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Biomedical subjects

R M Scott

Publications and source records attributed to R M Scott.

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

The socioeconomic impact of hepatitis E in Nepal.

Hepatitis E disease is responsible for substantial morbidity in Nepal. A socioeconomic analysis was performed to describe the costs and the effects of hepatitis E disease (HE) on health status in a Nepalese population living in the Kathmandu Valley. A modified health status index was used to quantify healthy days lost associated with HE. One hundred thirty-four individuals recently recovered from HE were interviewed in June 1998. The median age was 22 years and 60% were female. Study participants were sick and bedridden for a median of 22 and 10 days, respectively. The median healthy days lost per individual was 35 (768,000 total per region). The median cost of illness per individual, including direct and indirect, was $37 ($1,238,676 total per region). The percentage of yearly income lost for wage earners totaled 19.4%. Hepatitis E disease is associated with significant costs and loss of healthy days in Nepal. Further research is warranted to understand and limit this common disease.

Adolescent↗
PubMed1999

Management of cavernous malformations in the pediatric population.

The management of cavernous malformations (CMs) in a child is similar in many ways to that of CMs in an adult. There are specific general principles that need to be considered when approaching these lesions in children, however. The long life span anticipated in the pediatric patient may favor an aggressive surgical approach for single, small asymptomatic cavernous malformations or for certain symptomatic lesions in eloquent locations. The observed history of a given malformation may be the best guide to determine its treatment. The authors discuss some of these principles and review their experience with a series of children who have presented for management of cerebral CM.

Adolescent↗
PubMed1998

Moyamoya syndrome associated with cocaine abuse. Case report.

The authors report the case of a 30-year-old woman who was a long-term intranasal cocaine abuser and who presented with transient ischemic attacks and multiple cerebral infarctions that were associated with moyamoya syndrome. The authors suggest that, because of its sympathomimetic effects, chronic cocaine use may promote intracranial arterial stenosis, distal ischemia, and subsequent formation of moyamoya-like vessels. The patient has remained clinically stable with no new episodes of stroke 6 years after undergoing "pial synangiosis" (modified encephaloduroarteriosynangiosis) to revascularize both hemispheres. Cocaine abuse may lead to moyamoya syndrome and may represent a chronic effect on the cerebral vasculature.

Journal Article↗
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

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

Papillary glioneuronal tumor: a new variant of mixed neuronal-glial neoplasm.

We describe the clinicopathologic features of nine cases of a unique papillary glioneuronal tumor (PGNT) exhibiting astrocytic as well as extensive and varied neuronal differentiation. The four male and five female patients studied ranged in age from 11 to 52 years (mean 27.7 years). They either presented with mild neurologic symptoms or were asymptomatic. Magnetic resonance imaging showed demarcated cystic, 1.5-cm to 7-cm contrast-enhancing masses; five involved the temporal lobe, two the parietal, and two the frontal. All but one were totally resected. No recurrence was noted despite a follow-up period of 3 years. Two microscopic components were evident: 1) compact pseudopapillae composed of hyalinized vessels covered by a single layer of glial fibrillary acid protein (GFAP)-positive astrocytes and 2) synaptophysin-positive neuronal cells of varying size, including neurocytes, ganglioid cells, and ganglion cells within neuropil. Immunostains for chromogranin-A were negative, as was in situ hybridization for chromogranin-A mRNA. Ultrastructurally, neuronal cells featured microtubule-containing processes and aberrant synaptic terminals, but dense core granules were rare. Overall, cellularity was moderate and atypia was minimal. No mitotic activity or necrosis was noted. The proportions of the two components varied, but essential morphologic findings were identical in all cases. In that the clinical, radiographic, and morphologic characteristics of PGNT are distinctive, it appears to represent a previously undescribed form of mixed neuronal-glial tumor of the central nervous system.

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

Focal cortical dysplasia with glioproliferative changes causing seizures: report of 3 cases.

In contrast to neoplasia, lesions of focal cerebral dysplasia are thought to be completed developmental processes of abnormal neuronal migration. We present three children with seizures resulting from brain lesions which pathologically demonstrate regions of both clearcut focal cortical dysplasia and also hypercellularity and monomorphism typical of proliferative lesions such as low grade glial tumor. These cases suggest the existence of a distinct subgroup of patients with prominent glioproliferative changes in association with focal cortical dysplasia, challenging the conventional dichotomy between dysplastic and proliferative categories of brain lesions. Recognition of patients with dual pathology may be of practical as well as theoretical importance.

Brain Neoplasms↗
PubMed1998

Familial intracranial arteriovenous malformations. Case report and review of the literature.

Familial intracranial arteriovenous malformations (AVMs) are rare. We describe a father and son both presenting in childhood with cerebral AVMs. Both patients underwent successful surgical extirpation of the AVM. Familial AVMs present at a young age and tend to be multiple, as was the case in one of our patients. Imaging of asymptomatic family members may detect previously undiagnosed AVMs, and we recommend screening of the relatives of patients with a strong family history of such lesions.

Adolescent↗
PubMed1998

Surgical management of neonatal hydrocephalus.

Maintenance of normal intracranial pressure is crucial to the development of the neonatal brain. Certainly, neonatal hydrocephalus will perturb cerebral development and calls for careful and timely intervention. Many competing factors must be taken into account when evaluating the neonate with hydrocephalus. A neurosurgical approach to the management of neonatal hydrocephalus is presented with emphasis on practical treatment paradigms.

Cerebral Hemorrhage↗
PubMed1997

Childhood optic chiasm gliomas: radiographic response following radiotherapy and long-term clinical outcome.

PURPOSE: In children with chiasmal gliomas, radiation therapy can arrest progressive visual and neurologic impairment. We examined the radiographic response and clinical outcomes after irradiation. METHODS AND MATERIALS: Forty-two children (median age at diagnosis, 6.6 years) with chiasmal gliomas were managed as follows: 11 asymptomatic patients with neurofibromatosis-1 (NF-1) were observed only; 2 patients, less than 3 years old, underwent surgery and chemotherapy to delay irradiation; and 29 patients with progressive disease received radiation with or without prior surgery or chemotherapy. Time to radiographic response, long-term tumor control and late sequelae were reviewed for the 29 irradiated patients. RESULTS: The probability of at least 50% radiographic response at 24 months after irradiation was 18.1% and increased to 38.2% by 48 months and 45.9% by 60 months. By actuarial analysis, the median time for such radiographic response was 62 months. For the 29 irradiated patients, the 10-year freedom from progression and overall survival rates were 100% and 89%, respectively (median follow-up for surviving patients, 108 months). Stabilization or improvement in vision occurred in 81% of 26 evaluable irradiated patients. CONCLUSIONS: Notable radiographic response may be observed years after irradiation. Radiation therapy provides excellent long-term tumor control and vision preservation or improvement in the majority of patients with progressive chiasmal gliomas.

Adolescent↗
PubMed1997

Intracranial germinoma: the case for lower dose radiation therapy.

PURPOSE: To determine the optimal dose and treatment outcome of patients treated with radiation for intracranial germinoma. METHODS AND MATERIALS: Between 1975 and 1995, 40 patients with the diagnosis of intracranial germinoma were treated with radiation (RT) to the central nervous system. All patients received whole-brain (WB) RT (median dose: 32.4 Gy, range: 15-44.37 Gy) and a boost to the tumor volume (median total tumor volume dose: 52 Gy, range: 45-59.5 Gy). Thirty patients received RT to the spine (median dose: 26 Gy, range: 18.75-37.5 Gy). Four patients were treated with cisplatin-based chemotherapy and WB RT with a boost to the tumor volume (dose range: 51-54 Gy). A low-dose RT only group was defined as < or = 25.5 Gy to the WB (9 patients); < 50 Gy to the primary site (14 patients); and < 22 Gy to the spine (9 patients). Seventeen tumors were biopsy-proven germinoma, and 17 patients presented with multiple midline germinomas (MMG). Among 26 patients who had tumor markers measured, 27% had elevation of beta-human chorionic gonadotropin and by definition, no patient had an elevation of AFP. Twenty-four percent of 26 patients who had spine imaging or cerebral spinal fluid cytology had evidence of tumor seeding at diagnosis. The male to female ratio was 1.9:1. Median age at diagnosis was 14 years for male patients and 9.5 years for female patients (p = 0.02), (overall age ranges: 0.5-31 years). Median follow-up was 62 months (range: 3-226 months). Late effects of 29 patients with follow-up of > or = 20 months and adequate documentation in their medical records were analyzed. RESULTS: The 5-year actuarial rate of disease-free survival (DFS) and overall survival (OS) for biopsy-proven germinomas and presumed germinomas was 97%. No patient died of germinoma. There were no local failures regardless of the dose of RT, elevation of HCG tumor marker, or CSF dissemination at presentation. At presentation 22 patients had evidence of at least one endocrine abnormality. At follow-up there were no new patients diagnosed with an endocrine abnormality; however, 13 out of 22 patients had an increase in the number of endocrine deficiencies requiring hormone replacement. At presentation, 14 patients showed evidence of growth retardation. At follow-up there were no new cases of growth failure in the remaining patients. CONCLUSIONS: Germinomas are highly curable with RT alone. Lower doses of RT to the craniospinal axis without chemotherapy appear to produce equally effective DFS and OS as do higher doses of RT or combination chemotherapy and RT. Craniospinal RT may be indicated for patients with MMG or patients with evidence of spinal seeding. Long-term effects of growth retardation, and other endocrine deficiencies appear to be correlated with disease at presentation rather than solely with treatment.

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↗