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Biomedical subjects

D A Bruce

Publications and source records attributed to D A Bruce.

At least 91 records · Page 5Linked to original sources
PubMed1981

Improved relapse-free survival in medulloblastoma utilizing modern techniques.

Between 1969 and 1979, 22 patients with medulloblastoma were treated by the same surgical group and radiation therapy group. The patients were divided into two groups because of the clinical availability in December 1974 of the computed tomographic (CT) scanner and of the operating microscope used in the initial surgical procedure. There were 11 patients in each group. The percentage of patients with a relapse-free survival in the group treated between 1969 and 1974 (Group 1) was 38% at 4 years. The survival in the 11 patients treated between 1974 and 1979 (Group 2) was 84% at 4 years. This improvement is statistically significant (P less than or equal to 0.001). All patients received the same dose of radiation. Efforts to minimize the tumor burden by total surgical resection did not increase postoperative morbidity or mortality. These results are discussed, along with the relative impact of the CT scan, total resection at operation, and increased focus for radiation therapy on the improved outcome.

Cerebellar Neoplasms↗
PubMed1981

Diffuse cerebral swelling following head injuries in children: the syndrome of "malignant brain edema".

The commonest initial computerized tomography (CT) finding in head-injured children is bilateral diffuse cerebral swelling. Cerebral blood flow and CT density studies suggest that this swelling is due to cerebral hyperemia and increased blood volume, not to edema. The clinical history, course, and outcome of 63 children with this CT pattern are reviewed. Fourteen children had a Glasgow Coma Scale score of greater than 8; all made a complete recovery and follow-up CT scans were normal. Forty-nine children had Glasgow Coma Scale scores of 8 or less. Fifteen had a history of a lucid period following the initial unconsciousness. One of these children died of delayed brain swelling, the others recovered well with minimal neurological deficit. Thirty-four children were rendered immediately and continuously unconscious. There was a high incidence of second lesions on the CT scan, 50% of this group developed intracranial hypertension and five died. All of the others were in coma for periods ranging from weeks to months. Follow-up CT scans showed an extracerebral collection with a density of cerebrospinal fluid in 27% of the patients, and ventriculomegaly with large sulci in 35%, whereas this pattern was seen only once in those with a lucid period. The difference between those with and without a lucid period is related to the degree of primary diffuse impact injury to the white matter.

Adolescent↗
PubMed1980

Pediatric brain stem gliomas.

Sixty-two pediatric patients with brain stem glioma diagnosed between 1964 and 1978 have been reviewed. Posterior fossa eploration was performed on 53% of the patients. Pathology was obtained by biopsy in 58% of those explored. Fifty-four patients had definitive radiation therapy with a median dose of 5000 rads. The actuarial five-year survival for the entire group is 30%. A pathologic diagnosis was available from necropsy or biopsy on 36 of the 62 patients. One-half had malignant tumors, and none survived more than 16 months. The remaining patients with well-differentiated gliomas had five-year actuarial survival of 55%. The use of computed tomography (CT) has been found to be valuable in diagnosis and follow-up, as well as in the design of radiation therapy portals. The data demonstrate no dose response curve. We recommend local radiation therapy of 5000 to 5500 rads to the tumor area as defined by CT.

Actuarial Analysis↗
PubMed1980

Management of severe pediatric head trauma.

Except for prevention, nothing can alter the primary damage to the central nervous system tissues and blood vessels caused by the impact of traumatic forces over a few milli-seconds. However, damage to nervous system tissues secondary to transient reversible brain dysfunction may occur and lead to failure of respiration and circulation. Brain swelling and intracranial hypertension can develop and interfere with oxygen delivery and cellular metabolism of vital central nervous structures. A team approach with simultaneous treatment of the various disorders and recurrent evaluation is the hallmark of successful management.

Barbiturates↗
PubMed1980

Computed tomography of brain stem gliomas in children.

In 24 CT studies in children with brain stem gliomas, the CT appearance was seen to vary with the tumor's physical characteristics. Infiltrative tumors produce diffuse enlargement of the brain stem; they are isodense with brain parenchyma or of decreased density and may show partial enhancement. Some gliomas grow focally as an expansile mass or as a large exophytic lesion. These have heterogeneous density and show prominent enhancement. Early diagnosis depends on appreciation of displacement of the fourth ventricle and compression and distortion of the cisterns. The use of diagnostic studies and surgical and therapeutic results in the 24 cases are compared to 45 such cases diagnosed prior to the use of CT.

Adolescent↗
PubMed1980

Computed tomography of pineal, parapineal, and histologically related tumors.

Thirty-one of 32 pineal and related tumors were diagnosed by computed tomography (CT). There were 7 germinomas, 4 primary pineal tumors, 4 embryonal cell carcinomas, one teratoma, one epidermoid, one primitive neuroectodermal tumor, 8 astrocytomas and 6 lipomas. Histologic confirmation was obtained in 22. The CT characteristics allow differentiation of benign tumors such as teratomas and epidermoids from malignant germinal lesions such as germinoma and embryonal cell carcinoma. Abnormal calcification occurs most frequently in the primary pineal tumors, pineoblastoma and pineocytoma. The CT characteristics and consideration of the patient's age and sex often lead to histologic prediction and better treatment planning.

Adolescent↗
PubMed1980

The value of CAT scanning following pediatric head injury.

The CAT scan has proven invaluable in the management of severe pediatric head traumas. The most frequent findings are those of subarachnoid hemorrhage and diffuse swelling. Mass lesions are readily identified by the CAT scan, and it is easy to distinguish between hematoma and/or edema in the acute stages. Follow-up scans have produced a much better understanding of the long-term pathophysiologic effects of head trauma on the injured child.

Age Factors↗
PubMed1980

Global rostral midbrain dysfunction secondary to shunt malfunction in hydrocephalus.

Two cases of congenital hydrocephalus with shunt malfunction are described. Both patients presented with clinical syndromes suggestive of global rostral mesencephalic dysfunction, including the sylvian aqueduct syndrome, a parkinsonian-like state, and quadriparesis. Each had computed tomographic findings that showed marked dilatation of the lateral and 3rd ventricles, and both improved with revision of their shunts. The anatomical substrates of the clinical findings are reviewed. A discussion of the probable mechanism proposes that dilatation of the 3rd ventricle and rostral aqueduct sufficiently explains the entire syndrome. (Neurosurgery, 7: 322-325, 1980).

Adolescent↗
PubMed1980

Local cerebral blood volume in head-injured patients. Determination by emission computed tomography of 99mTc-labeled red cells.

Local cerebral blood volume (CBV) was mapped in 10 normal subjects and in 30 patients after head injury. In normal subjects, the mean CBV was 4.34 ml/100 gm. The coefficient of variation was 12% for the group mean, and 3% for values obtained in duplicate studies of individuals. Patients with head injuries were divided into three groups according to the stage of their illness: acute illness, early recovery, and later recovery. Averages of mean CBV were within one standard deviation of normal. In contrast, consistent changes were found in serial studies of the mean CBV in the same patient. Compared to recovery values, levels of mean CBV measured soon after injury were reduced, largely at the expense of the gray-matter compartment. In five adults with predominantly unilateral lesions, there was an average early reduction in mean CBV and cerebral blood flow of 15% and 36%, respectively. In three children with diffuse brain swelling, there was an average early mean CBV reduction of 12%; a single child had early increased mean CBV at a time when intracranial pressure was high. Greater changes were seen in local CBV on individual sections. There were mixed zones of hypervolemia and hypovolemia in regions of infarction and intracerebral hematoma. Subdural hematomas had consistent medial margins of increased local CBV, representing dilated blood vessels of the underlying cortex. The presence and displacement of this hypervolemic zone were sensitive indicators of persistent subdural collection and mass effect, even when the collection was lucent to x-ray computed tomography.

Adolescent↗
PubMed1980

The effects of cold-induced brain edema and white-matter ischemia on the somatosensory evoked response.

The electrophysiological effects of cold-lesion edema and white-matter ischemia were studied in cats by reference to the short-latency somatosensory evoked response. The primary cortical waves were found to be considerably delayed following a period of white-matter ischemia; hosever, cold-lesion edema appeared to have no significant effect on the evoked response. The authors conclude that vasogenic edema does not interfere with axonal functioning by an ischemic mechanism.

Animals↗
PubMed1980

Bioenergetics of acute vasogenic edema.

The bioenergetic mechanisms of vasogenic edema were studied by measuring concentrations of adenosine triphosphate (ATP), phosphocreatine (CrP), and lactate in rapidly frozen edematous white matter in cats. When edema was produced using a cold lesion, it was found that both ATP and CrP were reduced to one-half of control values, and that lactate was elevated. When a correction was applied for dilution, however, it was found that high-energy phosphates were equal to control values, and that lactate was even more significantly elevated. This pattern contrasted with that seen in white-matter ischemia, in which CrP is depressed out of proportion to ATP. Finally, it was found that the white-matter lactate-concentration in the plasma infusion model of edema was increased. It is concluded that vasogenic edema induces an increase in lactate, but does not deplete high-energy phosphate compounds in affected white matter.

Adenosine Triphosphate↗
PubMed1980

Hydranencephaly versus maximal hydrocephalus: an important clinical distinction.

To define better the syndromes of hydranencephaly and maximal hydrocephalus, we followed 10 neonates demonstrating (by computerized tomography) virtual absence of the cerebral substance with serial computerized tomographic (CT) scans, electroencephalograms (EEGs), and developmental evaluations. The follow-up period ranged from 4 to 23 months. Two well-defined syndromes emerged. Five patients showed absence of cortical activity on EEG and a CT picture of minimal occipital brain parenchyma connected by a thin bridge of tissue to intact basal ganglia. These patients were shunted and showed no improvement with time, either neurologically or radiologically. Five patients showed minimal frontal cerebral mantle on CT and the presence of electrical activity on EEG. These patients required bilateral shunts to control head size and showed remarkable progress with time. Serial CT scans demonstrated the appearance of considerable brain substance, and neurological development was either normal or slightly delayed. We believe that the former pattern of only minimal occipital brain and absent EEG activity defines true hydranencephaly, whereas the presence of small amounts of frontal brain tissue associated with EEG activity seems to represent maximal hydrocephalus. The differences in CT pattern, EEG, and clinical progress all suggest a different pathophysiology for these two conditions. (Neurosurgery, 6: 35--38, 1980).

Anencephaly↗
PubMed1979

Problems of diagnosis and treatment in the Dandy-Walker syndrome.

10 children with Dandy-Walker syndrome are presented to discuss their clinical assessment and therapy. The presence on physical examination of a large posterior fossa was the most reliable clinical finding and was diagnostic in 9 out of the 10 patients. The different diagnostic confirmatory studies are discussed. The most satisfactory treatment in this series was the combination of a shunt from the lateral ventricle and the posterior fossa to the peritoneum.

Cerebrospinal Fluid Shunts↗
PubMed1979

Pathophysiology, treatment and outcome following severe head injury in children.

The pathophysiology and outcome following severe head injury in 85 children are presented. The commonest initial CT diagnosis was of acute brain swelling. This swelling was associated with an increased white matter density on the CT scan which decreased to normal concomitant with recovery and increased ventricular size. CBF measurements in 6 of these patients revealed an increased blood flow despite a decreased CMRO2 and clinical coma. This CT pattern of diffuse swelling is believed to be due to acute cerebrovascular congestion and hyperemia and not to edema. Because of this, all children were treated with endotracheal intubation and controlled hyperventilation as part of the initial management. Mass lesions were uncommon, 20%. ICP was monitored in 40 children. The ICP rose above 20 Torr despite therapy in 80% of children with decerebrate or flaccid coma and in only 20% of children with spontaneous motor function. The ICP was at its highest between the second and fifth day. Aggressive therapy to control the ICP, with barbiturates if necessary, was successful in 80% of the patients. The overall results were useful recovery in 87.5% of the children, 3.5% were left vegetative or severely disabled and 9% died.

Adolescent↗
PubMed1979

Spinal lipomas in infancy and childhood.

The clinical course of 42 children with lipomatous lesions of the lower spine is reviewed. Good neurological exam, IVP and myelography are considered essential components of the preoperative studies. The surgical aim is to free all intra- to extradural adhesions with dural grafting, if necessary. The results suggest that early corrective surgery within the first few weeks to months of life is the most satisfactory approach to preserving normal neurological and urological function in these children. 88% of children not operated on early developed progressive loss of neurological function and while delayed surgery frequently stopped progression of the disease it rarely returned the children to a normal state.

Adolescent↗