Biomedical subjects
Publications and source records attributed to R M Scott.
Two childhood cases of intracranial melanotic neuroectodermal tumor, one benign and one malignant, are presented. The clinical, radiologic, and pathologic features of these cases are described and the relevant literature is reviewed.
From 1986 to 1991, 12 boys and 23 girls underwent surgery for lipomyelomeningocele removal. Of these patients 29 were 15 months old or younger (average age 3 months), while 6 were 4.5 to 19 years old (average age 10 years). Preoperative and postoperative urodynamic studies, including external urethral sphincter electromyography, were done on everyone. All 29 infants had a cutaneous lesion overlying the lower back and 14 had an abnormal neurological examination. Preoperative urodynamic studies were abnormal in 11 patients, consisting of an upper motor neuron lesion in 6, and a mixed upper and lower motor neuron lesion in 5. Postoperatively, 10 of 14 children with an abnormal neurological examination improved, while 9 of 11 with abnormal lower urinary tract function normalized. In 1 of 18 children (6%) with normal preoperative urodynamic studies detrusor-sphincter dyssynergia developed postoperatively. In all 6 older children urinary incontinence developed, and this led to the diagnosis. Everyone had an abnormal neurological examination and abnormal preoperative urodynamic studies. One child had a lower motor neuron lesion, and 5 had a mixed upper and lower motor neuron lesion. Postoperatively, the neurological examination improved in only 1 patient (16%), and the urological symptoms and urodynamic findings improved in another child. Lipomyelomeningocele has a progressive effect on lower spinal cord function because infants tend to present with fewer urinary manifestations and physical findings than older children. Individuals who escape early detection tend to have a more subtle cutaneous abnormality. As a result, older children are more likely to present with urological and neurological complaints. Surgical correction in infancy provides a degree of reversibility not seen in older children. It is imperative that early identification, evaluation and treatment be undertaken to prevent this progression and permanency of neurological changes and urinary dysfunction.
A small-scale study was carried out on friction and reinforcing materials containing Kevlar and glass fibres. Kevlar, an aramid fibre, and synthetic silicate fibres are being increasingly used in brake pads and shoes for cars and trucks. The fibre levels given out under abrasion in the laboratory were low. As a comparison, a brake pad containing asbestos was also tested and gave high levels of airborne fibres.
A surgical series of 19 patients under the age of 18 years with pathologically verified cavernous angioma is presented. Most lesions were located in the cerebral hemispheres, but four were in the pons or midbrain, two in the diencephalon, and one in the spinal cord. Fourteen patients presented with an acute or progressing neurological deficit, three with seizures, one infant with irritability, and one with headache alone. Five patients had family histories of vascular malformations of the central nervous system, and five had multiple lesions. Surgery for small or deep lesions was aided considerably by intraoperative ultrasonographic or stereotactic localization techniques. Pathological examination of the resected malformations revealed a complex histology containing not only typical closely approximated cavernous vessels, but also areas of marked proliferation of granulation tissue and partially re-endothelialized hemorrhage, suggesting a mechanism for the apparent growth of certain cavernous angiomas. The postoperative results were good, with only one patient suffering a permanent worsening of neurological status after surgery. Incomplete resection was initially carried out in five patients, two of whom rebled within 1 year after operation. Long-term follow-up findings in these patients have emphasized the unusual history of certain of these malformations.
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The authors reviewed 89 patients treated for cerebellar medulloblastoma between 1970 and 1989 to determine the impact of changing treatment (high-dose posterior fossa radiation therapy and chemotherapy) on the pattern of failure in medulloblastoma. Between 1970 and 1983, 50 patients (median follow-up, 110 months) were treated with surgery and postoperative craniospinal irradiation (CSI). Nineteen of the 50 (38%) recurred in the central nervous system (CNS). Isolated systemic (bone) metastases occurred in six. The median time to the development of bone metastases was 12 months. Since 1984, 39 patients (median follow-up, 27 months) were treated with preradiation chemotherapy consisting of cisplatin and vincristine for 9 weeks before initiation of CSI. Nine of the 39 (23%) patients recurred in the CNS. There were no systemic failures in this cohort. The actuarial 5-year disease-free survival was 55 +/- 7% for the earlier cohort and 72 +/- 8% for the later cohort (P equals 0.3). Posterior fossa recurrence was associated with radiation therapy to this area. The cumulative incidence of posterior fossa relapse was 50 +/- 13% in patients who received less than 5300 cGy and 18 +/- 7% in those who received 5300 cGy or more (P equals 0.005). All six bone relapses were in patients treated with CSI alone and 5300 cGy or more to the posterior fossa for a 5-year cumulative incidence of bone metastases of 18 +/- 7% compared with 0% for patients treated with 5300 cGy or more and chemotherapy (P equals 0.03). The authors concluded that high-dose radiation therapy has altered the pattern of relapse with an increase in systemic recurrence after radiation therapy alone that is now equivalent to the risk of recurrence in the posterior fossa. Chemotherapy may be indicated in an attempt to decrease this high risk of systemic metastases.
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Between 1970 and 1989, 29 patients with intracranial ependymomas were evaluated and treated at the Children's Hospital in Boston. With a median follow-up of 82 months, the actuarial survival rates at 5 and 10 years were 61 +/- 10% and 46 +/- 12%, respectively. Anaplastic histological findings were uncommon (2 of 29). Initial postoperative radiotherapy was given to 25 patients, with a median tumor dose of 5360 cGy. With a median time to recurrence of 22 months, local failure (within 2 cm of original enhancing mass) was the predominant pattern of relapse (15 of 16 failures). The presence of radiographic residual disease seen on postoperative magnetic resonance imaging or computed tomographic scans was the most important prognostic variable for patients with intracranial ependymoma. Analysis of the 19 patients who underwent postoperative imaging revealed a 75 +/- 15% 5-year freedom from progressive disease for 9 patients with no residual disease, as compared with 0% freedom from progressive disease for the 10 patients with gross residual disease (P = 0.03). In contrast, the surgical assessment of residual disease was not significant (P = 0.4). Age at presentation was also a significant prognostic factor. The overall actuarial survival rate at 12 years for infants 24 months or younger at diagnosis was 0%, as compared with 62 +/- 13% for older patients (P = 0.03). For non-anaplastic ependymomas, complete surgical resection followed by local-field, high-dose (greater than 54 Gy) radiotherapy appears to offer the greatest chance for long-term survival. Because of the markedly reduced survival rate for patients with radiologically apparent postoperative disease, maximal surgical resection and novel therapeutic endeavors appear warranted for this high-risk group. Future protocols should use postoperative imaging, not operative reports, to stratify patients with ependymoma.
We describe a transfalcine approach to clipping and subsequently excising an expanding mycotic callosomarginal aneurysm. The patient had a devastating dominant (left) hemispheric spontaneous intracranial hemorrhage and was neurologically improving at the time of surgery nearly 2 months later. To avoid retracting the left hemisphere, we approached this left callosomarginal aneurysm from the nondominant side through the falx. The approach was straight-forward, and the result was satisfactory.
Moyamoya disease is an idiopathic disorder characterized by progressive occlusion of the internal carotid and anterior and middle cerebral arteries, with formation of an extensive abnormal collateral circulation at the base of the brain. Many neurosurgical procedures have been designed to bypass these occluded vessels. The results of one of these procedures, modified encephaloduroarteriosynangiosis was reviewed in five children followed for 3 1/2 to 19 1/2 years. Modified encephaloduroarteriosynangiosis performed unilaterally in one and bilaterally in four of the children, appeared to halt neurologic deterioration, despite angiographic progression, in four of the five children.
Choroid plexus neoplasms are rare epithelial tumors of the central nervous system. A carcinoma of the choroid plexus occurred in a child from a family with the breast cancer-sarcoma syndrome (Li-Fraumeni or SBLA syndrome), an inherited condition characterized by the development of diverse neoplasms (sarcoma, breast cancer, brain tumors, leukemia, adrenal cortical carcinoma, and others). Choroid plexus carcinomas were identified in two kindreds previously reported with the syndrome. The literature contains reports of choroid plexus neoplasms occurring in families and in individuals with multiple primary tumors. Choroid plexus neoplasm may be a manifestation of the inherited proclivity to tumor development in the breast cancer-sarcoma syndrome.
We report on two patients in whom cervical myelopathy developed decades after they had undergone surgery for congenital cervical cutaneous lesions. Preoperative magnetic resonance imaging demonstrated dorsal tethering and cavitation of the cervical cord in the area of the previous surgery and was helpful in decision making regarding surgical exploration and in planning for it. We stress the importance of long-term follow-up by both clinical examination and magnetic resonance imaging in children who have been operated on for cervical cutaneous masses that may have central connections.
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To determine safety and immunogenicity, a single 0.5 ml dose of a monovalent live-attenuated dengue (DEN) 4 (341750 Carib) vaccine was given sc to 3 groups of flavivirus nonimmune volunteers in increasing concentrations. Two recipients received 10(3) plaque forming units (PFU)/dose (1:100 dilution of stock vaccine). One remained asymptomatic, but became viremic between days 12 and 15, experienced a mild elevation of temperature (37.4 degrees C), and developed DEN-4 specific antibody. Neither recipient of the 10(4) PFU became infected. Eight volunteers then received undiluted vaccine (10(5) PFU). Viremia and antibody (neutralizing, hemagglutination inhibition, and IgM) developed in 5 of the 8 (63%). These 5 volunteers also developed a scarcely noticeable macular, blanching rash and minimal temperature elevations (37.3, 38.1, 37, 37.9, and 37.9 degrees C). Clinically insignificant decreases in total white blood cell, lymphocyte, and polymorphonuclear cell counts and an elevation in mononuclear cell counts occurred in association with viremia. This vaccine is safe, reasonably immunogenic, and suitable for further evaluation.
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Extracranial internal carotid artery occlusive disease usually produces stroke in the middle cerebral artery territory or the border zone between the middle and anterior cerebral arteries. It is unusual for occipital infarction in the posterior cerebral artery territory to be caused by internal carotid artery disease despite the fact that the posterior cerebral artery may arise directly from the internal carotid artery as an anatomic variation. We describe a patient with a fetal posterior cerebral artery originating from the internal carotid artery, and the initial manifestation of his extracranial internal carotid artery occlusive disease was hemianopsia from occipital infarction.