William E. Allen

Effect of mannitol on the traumatized spinal cord. Microangiography, blood flow patterns, and electrophysiology.

The effects of mannitol on the spinal cord blood flow patterns in experimental traumatic paraplegia were correlated with microangiographic and electrophysiologic studies. At 1 hour following a therapeutic dose of mannitol (3 g/kg), an improved fluorescent intramedullary vascular pattern was detected among the mannitol-treated animals relative to those that were not treated. Within 4 hours, perfusion of many areas of the lateral white matter of the spinal cord often approximated normal in the mannitoltreated group. This pattern of perfusion was in striking contrast to that seen in the spinal cord of untreated animals, which displayed an almost total lack of fluorescing vessels at this later time. These findings correlated with an increased vascular caliber as revealed by microangiography and were postulated to be the result of a decrease in vasospasm and an expanded intramedullary blood volume following the administration of mannitol. Although mannitol therapy did not reverse the loss of the cortical evoked response observed during the 4-hour interval studied, the observation of improved blood flow patterns in the white matter is encouraging and warrants further study.

Gray scale ultrasonography, computerized tomography, and nephrotomography in evaluation of polycystic kidney and liver disease

A comparison of gray scale ultrasonography and computerized axial tomography in adults with known adult-type polycystic disease and of ultrasonography and high-dose nephrotomography in their progeny is being conducted. Although all three modalities have proved capable of demonstrating cysts of the kidney and liver, ultrasound has been the most consistent in identifying these lesions. Ultrasound is valuable in diagnosing polycystic disease in adult with large, poorly functioning kidneys; in addition, since cysts could be identified by ultrasound in children who had normal nephrotograms, it provides a safe and useful method of obtaining information for genetic counseling.

Correlation of microangiographic and electrophysiologic changes in experimental spinal cord trauma.

Following a controlled impact injury to the feline cervical spinal cord, hemorrhages appear within the central gray matter immediately post-trauma, and most likely result from direct tearing of vessel walls rather than ischemic necrosis. There is an absence of electrical activity in both the white and gray matter immediately following impact, though the microvasculature is essentially morphologically normal. Subsequent microvascular alterations in the gray and white matter correlate with the changes in the electrophysiological indices, implying that these latter changes in the neurophysiological function may be attributed to differential flow in the white and gray matter.

Orbital Hemorrhage with Loss of Vision

A 58-year-old woman had the sudden onset of unilateral painful proptosis, ophthalmoplegia, vomiting, and loss of vision. Computed axial tomography showed a mass that was greatly attenuated in the orbit. The initial reading of the internal carotid angiogram was normal, but a subtraction study showed a hypervascular lesion within the orbit with features indicating a hemangioma. Orbital decompression failed to restore the vision as intraorbital hemorrhage had irreparably damaged the optic nerve.

Direct coronal computerized tomography

The computerized tomographic examination is routinely performed in the axial plane. However, with several available CT units images in the coronal plane are easily obtained. These images are especially useful in the diagnosis of diseases of the facial bones, sinuses, orbits and parasellar area. This paper describes one years clinical experience with direct coronal computerized tomography.

Computerized tomography in pulmonary sarcoidosis.

Six patients with documented pulmonary sarcoidosis were selectively studied with the ACTA scanner. The CT scans were correlated with the standard chest radiographs of these patients. CT scans readily confirmed adenopathy, calcification, and pleural disease. Likewise, diffuse and isolated parenchymal disease was detected and in some cases unexpected lung involvement was noted.

Evaluation of the Neurotoxicity of Water-Soluble Myelographic Contrast Agents by Electrophysiological Monitors

The effects of subarachnoid injection of Conray (methylglucamine iothalamate) and its dimer (methylglucamine locarmate) in various concentrations were compared using electrophysiological monitors of the cortical evoked response (CER) and the H-reflex. Significant concentration-dependent differences were noted in the H-reflex, less marked with the dimer. No significant difference in the CER was noted. This differential alteration in neurophysiological parameters was independent of changes in blood and cerebrospinal fluid pressure, implying that these water-soluble contrast media have a direct toxic effect on the nervous system, possibly situated in the larger (group 1) root fibers.

The medial posterior choroidal artery as an indicator of masses at the foramen of monro

SummaryThe angiographic findings in five cases of tumors at the foramen of Monro are presented. Characteristic changes in the course and configuration of the medial posterior choroidal artery are described.

Computerized tomography in the assessment of diseases of the thorax.

Many of the diseases of the chest wall, heart, mediastinum, pleura and lungs can be successfully imaged by computerized tomography. Radiation therapy ports can be calculated and transcutaneous biopsies monitored. This paper deals with the many uses that we have had for computerized tomography in assessing diseases within the chest and thorax.

Duration of symptoms and disc configuration in chemonucleolysis

Previous studies have compared the effectiveness of chemonucleolysis with surgery, but currently, no objective criteria have been correlated with the clinical outcome. The authors reviewed 28 cases where the patients had undergone chymopapain injection to determine the significance of disc herniatlon size, disc space height reduction, and the duration of symptoms on clinical outcome. All patients had a complete history, physical examination, and discogram, and most had pre- and postinjection computerized tomography (CT) or myelogram. Nine of the 28 patients were considered clinical failures. Seven underwent laminectomy and discectomy and were improved markedly. Two patients were advised to have surgery but refused and were considered clinical failures. The causes of failure were unknown in three patients, free fragment in two patients, and diabetic neuropathy in one. Only two patients who did well showed complete resolution of the disc deformity on repeat CT scan. The remainder still had evidence of an avascular deformity that persisted although reduced in size. The failures showed no changes in disc size. The height of the disc space was too variable to be correlated with clinical outcome. Patients who failed had a longer duration of symptoms than the ones who did well (15.1 months for failures vs. 5 months). Therefore, some reduction of disc deformity size, but not necessarily complete reduction, is necessary for a good result, and the enzyme is not as effective in patients with long-standing symptoms.