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Biomedical subjects

R D Zimmerman

Publications and source records attributed to R D Zimmerman.

At least 55 records · Page 3Linked to original sources
PubMed1985

MR imaging of syringomyelia and hydromyelia.

The relative effectiveness of plain computed tomography (CT), metrizamide CT, conventional myelography, and magnetic resonance (MR) imaging was compared for the examination of cystic spinal cord lesions. Intramedullary cavities in 18 patients were demonstrated by MR imaging: cavities were uncomplicated in 13 patients, associated with spinal tumors in two, and studied after occipital craniectomy for treatment of Chiari malformation and syringomyelia in two. Cavities were shown by MR imaging in all enlarged spinal cords, but a cavity was shown in only one of four small cords. The rostral limits of the cavities were demonstrated better than were the caudal extensions. Ventricular communication was not demonstrated. Chiari malformation was shown only in cavities that did not involve the medulla. Syringes associated with tumor were indistinguishable from uncomplicated cavities, but the tumor had abnormal signal on long spin-echo sequences in two cases. Cystic cord tumor (one case) had an inhomogeneous appearance. Caudal displacement of the cerebellar hemisphere through the surgical defect associated with compression of the fourth ventricle was shown in two cases after posterior fossa craniectomy. Thirteen patients were studied with metrizamide CT also. MR imaging proved to be as accurate as metrizamide CT in the diagnosis of intramedullary cavities that result in spinal cord enlargement, but it was less sensitive in detecting cavities within normal-sized or diminished spinal cords. It had the advantage that tumor tissue could be distinguished from associated syrinx cavities by differences in signal characteristics; and cerebellar ectopia was evaluated easily on sagittal MR views.

Arnold-Chiari Malformation↗
PubMed1984

Cranial nuclear magnetic resonance imaging in head trauma.

Nuclear magnetic resonance imaging revealed focal intracranial lesions consisting of extraaxial hematomas or nonhemorrhagic contusions in 3 patients with severe neurological disability following head trauma. In all 3, standard skull radiography and computed tomography had been unremarkable.

Adult↗
PubMed1984

Subdural empyema: CT findings.

CT scans in 49 patients with surgically proven subdural empyema were evaluated. The empyemas were crescentic or lentiform extra-axial hypodense collections (density approximating that of cerebrospinal fluid) with prominent, sharply etched medial rim enhancement. Enhancement of the adjacent cerebral cortex was identified in many cases. Mass effect was always present and in 10 cases so extensive that it overshadowed a small extra-axial collection. CT allowed for precise localization of the lesion, including contiguous or isolated involvement of the interhemispheric subdural space. Mortality was 12% (6/49 cases), a marked improvement when compared with mortality figures obtained prior to the advent of CT (40%). CT findings indicative of involvement of the adjacent parenchyma via retrograde thrombophlebitis with resultant infarction and/or abscess formation were associated with poor prognosis. Improvement in prognosis since the advent of CT is the direct result of early accurate diagnosis and timely intervention.

Adolescent↗
PubMed1984

Cervical disk herniation: CT demonstration after contrast enhancement.

Two-millimeter-thick transverse axial CT scans were obtained at the 2, 3, or 4 cervical disk level in 25 patients with cervical radiculopathy. Scans were obtained before and after high dose (bolus/drip) intravenous administration of contrast medium. Clinical signs and symptoms were correlated with radiographic and surgical findings. Ventral epidural and intervertebral foraminal veins were consistently well visualized with this technique. Venous and dural enhancement provided better anatomic definition than did non-contrast CT. Visualization of posterior displacement of the enhanced epidural veins and epidural enhancement surrounding extruded disk fragments on postinfusion studies provided excellent delineation of disk extrusion and in some cases allowed demarcation of multiple discrete free disk fragments. Although noninfusion scans are usually diagnostic and sufficient, the improved anatomic information available from infusion CT may increase diagnostic certainty and in selected cases obviates the need for myelography for accurate diagnosis of patients with focal cervical radiculopathy.

Adult↗
PubMed1983

Brain stem infarction due to chiropractic manipulation of the cervical spine.

A case of brain stem infarction after chiropractic manipulation of the cervical spine is presented. Proposed mechanisms and sites of possible arterial injury are discussed. A diagnosis of vertebral artery occlusion was made using conventional brachial angiography. Digital intravenous angiography, a relatively new and less invasive vascular imaging technique which was used as an adjunct for evaluating the remainder of the cervicocephalic vessels, documented the vertebral occlusion. Chiropractic manipulation, which is increasing in popularity, may be a cause of potentially devastating neurologic disease.

Adolescent↗
PubMed1983

Brain stem infarction due to chiropractic manipulation of the cervical spine.

A case of brain stem infarction after chiropractic manipulation of the cervical spine is presented. Proposed mechanisms and sites of possible arterial injury are discussed. A diagnosis of vertebral artery occlusion was made using conventional brachial angiography. Digital intravenous angiography, a relatively new and less invasive vascular imaging technique which was used as an adjunct for evaluating the remainder of the cervicocephalic vessels, documented the vertebral occlusion. Chiropractic manipulation, which is increasing in popularity, may be a cause of potentially devastating neurologic disease.

Arterial Occlusive Diseases↗
PubMed1983

Spontaneous regression of intracerebral lymphoma.

Transient spontaneous regression of lesions was identified in four patients with intracerebral lymphoma. This finding, which may be related to cyclic changes in biological tumor activity as well as infarction and/or hemorrhage within the neoplasm, is not a good prognostic sign. Furthermore, when initial neuroradiologic studies suggest a diagnosis of lymphoma, subsequent spontaneous resolution of lesions should not be mistaken for a reliable sign of a benign, self-limiting disease. The diagnosis of this malignant neoplasm, despite regression of lesions, should be aggressively pursued early in the patient's clinical course when therapy would be most beneficial.

Aged↗
PubMed1983

Pseudospread of the atlas: false sign of Jefferson fracture in young children.

Jefferson fractures are rare prior to teen-age. Three young children examined after trauma exhibited the characteristic spread appearance of the atlas, but fractures were excluded radiographically and clinically. A retrospective study demonstrated a similar appearance, termed "pseudospread," in most children aged 3 months to 4 years, including over 90% during the second year. Pseudospread results from a discrepancy between the "neural" growth pattern of the atlas and the "somatic" pattern of the axis. An "atlas spread index" is defined and a normal range presented. When an atlas fracture is suggested by apparent lateral spread of the lateral atlas masses, computed tomography is useful to demonstrate an intact atlas ring.

Axis, Cervical Vertebra↗
PubMed1982

Falx and interhemispheric fissure on axial CT: I. Normal anatomy.

To determine the normal appearance of the flax and interhemispheric fissure, 200 consecutive normal CT scans were evaluated prospectively. On unenhanced scans, the normal falx is visualized in 90% of patients and therefore interhemispheric hyperdensity alone should not be considered a sign of subarachnoid hemorrhage. The flax is most often (88%) visualized in the posterior part of the interhemispheric fissure, as a hyperdense, pencil-thin line extending from the calvarium to the splenium of the corpus callosum. In the anterior part of the fissure, the falx is visualized in only 38% of patients, when its appearance differs significantly from that of the fissure. It is seen as a thin, hyperdense line extending posteriorly from the calvarium for a variable distance, but it never reaches the genu of the corpus callosum. The interhemispheric fissure is a hypodense structure broader than the falx with a zigzag configuration due to medial frontal sulci. The difference in configuration between the anterior part of the fissure and the anterior falx is very helpful in differentiating subarachnoid hemorrhage from normal falx visualization.

Adolescent↗
PubMed1981

Congenital facial palsy and ipsilateral deafness: association with maternal diabetes mellitus.

Congenital facial palsy and ipsilateral deafness were found in two children of unrelated insulin-requiring diabetics. Multidirectional tomography showed hypoplasia of the internal auditory canal in each case but the cochlea, vestibule and semicircular canals were radiologically normal. The malformation in these patients must have been determined before 23 weeks of gestational age when ossification of the inner ear is complete. The association of this malformation and maternal diabetes is unlikely to be coincidental.

Adult↗
PubMed1981

Computed tomography in cerebrotendinous xanthomatosis.

In nine patients with cerebrotendinous xanthomatosis (CTX), computed tomography (CT) demonstrated diffuse white matter hypodensity above and below the tentorium. This was attributed to sterol infiltration with secondary demyelination. In one patient, a focal right cerebellar hypodense lesion reflected a true xanthoma. These findings suggest that the neurologic symptoms, no matter how longstanding, result from metabolic encephalopathy rather than irreversible destruction of brain tissue by xanthomas.

Adolescent↗