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I A Awad

Publications and source records attributed to I A Awad.

At least 37 records · Page 2Linked to original sources
PubMed1999

A comparison of the clinical profile of cavernous malformations with and without associated venous malformations.

OBJECTIVE: Little is known about the clinical behavior of cavernous malformations (CMs) associated with venous malformations (VMs) of the brain. The aim of this study is to compare the clinical profile of patients harboring CMs with and without associated VMs. METHODS: A retrospective analysis of 55 consecutive patients harboring CMs of the brain who presented to a single neurovascular team during a 4-year period was performed. Forty-two patients (76%) had CMs alone (CM group), and 13 patients (24%) had CMs associated with VMs (CM + VM group). Detailed clinical information regarding each patient was gathered. Statistical analysis was performed using Fisher's exact test for binary variables and Mann-Whitney U test for continuous variables. RESULTS: The lesion location was infratentorial for 19 of the 70 CMs (27%) in the CM group and for 14 of the 21 CMs (67%) in the CM + VM group (P = 0.001). Familial histories of CMs were documented for 7 of the 42 patients (17%) in the CM group and none of the 13 patients in the CM + VM group. There was a female-to-male gender bias of 1.6:1 in the CM group and 3.3:1 in the CM + VM group. Sixteen of the 42 patients (38%) in the CM group and 8 of the 13 patients (62%) in the CM + VM group presented with symptomatic hemorrhage. Seizure presentation was documented in 11 of the 42 patients (26%) in the CM group and in 1 of the 13 patients (8%) in the CM + VM group. Repeated symptomatic hemorrhage was diagnosed in 4 of the 42 patients (9.5%) in the CM group and in 3 of the 13 patients (23%) in the CM + VM group. There were no apparent differences in the mean age at presentation, lesion size, or multiplicity between the two groups. CONCLUSION: Patients with CMs associated with VMs are more likely to be female patients, have associated symptomatic hemorrhage, have lesions in the posterior fossa (statistically significant), suffer from repeated symptomatic hemorrhage, and are less likely to present with seizures or to have familial histories when compared with patients with CMs alone. The possible mechanisms for these apparent differences in clinical profile are discussed.

Adult↗
PubMed1999

Spontaneous angiographic obliteration of cerebral arteriovenous malformations.

OBJECTIVE: The factors associated with spontaneous angiographic obliteration of cerebral arteriovenous malformations (AVMs) are not well understood. We present a review of the literature and a report of our experience with six cases (four with no previous treatment intervention and two postoperative residual malformations) that were identified as having occurred during a 20-year period and describe the clinical and lesion features associated with this rare phenomenon. We present the first detailed histological study of a spontaneously thrombosed AVM specimen, including immunohistochemical analysis of angiogenesis factor expression. METHODS: A combined experience in the management of approximately 700 AVMs during 20 years identified six cases of spontaneous angiographic obliteration of cerebral AVMs. A literature review revealed another 24 cases with angiographic documentation of the initial AVMs and follow-up data showing nonfilling of the lesions. Histological analysis of a recently excised lesion included immunostaining with monoclonal antibodies to the antigens of Factor VIII, Tie, vascular endothelial growth factor, and its receptors, Flt-1 and Flk. RESULTS: A single draining vein was a feature in each of our 6 cases and in 12 of 14 (86%) cases from the literature. Hemorrhage as the presenting symptom was identified in 5 of our 6 (83%) cases and in 17 of 24 (71%) of the literature cases. The size of the AVM was less than 6 cm in each of our 6 cases and in 22 of 24 (92%) of the literature cases. A histological examination of a thrombosed AVM surgical specimen revealed persistent patent vascular channels within the lesion. Immunohistochemical analysis with angiogenesis and endothelia-specific factors showed expression of these factors within the lumen of the thrombosed nidus vessels. CONCLUSION: We propose that the occlusion of a single draining vein may lead to total venous outflow obstruction and lesion thrombosis. Hemorrhagic presentation and small nidus may also predispose to this phenomenon. Immunohistochemical analysis of a thrombosed AVM revealed possible ongoing angiogenic changes within the AVM vessels 1 month after angiographically documented thrombosis. It is possible that neovascularization within a thrombosed AVM may lead to lesion recanalization; however, this phenomenon seems to be clinically exceedingly rare.

Adult↗
PubMed1999

Comparative localization of auditory comprehension by using functional magnetic resonance imaging and cortical stimulation.

OBJECT: The authors previously described a functional magnetic resonance (fMR) imaging task for the localization of auditory comprehension in which focal activation of posterior temporal and inferior frontal regions of the left hemisphere was reliably demonstrated. Because this study was conducted in neurologically normal volunteers, it was not possible to determine whether the activated regions were critical to the performance of language tasks; that is, whether the fMR imaging activations provided a valid measure of language processing. A direct comparison of fMR imaging language activation with cortical stimulation must be completed before it can be used with confidence in presurgical planning, and this comparison is performed in the present study. METHODS: The authors report on a series of 33 consecutive patients who underwent dominant hemisphere resection and in whom fMR imaging mapping of auditory comprehension was performed at the Yale neurosurgical program. In 23 of the 33 patients fMR imaging activation was consistent with the typical results obtained in normal participants in the earlier study. In 16 of these 23 patients language mapping was performed using either intra- or extraoperative cortical stimulation. Cortical stimulation failed to localize language areas in two of the 16 patients. Electrical stimulation that was performed in proximity to the fMR image activations interfered with auditory comprehension, object naming, or speech production in 12 of the remaining 14 patients. Five of the 10 cases in which evocation of reliable fMR imaging activation failed were attributable to technical problems and/or patient head movement. CONCLUSIONS: Cortical stimulation results and fMR imaging findings were consistent in all but two patients. However, the spatial extent of the activation produced by fMR imaging and the spatial extent of stimulation-induced language disruption that was caused by direct cortical stimulation did not always correspond. Problems in defining the extent of activation by both methods are discussed.

Adolescent↗
PubMed1999

De novo development of a cavernous malformation of the spinal cord following spinal axis radiation. Case report.

Analysis of recent reports has suggested that cavernous malformations (CMs) of the brain may have an acquired pathogenesis and a dynamic pathophysiological composition, with documented appearance of new lesions in familial cases and following radiotherapy. The authors report the first case of demonstrated de novo formation of an intramedullary CM following spinal radiation therapy. A 17 year-old boy presented with diabetes insipidus and delayed puberty. Evaluation of endocrine levels revealed hypopituitarism, and magnetic resonance (MR) imaging demonstrated an infundibular mass. The patient underwent a pterional craniotomy and removal of an infundibular germinoma. The MR image of the spine demonstrated normal results. The patient received craniospinal radiation therapy and did well. He presented 5 years later with acute onset of back pain, lower-extremity weakness and numbness, and difficulty with urination. An MR image obtained of the spine revealed an intramedullary T-7 lesion; its signal characteristics were consistent with a CM. The patient was initially managed conservatively but developed progressive myelopathy and partial Brown-Séquard syndrome. Although he received high-dose steroids and bed rest, his symptoms worsened. He underwent a costotransversectomy and excision of a hemorrhagic vascular lesion via an anterolateral myelotomy. Pathological examination confirmed features of a CM. The patient has done well and was walking without assistance within 4 weeks of surgery. De novo genesis of CMs may be associated with prior radiation therapy to the spinal cord.

Abnormalities, Radiation-Induced↗
PubMed1999

Protocols and critical pathways for stroke care.

We have presented a conceptual approach toward developing clinical protocols and critical pathways in a complex multidisciplinary environment with a commitment to clinical excellence, evidence-based practice methodology, and education. The process and the mood surrounding these have been more important in our view than any particular protocol or pathway. They have generated an attitude aiming toward avoidance of complications rather than crisis management. They have contributed to a philosophy of integrative multidisciplinary collaborations among various specialists, house staff, and nursing and paramedical personnel and a greater mutual sensitivity in interactions with medical center management and administration. The overall impact of this global approach has been quantifiable (Fig. 6), although the role(s) of one or more facets of it cannot be independently defined (21, 22). Protocols and clinical pathways should be viewed as components of total quality management. They should not be allowed to restrict the patient's or physician's choice of interventions, they should not inhibit in any way innovation or the introduction of novel methodologies. Yet, protocols and critical pathways should and do generate a pressure on every member of the health-care team, a sense of negative entropy constantly urging a move toward a higher level of excellence and quality.

Cerebral Hemorrhage↗
PubMed1998

Failure of the hypotensive provocative test during temporary balloon test occlusion of the internal carotid artery to predict delayed hemodynamic ischemia after therapeutic carotid occlusion.

BACKGROUND: Extensive experience and critical evaluation of the efficacy of a pharmacologic hypotensive challenge during conventional balloon test occlusion (BTO) of the internal carotid artery (ICA) is lacking. This prompted us to review our institution's most recent experience with this adjunctive provocative test before planned therapeutic balloon occlusion of the ICA. METHODS: Twenty consecutive cases of endovascular therapeutic balloon occlusion of the ICA were retrospectively reviewed. Conventional BTO under normotension and with hypotensive challenge were performed within a standardized protocol. RESULTS: Sixteen patients underwent provocative testing, of which 13 had BTO with hypotensive challenge. All patients in this group tolerated these maneuvers without acute neurologic deficit. Two (15%) of these patients developed delayed permanent neurologic deficits, which seemed to be attributable to hemodynamic ischemia. One of seven patients not undergoing hypotensive challenge also developed transient neurologic deficits after carotid occlusion. CONCLUSIONS: Despite the conceptually attractive and early positive experience of the hypotensive challenge in attempting to increase sensitivity and specificity of risk for developing delayed hemodynamic ischemia, we have found two significant false-negative results. This experience is reviewed in the context of risks of permanent balloon occlusion of the carotid artery after balloon test occlusion.

Adolescent↗
PubMed1998

Multilocus linkage identifies two new loci for a mendelian form of stroke, cerebral cavernous malformation, at 7p15-13 and 3q25.2-27.

Cerebral cavernous malformation (CCM) is a Mendelian model of stroke, characterized by focal abnormalities in small intracranial blood vessels leading to hemorrhage and consequent strokes and/or seizures. A significant fraction of cases is inherited as an autosomal dominant trait with incomplete penetrance. Among Hispanic Americans, virtually all CCM is attributable to a founder mutation localized to 7q ( CCM1 ). Recent analysis of non-Hispanic Caucasian kindreds, however, has excluded linkage to 7q in some, indicating at least one additional CCM locus. We now report analysis of linkage in 20 non-Hispanic Caucasian kindreds with familial CCM. In addition to linkage to CCM1, analysis of linkage demonstrates linkage to two new loci, CCM2 at 7p13-15 and CCM3 at 3q25.2-27. Multilocus analysis yields a maximum lod score of 14.11, with 40% of kindreds linked to CCM1, 20% linked to CCM2 and 40% linked to CCM3, with highly significant evidence for linkage to three loci (linkage to three loci supported with an odds ratio of 2.6 x 10(5):1 over linkage to two loci and 1.6 x 10(9):1 over linkage to one locus). Multipoint analysis among families with high posterior probabilities of linkage to each locus refines the locations of CCM2 and CCM3 to approximately 22 cM intervals. Linkage to these three loci can account for inheritance of CCM in all kindreds studied. Significant locus-specific differences in penetrance are identified. These findings have implications for genetic testing of this disorder and represent an important step toward identification of the molecular basis of this disease.

Cerebrovascular Disorders↗
PubMed1998

Occipital lobe vascular malformations: prevalence of visual field deficits and prognosis after therapeutic intervention.

BACKGROUND: The prevalence of visual field (VF) deficits in association with vascular malformations of the occipital lobe is not known, and the prognosis of the VF after therapeutic intervention has not been systematically documented. METHODS: We reviewed the clinical records of 23 consecutive patients who were managed at a single institution during a 3-year period with intracranial vascular malformations extending within the anatomic borders of the occipital lobe. Lesion location and treatment rendered were correlated with formal VF testing performed before and after therapeutic intervention. RESULTS: Twenty-one of the 23 patients underwent treatment of their lesions. Treatment included resection after preoperative embolization (12 patients), resection alone (2 patients with arteriovenous malformations and 3 patients with cavernous malformations), and stereotactic radiosurgery (4 patients; preceded by embolization in 3 of the 4). One patient was followed expectantly, and another died as a result of hemorrhage soon after undergoing endovascular embolization. The VFs were assessed before and after therapeutic intervention (follow-up assessment, 2-29 mo). New VF deficits or worsening of preexisting VF deficits were documented in 5 of the 21 treated patients (24%), but only 2 of these patients (9.5%) had persistent deficits at the time of their follow-up examinations. Among the 10 patients with pretreatment VF deficits, 5 improved and the other 5 were unchanged after treatment. CONCLUSION: Patients with occipital lobe vascular malformations frequently present with associated VF deficits. Surgical resection or stereotactic radiosurgery (with or without previous embolization) of these lesions can be performed with little risk of causing new VF deficits or worsening of preexisting ones. Many VF deficits can be expected to improve or resolve after therapy.

Adult↗
PubMed1998

Endothelial cell culture from human cerebral cavernous malformations.

BACKGROUND AND PURPOSE: The cerebral cavernous malformation (CCM) is a common and frequently unrecognized cause of stroke and epilepsy. It consists of blood-filled caverns lined by endothelial cells (EC) and devoid of mature vessel wall structure. Cultured EC obtained from CCM may express phenotypic and genotypic alterations contributing to CCM pathogenesis. We report the first successful isolation and growth in vitro of primary EC lines from human CCM lesions. METHODS: We developed a procedure for the isolation and growth of EC from human CCM, confirmed their EC origin by a panel of molecular markers, and determined by immunocytochemistry the basic expression patterns of 6 transmembrane receptor protein kinases comparing brain, skin, and CCM primary EC lines grown identically. RESULTS: Several CCM EC lines were established from 2 patients after we treated the excised specimens with 0.3% trypsin/1% EDTA, selective cloning, and growth in MCDB107 containing 0.3 g/L heparin, 0.15 g/L endothelial cell growth supplement, and 15% FBS. The CCM EC showed contact inhibition and a rounded cobblestone appearance. The cells expressed CD31, CD105, von Willebrand factor, and binding sites for Ulex europaeus agglutinin, type 1 and acetylated LDL. They showed low levels of Flt-1, Flk-1, transforming growth factor (TGF)-beta RI, and TGF-beta RII expression but stained strongly with antibodies against Tie-1 and Tie-2. CONCLUSIONS: Cultured CCM EC retained their endothelial phenotype. Brain, skin, and CCM EC lines did not significantly differ in their staining patterns with antibodies against Flt-1, Flk-1, TGF-beta RI, TGF-beta RII, Tie-1, and Tie-2. These cell lines will assist in defining molecular phenotype and genotype alterations in association with CCM.

Antibodies, Monoclonal↗
PubMed1998

Surgery for intracerebral hemorrhage.

Intracerebral hemorrhage (ICH) represents 8 to 15% of all strokes in the United States and 20 to 30% of all strokes in Japan and China. Although ICH represents a relatively small fraction of total strokes, it is a formidable disease, with a 30-day mortality rate two- to sixfold higher than that for ischemic stroke. Furthermore, it is a major cause of disability, with only 20% of patients becoming independent at 6 months. The most common risk factors for ICH are age, hypertension, and amyloid angiopathy, which are associated with damage to and weakening of the arterial/arteriolar wall leading to vessel rupture. The pathology is a dynamic one that continues to evolve over the first few days after onset. In 20 to 30% of ICH, clot volume increases over the first 24 hours and is generally associated with neurologic worsening. The final outcome from ICH is related not only to clot volume, compression, and destruction but also to potential neurotoxicity from the blood degradation products and associated neuronal ischemia. The treatment of ICH has been one of the most controversial and least well-studied areas from a medical or surgical perspective. Surgical treatment has evolved over the years and can be grouped into open and stereotactically guided surgery for hematoma evacuation. Seven thousand operations per year are performed in the United States for hematoma evacuation, although this approach has not been adequately investigated. Adjuvant medical therapies with neuroprotective agents require further investigation and may potentially have additive benefits.

Cerebral Hemorrhage↗
PubMed1998

MR of hereditary hemorrhagic telangiectasia: prevalence and spectrum of cerebrovascular malformations.

PURPOSE: Our goal was to describe the prevalence and types of cerebral vascular malformations (CVMs) seen with MR imaging in patients with hereditary hemorrhagic telangiectasia (HHT). METHODS: We reviewed retrospectively the brain MR images of 184 consecutive patients with HHT. Catheter angiography was performed in 17 patients with CVMs detected on MR images. RESULTS: MR imaging revealed 63 CVMs in 42 patients. Classic arteriovenous malformations (n = 10) had a conspicuous network of vessels with flow voids and enlarged adjacent pial vessels. Apparent venous malformations (n = 5) were best seen after administration of contrast material as a prominent vessel coursing through normal brain parenchyma. Indeterminate vascular malformations (n = 48) had a spectrum of appearances characterized by variable combinations of heterogeneous signal intensity, enhancement, or hemosiderin. Angiography in 17 patients revealed 47 CVMs. Forty-six were arteriovenous malformations (AVMs), including 25 CVMs not seen with MR imaging and 21 CVMs that by MR criteria included 8 AVMs and 13 indeterminate vascular malformations. Angiography confirmed 1 venous malformation seen with MR imaging but failed to detect 3 indeterminate lesions revealed by MR imaging. CONCLUSION: MR imaging of a large cohort of consecutive patients with HHT revealed a CVM prevalence of 23% (42/184). Most CVMs (48/63) have an atypical appearance for vascular malformations on MR images. Angiographic correlation suggests that MR imaging underestimates the prevalence of CVMs and that the majority of indeterminate CVMs, despite their variable MR appearance, are AVMs.

Cerebral Angiography↗