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Biomedical subjects

M K Edwards

Publications and source records attributed to M K Edwards.

At least 37 records · Page 2Linked to original sources

Cranial MR imaging in neurofibromatosis.

Cranial MR images of 53 patients with neurofibromatosis were reviewed to determine the nature, extent, and number of intracranial abnormalities present. All patients studied met tentative definitions established for the diagnosis of neurofibromatosis. Twenty-three were scanned for evaluation of known CNS of cranial nerve involvement; the remainder were neurologically asymptomatic patients without suspected lesions referred for screening. Single lesions were noted in 32 patients. Multiple lesions were identified in 14 patients. Seven had normal scans. In 23 patients small focal areas of increased signal on T2-weighted scans within the brain were though to represent heterotopias. Eight patients had chiasmal gliomas and two had optic nerve gliomas. Nine patients had parenchymal gliomas, two had ischemic changes, and one had a colloid cyst. Extraaxial lesions included acoustic neuromas (five patients), meningiomas (four), trigeminal neurofibromas (one), and dysplasia of a sphenoid wing (two). Of the 30 asymptomatic patients referred for screening, lesions were found in 23. MR was found to be an excellent method of imaging known disease and of detecting lesions in asymptomatic patients. Because of the large number of asymptomatic lesions detected in this population, a screening MR study is recommended in patients with neurofibromatosis.

Adolescent↗

Magnetic resonance imaging in multiple sclerosis: analysis of correlations to peripheral blood and spinal fluid abnormalities.

MRI of the brain, peripheral blood (PB) T cell subsets and B cells, CSF T cell subsets, CSF IgG concentration and incidence of CSF oligoclonal bands (OB), and plasma cells were studied in 32 clinically suspected MS patients. The CSF in MS patients with MRI lesions showed increased IgG concentration and higher incidence of plasma cells and OB compared with those without MRI lesions. In PB, the percentage of kappa light-chain positive B cells was significantly increased in patients with abnormal MRI as compared with controls. The correlation of MRI of the head and immunologic studies in MS will be helpful in better understanding the pathogenesis and dynamics of the disease.

Adult↗

Magnetic resonance imaging. Clinical correlation in 64 patients with multiple sclerosis.

Sixty-four patients with possible, probable, or definite multiple sclerosis (McAlpine criteria) were clinically evaluated using the expanded disability status scale (EDSS) and Scripps neurologic rating scale (NRS). All were examined with a 0.15T magnetic resonance scanner using T2- and T1-weighted images. Correlations between EDSS and NRS scores and severity of disease detected on magnetic resonance imaging were determined. Significant correlations existed between EDSS and NRS with magnetic resonance ratings. Moderate correlations were observed in the motor, cerebellar, and brainstem subgroups of the clinical scales. Significant low correlations existed in the mood/mentation, vision (optic nerves), and bowel/bladder subgroups. Clinical and neuroimaging limitations may account for the lack of higher correlations. Significant correlations suggest the utility of magnetic resonance imaging in monitoring disease progression, and it may prove to be the technique of choice in following up patients with multiple sclerosis.

Adolescent↗

Cerebrovascular disease: evaluation with transbrachial intraarterial digital subtraction angiography using a 4-F catheter.

Three hundred sixty-one patients underwent intraarterial digital subtraction angiography for definite or probable occlusive vascular disease of the carotid arteries. Examinations were performed with 65-cm-long, 4-F aortic catheters. A transbrachial approach was used. Images were good or excellent in nearly all cases. No postprocedural neurologic deficits or hematomas occurred. Permanent pulse deficit occurred in two patients, and temporary deficit occurred in three patients, an improvement over the frequency found in previous transbrachial series using 6-8-F catheters. While these results establish the efficacy of this technique, they also indicate a possible greater relative safety in men than in women.

Angiography↗

Single photon emission computed tomography (SPECT) brain imaging using N,N,N'-trimethyl-N'-(2 hydroxy-3-methyl-5-123I-iodobenzyl)-1,3-propanediamine 2 HCl (HIPDM): intractable complex partial seizures.

HIPDM-SPECT brain imaging was performed in four patients with intractable complex partial seizures (CPS). Three patients had an epileptogenic focus in one temporal lobe and underwent anterior temporal lobectomy. Interictal HIPDM-SPECT demonstrated decreased regional cerebral perfusion (rCP) in the epileptogenic area in only one patient, but ictal studies showed increased rCP in the epileptic foci of all three patients. In the fourth patient, interictal HIPDM-SPECT showed increased rCP in the area of epileptogenic focus; when antiepileptic medication was taken, rCP decreased. HIPDM-SPECT brain imaging is useful for localizing epileptogenic foci in CPS.

Adolescent↗

Multiple sclerosis: magnetic resonance imaging, evoked responses, and spinal fluid electrophoresis.

Magnetic resonance images (MRI), evoked responses (ER), and CSF findings were compared in 39 patients with possible, probable, or definite MS. MRI disclosed multiple lesions (72%) more often than ERs (55%) in the total group of patients. In possible MS, MRI showed multiple lesions in 71%, and ER abnormalities were found in 41%. MRI is the preferred test for patients with suspected MS, but ERs are useful when MRI is normal and in the evaluation of optic nerve or spinal cord lesions.

Adult↗

Multiple sclerosis: MRI and clinical correlation.

Fifty-three consecutive patients with suspected multiple sclerosis were studied to determine if the extent of disease apparent on MRI correlated with the clinical severity of the disease. MRI images were evaluated and compared with an assessment of the patient's disability using three neurologic rating scales. The severity of the disease seen on MRI showed a strong statistically significant correlation (p = 0.0001) with two of the three methods of clinical evaluation and a significant correlation (p less than 0.01) with the third rating scale. The severity of disease shown on MRI correlated only weakly (p = 0.05) with the length of time the patients had been symptomatic. Normal controls did not show any abnormality characteristic of multiple sclerosis on MRI or on neurologic exam.

Brain↗

Gliomas in children following radiation therapy for lymphoblastic leukemia.

Four children treated for acute lymphoblastic leukemia developed intracranial gliomas between 40 and 120 months following multiagent chemotherapy, prophylactic whole brain irradiation, and intrathecal Methotrexate. The diagnosis of glioma was confirmed in each case with biopsy or autopsy. These children were part of a larger series of 73 patients with acute lymphoblastic leukemia treated at Indiana University receiving 24 Gy as per the protocol guidelines of the Children's Cancer Study Group. Currently 42 patients of the original 73 children survive in continuous remission.

Brain Neoplasms↗

Pitfalls of computed tomography in diagnosis of discitis.

Sixteen patients with discitis from January 1980 through December 1983 underwent 18 CT scans for initial evaluation. In six scans the study produced a false negative result (sensitivity 63%, 11/16). In three of these six the scan was performed at the wrong disc level, and in three the error was interpretive. During the same time period 6 patients had a CT diagnosis of discitis which proved incorrect (positive predictive value 63%), three of which had fractures, two had normal post discectomy changes, and one had a neuropathic arthropathy. These studies were reviewed in a blinded fashion along with 30 CT scans of post operative patients without clinical or laboratory evidence of discitis. The CT findings in the discitis patients were: (a) anterior paravertebral soft tissue swelling with obliteration of paravertebral fat planes, (b) fragmentation or erosions of vertebral end plates, and (c) paravertebral fluid collection (abscess). Both (a) and (b) were seen in 13/15 patients, (a) alone in 1/15, (b) alone in 1/15, and all three (a, b, c) in 2/15. The CT scan is diagnostic of discitis in those with all three findings. In those patients with only (a) or both (a) and (b), the CT can be suggestive of discitis in the proper clinical setting when correlated with plain film findings: however, these CT findings are also observed in other conditions. Involvement of the spinal canal by inflammatory mass was seen in 6/16 patients with discitis. Low attenuation (hypodensity) of the affected disc was not observed.

Adolescent↗

Cerebral venous angiomas: MR imaging.

Seven patients with angiographically proved cerebral venous angiomas were imaged by magnetic resonance. The venous angioma was identified in all cases. The most characteristic feature was an enlarged transcerebral draining vein (86%), followed by increased signal on T2-weighted images (57%) and decreased signal on T1-weighted images (40%) in adjacent parenchyma. Mass effect was absent in all cases. T2 imaging was more successful in showing the lesions than was T1 imaging.

Adolescent↗

Screening for occlusive vascular disease with intraarterial DSA: preliminary experience with a high flow 4-F catheter.

Forty-two patients underwent intraarterial digital subtraction angiography (DSA) of the carotid or renal arteries, utilizing a new 4-F aortic flush catheter; 37 procedures were percutaneous transbrachial, five were percutaneous transfemoral. Image quality was consistently good or excellent. The safety of nonselective intraarterial DSA screening for occlusive vascular disease is being evaluated in our ongoing series.

Angiography↗

Location of specific messenger RNAs in Caenorhabditis elegans by cytological hybridization.

We have developed an autoradiographic technique for detecting specific Caenorhabditis elegans messenger RNA molecules in situ by hybridization of labeled, cloned DNA probes to fixed tissue sections and squashes of embryos and adults. We report analyses with probes of actin and collagen gene sequences from a C. elegans genomic clone library. Hybridization is RNase sensitive and tissue specific. In adults the actin probe, which recognizes cytoplasmic as well as muscle actin mRNA, hybridizes strongly to muscle and distal gonad (ovary), somewhat less strongly to maturing oocytes, and weakly to intestine. The collagen probe hybridizes weakly to distal gonad and intestine and very strongly to subcuticular tissues, in particular to the hypodermal cells and syncytial cytoplasm of the lateral hypodermal ridges, which are the sites of cuticle synthesis. In embryos, hybridization to squashes indicates that actin message is present at fertilization, decreases during early cleavage, and then increases again during morphogenesis. By contrast, collagen message is absent until the 100-cell stage and then increases rapidly during morphogenesis. The number of cells labeled is consistent with the view that the collagen probe hybridizes to hypodermal precursor cells. We estimate that our present methods can detect messages representing about 0.2% or more of the total mRNA population, and increases in this sensitivity should be possible. Therefore, the cytological hybridization technique should be useful for determining temporal and spatial patterns of specific mRNA distributions during development, at least for abundant and moderately abundant messages.

Actins↗