presenting TIA. Two clinical characteristics were associated with a significantly increased risk of cerebral infarction: diabetes mellitus (p < 0.001) and history of multiple TIAs > 1/month at the time of presentation (p = 0.005). Patients presenting with a recent TIA and these risk factors may benefit from more aggressive treatment.

Indications for Carotid Endarterectomy: Surgeons vs Neurologists

The purpose of this study was to evaluate the indications for carotid endarterectomy (CEA) in the authors' geographic area and compare responses of vascular surgeons and neurologists. Results were also compared with the recommendations of the Rand panel. Vascular surgeons and neurologists agreed that multiple transient ischemic attacks (TIA) in patients receiving medical treatment and in those with crescendo ischemic attacks were appropriate indications for endarterectomy. However, surgeons favored CEA significantly more (p &lt; 0.0001) than neurologists for other symptomatic patients. No agreement could be found between surgeons and neurologists for endarterectomy in patients with asymptomatic carotid disease. Although a national panel of experts has identified appropriate indications for CEA, the authors' medical community (Eastern Pennsylvania) has significant variations when responses of vascular surgeons and neurologists are compared. Therefore, patient treatment depends mainly on the referral patterns of the primary care physician. Further prospective studies are required to achieve unanimity regarding indications for this operation.

Long-Term Prognosis of Transient Ischemic Attacks and Reversible Ischemic Neurologic Deficits: A Hospital-Based Study

A hospital-based series of 712 patients with either transient ischemic attacks (TIAs) or reversible ischemic neurologic deficits (RINDs) was followed prospectively for 4 years in order to determine the long-term prognosis for cerebral and cardiac events in this group. The annual recurrence rates for new TIAs were 15.9, 5.3, 4.7 and 3.5 % in the 1st, 2nd, 3rd and 4th year, respectively, and the corresponding ones for fatal and nonfatal strokes were 3.37, 2.36, 1.7 and 1.3%. Strokes tended to occur in the 1st follow-up year (51%). The ratio of cerebral to cardiac deaths was 2.4. The survival of patients with RIND was similar to that of patients with TIA. Both survival rates were lower than those of an age- and sex-matched cohort sampled from the general population. Male gender emerged as a reliable predictor for cardiac events (p < 0.01), multiple TIA or RIND on admission predicted subsequent TIA (p < 0.001) but not stroke. A history of hypertension predicted cerebral death (p < 0.01), and a history of cardiac disease predicted cerebral (p < 0.01) and cardiac death (p < 0.05). Overall mortality depended on an age > 60 years (p < 0.05), hypertension (p < 0.05) and cardiac disease (p < 0.001).

Multiple transient ischaemic attacks and a mild thrombotic stroke in a HIV-positive patient with anticardiolipin antibodies

Antiphospholipid antibodies (APA) have been reported to be associated with thrombosis in systemic lupus erythematosus (SLE) and in many other clinical groups. However, although these antibodies have been identified in a substantial number of patients infected with the human immunodeficiency virus (HIV), in this case an association with thrombosis has not been evident. We describe a patient with HIV infection who had anticardiolipin antibodies (ACA) but no lupus anticoagulant (LA) who had recurrent transient ischaemic attacks (TIAs) and a mild stroke.

Noninvasive evaluation of the extracranial carotid arteries in patients with cerebrovascular events and atrial fibrillation

<i>To the Editor</i>.—The authors of the recent article by Weinberger et al¹ought to be congratulated for attempting to dissect the causes of cerebrovascular events in a group of patients with nonvalvular atrial fibrillation, thereby drawing attention to the fact that a cerebrovascular event in a patient with atrial fibrillation is not necessarily caused by embolic complications related to atrial fibrillation, but may actually be due to atherosclerotic lesions at the carotid bifurcation. However, cerebrovascular events may also be caused by intracranial disease, and this possibility has not been adequately addressed by the study. In attempting to determine whether a stroke is due to a cardiac embolism or disease of the carotid bifurcation, the presence of multiple transient ischemic attacks (TIAs) occurring with a similar pattern in 94% of patients with disease of the carotid bifurcation and 88% of patients with basilar artery disease is noted to occur

Short-Term Outcome of Medically Treated Patients with Transient Ischemic Attacks, Reversible Ischemic Neurologic Deficits and Strokes with Minimum Residuum

62 patients with transient ischemic attack (TIA), 60 with reversible ischemic neurologic deficit (RIND) and 57 with stroke with minimum residuum (SMR) were followed, in a retrospective survey, from the first 7 days to the 3rd month of evolution. 90 received anticoagulant treatment, 66 antiplatelet treatment and 23 other or no treatment. 5 patients developed strokes with moderate or severe disability; no patient suffered a myocardial infarction or died. No influence of the type of treatment or of the clinical group (TIA, RIND and SMR) on the follow-up complications could be detected. There seems to be a group with a greater risk of developing further cerebral infarction, which is characterized by the occurrence of multiple TIAs for several days before the event.

Recurrent transient ischemic attacks after carotid endarterectomy.

The postoperative courses of 113 patients undergoing 121 carotid endarterectomies between 1974 and 1979 were analyzed for recurrent transient ischemic attacks (TIAs). The TIAs were the indication for the original operation in all patients; 31 patients had a stable neurologic deficit prior to operation. Two patients sustained major strokes and three had nondisabling minor strokes. Three patients had late strokes. Recurrent TIAs occurred during follow-up in 28 patients, and these were classified into four distinct categories: (1) Ten patients had single TIAs in the distribution of the carotid artery operated on in the early postoperative days. (2) Four patients had late, repetitive TIAs related to the operated side. (3) Five patients had late TIAs in the distribution of the contralateral artery. (4) Nine patients had single or multiple TIAs owing to recurrent vertebrobasilar insufficiency. Close, long-term follow-up of postendarterectomy patients is recommended to locate those who will have surgically correctable lesions.