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Biomedical subjects

R L Robertson

Publications and source records attributed to R L Robertson.

At least 37 records · Page 2Linked to original sources
PubMed1998

Neurologic complications of cerebral angiography in childhood moyamoya syndrome.

Purpose. To determine the incidence of neurologic complications of cerebral angiography in children with moyamoya syndrome (MMS) as compared to children without MMS. Materials and methods. One-hundred-ninety consecutive cerebral angiograms obtained in 152 children were evaluated. Sixty of these angiograms were obtained in 40 children with MMS. Patients underwent neurologic evaluation prior to and after the procedure. For this study, a neurologic complication was defined as any new focal neurologic deficit or alteration in mental status occurring during the procedure or within the ensuing 24 hours. Results. There were 2 neurologic complications within 24 hours of angiography, one in the MMS group and one in the non-MMS group. One patient with MMS became mute following angiography. The symptom resolved within 12 hours. One patient without MMS being examined postoperatively for residual arteriovenous malformation developed intracranial hemorrhage requiring reexploration 12 hours after the angiogram. Using a two-tail Fisher's exact test, there was no significant statistical difference in the ischemic (P = 0.3) or hemorrhagic (P = 1.0) complication rates between the group of patients with MMS and the non-MMS groups. Conclusion. The risk of a neurologic complication from cerebral angiography in children with MMS is low and not statistically different from the risk in children with other cerebrovascular disorders.

Adolescent↗
PubMed1998

Diagnostic imaging in the evaluation of vascular birthmarks.

This article reviews the role of modern diagnostic imaging in the evaluation of patients with vascular birthmarks. There are two main categories of vascular anomalies: hemangiomas and vascular malformations. The findings on plain radiography, sonography, computed tomography (CT), magnetic resonance imaging (MRI) and angiography, and the appropriate sequence of investigation for the different vascular anomalies are discussed.

Adolescent↗
PubMed1998

Cerebral vasculopathy and neurologic sequelae in infants with cervicofacial hemangioma: report of eight patients.

PURPOSE: To determine the association of cerebral arterial anomalies and progressive cerebral arterial occlusive disease in infants with facial hemangiomas. MATERIALS AND METHODS: The cases of eight infants (seven girls and one boy) with the diagnosis of cervicofacial hemangioma and intracranial arterial anomalies were reviewed retrospectively. Findings from clinical and imaging examinations--including cranial computed tomography, magnetic resonance imaging and angiography, and catheter angiography--were evaluated. Serial imaging findings were studied to document progressive intracranial vascular changes. RESULTS: Five patients had additional associated congenital anomalies. Seven were treated with corticosteroids, interferon alfa-2a, or both. Progressive cerebrovascular occlusive changes were documented in four of the seven patients with serial imaging findings. Four other patients (all treated pharmacologically) had MR imaging documentation of cerebral infarction, and all had consistent, acquired neurologic symptoms. CONCLUSION: Intracranial arterial anomalies can coexist with cervicofacial hemangioma. Aneurysmal and occlusive changes are potentially progressive and can result in cerebral infarction. A causative association between occlusive cerebrovascular disease and pharmacologic treatment has not been excluded.

Abnormalities, Multiple↗
PubMed1998

Surgical management of cutis aplasia with high-flow sinus pericranii.

Cutis aplasia (cutis aplasia congenita cystica) is a rare congenital disorder with failure of completion of the extracerebral coverings, involving a defect in the scalp and often a cranial defect. A case of cutis aplasia is reported with an associated high-flow venous fistula or sinus pericranii, resulting in altered venous drainage of sagittal sinus blood through dilated scalp veins. Radiological workup to ensure patency of the superior sagittal sinus was critical to the surgical management in this case.

Adult↗
PubMed1998

Neonatal central nervous system vascular disorders.

Central nervous system vascular disorders in the neonate comprise structural anomalies or malformations of arteries and veins and physiologic alterations of cerebral blood flow, which can mimic structural vascular disease. Clinical , imaging, and transcatheter therapeutic aspects of neonatal cerebral vascular malformations are described. Symptomatic high-flow vascular malformations characteristically present with cardiac failure and associated systemic problems in the neonate, whereas infants typically present with macrocephaly and hydrocephalus and older children with hemorrhage, developmental delay, or focal deficits. Neonatal cerebral hemorrhage is typically primary or associated with immaturity, parturitional trauma, or coagulopathy. Likewise, cerebral ischemic lesions are more likely secondary to hypoxic, ischemic events than to thromboembolic or structural cerebrovascular occlusive disease. The role of the current noninvasive imaging modalities in each of these clinical problems is reviewed and illustrated.

Cerebral Angiography↗
PubMed1998

Efficacy of fast screening MR in children and adolescents with suspected intracranial tumors.

PURPOSE: Our purpose was to determine the sensitivity, specificity, and receiver operator characteristic (ROC) curve of a fast screening MR protocol in children and adolescents with suspected intracranial tumors. METHODS: One hundred forty-one patients (mean age, 9.7 years; range, 2 months to 23.5 years) with suspected brain tumor were entered in a case-control study. Eighty-seven patients had intracranial tumors (31 suprasellar/hypothalamic, 27 supratentorial, 26 infratentorial, and three pineal) and 54 patients in the control group had other disorders. Two neuroradiologists reviewed blindly a detailed three-sequence conventional protocol (acquisition time, 8 minutes 27 seconds) and a two-sequence fast screening MR protocol (acquisition time, 4 minutes 44 seconds). RESULTS: Sensitivity and specificity of the fast screening protocol for intracranial tumors was 100% and 92.6%, respectively. The areas under the ROC curves were 0.966 for the fast screening and 0.980 for the conventional MR protocol. No diagnostic performance difference was found between the ROC curves using the Az index. A kappa statistic of .93 for both examinations indicated excellent interobserver agreement. Additional MR sequences and other neuroimaging studies were not deemed necessary to exclude the presence of an intracranial tumor. CONCLUSION: A fast dual-plane brain MR protocol may be adequate to screen children and adolescents thought to have an intracranial tumor. The less than 5 minute acquisition time allows a complete examination (including preparation) to be performed in 10 to 15 minutes. Future studies are recommended before this time-efficient neuroimaging examination is incorporated into clinical practice.

Adolescent↗
PubMed1997

Childhood moyamoya disease: hemodynamic MRI.

BACKGROUND: Childhood moyamoya disease is a rare progressive cerebrovascular disease. OBJECTIVE: To evaluate cerebral hemodynamics using dynamic Gd-DTPA-enhanced imaging in children with moyamoya disease. MATERIALS AND METHODS: Eight children (2-11 years of age) with the clinical and angiographic findings typical of moyamoya disease, before and/or after surgical intervention (pial synangiosis), underwent conventional MR imaging (MRI) and hemodynamic MR imaging (HMRI). HMRI used a spoiled gradient-echo with low flip angle (10 deg) and long TE (TR/TE = 24/15 ms) to minimize T 1 effects and emphasize T 2* weighting. Raw and calculated hemodynamic images were reviewed. Three-dimensional time-of-flight MR angiography (MRA) and perfusion brain single photon emission computed tomography (SPECT) were also performed. RESULTS: Abnormal hemodynamic maps resulting from vascular stenosis or occlusion and basal collaterals were observed in six patient studies. HMRI depicted perfusion dynamics of affected cerebrovascular territories, detected cortical perfusion deficits, and complemented conventional MRI and MRA. HMRI findings were consistent with those of catheter angiography and perfusion SPECT. CONCLUSION: Our preliminary experience suggests that HMRI may be of value in the preoperative and postoperative evaluation of surgical interventions in moyamoya disease.

Brain↗
PubMed1997

Thrombocytopenic coagulopathy (Kasabach-Merritt phenomenon) is associated with Kaposiform hemangioendothelioma and not with common infantile hemangioma.

Children with a large vascular tumor and associated Kasabach-Merritt coagulopathy respond inconsistently to therapy and have a high mortality rate. For this reason, we undertook a retrospective study of 21 such patients, and focused on clinical, radiographic, and histopathologic features. The male to female ratio was 1:1.6. Tumor was noted at birth in 50 percent of patients; the remainder appeared throughout infancy. The location was cervicofacial (n = 2), shoulder/upper limb (n = 4), trunk including retroperitoneum (n = 11), and lower limb (n = 4). These tumors grew rapidly to large size and were characterized by cutaneous purpura, edema, and an advancing ecchymotic margin. In contrast to common hemangioma, magnetic resonance imaging showed diffuse enhancement with ill-defined margins, cutaneous thickening, stranding of subcutaneous fat, hemosiderin deposits, and small feeding and draining vessels. All tumors were Kaposiform hemangioendothelioma (KHE); none were infantile hemangioma. Light microscopy showed irregular lobules or sheets of poorly formed, small vascular channels infiltrating and entrapping normal tissues. Characteristic features included spindle-shaped endothelial cells, diminished pericytes and mast cells, microthrombi, and hemosiderin deposits. Wide endothelial intercellular gaps and incomplete basement membranes were seen by electron microscopy. Dilated, hyperplastic, lymphaticoid channels were prominent in one tumor. KHE in 14 infants was treated with interferon alpha-2a: 6 had accelerated regression; 2 had stabilization of growth; and 6 evidenced no response. The mortality rate was 24 percent (5 of 21); this included three infants with retroperitoneal KHE. Kasabach-Merritt phenomenon does not occur with common hemangioma. Rather it is associated with the more aggressive KHE and rarely with other vascular neoplasms. Variable response to current pharmacologic therapy underscores our inadequate knowledge of the pathogenesis of thrombocytopenia in KHE.

Adipose Tissue↗
PubMed1997

Elevation of cerebrospinal fluid levels of basic fibroblast growth factor in moyamoya and central nervous system disorders.

Moyamoya syndrome is a vaso-occlusive disease involving the intracranial vessels of the circle of Willis which is accompanied by an intense compensatory recruitment of new vessels. Angiogenic substances such as basic fibroblast growth factor (bFGF) present in the cerebrospinal fluid (CSF) have been proposed as possible mediators of the neovascular response. We analyzed CSF samples collected intraoperatively from predominantly pediatric patients with moyamoya and other conditions such as Chiari malformation (Ch), tethered cord (TC), arteriovenous malformation (AVM), brain tumor (BT) and hydrocephalus (HCP). We found that CSF bFGF was significantly elevated in patients with moyamoya (141 pg/ml, n = 37), Ch (56.7 pg/ml, n = 22), TC (55.1 pg/ml, n = 23), AVM (354 pg/ml, n = 5), and BT (208 pg/ml, n = 5) compared to patients with HCP (5.5 pg/ml, n = 7) and controls (1.6 pg/ml, n = 25; p < 0.05). There was no dependence of CSF bFGF on patient age or gender. Although CSF bFGF in the moyamoya group showed no correlation with the Suzuki radiographic stage at either pre- or post-operative (1-year follow-up) angiography, it showed a trend with the Matsushima angiographic score with increasing collateral vascularization from the synangiosis developing at higher levels of CSF bFGF. Our findings suggest that CSF bFGF may be playing a wide-ranging role in a number of central nervous system conditions associated with ischemia and hypervascularity. Although not a specific marker for moyamoya, elevated CSF bFGF may serve as a weak predictor of the extent of angiogenesis to be expected in indirect revascularization procedures.

Adolescent↗
PubMed1997

Angiographic changes after pial synangiosis in childhood moyamoya disease.

PURPOSE: To describe the angiographic changes accompanying the surgical treatment of moyamoya disease by pial synangiosis and to compare these changes with patient outcome. METHODS: The preoperative and postoperative cerebral angiograms, MR images, and clinical records of 13 children treated with pial synangiosis for moyamoya disease were reviewed. RESULTS: After synangiosis, 10 patients had significant neurologic improvement and three had minimal or no improvement. Postoperative MR images showed no new infarctions. Well-developed (grade A or B) transpial or transdural collaterals to the brain were present at the site of synangiosis in 84% of the surgically treated hemispheres. Cerebrovascular occlusive changes increased postoperatively in 76% of hemispheres. After synangiosis, moyamoya collaterals were increased in 48%, unchanged in 16%, and decreased in 36% of surgically treated hemispheres. All 10 patients with grade A or B collaterals bilaterally after synangiosis were asymptomatic or improved on follow-up. CONCLUSION: Pial synangiosis typically results in an increase in collaterals from the superficial temporal artery or middle meningeal artery to the brain. Synangiosis appears to result in stabilization or improvement in neurologic symptoms but does not prevent the angiographic progression of disease or the development of moyamoya collaterals. The angiographic demonstration of well-formed collaterals after synangiosis is associated with a favorable clinical outcome.

Adolescent↗
PubMed1996

Moyamoya and Down syndrome. Clinical and radiological features.

BACKGROUND AND PURPOSE: Moyamoya disease is a chronic occlusive cerebrovascular disorder characterized by progressive stenosis of the supraclinoid internal carotid artery, with the secondary development of enlarged basal collateral vessels. It may occur as a primary disease or as a syndrome in association with a variety of conditions, and its pathogenesis remains unexplained. There are relatively few reports describing the occurrence of moyamoya in Down syndrome. The aim of this study is to describe the clinical and radiological features of moyamoya syndrome associated with Down syndrome (MM-DS) and to explore theories of moyamoya pathogenesis in these patients. METHODS: Seven children with MM-DS underwent brain imaging, transfemoral angiography, and serial neurological exams. Neurological deficits, poststroke recovery, radiographic infarct characteristics, and angiographic abnormalities were reviewed. RESULTS: The clinical and radiological features of primary moyamoya disease overlap with those of MM-DS. Hemiplegia and aphasia were the most common presentations. Motor recovery was excellent in five of seven cases. Cerebral infarcts were superficial or deep and can occur in a watershed distribution. Angiography demonstrated involvement of the internal carotid artery and its branches bilaterally in all seven cases and the posterior cerebral arteries in four cases. CONCLUSIONS: The clinical and radiological features of MM-DS overlap with primary moyamoya disease. We postulate that a protein encoded on chromosome 21 may be related to the pathogenesis of moyamoya disease. Although the neuronal substrate is abnormal in Down syndrome patients, recovery from hemiplegic stroke in patients with MM-DS is comparable to recovery in patients with primary moyamoya.

Adolescent↗
PubMed1996

Angiography and the evaluation of cerebrovascular disease in childhood.

This article outlines indications and techniques for and findings on angiography in pediatric cerebrovascular disease. The clinical entities described and illustrated include extracranial and intracranial pediatric vascular anomalies (hemangiomas and vascular malformations), pediatric aneurysms and occlusive cerebrovascular disease. Features specific to or more common in children are emphasized.

Blood Flow Velocity↗
PubMed1996

Pediatric orbital and visual pathway lesions.

This article presents the clinical and imaging aspects of some common and important orbital and optic pathway lesions occurring in childhood. Lesions that arise outside of and encroach on the orbit and visual pathways are included. Abnormalities intrinsic to the globe are covered elsewhere in this issue.

Adolescent↗
PubMed1994

Lupus-related myelitis: serial MR findings.

PURPOSE: To correlate the MR findings in transverse myelitis secondary to systemic lupus erythematosus with clinical findings during disease exacerbation and remission. METHODS: Four patients (ages 33 to 47 years) with episodes of transverse myelitis secondary to systemic lupus erythematosus were identified. Three patients had recurrent transverse myelitis episodes (one patient with two recurrences), for a total of eight episodes. MR examinations (six after contrast administration) were performed during each transverse myelitis episode, as well as during four periods of remission (in three patients) after therapy with steroids and/or immunosuppressive agents. MR examinations were reviewed for the presence of spinal cord enlargement, intramedullary signal abnormality, and contrast enhancement. RESULTS: Prolongation of T1 or T2 signal (or both) was seen in eight episodes (100%). Spinal cord enlargement was seen in six (75%) of eight transverse myelitis episodes, although it was mild during two episodes. Contrast enhancement was seen in three of six transverse myelitis episodes (dense, inhomogeneous enhancement during two episodes in one patient, and a small focus of enhancement in one patient). During periods of remission, spinal cord diameter returned to normal, and no contrast enhancement was seen, although abnormal signal was present in three examinations performed within 2 months of a transverse myelitis episode. CONCLUSION: Spinal cord widening and signal abnormalities are common MR findings during episodes of transverse myelitis related to systemic lupus erythematosus, and contrast enhancement is less frequently seen. Improvement or resolution of these findings correlates with clinical improvement.

Adrenal Cortex Hormones↗
PubMed1994

Normal anatomy of the skull base.

CT and MR imaging increasingly are being used for the evaluation of the skull base. New innovative techniques have revolutionized radiologic understanding of normal skull base anatomy. Thus, normal anatomic relationships with radiographic correlation are vital for accurate pathologic assessment.

Humans↗
PubMed1991

Primary health services in Ecuador: comparative costs, quality, and equity of care in Ministry of Health and rural social security facilities.

This study of costs, quality and financial equity of primary health services in Ecuador, based on 1985 data, examines three assumptions, common in international health, concerning Ministry of Health (MOH) and Social Security (SS) programs. The assumptions are that MOH services are less costly than SS services, that they are of lower quality than SS services, and that MOH programs are more equitable in terms of the distribution of funds available for PHC among different population groups. Full costs of a range of primary health services were estimated by standard accounting techniques for 15 typical health care establishments, 8 operated by the MOH and 7 by the rural SS program (RSSP), serving rural and peri-urban populations in the two major geographical regions of Ecuador. Consistent with the conventional premise, MOH average costs were much lower than RSSP costs for several important types of services, especially those provided by physicians. Little difference was found for dental care. The lower MOH physician service costs appeared to be attributable primarily to lower personnel compensation (only partially offset by lesser productivity) and to greater economies of scope. Several measures of the quality of care were applied, with varying results. Based on staff differences and patterns of expenditures on resource inputs, notably drugs, RSSP quality appeared higher, as assumed. However, contrary to expectation, a questionnaire assessment of staff knowledge and procedures favored the MOH for quality. Program equity was judged in terms of per capita budgeted expenditures (additional measures, such as the likelihood of receiving necessary care, would have required household survey data beyond the scope of this program-based study). The results support the assumption of greater MOH financial equity, as its program reveals less variation in budgeted expenditures between different population groups covered. Additional evidence of equity, using other indicators, would be helpful in future research. The paper's findings have policy implications not only for Ecuador's health sector but also for policy-makers in other countries at similar levels of socioeconomic development. These implications are spelled out in order to guide officials wrestling with issues of efficiency, quality, and equity as they search for the best use of scarce resources to promote health.

Costs and Cost Analysis↗