Co-occurrence of a cavernous malformation and contralateral moyamoya.
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Adult↗
Biomedical subjects
M T Lawton
Publications and source records attributed to M T Lawton.
C-reactive protein levels and viable Chlamydia pneumoniae in carotid artery atherosclerosis.
BACKGROUND AND PURPOSE: An elevated serum level of C-reactive protein, an inflammatory marker, is an independent predictor of stroke and coronary artery disease. To determine whether chronic infection with Chlamydia pneumoniae, which has been identified in atherosclerotic plaques, is responsible for systemic inflammation, we studied the association between serum C-reactive protein levels and infection of carotid artery atherosclerotic plaque with viable C pneumoniae. METHODS: Serum C-reactive protein levels were obtained before endarterectomy for carotid artery stenosis. Plaques were tested for C pneumoniae mRNA, an indicator of viability, and DNA by polymerase chain reaction of DNA and cDNA, respectively. RESULTS: Forty-eight samples were studied, of which 18 (38%; 95% CI, 23 to 50) were infected with viable C pneumoniae as evidenced by isolated chlamydial mRNA. All 18 of these samples, plus 1 additional sample, were positive for chlamydial DNA. Serum C-reactive protein levels were higher in those with viable C pneumoniae compared with those without infection (median, 8 mg/L versus undetectable; P=0.045 by Wilcoxon rank-sum test). In multivariable models, the only independent predictor of the presence of viable C pneumoniae was a detectable C-reactive protein level (odds ratio, 4.2; 95% CI, 1.1 to 17; P=0.04). CONCLUSIONS: Viable C pneumoniae are present in a substantial portion of carotid artery atherosclerotic plaques and are associated with increased serum C-reactive protein levels. These findings may explain the link between elevated C-reactive protein levels and the risk of cardiovascular disease and stroke but should be reproduced in a larger cohort.
Aged↗
Abnormal balance in the angiopoietin-tie2 system in human brain arteriovenous malformations.
Brain arteriovenous malformations (BAVMs) are congenital vascular lesions that often present as cerebral hemorrhage in young adults. The variable nature of the clinical course, especially with respect to spontaneous hemorrhage, recurrence, growth, and regression, suggests that BAVMs are lesions with active angiogenesis and vascular remodeling. We examined mRNA and protein expression of angiopoietin 1 (Ang1) and Ang2 by semiquantitative reverse transcriptase-polymerase chain reaction, in situ hybridization, and Western blot in BAVMs and control brains obtained from temporal lobectomy for medically intractable seizures. Although Ang1 mRNA levels were similar in BAVMs and controls, Ang1 protein levels were 30% lower in BAVMs than in controls. Ang2 mRNA levels were 40% higher and Ang2 protein levels were 8-fold higher in BAVMs than in controls. In situ hybridization showed that the Ang2 mRNA was localized to the perivascular area in BAVMs. This abnormal balance in the Ang-Tie2 system may, in part, explain the aberrant vascular phenotype in BAVMs.
Adolescent↗
The tandem bypass: subclavian artery-to-middle cerebral artery bypass with dacron and saphenous vein grafts. Technical case report.
BACKGROUND: Fusiform or dolichoectatic intracranial aneurysms often cannot be managed with conventional surgical or endovascular techniques, and instead require trapping and revascularization techniques. On rare occasions in elderly patients, extracranial sites used for anastomosing the bypass have been previously repaired with synthetic vascular prostheses. This circumstance in an elderly subarachnoid hemorrhage patient led to a novel bypass procedure, the tandem bypass: a long extracranial-to-intracranial bypass with two grafts of different materials assembled in series. CASE DESCRIPTION: A 71-year-old man with carotid artery atherosclerotic disease and a previous vascular reconstruction (subclavian artery-to-internal carotid artery Dacron interposition graft) presented with a subarachnoid hemorrhage from a dolichoectatic supraclinoid ICA aneurysm. The aneurysm was treated with trapping and distal revascularization. The final construct was a subclavian artery-to-middle cerebral artery bypass, with the graft being the previous Dacron prosthesis and a long saphenous vein. The vein graft was anastomosed end-to-side to the Dacron graft proximally, and end-to side to the middle cerebral artery distally. Subsequently, inflow to the aneurysm was occluded with clips on the Dacron graft beyond the proximal anastomosis of the vein graft, and outflow from the aneurysm was occluded with clips on the supraclinoid ICA. CONCLUSIONS: The tandem bypass, which uses prosthetic graft material and saphenous vein in succession, is a technically straightforward technique in patients who need extracranial-to-intracranial bypasses and who also have pre-existing carotid reconstructions or lack sufficient saphenous vein to complete a long bypass.
Aged↗
Current multimodality management of infectious intracranial aneurysms.
OBJECTIVE: To implement an algorithm for and assess multimodality (medical, endovascular, and microsurgical) treatment of patients with infectious intracranial aneurysms. METHODS: Twenty patients with 27 infectious aneurysms were treated during a 10-year period. Bacterial endocarditis was the most common cause (65%). Most aneurysms presented with rupture (75%), and the middle cerebral artery was the most common location (70%). RESULTS: Five patients were treated endovascularly, with direct coiling for three patients and parent artery occlusion for two patients. Ten patients (15 aneurysms) were treated surgically, with 6 aneurysms being trapped/resected, 2 trapped/bypassed, 4 clipped, and 3 wrapped. Five patients were treated medically. Treatment-associated neurological morbidity was observed for two patients (10%), and two patients died (10%). Good outcomes were observed for 16 patients (80%). CONCLUSION: Factors that guide management decisions for these patients include aneurysm rupture, hematomas with increased intracranial pressure, and the eloquence of brain tissue supplied by the parent artery. Patients with unruptured infectious aneurysms are initially treated medically, with antibiotics and serial angiography. Patients with ruptured aneurysms that are not associated with hematomas and that do not involve eloquent vascular territory are treated endovascularly. Patients with ruptured aneurysms are treated surgically when there is a hematoma or the risk of ischemic complications in eloquent territory. Therefore, endovascular therapy is the first option for patients in stable condition with ruptured aneurysms; surgical therapy is the first option for patients in unstable condition with ruptured aneurysms and the second option for patients in stable condition who experience failure of endovascular therapy. Medically treated patients with enlarging or dynamic unruptured aneurysms also require direct surgical or endovascular intervention. Favorable patient outcomes can be achieved with this multimodality management.
Adolescent↗
Evidence of increased endothelial cell turnover in brain arteriovenous malformations.
OBJECTIVE: We hypothesized that human brain arteriovenous malformations (BAVMs) are nonstatic vascular lesions with active angiogenesis or vascular remodeling. To test this hypothesis, we assessed endothelial cell turnover in BAVMs. METHODS: We identified nonresting endothelial cells by use of immunohistochemistry for the Ki-67 antigen. From archived paraffin blocks, we selected BAVM vessels without intravascular thrombosis or embolic material in areas nonadjacent to the nidus edge. For controls, we used 50- to 100-microm diameter cortical vessels from temporal lobe cortex removed for epilepsy treatment. The Ki-67 index was calculated as a percentage of Ki-67-positive endothelial cells. The data were analyzed by the nonparametric Mann-Whitney test and reported as mean +/- standard deviation. RESULTS: Thirty-seven specimens that met the above criteria were selected. There were 26 +/- 15 vessels counted in each BAVM specimen versus 18 +/- 5 in each control cortex (n = 5). The mean Ki-67 index was higher for BAVM vessels than control cortical vessels (0.7 +/- 0.6 versus 0.1 +/- 0.2%; P = 0.005), which represented an approximately seven-fold increase in the number of nonresting endothelial cells. In the BAVM group, there was a trend for younger patients to have a wider variation and higher Ki-67 index than older patients; no trend was evident in the control group. CONCLUSION: Compared with control vessels, BAVM vessels have higher endothelial cell turnover, which suggests the presence of active angiogenesis or vascular remodeling in BAVMs.
Adult↗
Conus perimedullary arteriovenous fistula with intracranial drainage: case report.
OBJECTIVE AND IMPORTANCE: Perimedullary arteriovenous fistulae (AVFs) do not commonly present with subarachnoid hemorrhage or intracranial venous drainage causing neurological symptoms. We present a case with both of these features. The patient was inadvertently treated for an unruptured intracranial aneurysm before his true problem was recognized. CLINICAL PRESENTATION: A 65-year-old man presented with sudden-onset lower-extremity weakness, diplopia, nausea, and dysarthria on the day of admission. A lumbar puncture documented subarachnoid hemorrhage, and imaging studies revealed a left middle cerebral artery aneurysm. It was noted during surgery that this aneurysm was unruptured, and the patient did not exhibit improvement after surgery. INTERVENTION: Spinal angiography demonstrated a spinal perimedullary AVF feeding from the left T12 radicular artery; venous drainage extended rostrally into the posterior fossa venous system. The AVF was surgically occluded via a posterior laminectomy at the level of the AVF. After surgery, the patient's symptoms began to abate. CONCLUSION: Conus perimedullary AVFs can have venous drainage that extends as far as intracranial veins, which can lead to confusing clinical findings because the symptoms may suggest an intracranial process, although the lesion is in the spine. Surgeons must be aware of this confusing presentation.
Aged↗
A neurocytoma and an associated lenticulostriate artery aneurysm presenting with intraventricular hemorrhage: case report.
OBJECTIVE AND IMPORTANCE: Hemorrhage associated with central neurocytoma has been described previously, but never in association with an aneurysm originating from a feeding artery. We present the first reported case of a central neurocytoma in a patient with intraventricular hemorrhage caused by rupture of an aneurysm on a lenticulostriate artery that supplied the tumor. CLINICAL PRESENTATION: A 35-year-old man who presented with an intraventricular hemorrhage underwent magnetic resonance imaging and cerebral angiography that disclosed a right lateral intraventricular mass and a 7-mm fusiform aneurysm from a lateral lenticulostriate branch of the right middle cerebral artery. INTERVENTION: The patient underwent a contralateral transcallosal exploration and resection of the tumor, with excision of the adjacent lenticulostriate artery aneurysm. Pathological review demonstrated that the tumor was a neurocytoma. The aneurysm was discrete from the tumor but occurred on a vessel that supplied the tumor. CONCLUSION: Previous reports have demonstrated that intraventricular neurocytoma may present with tumor hemorrhage. In this case, an aneurysm separate and distinct from the tumor was the bleeding culprit, and the aneurysm was on an artery that fed into the tumor. Any such aneurysm must be identified and treated appropriately for therapy to be complete.
Adult↗
Fenestration of the posteroinferior cerebellar artery: case report.
OBJECTIVE AND IMPORTANCE: Fenestrations of cerebral arteries are rare, but very important to diagnose given their high association with saccular aneurysms. We present the first reported case of a fenestration of the posteroinferior cerebellar artery (PICA). CLINICAL PRESENTATION: A 62-year-old man who presented with a subarachnoid hemorrhage underwent repeated four-vessel cerebral angiography. An isolated right PICA abnormality consistent with a dissection or fenestration was revealed. INTERVENTION: The patient underwent surgical exploration of his PICA, which confirmed a PICA fenestration without an associated saccular aneurysm. The fenestration was wrapped with cotton. CONCLUSION: Our case report illustrates the novel anatomic finding of a fenestration of the PICA. Knowledge of this entity would be helpful in the differential diagnosis of a posterior fossa subarachnoid hemorrhage.
Cerebellum↗
Endovascular treatment of cerebral artery aneurysms during pregnancy: report of three cases.
Historically, surgical management of cerebral aneurysms during pregnancy has been controversial. Debate originally focused on early versus late intervention, before or after delivery of the fetus. More recently, treatment has centered on rapid intervention. We describe the endovascular treatment of cerebral artery aneurysms with Guglielmi detachable coils in three pregnant women.
Adult↗
Surgical strategies for giant intracranial aneurysms.
Untreated giant intracranial aneurysms have a dismal natural history as a result of hemorrhage, cerebral compression, and thromboembolism. The poor prognosis of patients with giant aneurysms therefore warrants aggressive treatment. A surgical approach is chosen to maximize the operative exposure of the aneurysm and depends mainly on the aneurysm's location. Once exposed, vascular control of the aneurysm is required not only to manage an intraoperative rupture, but also to collapse the aneurysm, to increase working space, and to improve visualization of the anatomy. Hypothermic circulatory arrest may be indicated in select patients with complex posterior circulation aneurysms. Direct clipping of giant aneurysms, with meticulous preservation of parent and branch arteries, is the preferred method of occlusion. Unclippable aneurysms require alternative techniques (e.g., trapping, parent artery occlusion, excision, and aneurysmorrhaphy) that compromise parent arteries and may require revascularization to restore adequate cerebral blood flow. Giant aneurysms are complex lesions that demand thorough surgical planning, individualized strategies, and a multidisciplinary effort in specialized neurovascular centers.
Adolescent↗
Evaluating patients with vertebrobasilar transient ischemic attacks.
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Basilar Artery↗
Spinal dural arteriovenous fistula with an associated feeding artery aneurysm: case report.
OBJECTIVE AND IMPORTANCE: A case of a spinal dural arteriovenous fistula (DAVF) with two associated feeding artery aneurysms is reported. Intradural spinal arteriovenous malformations have been associated with aneurysms that present with subarachnoid hemorrhage and with venous varices that produce mass effect, but spinal DAVFs have not previously been described in association with feeding artery aneurysms. CLINICAL PRESENTATION: A 71-year-old man presented with progressive spastic paraparesis, constipation, and overflow incontinence. Magnetic resonance imaging demonstrated a spinal vascular lesion and venous ischemia in the lower spinal cord. Diagnostic spinal angiography revealed a DAVF originating from the left T11 radicular artery and having the unusual feature of two proximal feeding artery aneurysms. INTERVENTION: The patient deteriorated neurologically after undergoing angiography, prompting emergent surgery. The DAVF was resected through a T11 transpedicular approach. One aneurysm was dolichoectatic and therefore unclippable, requiring proximal occlusion of the parent artery after establishing tolerance of test occlusion using somatosensory evoked potentials; the second aneurysm was adjacent to the fistula and was resected with the DAVF. CONCLUSION: Feeding artery aneurysms in association with spinal DAVFs have not been previously reported. They present additional risk to patients and, with simple modifications of the standard operative approaches, can easily be treated as part of the surgery for the DAVF.
Aged↗
Ethmoidal dural arteriovenous fistulae: an assessment of surgical and endovascular management.
OBJECTIVE: Endovascular treatment of ethmoidal dural arteriovenous fistulae (DAVFs) has become technically feasible, but its relative risks and benefits have not justified its use. We present a series of patients with ethmoidal DAVFs treated almost exclusively with surgery at an institution where expert endovascular therapy was available. Surgical risks, treatment efficacy, and patient outcomes were determined for comparison with published endovascular data. METHODS: Sixteen patients with ethmoidal DAVFs were treated during a 17-year period from 1982 to 1999. In three patients, feeding arteries from the internal maxillary artery were embolized; no ophthalmic artery embolizations were performed. A low bifrontal surgical approach was used in most patients to expose, coagulate, and divide the fistulous site. RESULTS: Ethmoidal DAVFs were occluded grossly and angiographically in all 16 patients. There was no treatment-associated neurological morbidity, and clinical outcomes were good in all but one patient who was comatose initially. CONCLUSION: Review of our surgical experience with ethmoidal DAVFs as well as published endovascular results for these lesions suggests that endovascular management of ethmoidal DAVFs has a small but clinically significant risk to vision, is rarely effective in curing the fistula, and does not eliminate the need for surgery. In contrast, surgical management has no associated risk to vision, is highly effective at obliterating the fistula, and can contribute to good clinical outcomes in most patients. For these reasons, surgical management of ethmoidal DAVFs remains the treatment of choice.
Aged↗
Cavernous malformations of the brainstem: experience with 100 patients.
OBJECT: In this study the authors review surgical experience with cavernous malformations of the brainstem (CMBs) in an attempt to define more clearly the natural history, indications, and risks of surgical management of these lesions. METHODS: The authors retrospectively reviewed the cases of 100 patients (38 males and 62 females; mean age 37 years) harboring 103 lesions at treated a single institution between 1984 and 1997. Clinical histories, radiographs, pathology records, and operative reports were evaluated. The brainstem lesions were distributed as follows: pons in 39 patients, medulla in 16, midbrain in 16, pontomesencephalic junction in 15, pontomedullary junction in 10, midbrain-hypothalamus/thalamus region in two patients, and more than two brainstem levels in five. The retrospective annual hemorrhage rate was most conservatively estimated at 5% per lesion per year. Standard skull base approaches were used to resect lesions in 86 of the 100 patients. Intraoperatively, all 86 patients were found to have a venous anomaly in association with the CMB. Follow up was available in 98% (84 of 86) of the surgical patients. Of these, 73 (87%) were the same or better after surgical intervention, eight (10%) were worse, and three (4%) died. Two surgical patients were lost to follow-up review. Incidences of permanent or severe morbidity occurred in 10 (12%) of the surgically treated patients. The average postoperative Glasgow Outcome Scale score for surgically treated patients was 4.5, with a mean follow-up period of 35 months. CONCLUSIONS: The natural history of CMBs is worse than that of cavernous malformations in other locations. These CMBs can be resected using skull base approaches, which should be considered in patients with symptomatic hemorrhage who harbor lesions that approach the pial surface. Venous anomalies are always associated with CMBs and must be preserved.
Adolescent↗
Late angiographic follow-up review of surgically treated aneurysms.
OBJECT: This study was undertaken to evaluate the long-term angiographic outcome of surgically treated aneurysms, which is unknown. Specifically, the incidence of recurrent aneurysms, the fate of residual necks, and the de novo formation of aneurysms were evaluated. METHODS: One hundred two patients (80 females and 22 males; mean age 49 years; range 12-78 years) harboring a total of 167 aneurysms underwent late follow-up angiography; 160 aneurysms were surgically treated. Late angiographic follow-up review was obtained at a mean of 4.4 +/- 1.6 years postsurgery (range 2.6-9.7 years). Late follow-up angiography revealed two recurrent aneurysms (1.5%) of 135 clipped aneurysms without residua. Of 12 aneurysms with known residua, there were eight "dog-ear" residua, of which two (25%) enlarged. One hemorrhage was noted, yielding a hemorrhage risk of 1.9% per year. A second subgroup with broad-based residua revealed dramatic regrowth in three of four cases. Eight de novo aneurysms were found in six patients, for an annual risk of 1.8% per year. A history of multiple aneurysms was associated with de novo aneurysm formation (p = 0.049, chi-square analysis). CONCLUSIONS: This study confirms the long-term efficacy of aneurysm clip ligation. In addition, the authors found there is a small but significant risk of de novo aneurysm formation, particularly in patients with multiple aneurysms. Most residual aneurysm rests appear to remain stable, although a subset may enlarge or rupture. These findings support the rationale for late angiographic follow-up review in patients with aneurysms.
Adolescent↗
Subdural hematoma from a Type I spinal arteriovenous malformation. Case report.
The authors report a patient in whom a subdural hematoma developed from a Type I spinal arteriovenous malformation (AVM). The patient became symptomatic with back pain, and magnetic resonance imaging revealed a spinal subdural hematoma. Selective spinal angiography, however, failed to demonstrate a pathological process. The patient underwent exploratory laminoplasty that revealed a subdural extraarachnoid hematoma with an underlying Type I spinal AVM, which was surgically obliterated. The patient recovered completely. Subdural hematomas that affect the spine are rare. Although a negative result was obtained using selective spinal angiography, exploratory surgery should be considered for the evacuation of a subdural hematoma and possibly for the definitive treatment of a spinal AVM.
Adult↗
Medulloblastoma presenting with tentorial "dural-tail" sign: is the "dural-tail" sign specific for meningioma?
To the best of our knowledge, the association of a medulloblastoma with a "dural-tail" sign has not been previously reported. A 24-year-old male developed severe headaches and right-sided dysmetria that worsened over 1 month. Magnetic resonance (MR) imaging of the brain demonstrated a heterogeneously enhancing lesion in the posterior fossa. The lesion appeared to be tentortally-based and exhibited a characteristic "dural-tail" sign, which is considered pathognothonic for meningioma. Cerebellar tonsil ectopia and hydrocephalus were also present. The presumptive diagnosis of tentorial meningioma was made. The lesion was resected by a posterior fossa approach. At surgery, the appearance of the tumor was inconsistent with the diagnosis of meningioma, and histopathologic evaluation yielded the diagnosis of medulloblastonia. This case and the literature demonstrate that malignant tumors can present with the characteristic MR imaging appearance of a meningioma. This possibility must be considered when treatment is planned, especially if a nonoperative course is favored.
Case Reports↗