Biomedical subjects

K Terstegge

Publications and source records attributed to K Terstegge.

16 recordsLinked to original sources

PubMed1997

MR anatomy and small lesions of the eye: improved delineation with a special surface coil.

To develop an improved investigation protocol for MRI studies of intraocular lesions, imaging with a small surface coil (diameter 6 cm) was compared with a standard surface coil (diameter 11 cm). Both coils were assessed initially on an eye phantom and then by studying 22 patients with uveal melanoma and similar lesions of the eye. The influence of bandwidth and field or view (FOV) were systematically studied and evaluated quantitatively. A smaller bandwidth improved image quality independent of surface coil size. The subsequent secondary increase in chemical shift artefact was acceptable. Smaller FOVs (60-80 mm) necessitated the use of a smaller surface coil. A smaller bandwidth also proved to be advantageous with the use of the smaller surface coil. In conclusion, a smaller-diameter surface coil improves MR imaging of ocular lesions. Pulse sequences with a small bandwidth maintain an acceptable signal-to-noise ratio when the FOV is reduced.

Artifacts↗

PubMed1996

Fast spin-echo MR imaging of the eye.

Magnetic resonance imaging of the eye usually includes T2-weighted images both for screening purposes and for characterization of melanoma. Conventional T2-weighted spin-echo (SE) imaging suffers both from long acquisition times and incomplete recovery of the vitreous' signal. A fast SE sequence was therefore compared prospectively with conventional sequences in 29 consecutive patients with lesions of the eye. Fast SE images delineated melanoma and other lesions of the eye from vitreous better than conventional T2-weighted images. Image quality and lesion conspicuity were improved on the fast sequence. Whereas melanoma appeared hypointense to vitreous on both types of images, subretinal effusion was hypointense on fast images and hyperintense on conventional T2-weighted images. Ghosting of the globe, which, however, did not decrease diagnostic value, was more pronounced on fast images. Conventional T2-weighted images may be replaced by fast SE images in MR studies of the eye with a gain in lesion conspicuity and significant time saving.

Eye Neoplasms↗

PubMed1996

Regional association of developmental venous anomalies with angiographically occult vascular malformations.

This study reviews the neuroradiological findings of 43 patients with a developmental venous anomaly in order to discuss the clinical significance of this entity. All patients underwent unenhanced and contrast-enhanced computer tomography and magnetic resonance tomography, as well as selective angiography, and were followed for at least 2 years. In 40% (17 of 43) of patients a cryptic vascular malformation was found in the proximity to the developmental venous anomaly. Neurological symptoms were present in 8 of 17 patients (47%) in this group. Patients with an isolated developmental venous anomaly had symptoms in 19% (5 of 26), but none of them had experienced a hemorrhage. Magnetic resonance was the most sensitive method for the diagnosis of both types of lesions and alterations of the adjacent parenchyma. These results further support that developmental venous anomalies represent a clinically benign entity. However, patients with an association of a developmental venous anomaly and a cryptic vascular malformation are at risk for hemorrhage from their angiographically occult vascular malformation. Magnetic resonance proved to be the imaging modality of choice for both entities and is appropriate for diagnosis and follow-up.

Adolescent↗

PubMed1995

Otorhinolaryngological complications of progressive facial hemiatrophy (Romberg's disease).

Progressive facial hemiatrophy (PFH) is characterized by slowly progressive atrophy of subcutaneous tissue. Bone, muscles, nerves, the eye, and the brain may be affected by atrophy. Four patients suffering from various otorhinolaryngological complications of PFH or Romberg's disease are reported. Unilateral hearing loss could be located in the inner ear of one patient by audiologic examination. Localized bone destruction and disintegration of a portion of the anterior wall of the frontal sinus were observed in a patient after more than three decades. Marked shrinking of the homolateral parotid gland and homolateral masticatory spasm are reported as further otorhinolaryngological manifestations. The various complications of PFH call for close interdisciplinary cooperation.

Child↗

PubMed1995

[Magnetic resonance of brain involvement in progressive facial hemiatrophy (Romberg's disease). Reconsideration of a syndrome].

UNLABELLED: Progressive facial hemiatrophy (PFH) is a sporadic disease of unclear etiology, characterized by shrinking and deformation of one side of the face. Reports and interpretations of CNS involvement in PFH, as deduced from the occurrence of seizures in some patients and documented by pneumoencephalography and CT findings in small series of patients, are contradictory. We examined three female patients with PFH, one with partial epilepsy, with the view to gaining further insight into the pathogenesis of the disease. METHODS: Routine MR examinations of the head and face were performed. RESULTS: Only the patient with epilepsy showed pathological findings, confined to the cerebral hemisphere homolateral to the facial hemiatrophy, and including monoventricular enlargement, meningo-cortical dysmorphia and white matter changes. CONCLUSIONS: The MR morphology, and corresponding neuroradiological and histopathological findings disclosed by a review of the literature, indicate that homolateral hemiatrophy is a typical finding for a subgroup of PFH patients, but do not support the model of a simple or nutritive atrophic process. We reconsider chronic localized meningo-encephalitis with vascular involvement as possible underlying cause of the occasional brain involvement in PFH.

Adult↗

PubMed1995

[Magnetic resonance angiography of intracranial aneurysms after subarachnoid hemorrhage].

Magnetic resonance angiography is now commercially available for a variety of scanners and is being increasingly applied in the diagnosis of cerebrovascular disorders. Considering the clinical consequences, especially in intracranial aneurysms, studies to determine the sensitivity and specificity of the method are essential. Here we report our experience with a 3D-FISH time-of-flight magnetic resonance angiography protocol in 52 patients who have suffered an acute subarachnoid hemorrhage. In 26 of the 52 patients, conventional angiography identified 31 aneurysms (3-20 mm) that were confirmed during surgery or autopsy. Magnetic resonance angiography correctly identified 28 of the 31 aneurysms (sensitivity 90.3%) and missed one ruptured (3 mm) and two incidental aneurysms (3 mm) in patients with multiple aneurysms. The sensitivity for a ruptured aneurysm was 96%. The 26 patients who suffered subarachnoid hemorrhage without evidence of an intracranial aneurysm on repeated angiography served as a control group. Magnetic resonance angiography revealed no false-positive findings, resulting in a specificity of 100%. In correlation with the literature, we conclude that magnetic resonance angiography is not sensitive enough for the management of acute subarachnoid hemorrhage. However, the method provides important complementary information for definition of the bleeding site in patients with multiple aneurysms. In addition, the calculation of projections not possible with conventional angiography can aid surgical planning. Since only very small aneurysms were missed by magnetic resonance angiography, the sensitivity seems appropriate to screen asymptomatic patients who are at risk for intracranial aneurysms.

Adolescent↗

PubMed1994

Wernicke's encephalopathy--causes to consider.

Wernicke's encephalopathy (WE) is a thiamine deficiency disorder and is characterized clinically by the triad of ocular abnormalities, ataxia and disturbances of consciousness. We report on 3 patients with WE, of whom 2 had insufficient thiamine substitution. In the first patient symptoms disappeared during thiamine substitution. In the second patient acute WE was the terminating event in the sequence of parenteral nutrition, lactic acidosis and cardio-pulmonary decompensation. Possibly due to hereditary deficits WE developed in the third patient despite sufficient thiamine substitution. Attention to thiamine deficiency should be paid in all patients with history of alcoholism, malnutrition, malabsorption, tumors, inflammation, other severe diseases and in parenteral hyperalimentation. In order to prevent WE thiamine should be substituted with at least 100 mg/day i.v. or i.m.

Adult↗

PubMed1994

Vasculitic, hypoxic-ischemic leukoencephalopathy.

The case of a 67-year-old woman with terminal renal insufficiency, who developed extensive encephalopathy with predominant involvement of the white matter is reported. The encephalopathy was the consequence of preexisting hypertensive alterations, acidosis, hypoxia, ischemia, bacteremia and varicella-zoster meningoencephalitis. The vasculitic alterations associated with meningoencephalitis had a major influence on the development and the extent of the leukoencephalopathy.

Aged↗

PubMed1994

MR of brain involvement in progressive facial hemiatrophy (Romberg disease): reconsideration of a syndrome.

PURPOSE: To gain further insight into the pathogenesis of progressive facial hemiatrophy, a sporadic disease of unclear etiology characterized by shrinking and deformation of one side of the face. METHODS: We investigated possible brain involvement. MR of the head and face was performed in three female patients with progressive facial hemiatrophy. The central-nervous-system findings were correlated to a clinical protocol and a review of the literature. RESULTS: One patient with epilepsy had abnormal brain findings confined to the cerebral hemisphere homolateral to the facial hemiatrophy. These consisted of monoventricular enlargement, meningocortical dysmorphia, and white-matter changes. CONCLUSIONS: These MR findings, and corresponding neuroradiologic data disclosed by the review, indicate that homolateral hemiatrophy occasionally occurs in a subgroup of patients with progressive facial hemiatrophy. The MR features do not seem consistent with an underlying simple or nutritive atrophic process. We propose chronic localized meningoencephalitis with vascular involvement as a possible underlying cause of the occasional brain involvement in progressive facial hemiatrophy.

Adult↗

PubMed1994

Hyperostosis in meningiomas: MR findings in patients with recurrent meningioma of the sphenoid wings.

PURPOSE: We used MR imaging to analyze retrospectively the pattern of hyperostosis occurring concomitantly with recurrent sphenoid wing meningiomas. METHODS: Bone involvement was compared in 12 corresponding CT and MR studies of 10 female patients with sphenoid wing meningiomas recurrence after earlier surgical treatment. Four of these had histologically confirmed meningiomatous infiltration of the bone. RESULTS: All patients had CT findings of localized hyperostosis of parts of the sphenoid wings. MR revealed inhomogeneous areas of slightly increased signal intensity in hyperostotic bone on T2-, proton density- and T1-weighted sequences. In nine of 10 patients, segments of the hyperostotic bone showed different degrees of gadolinium enhancement. CONCLUSIONS: Because earlier studies have revealed high incidences of meningiomatous bone infiltration in sphenoid wing meningiomas, and because infiltration was confirmed in four of our patients, we postulate that the gadolinium enhancement in the area of hyperostosis may be related to meningiomatous bone infiltration.

Adult↗

PubMed1993

Spectral power and coherence analysis of sleep EEG in AIDS patients: decrease in interhemispheric coherence.

Fifteen patients aged between 26 and 55 years with the acquired immunodeficiency syndrome (AIDS) and various cerebral manifestations of the disease underwent an all-night sleep electroencephalogram (EEG) registration. The recordings of 15 age-matched volunteers were examined as controls. Sleep stages were determined visually and the following spectral analysis was based on corresponding artifact-free 40-second periods. The sampling rate was 64 second-1, the spectral resolution was 0.25 Hz and the frequency ranged from 0.25-24 Hz. The power density spectra of eight EEG derivations (left and right frontopolar, frontal, central and occipital; reference montage to the ipsilateral Cb electrodes) and the coherence spectra of interhemispheric (interfrontal, interoccipital) and intrahemispheric (frontooccipital, left and right) channel pairs were computed. The power density of the patients in the 11.5-13-Hz frequency range of nonrapid eye movement (NREM) sleep was considerably lower than that of the controls (p < 0.05 and p < 0.01 at left and right frontal derivations, two-tailed Mann-Whitney U test). The power density of rapid eye movement (REM) sleep showed no consistent differences between the two groups. The interfrontal coherence of the whole frequency range below 12 Hz was markedly lower in the patient group. This applied to NREM sleep and also to REM sleep (p < 0.01 and p < 0.001 for different frequency bands between 1 and 12 Hz in NREM and REM sleep). Possible relations to clinical features are discussed.

Acquired Immunodeficiency Syndrome↗

PubMed1993

[Cerebral manifestations of progressive facial hemiatrophy (Romberg's disease). Nuclear spin tomographic findings and literature review].

Progressive facial hemiatrophy (PFH) is a sporadic disease of unknown etiology. It is characterized by shrinking and deformation of one side of the face. Potential CNS involvement has repeatedly been suspected in some patients, but is still a matter of controversy. In this article we describe the clinical and MR imaging findings of the CNS in three female patients with PFH and present a comprehensive review of the literature. One of three PFH patients had partial epilepsy. MRI showed ventricular enlargement, white matter lesions, flattening of the cortical surface and meningeal adhesions homolateral to the facial hemiatrophy. Two other patients had completely normal intracranial findings. These findings confirm that cerebral hemiatrophy occurs in a subgroup of PFH patients. The MRI pattern, however, does not seem to be consistent with a simple atrophic or malnutritional process. We consider chronic localized meningoencephalitis with vascular involvement as a possible underlying mechanism for the occasional CNS involvement in PFH.

Adult↗

PubMed1991

Oxalate-induced encephalitis after infusions of sugar surrogates.

The case of a 55-year-old female with oxalate-induced lethal encephalitis following infusions of sugar surrogates is reported. Renal failure and subsequent central coma developed following the use of xylitol, fructose and sorbitol above the recommended dosages. The patient died due to raised intracranial pressure. Cerebral damage was caused by encephalitis due to calcium oxalate crystals. Oxalosis induced by sugar surrogates may be explained either by dose-dependent toxic effects or genetically fixed intolerance.

Biopsy↗

PubMed1989

[Visual motor coordination of AIDS patients, HIV-positive asymptomatic probands and healthy persons during video-tracking].

Here we investigated the applicability of a computer-aided video-tracking as a method for evaluating potential deficits of neural information processing in patients with AIDS and those showing only positive HIV-seroreactivity. Video-tracking was accompanied with a simultaneous recording of EEG. Eight HIV-positive asymptomatic volunteers and eight AIDS-patients with cerebral manifestation of the disease participated in the pilot study. Two groups of eight normals each served as a control. Video-tracking performance of the HIV-positive volunteers and AIDS-patients significantly differed (p less than 0.05) from those of the healthy volunteers. Although the AIDS-patients' performance tended to be worse than that of the HIV-group, this difference was not significant. Power spectrum analysis of the EEG-data indicated that the diminished performance of the two test groups (AIDS and HIV-positives), accompanied by an increased spectral power across the entire frequency range measured in the study, could be an expression of an enhanced synchronization in cortical neuronal networks. The synchronization in turn could be a sign of possible organic brain damage resulting from HIV-infection. In conclusion, we suppose that video-tracking measures parameters which may indicate early deficits of information processing in CNS.

Acquired Immunodeficiency Syndrome↗

PubMed1989

[Effects of flurazepam on disturbed sleep in patients with AIDS].

Polysomnograms were recorded of twelve patients with acquired immune deficiency syndrome (AIDS) during different stages in an open design. During the first night no hypnotics were administered, during the second night 30 mg flurazepam per os were given. Flurazepam affected mainly the NREM parameters. The times "awake" during the night were reduced, sleep stage 2 showed an increase, and the effective sleep time was also increased. The increase in sleep spindle density was remarkable, however, delta sleep and generation of K-complexes were not affected. Flurazepam did not affect REM sleep at all. The amount of REM sleep showed a slight increase. REM distribution during the night did not show the "bell shaped" increase and the decrease in the morning; the degree of the illness correlated with a flattening of REM distribution.

Acquired Immunodeficiency Syndrome↗

PubMed1989

[Spectral power density and coherence in sleep EEG in patients with acquired immunodeficiency syndrome].

15 male AIDS-patients from 26 to 55 years (mean 41.8 +/- 8.5) with various cerebral manifestations had a whole-night-sleep-EEG registration. As control the recordings of 15 age-matched volunteers (26-55 years, mean 41.8 +/- 9.8) were examined. Spectral characteristics of elementary EEG-epochs of 40 s length were computed, and sleep staging was performed visually for these intervals. The spectral power density of eight EEG-derivations (left and right frontopolar, frontal, central and occipital electrodes, reference montage to the ipsilateral Cb) were measured (sampling rate 64(-1) s, spectral resolution .25 Hz, frequency range from .25 to 24 Hz). Interhemispherical coherences of the frontal and occipital derivation pairs, and intrahemispherical fronto-occipital coherences of the left and right hemisphere, were computed. In the patients the frontal power density of NREM sleep showed lower values in the frequency range of 10 to 14 Hz. In central and in occipital derivations the power density between 12.5 and 15 Hz was lower in the patients, but the difference was less accentuated. The spectral power density of REM sleep showed similar characteristics in both groups. The interhemispherical frontal coherence of the whole frequency range below 13 Hz was markedly lower in the patient group. This was true for the NREM sleep, and, slightly less, for the REM sleep, too. The interoccipital spectral coherence was generally slightly lower in the patient group; the difference was most clearly in the 12.5 to 15 Hz range of NREM sleep.

Acquired Immunodeficiency Syndrome↗