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Biomedical subjects

R M Scott

Publications and source records attributed to R M Scott.

At least 271 records · Page 15Linked to original sources
PubMedDate not supplied

201Tl/99mTc-HMPAO SPECT imaging of treated childhood brain tumors.

To assess whether thallium-201 thallous chloride (Tl) can detect childhood tumors and whether diagnostic effectiveness improves with combined blood flow imaging, 28 children (1.0-18.6 years) were studied using single photon emission computed tomography (SPECT): Tl (1.3-1.8 mCi intravenously), followed in 13 of the patients by technetium-99m-hexamethylpropyleneamine oxime (99mTc-HMPAO; 8-18 mCi intravenously). Tl-uptake was markedly increased with histologically confirmed recurrent brain tumors (N = 12). Tl-avid tumors comprised several histologic types, including 6 astrocytomas/gliomas as well as nonastrocytic neoplasms, such as medulloblastoma and ependymoma. A questionable false-positive study was observed with a treated medulloblastoma. Tl failed to detect 5 tumors (i.e., 2 medulloblastomas, 1 ependymoma, 1 malignant schwannoma, and initially 1 low-grade astrocytoma). The sensitivity and specificity of 201Tl-SPECT for detection of childhood brain tumors was 76.9% and 93.3%, respectively. The mean tumor-to-normal brain ratio for Tl was 2.5 +/- 0.5 (N = 7). In some of the patients, 201Tl-SPECT allowed a more precise assessment of the functional state of the tumor than was possible with computed tomography and magnetic resonance imaging. HMPAO distribution was variously normal, increased or decreased at the site of tissue abnormality, and abnormal blood flow was demonstrated in the remaining neuraxis, in 3 of the 7 patients. Changes in tissue perfusion did not correlate with Tl findings, but were evaluated in only one false-negative study.

Adolescent↗
PubMedDate not supplied

Brain stem cavernous angiomas in children.

In an operative series of 20 patients under the age of 18 years with pathologically verified cavernous angiomas, 4 children had cavernous malformations in the pons or midbrain. These patients each presented with an acute or subacute neurologic deficit. None had family histories of similar lesions and only one had multiple lesions. Subtotal resection of the cavernous angioma was carried out in each case because of an inability to visualize and safely resect deep extensions of the malformation. One patient with a midbrain malformation suffered a permanently increased neurologic deficit postoperatively, but 2 of the patients are neurologically normal despite serious preoperative deficits. There has been no long-term rebleeding in these patients after follow-up of 2, 4, 7 and 10 years. These patients demonstrate the unpredictable natural history of certain cavernous malformations located in the brain stem.

Brain Neoplasms↗
PubMedDate not supplied

Clival chondroma in a child with Ollier's disease. Case report.

An 8-year-old female with Ollier's disease (multiple enchondromatosis) developed an intracranial chondroma arising from the clivus, which was diagnosed by both computed tomography and magnetic resonance imaging. The clinical presentation, differential diagnosis, and management of this rare pediatric intracranial tumor are discussed.

Cartilage↗
PubMedDate not supplied

The fellowship in pediatric neurosurgery.

Subspecialty training in pediatric neurosurgery has been a widely discussed topic over the past several years. This paper will discuss the rationale for subspecialization in neurosurgery, describe what makes pediatric neurosurgery unique as a subspecialty area of neurosurgery, and present a rationale for fellowship training in pediatric neurosurgery following the completion of a general residency in neurosurgery. The difference between fellowship and residency training is outlined, and the importance of integrating the fellowship with the neurosurgical training program is emphasized. Controversies regarding structure of the pediatric neurosurgical fellowship, 'certification' of the fellowship training, and issues of supply and demand are reviewed.

Certification↗
PubMedDate not supplied

Effect of surgical repair on the neurologic function in infants with lipomeningocele.

Eighteen children under the age of 1 year underwent surgery for lipomeningocele at our institution between 1983 and 1991. All the patients had neurologic exams and urodynamic studies (UDS) including a cystometrogram and electromyography of the external urethral sphincter pre- and postoperatively. The surgical procedure performed included an untethering of the spinal cord, laser debulking of the lipoma and placement of a dural graft. All the infants presented with a lesion on their back. Two of 10 infants with a normal neurological exam had abnormal UDS preoperatively. Early surgery normalized abnormal preoperative UDS in 5 of 6 (83%) infants with abnormal UDS. Moreover, 3 of 8 (38%) infants with an abnormal neurological exam preoperatively improved after surgery and none worsened. These observations suggest that abnormal urinary tract function in infants with lipomeningocele may be reversible with early prophylactic surgery.

Female↗
PubMedDate not supplied

Effect of intravenous ethanol on cerebral vasospasm produced by subarachnoid blood.

The cat basilar artery was exposed using the transclival approach. After administration of 5% ethanol via intravenous infusion, vasospasm was produced by applying the animal's fresh arterial blood to the exposed artery. The resultant vasospasm was of markedly reduced intensity and duration as compared to vasospasm in control animals. In ethanol-treated animals with spasm induced from non-autogenous fresh arterial bloof free of ethanol, a reduction in the duration of vasospasm was noted although the initial intensity of spasm was similar to control animals. There was no anti-spasm effect if the ethanol infusion followed the production of vasospasm.

Animals↗
PubMedDate not supplied

Auscultation of cervical and ocular bruits in extracranial carotid occlusive disease: a clinical and angiographic study.

The clinical and angiographic features of cervical and ocular bruits were correlated in 50 consecutive patients with severe extracranial internal carotid artery occlusive disease. Cervical bruits, generally localized to the carotid bifurcation, were highly associated (P = 0.004) with "tight" (residual lumen less than or equal to 2 mm) internal carotid artery stenosis, but significantly less often with a widely patent or occluded internal carotid artery. Angiographic features of a "slow-flow" state through a patent, but "tight" stenosis were identified as the apparent explanation for the absence of bruit in some patients. A unilateral ocular bruit contralateral to the side of internal carotid artery occlusion occurred in 9 of 10 patients, more often than an associated cervical bruit, and was interpreted as a sign of augmentation flow.

Arterial Occlusive Diseases↗
PubMedDate not supplied

Limb shaking--a carotid TIA.

Eight patients are described with an unusual form of carotid transient ischemic attack, limb shaking. The basic features included a brief, involuntary, coarse, irregular, wavering movement or tremble involving arm-hand alone, or arm-hand and leg together. In 2 patients limb shaking was the initial manifestation of carotid occlusive disease, and all but one patient had other typical carotid transient ischemic attacks. Major atheromatous carotid occlusive disease was present in all patients on the side opposite the limb movements. Four patients had bilateral carotid occlusive disease. Cerebral ischemia from a carotid territory low-perfusion state may be the pathogenesis of these limb movements, an idea supported by the apparent benefit of surgical revascularization in abolishing or reducing the limb shaking in 6 patients. There was no clinical or EEG evidence to document an epileptiform etiology. Recognition of this uncommon form of carotid transient ischemic attack may be important in the early diagnosis and treatment of carotid occlusive disease.

Adult↗
PubMedDate not supplied

Arachnoiditis and VECP change.

A five-year-old boy presented with tuberculous meningitis and subsequently developed amaurosis with optochiasmatic arachnoiditis (OCA) late in the convalescent stage of the illness. The visual evoked cortical potentials were correlated with the decreased and improved postoperative acuity. The diagnosis and classification of OCA have been discussed with emphasis given to prompt neurosurgical treatment.

Arachnoiditis↗
PubMedDate not supplied

Chiari II malformation.

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Arnold-Chiari Malformation↗