Issam A. Awad

Incidental subcortical lesions identified on magnetic resonance imaging in the elderly. I. Correlation with age and cerebrovascular risk factors.

Patchy subcortical foci of increased signal intensity are frequently identified on magnetic resonance imaging (MRI) in the elderly. The incidence and clinical correlates of these lesions remain unknown. In this report, 240 consecutive MRI scans performed over a 6-month period were reviewed (excluding patients with recent brain trauma or known demyelinating disease). Subcortical incidental lesions (ILs) were identified, which could not be accounted for by the patients current clinical diagnosis, neurological status, or CT scan. The ILs were graded according to size, multiplicity, and location. The incidence and severity of ILs increased with advancing age (p less than 0.0005). Among patients over 50 years of age, the incidence and severity of ILs were correlated with a previous history of history of ischemic cerebrovascular disease (p less than 0.05) and with hypertension (p less than 0.05). Multivariable regression analysis identified age, prior brain ischemia, and hypertension as the major predictors of ILs in the elderly. Diabetes, coronary artery diseases, and sex did not play a significant role. With the exception of cerebrovascular disease, there was no association between ILs and any particular clinical entity, including dementia. It is concluded that subcortical parenchymal lesions are frequent incidental findings on MRI in the elderly, and may represent an index of chronic cerebrovascular diseases in such patients.

Recommendations for the Management of Intracranial Arteriovenous Malformations A Statement for Healthcare Professionals From a Special Writing Group of the Stroke Council, American Stroke Association

Intracranial arteriovenous malformations (AVMs) are relatively uncommon but increasingly recognized lesions that can cause serious neurological symptoms or death. Although AVMs can present with hemorrhage or seizure, since the advent of contemporary brain imaging techniques, an increasing number are detected before rupture. Over the last decade, there have been significant developments in the management of intracranial AVMs. There has been an evolution of microsurgical as well as endovascular and radiosurgical techniques to treat these lesions. As the management options have evolved, individual and combined modality treatment protocols have been developed in different institutions for the management of AVMs. A writing group was formed by the Stroke Council of the American Stroke Association to review published data for intracranial AVMs to develop practice recommendations regarding epidemiology, natural history, potential treatment strategies, and outcomes. The reports reviewed for this synthesis were selected on the basis of study design, sample size, and relevance to a particular topic. Each report was graded according to previously defined criteria.1 2 After review of the available literature, recommendations for current practice standards have been made according to 3 separate grades (Table 1⇓). View this table: Table 1. Levels of Evidence in Grading of Recommendations for Treatment of Patients With Subarachnoid Hemorrhage By the design of this type of review, the recommendations in this report represent an overview of existing treatment protocols that may vary considerably. These guidelines were developed to serve as a basis for the development of treatment strategies for AVMs, which overall represent a fairly heterogeneous group of cerebrovascular lesions and which may demonstrate different natural histories. In addition, for brain AVMs, no level I or II data are available in the literature. Because of the heterogeneity of these lesions and their relatively infrequent occurrence, strictly defined subcategories for comparison of the efficacy of various treatment modalities …

Clinical vasospasm after subarachnoid hemorrhage: response to hypervolemic hemodilution and arterial hypertension.

Delayed neurologic deterioration from vasospasm remains the greatest cause of morbidity and mortality following subarachnoid hemorrhage. The authors assess the incidence and clinical course of symptomatic vasospasm following subarachnoid hemorrhage using a uniform management protocol over a 24-month period. One hundred eighteen consecutive patients were admitted to the neurovascular surgery service within 2 weeks of subarachnoid hemorrhage not attributed to trauma, tumor, or vascular malformation (113 patients had aneurysms). Early surgery was performed whenever possible, and hypertensive hypervolemic hemodilution therapy was instituted at the first sign of clinical vasospasm. Forty-two patients (35.6%) developed characteristic signs and symptoms of clinical vasospasm with angiographic verification of spasm in 39 cases. All patients with clinical vasospasm received hypervolemic hemodilution therapy aiming for a hematocrit of 33-38%, a central venous pressure of 10-12 mm Hg (or a pulmonary wedge pressure of 15-18 mm Hg), and a systolic arterial pressure of 160-200 mm Hg (120-150 mm Hg for unclipped aneurysms) for the duration of clinical vasospasm. Over the course of treatment, 60% of patients with clinical vasospasm had sustained improvement by at least 1 neurologic grade, 24% maintained a stable neurologic status, and 16% continued to worsen. At the end of hypervolemic hemodilution therapy, 47.6% had become neurologically normal, 33.3% had a minor neurologic deficit, and 19% had a major neurologic deficit or were dead. There were 3 instances of cardiopulmonary deterioration (7%), all of which were in patients without Swan-Ganz catheters, and all resolved with appropriate diuresis. One patient rebled and died while on hypervolemic hemodilution therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Recommendations for the management of patients with unruptured intracranial aneurysms: A statement for healthcare professionals from the Stroke Council of the American Heart Association.

Aneurysmal subarachnoid hemorrhage (SAH) has a 30-day mortality rate of 45%, with approximately half the survivors sustaining irreversible brain damage.1 On the basis of an annual incidence of 6 per 100 000, ≈15 000 Americans will have an aneurysmal SAH each year. Population-based incidence rates vary considerably from 6 to 16 per 100 000, with the highest rates reported from Japan and Finland.2 3 4 5 Approximately 5% to 15% of stroke cases are secondary to ruptured saccular aneurysms. Although the prevention of hemorrhage has been advocated as the most effective strategy aimed at lowering mortality rates,6 the optimal management of patients with unruptured intracranial aneurysms (UIAs) remains controversial. Management decisions require an accurate assessment of the risks of various treatment options compared with the natural history of the condition. The natural history of UIAs and treatment outcomes are influenced by (1) patient factors, such as previous aneurysmal SAH, age, and coexisting medical conditions; (2) aneurysm characteristics, such as size, location, and morphology; and (3) factors in management, such as the experience of the surgical team and the treating hospital. These many influences have contributed to considerable variability in the reported risks for aneurysmal SAH and the treatment of UIAs. There are no prospective randomized trials of treatment interventions versus conservative management to date, and it is possible that no such studies will be carried out in the future. According to a classification system suggested by Cook et al,7 randomized clinical trials with low likelihoods of false-positive and false-negative errors provide the highest level of evidence (level I) that can be applied to a clinical recommendation. Randomized trials with high likelihoods of false-negative and positive errors provide level II evidence. Level III evidence is generated with nonrandomized concurrent cohort comparisons between contemporaneous patients who did and …

Intractable epilepsy and structural lesions of the brain: mapping, resection strategies, and seizure outcome.

Summary: Forty‐seven patients with structural brain lesions on neuroimaging studies and partial epilepsy intractable to medical therapy were studied. Prolonged noninvasive interictal and ictal EEG recording was performed, followed by more focused mapping using chronically implanted subdural electrode plates. Surgical procedures included lesion biopsy, maximal lesion excision, and/or resection of zones of epileptogenesis depending on accessibility and involvement of speech or other functional areas. The epileptogenic zone involved exclusively the region adjacent to the structural lesion in 11 patients. It extended beyond the lesion in 18 patients. Eighteen other patients had remote noncontiguous zones of epileptogenesis. Postoperative control of epilepsy was accomplished in 17 of 18 patients (94%) with complete lesion excision regardless of extent of seizure focus excision. Postoperative control of epilepsy was accomplished in 5 of 6 patients (83%) with incomplete lesion excision but complete seizure focus excision and in 12 of 23 patients (52%) with incomplete lesion excision and incomplete focus excision. The extent of lesion resection was strongly associated with surgical outcome either in itself (p < 0.003), or in combination with focus excision. Focus resection was marginally associated with surgical outcome as a dichot‐omous variable (p = 0.048) and showed a trend toward significance (p = 0.07) only as a three‐level outcome variable. We conclude that structural lesions are associated with zones of epileptogenesis in neighboring and remote areas of the brain. Maximum resection of the lesion offers the best chance at controlling intractable epilepsy; however, seizure control is achieved in many patients by carefully planned subtotal resection of lesions or foci. Strategies for mapping and for resection of lesions and foci are discussed, including cases in which invasive recordings may or may not be necessary.

Guidelines for the Prevention of Stroke in Women A Statement for Healthcare Professionals From the American Heart Association/American Stroke Association

Purpose— The aim of this statement is to summarize data on stroke risk factors that are unique to and more common in women than men and to expand on the data provided in prior stroke guidelines and cardiovascular prevention guidelines for women. This guideline focuses on the risk factors unique to women, such as reproductive factors, and those that are more common in women, including migraine with aura, obesity, metabolic syndrome, and atrial fibrillation. Methods— Writing group members were nominated by the committee chair on the basis of their previous work in relevant topic areas and were approved by the American Heart Association (AHA) Stroke Council’s Scientific Statement Oversight Committee and the AHA’s Manuscript Oversight Committee. The panel reviewed relevant articles on adults using computerized searches of the medical literature through May 15, 2013. The evidence is organized within the context of the AHA framework and is classified according to the joint AHA/American College of Cardiology and supplementary AHA Stroke Council methods of classifying the level of certainty and the class and level of evidence. The document underwent extensive AHA internal peer review, Stroke Council Leadership review, and Scientific Statements Oversight Committee review before consideration and approval by the AHA Science Advisory and Coordinating Committee. Results— We provide current evidence, research gaps, and recommendations on risk of stroke related to preeclampsia, oral contraceptives, menopause, and hormone replacement, as well as those risk factors more common in women, such as obesity/metabolic syndrome, atrial fibrillation, and migraine with aura. Conclusions— To more accurately reflect the risk of stroke in women across the lifespan, as well as the clear gaps in current risk scores, we believe a female-specific stroke risk score is warranted.

Intracranial Cavernous Malformations: Lesion Behavior and Management Strategies

Intracranial cavernous malformations are vascular anomalies consisting of endothelium-lined caverns filled with blood at various stages of thrombosis and organization and separated by a collagenous stroma devoid of mature vessel wall elements. They occur in an estimated 0.45 to 0.9% of the population, with male and female patients equally affected and all ages represented. They commonly manifest as seizures, gross intracranial hemorrhage, and focal neurological deficits. Lesions are frequently multiple in the same patient, and 10 to 30% are associated with familial clustering. Several reports have documented a dynamic clinical-radiological lesion behavior with de novo lesion genesis, intralesional and perilesional hemorrhage, and corresponding fluctuations in lesion size. Hemorrhagic risk and neurological disability seem to be related to multiple factors, including lesion location, age, gender, state of reproductive cycle, and previous hemorrhage. Lesions may behave aggressively with repetitive hemorrhages and cumulative disability or may remain quiescent for many years. Management strategies include expectant follow-up in patients with asymptomatic or inaccessible lesions, excision of symptomatic and accessible lesions, and radiosurgery of progressively symptomatic lesions in inoperable locations. Relevant disease-specific outcome parameters are proposed to guide clinical decisions and future research. Prospective, stratified, hypothesis-driven studies using rigorous epidemiological methods must be undertaken to delineate patient and lesion factors influencing clinical aggressiveness. Biological studies are essential to uncover strategies to predict and modify lesion behavior.

Effect of local anaesthetic volume (20 vs 5 ml) on the efficacy and respiratory consequences of ultrasound-guided interscalene brachial plexus block

BACKGROUND Interscalene brachial plexus block (ISBPB) is an effective nerve block for shoulder surgery. However, a 100% incidence of phrenic nerve palsy limits the application of ISBPB for patients with limited pulmonary reserve. We examined the incidence of phrenic nerve palsy with a low-volume ISBPB compared with a standard-volume technique both guided by ultrasound. METHODS Forty patients undergoing shoulder surgery were randomized to receive an ultrasound-guided ISBPB of either 5 or 20 ml ropivacaine 0.5%. General anaesthesia was standardized. Both groups were assessed for respiratory function by sonographic diaphragmatic assessment and spirometry before and after receiving ISBPB, and after surgery. Motor and sensory block, pain, sleep quality, and analgesic consumption were additional outcomes. Statistical comparison of continuous variables was analysed using one-way analysis of variance and Students t-test. Non-continuous variables were analysed using chi(2) tests. Statistical significance was assumed at P<0.05. RESULTS The incidence of diaphragmatic paralysis was significantly lower in the low-volume group compared with the standard-volume group (45% vs 100%). Reduction in forced expiratory volume in 1 s, forced vital capacity, and peak expiratory flow at 30 min after the block was also significantly less in the low-volume group. In addition, there was a significantly greater decrease in postoperative oxygen saturation in the standard-volume group (-5.85 vs -1.50, P=0.004) after surgery. There were no significant differences in pain scores, sleep quality, and total morphine consumption up to 24 h after surgery. CONCLUSIONS The use of low-volume ultrasound-guided ISBPB is associated with fewer respiratory and other complications with no change in postoperative analgesia compared with the standard-volume technique.

Mixed vascular malformations of the brain: clinical and pathogenetic considerations.

The clinical relevance of any scheme for classification of vascular malformations of the brain remains controversial. Widely accepted pathologic classifications include discrete venous, arteriovenous, capillary, and cavernous malformations. Of 280 cases of possible vascular malformations evaluated by a single cerebrovascular service during a 5-year period, 14 were instances of mixed vascular malformations including definite features of more than one pathologically discrete type of malformation within the same lesion. There were six instances of mixed cavernous and venous malformations in the same lesion; in all instances, the cavernous malformation accounted for the clinical presentation. There were three cases of mixed venous and arteriovenous malformations (arterialized venous malformations), presenting with the typical histoarchitectural appearance of a venous malformation, but with arteriovenous shunting; all cases were symptomatic, two with hemorrhage and one with focal neurological symptoms. There were five cases of predominantly cavernous malformations with features of arteriovenous malformation or capillary telangiectasia in the same lesion. These five cases presented clinically as angiographically occult lesions indistinguishable from a cavernous malformation. Lesions including a venous malformation were recognizable preoperatively because of characteristic imaging features of the venous malformation. Other mixed vascular malformations were indistinguishable on diagnostic studies from pure cavernous malformations. Of the 14 mixed vascular malformations, 11 included a cavernous malformation that was usually responsible for the symptomatic presentation. In the other three cases, manifestations of clinical lesions were due to arteriovenous shunting within a venous malformation. We conclude that mixed vascular malformations of the brain are rare entities with distinct clinical, radiological, and pathological profiles. Their identification generates several hypotheses about common pathogenesis or causation-evolution among different types of lesions.

Recommendations for the Management of Patients With Unruptured Intracranial Aneurysms A Statement for Healthcare Professionals From the Stroke Council of the American Heart Association

Aneurysmal subarachnoid hemorrhage (SAH) has a 30-day mortality rate of 45%, with approximately half the survivors sustaining irreversible brain damage.1 On the basis of an annual incidence of 6 per 100 000, ≈15 000 Americans will have an aneurysmal SAH each year. Population-based incidence rates vary considerably from 6 to 16 per 100 000, with the highest rates reported from Japan and Finland.2 3 4 5 Approximately 5% to 15% of stroke cases are secondary to ruptured saccular aneurysms. Although the prevention of hemorrhage has been advocated as the most effective strategy aimed at lowering mortality rates,6 the optimal management of patients with unruptured intracranial aneurysms (UIAs) remains controversial. Management decisions require an accurate assessment of the risks of various treatment options compared with the natural history of the condition. The natural history of UIAs and treatment outcomes are influenced by (1) patient factors, such as previous aneurysmal SAH, age, and coexisting medical conditions; (2) aneurysm characteristics, such as size, location, and morphology; and (3) factors in management, such as the experience of the surgical team and the treating hospital. These many influences have contributed to considerable variability in the reported risks for aneurysmal SAH and the treatment of UIAs. There are no prospective randomized trials of treatment interventions versus conservative management to date, and it is possible that no such studies will be carried out in the future. According to a classification system suggested by Cook et al,7 randomized clinical trials with low likelihoods of false-positive and false-negative errors provide the highest level of evidence (level I) that can be applied to a clinical recommendation. Randomized trials with high likelihoods of false-negative and positive errors provide level II evidence. Level III evidence is generated with nonrandomized concurrent cohort comparisons between contemporaneous patients who did and …