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Fredric B Meyer

Publications and source records attributed to Fredric B Meyer.

At least 19 recordsLinked to original sources
PubMed2003

Symptomatic vasospasm and outcomes following aneurysmal subarachnoid hemorrhage: a comparison between surgical repair and endovascular coil occlusion.

OBJECT: The authors studied patients with aneurysmal subarachnoid hemorrhage (SAH) to determine whether the incidence of symptomatic vasospasm or overall clinical outcomes differed between patients treated with craniotomy and clip application and those treated by endovascular coil occlusion. METHODS: The authors reviewed 415 consecutive patients with aneurysmal SAH who had been treated with either craniotomy and clip application or endovascular coil occlusion at a single institution between 1990 and 2000. Three hundred thirty-nine patients underwent surgical clip application procedures, whereas 76 patients underwent endovascular coil occlusion. Symptomatic vasospasm occurred in 39% of patients treated with clip application, 30% of patients treated with endovascular coil occlusion, and 37% of patients overall. Compared with patients treated with clip application, patients treated with endovascular coil occlusion were more likely to suffer acute hydrocephalus (50 compared with 34%, p = 0.008) and were more likely to harbor aneurysms in the posterior circulation (53 compared with 20%, p < 0.001). Logistic regression models controlling for patient age, admission World Federation of Neurosurgical Societies (WFNS) grade, acute hydrocephalus, aneurysm location, and day of treatment revealed that, among patients with an admission WFNS grade of I to III, endovascular coil occlusion carried a lower risk of symptomatic vasospasm (odds ratio [OR] 0.34, 95% confidence interval [CI] 0.14-0.8) and death or permanent neurological deficit due to vasospasm (OR 0.28, 95% CI 0.08-1) compared with craniotomy and clip application. Similar models revealed no difference in the likelihood of a Glasgow Outcome Scale score of 3 or less at the longest follow-up review (median 6 months) between treatment groups (OR 0.58, 95% CI 0.28-1.21). CONCLUSIONS: Patients with better clinical grades (WFNS Grades I-III) at hospital admission were less likely to suffer symptomatic vasospasm when treated by endovascular coil occlusion, compared with craniotomy and clip application. Nevertheless, there was no significant difference in overall outcome at the longest follow-up examination between the two treatment groups.

Adolescent↗
PubMed2003

Nonlesional central lobule seizures: use of awake cortical mapping and subdural grid monitoring for resection of seizure focus.

OBJECT: Surgical treatment options for intractable seizures caused by a nonlesional epileptogenic focus located in the central sulcus region are limited. The authors describe an alternative surgical approach for treating medically refractory nonlesional perirolandic epilepsy. METHODS: Five consecutive patients who were treated between 1996 and 2000 for nonlesional partial epilepsy that had originated in the central lobule were studied. The patients' ages ranged from 16 to 56 years (mean 28.6 years; there were four men and one woman). The duration of their epilepsy ranged from 8 to 39 years (mean 20.2 years), with a mean seizure frequency of 19 partial seizures per week. Preoperative assessment included video electroencephalography (EEG) and subtracted ictal-interictal single-photon emission computerized tomography coregistered with magnetic resonance imaging (SISCOM). Patients underwent an awake craniotomy stereotactically guided by the ictal EEG and SISCOM studies. Cortical stimulation was used to identify the sensorimotor cortex and to reproduce the patient's aura. A subdural grid was then implanted based on these results. Subsequent postoperative ictal electrocorticographic recordings and cortical stimulation further delineated the site of seizure onset and functional anatomy. During a second awake craniotomy, a limited resection of the epileptogenic central lobule region was performed while function was continuously monitored intraoperatively. One resection was limited to the precentral gyrus, two to the postcentral gyrus, and in two the excisions involved regions of both the pre- and postcentral gyri. In three patients a hemiparesis occurred postsurgery but later resolved. In the four patients whose resection involved the postcentral gyms, transient cortical sensory loss and apraxia occurred, which completely resolved in three. Two patients are completely seizure free, two have experienced occasional nondisabling seizures, and one patient has benefited from a more than 75% reduction in seizure frequency. The follow-up period ranged from 2 to 5.5 years (mean 3.5 years). CONCLUSIONS: A limited resection of the sensorimotor cortex may be performed with acceptable neurological morbidity in patients with medically refractory perirolandic epilepsy. This procedure is an alternative to multiple subpial transections in the surgical management of intractable nonlesional epilepsy originating from the sensorimotor cortex.

Adolescent↗
PubMed2003

Small aneurysms.

Explore the source record for details and available documents.

Carotid Arteries↗
PubMed2003

Neurostimulation therapy for epilepsy: current modalities and future directions.

Neurostimulation is a recent development in the treatment of epilepsy. Vagus nerve stimulation (VNS), the only approved neurostimulation therapy for epilepsy to date, has proved to be a viable adjunctive treatment option. The exact mechanism of action of VNS is not fully understood. In 2 randomized double-blind trials, seizure frequency declined approximately 30% after 3 months of treatment. Long-term follow-up studies suggest that response improves over time, with approximately 35% of patients experiencing a 50% reduction and 20% experiencing a 75% reduction in seizure frequency after 18 months of treatment. Unfortunately, the number of patients rendered medication-free and seizure-free with VNS is low. Vagus nerve stimulation is best viewed as an option for patients who are not surgical candidates or who hesitate to take the risk of surgery yet continue to have seizures despite maximal medical therapy. Stimulation of other regions of the central nervous system for treating epilepsy, including the anterior and centromedian nuclei of the thalamus, the hippocampus, the subthalamic nucleus, and the cerebral neocortex, is currently under investigation. We review the history, proposed mechanisms of action, clinical trials, adverse effects, and future direction of VNS and other modalities of neurostimulation therapy for epilepsy.

Electric Stimulation Therapy↗
PubMed2003

Guglielmi detachable coil treatment of ruptured saccular cerebral aneurysms: retrospective review of a 10-year single-center experience.

BACKGROUND AND PURPOSE: We retrospectively analyzed our results with Guglielmi detachable coils (GDCs) for the endovascular occlusion of acutely ruptured saccular cerebral aneurysms over 10 years. METHODS: Between 1991-2000, 83 patients (mean age, 56.1 years) with aneurysmal subarachnoid hemorrhage were treated with endovascular GDCs. Patients with aneurysms due to trauma or dissection and those with mycotic or fusiform aneurysms were excluded. Mean follow-up in survivors was 19.1 months, and the mean Hunt-Hess grade at admission was 2.2. Angiographic follow-up was performed in 93% of surviving patients (mean interval, 11.6 months). The basilar caput (34 patients) and anterior communicating artery complex (19 patients) were most commonly treated. RESULTS: Sixty-four patients (77%) had a Glasgow Outcome Scale score (GOS) of 4 or 5, nine (11%) had a score of 2 or 3, and 10 (12%) died. At follow-up, 24 patients (35%) had complete aneurysm occlusion, 18 (26%) had a dog-ear remnant, 24 (35%) had a residual neck, and two (3%) had residual aneurysm filling. No treated aneurysm rebled. Three patients required surgical repair after incomplete endovascular treatment. Two or more GDC occlusion procedures were required in 28 patients (34%). Major procedural complications occurred in two patients (2%), resulting in serious neurologic disability or death. CONCLUSION: Endovascular treatment of ruptured cerebral aneurysms with GDCs has low morbidity, and it facilitates good overall outcomes in patients after subarachnoid hemorrhage. The short-term effectiveness of GDC occlusion in preventing aneurysmal rebleeding was excellent. Durability of the treatment in preventing long-term rebleeding as compared with direct surgical clipping warrants further study. Advances in device technology and technique may improve future outcomes.

Acute Disease↗
PubMed2003

Pulmonary complications of aneurysmal subarachnoid hemorrhage.

OBJECTIVE: Pulmonary complications challenge the medical management of patients who have sustained aneurysmal subarachnoid hemorrhage (SAH). We assessed the frequency and types of pulmonary complications after aneurysmal SAH and analyzed the impact of pulmonary complications on patient outcome. METHODS: We reviewed the records of all patients with acute SAH treated at our institution between 1990 and 1997. Three hundred five consecutive patients with an aneurysmal hemorrhage source documented by angiography and treated within 7 days of ictus were analyzed. Outcomes at longest follow-up (mean, 16 mo) were measured by use of the Glasgow Outcome Scale. RESULTS: Pulmonary complications were documented in 66 patients (22%). The pulmonary complications were nosocomial pneumonia in 26 patients (9%), congestive heart failure in 23 (8%), aspiration pneumonia in 17 (6%), neurogenic pulmonary edema in 5 (2%), pulmonary embolus in 2 (<1%), and other pulmonary disorders in 4 (1%); 11 patients had two pulmonary complications. The incidence of symptomatic vasospasm was greater in patients with pulmonary complications (63%) than in patients without pulmonary complications (31%) (P = 0.001), and this association was independent of age and clinical grade at admission (odds ratio, 3.68; P < 0.001). Overall clinical outcomes were worse in patients with pulmonary complications (mean Glasgow Outcome Scale score, 3.3) than in patients without pulmonary complications (mean Glasgow Outcome Scale score, 4.0; P = 0.0001), but pulmonary complications were not an independent predictor of worse outcome when adjusted for age and clinical grade at admission (odds ratio, 1.38; P = 0.315). CONCLUSION: Patients who experience pulmonary complications after aneurysmal SAH have a higher incidence of symptomatic vasospasm than do patients without pulmonary complications. This most likely reflects both the failure to maintain aggressive hypervolemic and hyperdynamic therapy in patients with pulmonary compromise and the possible precipitation of congestive heart failure by hypervolemic therapy in patients with preexisting delayed ischemic neurological deficit. Although patients with pulmonary complications have worse overall clinical outcomes than do patients without pulmonary complications, this is attributable to older age and worse clinical grades at admission.

Adolescent↗
PubMed2002

Is neuroprotective efficacy of nNOS inhibitor 7-NI dependent on ischemic intracellular pH?

The purpose of this study was to test the hypothesis that the efficacy of 7-nitroindazole (7-NI), a selective neuronal nitric oxide (NO) synthase (NOS) inhibitor, is pH dependent in vivo during focal cerebral ischemia. Wistar rats underwent 2 h of focal cerebral ischemia under 1% halothane anesthesia. 7-NI, 10 and 100 mg/kg in 0.1 ml/kg DMSO, was administered 30 min before occlusion. Ischemic brain acidosis was manipulated by altering serum glucose concentrations. Confirmation of the effects of these serum glucose manipulations on brain intracellular pH (pH(i)) was confirmed in a group of acute experiments utilizing umbelliferone fluorescence. The animals were euthanized at 72 h for histology. 7-NI significantly (P < 0.05) reduced infarction volume in both the normoglycemic by 93.3% and hyperglycemic animals by 27.5%. In the moderate hypoglycemic animals, the reduction in infarction volume did not reach significance because moderate hypoglycemia in itself dramatically reduced infarction volume. We hypothesize that a mechanism to explain the published discrepancies on the effects of neuronal NOS inhibitors in vivo may be due to the effects by differences in ischemic brain acidosis on the production of NO.

Animals↗
PubMed2002

Frontal lobe epilepsy: diagnosis and surgical treatment.

Frontal lobe epilepsy has been better understood during the past two decades with the advent of technologies with improved localizing capabilities. Major technological advances in the ability to delineate structural and functional brain regions have led to a resurgence of interest in epilepsy surgery. Neuroimaging modalities have broadened the scope of what are now considered surgically remediable syndromes. In the following article, we attempt to review the current concepts regarding diagnosis and surgical management of frontal lobe epilepsy.

Epilepsy, Frontal Lobe↗
PubMed2002

Protection of focal cerebral ischemia by alkalinization of systemic pH.

OBJECT: It has been demonstrated in many studies that intracellular brain acidosis during cerebral ischemia is a significant factor in perpetuating the cycle of cellular dysfunction leading to neuronal injury. The purpose of this study was to determine whether preischemic administration of alkalotic agents could reduce neuronal injury after focal cerebral ischemia. METHODS: Fifteen fasted rabbits under 1.0% halothane anesthesia were randomized into three groups: Group 1 rabbits were ischemic controls (n = 5) that underwent 4 hours of focal cerebral ischemia. Groups 2 and 3 rabbits underwent a paradigm similar to that of Group 1, except that they were pretreated with either sodium bicarbonate or Carbicarb at similar buffering capacities. Intracellular brain pH (pH(i)), regional cortical blood flow (rCBF), and intrinsic reduced nicotinamide adenine dinucleotide (NADH) fluorescence were measured with in vivo fluorescence imaging. At the end of each experiment, infarct volume expressed as a percentage of hemispheric volume was measured by triphenyltetrazolium chloride staining. RESULTS: Preischemic alkalinization did not alter brain pH(i), rCBF, or NADH fluorescence. After 4 hours of ischemia, brain pH(i), rCBF, NADH fluorescence, and infarct volume measured 6.40 +/- 0.09 (mean +/- standard error), 11 +/- 2 ml/100 g/min, 165 +/- 8% of baseline control, and 37 +/- 3% in ischemic controls, respectively. In Group 2 animals treated with sodium bicarbonate, brain pH(i), rCBF, NADH fluorescence, and infarct volume improved significantly (P < 0.05, analysis of variance) to 6.74 +/- 0.08, 24 +/- 6 ml/100 g/min, 137 +/- 6% of baseline control, and 22 +/- 4%, respectively. Group 3 Carbicarb animals demonstrated improvements in brain pH(i), rCBF, and NADH fluorescence, with a significant reduction in infarct volume. CONCLUSION: These findings suggest that pretreatment with alkalinizing agents may be a useful intervention to provide intraoperative cerebral protection from ischemic injury.

Alkalies↗
PubMed2002

Aprotinin and deep hypothermic cardiopulmonary bypass with or without circulatory arrest for craniotomy.

Deep hypothermic cardiopulmonary bypass with or without circulatory arrest has been used to facilitate the surgical repair of complex cerebrovascular lesions. The advantages of deep hypothermia have been tempered by the occurrence of coagulopathy that is associated with substantial morbidity and mortality. This study analyzed retrospectively the records of 13 patients who underwent cerebrovascular neurosurgery using deep hypothermic cardiopulmonary bypass with or without circulatory arrest during the period 1993 through 1999. All patients received the serine protease inhibitor aprotinin in an effort to avoid the development of a coagulopathy, defined as hemorrhage requiring reoperation. No patients developed postoperative intracranial hemorrhage. There was also no evidence of renal dysfunction, deep venous thrombosis, myocardial infarction, or pulmonary embolism. In conclusion, this study suggests that aprotinin may be beneficial to avoid the coagulopathy that is more likely to occur if deep hypothermic cardiopulmonary bypass with or without circulatory arrest is used for craniotomy without adverse effects on renal function or apparent thrombotic complications.

Aprotinin↗
PubMed2002

Surgical treatment of fibrous dysplasia of the skull in children.

INTRODUCTION: We evaluate the role of surgery in the treatment of fibrous dysplasia of the skull in children. METHODS: We identified 48 consecutive cases of fibrous dysplasia of the skull that were surgically treated at a single institution over a 23-year interval. The 28 patients that initially presented during the first two decades of life were selected for further analysis. Presenting symptoms, signs, surgical treatment, surgical outcome and the state of the disease at the extended follow-up interval were recorded. RESULTS: Fibrous dysplasia of the skull in children most often involved the frontal, sphenoid and ethmoid bones. Most patients presented with facial asymmetry or proptosis. A gross total resection was achieved in 7 patients, subtotal resection in 17 patients, and 4 patients underwent biopsy alone. Over the follow-up interval, 7 patients had symptomatic progression of subtotally resected fibrous dysplasia and 3 patients had asymptomatic progression. The extent of resection was correlated with recurrence risk. CONCLUSIONS: In order to prevent progression of disease, an attempt at gross total resection is indicated in cases of fibrous dysplasia of the skull in childhood where the risk of neurologic morbidity is low and cosmetic results will be acceptable.

Child↗
PubMed2002

Spontaneous spinal cerebrospinal fluid leaks and minor skeletal features of Marfan syndrome: a microfibrillopathy.

OBJECT: Spontaneous spinal cerebrospinal fluid (CSF) leaks are increasingly recognized as a cause of postural headaches. The authors examined a group of patients suffering from spontaneous spinal CSF leaks who also had minor skeletal features of Marfan syndrome for abnormalities of fibrillin-containing microfibrils. METHODS: Patients with spontaneous CSF leaks were evaluated for the clinical characteristics of connective tissue disorders. Skin biopsies were obtained in three patients with skeletal manifestations that constitute part of the Marfan syndrome phenotype. Cultured fibroblasts were studied for fibrillin-1 synthesis and incorporation into the extracellular matrix (ECM) by performing quantitative metabolic labeling and immunohistochemical analysis. Among 20 consecutive patients found to have spinal CSF leaks, four (20%) exhibited minor skeletal features of Marfan syndrome, but lacked any ocular or cardiovascular abnormalities. The mean age of these patients (30 years) was lower than that of the 16 patients without skeletal abnormalities (44 years; p = 0.01). Abnormalities in fibrillin-1 metabolism and immunostaining were detected in all three patients with the skeletal abnormalities who underwent examination, but not in a control patient without these skeletal manifestations. CONCLUSIONS: Twenty percent of patients who experience spontaneous spinal CSF leaks have minor skeletal features of Marfan syndrome. The authors demonstrated abnormalities in fibrillin-1 protein deposition in all patients examined, but only one person was found to have a fibrillin-1 abnormality typically found in classic Marfan syndrome. The results indicate that there is a heterogeneous involvement of other components of ECM microfibrils at the basis of this cerebrospinal manifestation. In addition, the authors identified a connective-tissue etiological factor in a group of disorders not previously classified as such.

Adult↗
PubMed2002

Intraoperative lidocaine injection into the carotid sinus during endarterectomy.

OBJECT: Many surgeons inject a local anesthetic agent into the carotid sinus before carotid endarterectomy in an attempt to ameliorate perioperative hemodynamic instability. The purpose of this study is to analyze the effect of carotid sinus injection with lidocaine on perioperative hemodynamics and complications. METHODS: The authors prospectively studied 92 patients in whom 100 consecutive carotid endarterectomies were performed by a single surgeon (eight procedures were bilateral). Patients were randomly assigned to one of two groups, in which either 0.5 ml of 1% lidocaine was injected into the carotid sinus nerve or no injection of lidocaine was administered before the arteriotomy. All patients were treated postoperatively according to a standard endarterectomy protocol. There were no significant differences between the two groups in the incidence of hypertension, hypotension, or the use of vasoactive medications in the operating room following restoration of carotid artery (CA) blood flow, in the recovery room, or in the intensive care unit. CONCLUSIONS: Injection of lidocaine into the carotid sinus at the time of endarterectomy is not associated with a significant improvement in any hemodynamic factor, from the time of restoration of CA blood flow to postoperative Day 1.

Aged↗
PubMed2002

Volumetric quantification of Fisher Grade 3 aneurysmal subarachnoid hemorrhage: a novel method to predict symptomatic vasospasm on admission computerized tomography scans.

OBJECT: Predicting which patients with aneurysmal subarachnoid hemorrhage (SAH) will develop delayed ischemic neurological deficit (DIND) due to vasospasm remains subjective and unreliable. The authors analyzed the utility of a novel software-based technique to quantify hemorrhage volume in patients with Fisher Grade 3 aneurysmal SAH. METHODS: Patients with aneurysmal SAH in whom a computerized tomography (CT) scan was performed within 72 hours of ictus and demonstrated Fisher Grade 3 SAH were analyzed. Severe DIND was defined as new onset complete focal deficit or coma. Moderate DIND was defined as new onset partial focal deficit or impaired consciousness without coma. Fifteen consecutive patients with severe DIND, 13 consecutive patients with moderate DIND, and 12 consecutive patients without DIND were analyzed. Software-based volumetric quantification was performed on digitized admission CT scans by a single examiner blinded to clinical information. There was no significant difference in age, sex, admission Hunt and Hess grade, or time to admission CT scan among the three groups (none, moderate, or severe DIND). Patients with severe DIND had a significantly higher cisternal volume of hemorrhage (median 30.5 cm3) than patients with moderate DIND (median 12.4 cm3) and patients without DIND (median 10.3 cm3; p < 0.001). Intraparenchymal hemorrhage and intraventricular hemorrhage were not associated with DIND. All 13 patients with cisternal volumes greater than 20 cm3 developed DIND, compared with 15 of 27 patients with volumes less than 20 cm3 (p = 0.004). CONCLUSIONS: The authors developed a simple and potentially widely applicable method to quantify SAH on CT scans. A greater volume of cisternal hemorrhage on an admission CT scan in patients with Fisher Grade 3 aneurysmal SAH is highly associated with DIND. A threshold of cisternal hemorrhage volume (> 20 cm3) may exist above which patients are very likely to develop DIND. Prospective application of software-based volumetric quantification of cisternal SAH may predict which patients will develop DIND.

Adult↗