Incidence and evolution of subependymal and intraventricular hemorrhage: A study of infants with birth weights less than 1,500 gm

Medical practice is constantly changing. The rate of change is accelerating, and physicians can be forgiven if they often find it dizzying. How can physicians learn about new information and innovations, and decide how (if at all) they should modify their practice? Possible sources include summaries from the medical literature (review articles, practice guidelines, consensus statements, editorials, and summary articles in "throwaway" journals); consultation with colleagues who have special expertise; lectures; seminars; advertisements in medical journals; conversations with representatives from pharmaceutical companies; and original articles in journals and journal supplements. Each of these sources of information might be valuable, though each is subject to its own particular biases. 1,2 Problems arise when, as is often the case, these sources of information provide different suggestions about patient care. See also p 2093. Without a way of critically appraising the information they receive, clinicians are relatively helpless in deciding what new information

https://hopkinsmedicine.org/gim/_pdf/jama/17-screening.pdf

Users' Guides to the Medical Literature

The type, frequency, and extent of MR signal abnormalities in Alzheimer9s disease and normal aging are a subject of controversy. With a 1.5-MR unit we studied 12 Alzheimer patients, four subjects suffering from multiinfarct dementia and nine age-matched controls. Punctate or early confluent high-signal abnormalities in the deep white matter, noted in 60% of both Alzheimer patients and controls, were unrelated to the presence of hypertension or other vascular risk factors. A significant number of Alzheimer patients exhibited a more extensive smooth “halo” of periventricular hyperintensity when compared with controls (p = .024). Widespread deep white-matter hyperintensity (two patients) and extensive, irregular periventricular hyperintensity (three patients) were seen in multiinfarct dementia. Areas of high signal intensity affecting hippocampal and sylvian cortex were also present in five Alzheimer and two multiinfarct dementia patients, but absent in controls. Discrete, small foci of deep white-matter hyperintensity are not characteristic of Alzheimer9s disease nor do they appear to imply a vascular cause for the dementing illness. The frequently observed “halo” of periventricular hyperintensity in Alzheimer9s disease may be of diagnostic importance. High-signal abnormalities in specific cortjcal regions are likely to reflect disease processes localized to those structures.

http://www.ajnr.org/content/ajnr/8/3/421.full.pdf

MR Signal Abnormalities at 1.5 T in Alzheimer's Dementia and Normal Aging

background Previous studies have suggested that the obstructive sleep apnea syndrome may be an important risk factor for stroke. It has not been determined, however, whether the syndrome is independently related to the risk of stroke or death from any cause after adjustment for other risk factors, including hypertension. methods In this observational cohort study, consecutive patients underwent polysomnography, and subsequent events (strokes and deaths) were verified. The diagnosis of the obstructive sleep apnea syndrome was based on an apnea–hypopnea index of 5 or higher (five or more events per hour); patients with an apnea–hypopnea index of less than 5 served as the comparison group. Proportional-hazards analysis was used to determine the independent effect of the obstructive sleep apnea syndrome on the composite outcome of stroke or death from any cause. results Among 1022 enrolled patients, 697 (68 percent) had the obstructive sleep apnea syndrome. At baseline, the mean apnea–hypopnea index in the patients with the syndrome was 35, as compared with a mean apnea–hypopnea index of 2 in the comparison group. In an unadjusted analysis, the obstructive sleep apnea syndrome was associated with stroke or death from any cause (hazard ratio, 2.24; 95 percent confidence interval, 1.30 to 3.86; P=0.004). After adjustment for age, sex, race, smoking status, alcohol-consumption status, body-mass index, and the presence or absence of diabetes mellitus, hyperlipidemia, atrial fibrillation, and hypertension, the obstructive sleep apnea syndrome retained a statistically significant association with stroke or death (hazard ratio, 1.97; 95 percent confidence interval, 1.12 to 3.48; P=0.01). In a trend analysis, increased severity of sleep apnea at baseline was associated with an increased risk of the development of the composite end point (P=0.005). conclusions The obstructive sleep apnea syndrome significantly increases the risk of stroke or death from any cause, and the increase is independent of other risk factors, including hypertension.

https://www.nejm.org/doi/pdf/10.1056/NEJMoa043104

Obstructive sleep apnea as a risk factor for stroke and death.

All X-ray computerised tomography systems that are available or proposed base their reconstructions on measurements that integrate over energy. X-ray tubes produce a broad spectrum of photon energies and a great deal of information can be derived by measuring changes in the transmitted spectrum. It is shown that for any material, complete energy spectral information may be summarised by a few constants which are independent of energy. A technique is presented which uses simple, low-resolution, energy spectrum measurements and conventional computerised tomography techniques to calculate these constants at every point within a cross-section of an object.

https://iopscience.iop.org/article/10.1088/0031-9155/21/5/002/pdf

Energy-selective reconstructions in X-ray computerized tomography.

Twenty-eight patients with dural arteriovenous malformations, mostly located along the cranial base and in the occipitomastoid region, were studied angiographically. It was often possible to define a relationship between the clinical syndrome and the angiographic pattern of venous drainage. Intracranial hemorrhages occurred in those patients in whom the venous drainage of the arteriovenous malformation was limited to the pial veins, while the syndrome of a cavernous sinus fistula was present when retrograde venous drainage from the anomaly extended through the distensible ophthalmic veins. If the venous outflow was antegrade through the usual channels, the clinical syndrome reflected only the presence and volume of the arteriovenous shunt.

Intracranial dural arteriovenous malformations.

The lateral cervical roentgenogram is a useful guide in evaluating the bony and soft-tissue relationships of the neck. In an effort to establish certain normal measurements in this area we reviewed 700 lateral cervical roentgenograms from the files of the Mayo Clinic, of which 600, technically adequate and without detectable abnormalities, were included in the study. The roentgenograms were taken with the patient sitting erect and with the neck in the neutral position. The target-to-film distance was 60 inches. Measurements were made from the films without correction for the minor error due to magnification. Regions Evaluated Retropharyngeal Space: In Figure 1 the retropharyngeal space is indicated by the letter A. For convenience, we chose to measure this from the antero-inferior aspect of the second cervical vertebra to the posterior wall of the pharynx. Retrotracheal Space: The retrotracheal space, represented in Figure 1 by the letter B, was measured from the anteroinferior aspect of the sixth cervica...

The lateral roentgenogram of the neck; with comments on the atlanto-odontoid-basion relationship.

Our experience with 68 patients with strictly defined, myelographically proven, surgically confirmed lumbar spinal stenosis seen over a 30-month period was reviewed. Pseudoclaudication was the commonest symptom (94%) and was described by patients as pain (93%), numbness (63%), or weakness (43%). Symptoms were frequently bilateral (68%) and generally relieved by flexing the lumbosacral spine. Neurologic abnormalities were found in a minority of patients and were usually mild. Electromyography showed one or more lumbosacral radiculopathies in 34 of 37 patients examined. Radiographic evidence of degenerative disk or joint disease was found in 63 patients. All patients had stenosis on myelography, with narrowing at L2, L3, and L4 being the commonest; 30% had multi-level stenosis. Two of ten computed tomograms were normal. Surgery was extensive; 72% of patients had three or more laminae removed. At a mean of 4 years after surgery, 84% of patients reported that surgery had yielded good to excellent results.

Lumbar spinal stenosis. Clinical features, diagnostic procedures, and results of surgical treatment in 68 patients.

Cervical cephalic dissections are uncommon acute disruptions of the arterial wall occurring predominantly in middle-aged women. Clinically, most patients present with unilateral headache, oculosympathetic palsy, or ischemic neurologic symptoms. Usually, a single internal carotid artery, predominantly the right, is affected, but simultaneous multivessel dissections are evident in about one-third of patients. Angiographically, the appearance of the dissection varies, depending on its severity, extent, and the interval between onset and angiography. In the patients reported, the disruption was manifested initially by eccentric tapered stenosis in 47%, tapered stenosis and a dissecting aneurysm in 28%, occlusion in 18%, or a dissecting aneurysm alone in 7%. Subsequently, stenotic dissections resolved in 60%, improved in 20%, and progressed in 15%, while dissecting aneurysms diminished in half and resolved in one-fourth of patients. An angiographic residuum, temporally remote to its onset, was evident in 25% of dissections. Hence, carotid arterial dissections tend to resolve, sometimes progress, but seldom recur.

http://www.ajnr.org/content/ajnr/5/1/27.full.pdf

Spontaneous cervical cephalic arterial dissection and its residuum: angiographic spectrum.

The clinical, radiologic, and neuropathologic findings in 13 patients with central pontine myelinolysis were reviewed. Antemortem computed tomography (CT) had been performed in nine, and ante- or postmortem magnetic resonance (MR) imaging in 11. Chronic alcoholism or rapid correction of hyponatremia was present in over 75% of cases. One CT scan was positive, but only on retrospective review. In all but one patient, MR imaging eventually revealed an abnormality within the pons; in two patients the initial study was normal. The lesions varied in shape, with peripheral involvement in two patients and extrapontine involvement in four. The abnormality was smaller at 6-month follow-up in one patient and unchanged at 1 year in another. One patient never had a demonstrable pontine lesion but did have symmetric basal ganglia abnormalities, which were consistent with extrapontine myelinolysis. MR imaging disclosed similar central pontine alterations resulting from infarct, metastasis, glioma, multiple sclerosis, encephalitis, and radiation or chemotherapy; thus, such changes are not unique.

Hillier L. Baker

Papers

Intracranial dural arteriovenous malformations.

The lateral roentgenogram of the neck; with comments on the atlanto-odontoid-basion relationship.

Lumbar spinal stenosis. Clinical features, diagnostic procedures, and results of surgical treatment in 68 patients.

Spontaneous cervical cephalic arterial dissection and its residuum: angiographic spectrum.

Central pontine myelinolysis and its imitators: MR findings.