MRI of neuromyelitis optica: evidence for a distinct entity.
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Adult↗
Biomedical subjects
H Offenbacher
Publications and source records attributed to H Offenbacher.
Assessment of cerebrovascular risk profiles in healthy persons: definition of research goals and the Austrian Stroke Prevention Study (ASPS).
The advent of new laboratory methods and noninvasive imaging modalities has extended the diagnostic possibilities in normal individuals. This article elaborates the new options for the assessment of stroke risk offered by these techniques. In this context we present the Austrian Stroke Prevention Study, which is the first prospective long-term investigation of normals that includes Doppler sonography, magnetic resonance imaging and single photon emission computed tomography. The design, utility and limitations of this study are discussed.
Aged↗
Measurement of ionized magnesium with neutral carrier based ISE's. Progress and results with the AVL 988-4 magnesium analyzer.
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Cations↗
Bilateral medial medullary infarction: magnetic resonance imaging and correlative histopathologic findings.
Bilateral medial medullary infarction is a rare event which clinically presents with flaccid tetraplegia sparing the face, bilateral disturbance of deep sensation, hypoglossal nerve palsy and respiratory failure. We here report a patient with such symptoms in whom magnetic resonance imaging enabled the detection of signal abnormalities in the lower brainstem as soon as 9 h after onset. Results of a control study 3 weeks later correlated well with the extent of infarction that was seen at autopsy. Early lesion detection in the lower medulla by magnetic resonance imaging and the unfavorable prognosis of patients with ischemic damage at that location may provide the rationale for aggressive therapeutic strategies in such a condition.
Cerebral Infarction↗
Neuropsychologic correlates of MRI white matter hyperintensities: a study of 150 normal volunteers.
To determine the effects of MRI white matter hyperintensities (WMH) on cognitive functioning, we used neuropsychologic tests and MRI to study 150 elderly volunteers free of neuropsychiatric or general disease. There were 76 (50.3%) individuals without and 74 (49.7%) with WMH. The latter subset was older (61.3 +/- 6.6 years versus 58.5 +/- 5.8 years, p = 0.005), had a higher mean arterial blood pressure (103.7 +/- 11.4 mm Hg versus 99.9 +/- 10.3 mm Hg, p = 0.03), and a larger ventricular-to-intracranial-cavity ratio (6.3 +/- 5.6% versus 4.7 +/- 1.6%, p = 0.02). Individuals with WMH performed worse than their counterparts without such abnormalities on all tests administered. After adjusting for the group differences in age, arterial blood pressure, and ventricular size, we noted statistically significant results on form B of the Trail Making Test (121.8 +/- 37.8 msec versus 100.3 +/- 47.9 msec, p = 0.04), a complex reaction time task (680.8 +/- 104.9 msec versus 607.1 +/- 93.9 msec, p = 0.001), and the assembly procedure of the Purdue Peg-board Test (27.5 +/- 5.8 versus 30.6 +/- 5.9, p = 0.02). Partial correlations did not reveal any relationship between test scores and the semiautomatically assessed total area of WMH. Our data suggest that the presence of WMH exerts a subtle effect on neuropsychologic performance of normal elderly individuals, which becomes particularly evident on tasks measuring the speed of more complex mental processing.
Adult↗
Brain magnetic resonance imaging in coronary artery bypass grafts: a pre- and postoperative assessment.
We undertook a study to determine (1) the frequency and prognostic significance of preexisting MRI brain abnormalities in patients undergoing coronary artery bypass grafts (CABG) and (2) whether MRI can detect surgery-related brain damage in 31 neurologically asymptomatic CABG patients (mean age, 61.0 +/- 6.6 years). MRIs were performed within 7 days before and 8 to 17 days after surgery. When we compared the preoperative images with those of 31 age- and risk factor-matched neurologically asymptomatic controls free of cardiac disease (mean age, 60.3 +/- 6.1 years), higher rates of thromboembolic infarcts (16% versus 0%), lacunes (58.1% versus 32.3%), and brainstem lesions (22.6% versus 3.8%) were noted. Subjective rating demonstrated significantly larger ventricles in patients than in controls (p = 0.002). CABG candidates also had significantly increased ventricular-to-intracranial cavity ratios (VICR) as determined by semiquantitative volumetric measurements (6.9 +/- 2.5% versus 4.9 +/- 1.6%; p = 0.0004). Eleven patients had postsurgical complications, with eight having symptoms consistent with diffuse encephalopathy. The only MRI finding that separated encephalopathic from complication-free patients was ventricular size (VICR 9.0 +/- 2.5% versus 4.9 +/- 1.6%; p = 0.006). This difference remained statistically significant after adjustment for the effects of age (p = 0.04). Postoperative MRI consistently failed to demonstrate surgery-related brain damage responsible for the encephalopathy.
Aged↗
Assessment of MRI criteria for a diagnosis of MS.
To test the reliability of four previously proposed MRI criteria for the diagnosis of MS, we reviewed 1,500 consecutive brain scans for the presence, number, size, and location of areas of increased signal (AIS) on proton-density and T2-weighted images, unaware of the patients' clinical presentations and ages. This series included 134 subjects with a clinical diagnosis of MS. Relying exclusively on the presence of at least three or four AIS for a positive diagnosis of MS resulted in high sensitivity (90% for three AIS and 87% for four) but inadequate specificity (71% for three AIS and 74% for four) and positive predictive value (23% for three AIS and 25% for four). If one of these lesions was required to border the lateral ventricles, specificity was 92% and positive predictive value was 50% at a sensitivity of 87%. Using the Fazekas criteria (at least three AIS and two of the following features: abutting body of lateral ventricles, infratentorial lesion location, and size > 5 mm) led to a further highly significant improvement of specificity (96%; p = 0.0000) and increase of the positive predictive value (65%) at the expense of a less significant decrease in sensitivity (81%; p < 0.01).
Adolescent↗
Pathologic correlates of incidental MRI white matter signal hyperintensities.
We related the histopathologic changes associated with incidental white matter signal hyperintensities on MRIs from 11 elderly patients (age range, 52 to 82 years) to a descriptive classification for such abnormalities. Punctate, early confluent, and confluent white matter hyperintensities corresponded to increasing severity of ischemic tissue damage, ranging from mild perivascular alterations to large areas with variable loss of fibers, multiple small cavitations, and marked arteriolosclerosis. Microcystic infarcts and patchy rarefaction of myelin were also characteristic for irregular periventricular high signal intensity. Hyperintense periventricular caps and a smooth halo, however, were of nonischemic origin and constituted areas of demyelination associated with subependymal gliosis and discontinuity of the ependymal lining. Based on these findings, our classification appears to reflect both the different etiologies and severities of incidental MRI signal abnormalities, if it is modified to treat irregular periventricular and confluent deep white matter hyperintensities together.
Aged↗
Magnetic resonance imaging signal hyperintensities in the deep and subcortical white matter. A comparative study between stroke patients and normal volunteers.
Mixed population studies suggest a relationship between deep and subcortical white matter hyperintensities on magnetic resonance imaging and cerebrovascular disease. To further clarify this issue we compared the prevalence and extent of such signal abnormalities between a group of 133 consecutive stroke patients (mean age, 54.7 +/- 16.7 years) and 101 normal volunteers (mean age, 54.7 +/- 13.1 years). Diabetes and cardiac disease were significantly more common in patients than in normal subjects. Prevalence rates of clinically silent lesions were 44% and 47.5%, respectively. Beginning confluent and confluent foci were seen in 19.5% of patients, but in only 7.5% of normal subjects. Significant univariate correlations were found for the presence and extent of lesions with age, diabetes, cardiac disease, severity of extracranial carotid arteriosclerosis, and arterial hypertension, but not with the diagnosis of stroke or the type of brain infarction. Multivariate regression analysis established age and diabetes mellitus as the only independent predictors of white matter damage. We conclude that more extensive white matter abnormalities in stroke patients stem from their higher rate of cerebrovascular risk factors but are unrelated to the occurrence of ischemic attacks per se.
Adolescent↗
The prevalence of cerebral damage varies with migraine type: a MRI study.
Studies on the prevalence of MRI signal abnormalities in the brains of migraineurs have yielded controversial results. In order to provide further data on this issue we reviewed the MRI scans of 38 migraine patients without current neurologic symptoms (mean age 35.8 +/- 11.9 years). In addition, we compared the findings in those 24 migraineurs under 50 years without major cerebrovascular risk factors (mean age 30.1 +/- 9.0 years) to that in 14 headache and risk factor free volunteers (mean age 37.8 +/- 5.3 years). Overall, focal areas of hyperintense signal were seen in 15 (39%) patients. They were present on both proton density and T2-weighted spin-echo sequences. Lesion prevalence varied according to the type of headache (18% in migraine without aura, 53% in migraine with typical aura, 38% in basilar migraine). The subset of migraine patients under 50 years exhibited MRI signal abnormalities more than twice as often as controls (33% vs. 14%). Punctate white matter hyperintensities were the predominant finding and were seen in 10 of 15 individuals with MRI lesions. More striking signal abnormalities consisted of symmetrical areas of hyperintensity lateral to the posterior horns in two 24 year old patients and of extensive white matter damage with lacunar infarcts in a 59 year old woman. Our findings confirm a higher prevalence of MRI lesions in a mixed group of migraineurs than in headache free individuals. Signal abnormalities are most often non-specific, however their occurrence relates to the type of migraine.
Adolescent↗
The diagnostic impact of magnetic resonance imaging on the evaluation of suspected spinal cord disease.
The data from 262 patients studied consecutively for suspected spinal cord disease were analysed to determine the utility of magnetic resonance imaging (MRI) in this clinical setting. Damage to the spinal cord was detected in a total of 188 (72%) patients and was caused by myelocompression in two thirds and by intramedullary lesions in one third of the patients. Misleading sensory levels 5 to 12 segments below the actual lesion site were seen in 26% of patients with both extra- and intramedullary types of abnormality. A negative spinal MRI implied predominantly demyelinating or inflammatory origin of the clinical symptomatology, as was indicated by additional MRI studies of the brain and CSF findings. It is concluded that MRI is the procedure of choice for assessing patients with medullary symptoms. Irrespective of localizing neurologic findings the evaluation of the entire spine and even of the brain may be necessary to obtain maximum diagnostic information.
Adolescent↗
Magnetic resonance imaging white matter lesions and cognitive impairment in hypertensive individuals.
To search for a morphologic basis of cognitive impairment possibly associated with essential hypertension, we studied 35 otherwise asymptomatic hypertensive individuals (mean age, 38.7 years; range, 22 to 49 years) and 20 normotensive control subjects (mean age, 37.9 years; range, 26 to 49 years) using neuropsychologic tests and magnetic resonance imaging. Irrespective of drug treatment, hypertensive individuals performed significantly worse than did control subjects when assessed for verbal memory and total learning and memory capacity, while there were no differences in test results of visual memory, attention, vigilance, and reaction time. The hypertensive individuals also described themselves as less active but ranked similar on five other mood subscales. Punctate high-signal intensities of the white matter were found almost twice as often in the hypertensive group (38%) as in the control group (20%). There was no difference in test performance between hypertensive individuals with and those without white matter lesions, however. Our results confirm the presence of subtle neuropsychologic deficits and indicate a higher frequency of white matter signal abnormalities in essential hypertension, as shown on magnetic resonance imaging, but do not indicate a correlation of these findings with each other.
Adult↗
MRI in tuberculous meningoencephalitis: report of four cases and review of the neuroimaging literature.
The contribution of MRI is reported in four adult patients with tuberculous meningoencephalitis (TbM) and with autopsy correlation in one. Contrast-enhanced T1-weighted MRI revealed the characteristic basal meningeal inflammation of TbM and its focal spreading into adjacent brain. Mixed and T2-weighted pulse sequences delineated a plethora of parenchymal abnormalities. Their relation to TbM was established by a close matching of the patient's neurological findings, contrast enhancement or a change in lesion size. The latter accurately reflected the clinical course in all patients. It remained difficult, however, to distinguish between ischaemic and inflammatory changes, which in some locations were intermixed even histologically. From our experience and that of other groups, MRI provides more diagnostic information in TbM than CT. Moreover, MRI promises to be a useful tool for monitoring treatment response.
Adolescent↗
Brain magnetic resonance imaging and neuropsychologic evaluation of patients with idiopathic dilated cardiomyopathy.
We compared brain magnetic resonance imaging and neuropsychologic performance in 20 neurologically asymptomatic patients suffering from idiopathic dilated cardiomyopathy (mean age 41 [range 18-49] years) and 20 age-matched controls (mean age 38 [range 28-49] years). Patients exhibited a significantly higher rate of cerebral infarcts (20% versus 0%, p less than 0.05) and cortical (50% versus 5%, p less than 0.01) and ventricular (55% versus 15%, p less than 0.02) atrophy than controls. Accordingly, semiquantitative volumetric measurements yielded a significantly increased ventricular-to-intracranial cavity ratio in the patients (6.2 +/- 2.9% versus 4.1 +/- 1.3%, p less than 0.01). This ratio and the cortical atrophy ratings correlated positively with disease duration (r = 0.63 and 0.54, p less than 0.05). Cognitive test performance was significantly worse in patients than in controls and was most impaired in those patients with morphologic cerebral abnormalities.
Adult↗
Superficial siderosis of the spinal cord: a rare cause of myelopathy diagnosed by MRI.
Repeated bleeding into CSF spaces may cause superficial siderosis with progressive neurologic impairment. The unique physical properties of MRI provide a basis for the in vivo diagnosis of this entity.
Female↗
White matter signal abnormalities in normal individuals: correlation with carotid ultrasonography, cerebral blood flow measurements, and cerebrovascular risk factors.
We studied 52 asymptomatic subjects using magnetic resonance imaging, and we compared age-matched groups (51-70 years old) with and without white matter lesions with respect to carotid ultrasonography, cerebral blood flow (xenon-133 injection), and cerebrovascular risk factors. In the group with white matter signal abnormalities, we noted a higher frequency of extracranial carotid artery disease, a lower mean gray matter blood flow (F1), and a significant reduction (p less than 0.05) in blood flow of the slow-flowing (F2) compartment. Hypertension, diabetes mellitus, and cardiac diseases (p less than 0.002) were found more often in this group. Our results indicate that a higher incidence of changes known to be associated with an increased risk for stroke exists in the presence of white matter lesions in normal elderly individuals.
Adult↗
Nuclear magnetic resonance image white matter lesions and risk factors for stroke in normal individuals.
The incidence, average number, and localization of lesions of the white matter detected by the T2-weighted nuclear magnetic resonance images among volunteers without cerebrovascular symptoms have been correlated with the number of risk factors for stroke. Accepted risk factors were arterial hypertension, diabetes mellitus, smoking, hypercholesterolemia, and cardiac disease. The 42 subjects examined were divided into Group A (0-1 risk factor, mean age 59.36 +/- 5.73 years), Group B (2 risk factors, mean age 61.54 +/- 8.33 years), and Group C (greater than or equal to 3 risk factors, mean age 62.57 +/- 9.83 years). Multiple risk factors among the age-matched groups was accompanied by a highly significant increase (p less than 0.001, Group A versus Group B; p less than 0.01, Group A versus Group C) of the incidence of white matter lesions. The average number of white matter lesions was increased (p less than 0.001) when Group A was compared with Groups B and C. Ninety-two percent of the white matter lesions were localized in watershed zones. Only 11 of the 155 abnormalities of the white matter detected by nuclear magnetic resonance imaging could be detected by computed tomography. White matter lesions in T2-weighted images appear to be an early stage of cerebrovascular disease.
Brain↗
Criteria for an increased specificity of MRI interpretation in elderly subjects with suspected multiple sclerosis.
We reviewed the MRIs of 49 asymptomatic volunteers (age range, 31 to 77 years) and of 50 MS patients (age range, 14 to 63) for areas of increased signal (AIS) and features discriminating MS lesions from lesions seen with normal aging. We obtained optimal specificity of MRI interpretation (100%) if we required at least two of the following three AIS features--size greater than or equal to 6 mm, abutting ventricular bodies, infratentorial location--for a positive MRI diagnosis of MS. Applying these criteria to the MRIs of elderly patients with suspected MS should significantly improve specificity (p less than 0.001) over current quantitative criteria (at least three AIS greater than or equal to 3 mm) without significantly decreasing sensitivity.
Adolescent↗