Biomedical subjects
Publications and source records attributed to J S Lapointe.
Morphological asymmetry of the posterior sylvian region was measured in carotid arteriograms of patients with medically refractory seizures. Anatomical asymmetry correlated with ear superiority on dichotic listening tests.
The prevalence of Kawasaki's disease has increased in the last decade and it is now recognized worldwide. Coronary aneurysms are an important complication often causing death. The widespread vascular changes which can occur are illustrated by a patient who presented with a cerebral infarct and who developed widespread aneurysmal disease which regressed.
The authors have reviewed 15 cases of orbital dermoids representing 6% of orbital tumours seen at the University of British Columbia Orbital Clinic. They tended to occur as either asymptomatic superficial lesions in children or as complicated deep lesions in adolescents and adults. The superficial lesions were as frequent medially as laterally and could be dealt with by a direct uncomplicated surgical approach. The deep lesions in contrast, were frequently extensive and difficult to remove, requiring careful preoperative planning. Sites of origin, presentation, differential diagnosis, and management are discussed.
Sixty-eight patients with intraventricular hemorrhage (IVH) diagnosed by computed tomography (CT) were reviewed retrospectively to determine the etiology and prognosis, relationship to delayed hydrocephalus, and effect on neurological outcome. The most common causes were a ruptured aneurysm, trauma, and hypertensive hemorrhage. Ruptured aneurysms of the anterior communicating artery can often be predicted from the nonenhanced CT scan. The total mortality rate was 50%; however, 21% of patients returned to normal or had only mild disability. Patients in whom no cause was identified had a better prognosis. Delayed hydrocephalus was related to the effects of subarachnoid hemorrhage rather than obstruction of the ventricular system by blood. IVH per se is seldom a major factor in the neurological outcome.
Eight patients were studied 3 to 16 years (mean, 10 years) after cerebral hemispherectomy. Seven have infantile hemiplegia, and one had Sturge-Weber disease. Preoperative assessment included EEG responses to intracarotid drug injections. Postoperative complications occurred in seven patients. The operation was followed by a marked reduction in seizure frequency and improvement in behavior, with little change in intellect or hemiplegia. Neuropsychological assessment performed in four patients showed that they were not aphasic, but nonverbal spatial abilities were poor. CT showed marked shift of the remaining hemisphere in five of six patients scanned.
CT scanning of the posterior fossa has been available for eight years, with continued and marked improvements in the scanning accuracy and resolution, particularly in the past three years. Newer computer programs combined with thin axial and coronal slices allow discovery of lesions that are millimeters in size. CT scanning has become the method of choice for screening patients with symptoms referrable to the posterior fossa and is also the most accurate radiographic method of detection. By demonstrating lesions less than one cm in size, CT has greatly enhanced the diagnosis and improved the management of patients who suffer from posterior fossa lesions.
Acute orbital pseudotumors are inflammatory lesions of unknown etiology that may affect part or, less often, all of the tissue within the orbit. A retrospective computed tomographic (CT) study of 16 patients demonstrated that these lesions occur in one of five specific anatomic patterns: anterior, posterior, diffuse, lacrimal, or myositic. The most common location was lacrimal followed by anterior pseudotumors. Posterior, most common location was lacrimal followed by anterior pseudotumors. Posterior, diffuse, and myositic pseudotumors were equally frequent. Localization on the basis of clinical features correlated with the CT localization. Illustrative cases of each of the five types are included. The role of CT in evaluating the therapeutic response is discussed.
This prospective study of 90 patients after lumbar metrizamide myelography indicates that the semiupright position at 45 degrees in bed or early ambulation reduces postprocedure vomiting but does not reduce the frequency of headache. Ambulatory patients have less frequent nausea than patients kept in bed.
Sixty patients from the University of British Columbia, Vancouver General Hospital, and University of Alberta Hospitals Edmonton participated in an open-labelled clinical study on the safety, tolerability and efficacy of ioxaglic acid (Hexabrix) in cerebral angiography. Only 4% of patients experienced significant pain during carotid and brachiocephalic injections of Hexabrix. No increased incidence of side effects or adverse effects were encountered. In addition, radiographic film quality overall was excellent and comparable to that obtained using conventional contrast agents. Hexabrix is a safe and effective contrast agent for cerebral angiography.
In this report we document the clinical, radiologic, surgical, and pathologic features of a cerebellopontine angle (CPA) lipoma, including the CT visualization of the seventh and eighth cranial nerves passing through the middle of the lesion, a feature previously undescribed. Comparison is made with other reported CPA lipomas.
Seventy-one patients with acute subdural hematomas were examined by CT within 72 hr of a documented head injury. Lesions often did not have the classical appearance of a homogeneous, high-density extracerebral collection of blood in a crescentic configuration. Specifically, 28 patients (39%) had mixed-density subdural hematomas (MDSDH) with various degrees of low-density blood within the subdural space. In 10 of these 28 patients, the hematoma had a relatively localized mass effect with a convex inner margin, occasionally mimicking the appearance of an epidural hematoma. The MDSDH group differed from the typical homogeneous high-density subdural hematomas in that they were larger (average maximal thickness was 18.1 mm versus 8.0 mm), had more midline shift, and had a higher mortality rate (50% versus 26%). Four patients with MDSDH demonstrated an unusual pattern of ventricular compression with trapping of cerebrospinal fluid in the body of the ipsilateral ventricle and compression of the body of the contralateral ventricle. This pattern has to our knowledge not been previously described. Possible causes of the low-density regions within the hematomas include unclotted blood in an early stage of hematoma development, serum extruded during the early phase of clot retraction, or cerebrospinal fluid within the subdural space due to an arachnoid tear.
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