[Unusual appearance picture of intracranial extra-axial metastasis of prostatic carcinoma].
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Aged↗
Biomedical subjects
M Knauth
Publications and source records attributed to M Knauth.
[Tuberculous osteomyelitis of the skull cap with epidural and subgaleal tuberculoma].
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Adolescent↗
Trigemino-cardiac reflex during skull base surgery: a new entity of ischaemic preconditioning? The potential role of imaging.
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Autonomic Nervous System Diseases↗
[Transcranial color-coded duplex ultrasonography of arteriovenous malformations].
PURPOSE: Using transcranial color coded duplex sonography (TCCS) it is possible to visualize intracranial arteriovenous malformations (AVMs). The purpose of this study is to describe their typical ultrasonographic features and to define sensitivity for diagnosis with regard to the localization of an AVM. MATERIALS AND METHODS: Over a period of six years we prospectively examined 54 intracranial AVMs confirmed by angiography. Using TCCS the vessels of the circle of Willis were identified by location, course and direction of flow on color flow images. The examination was performed during the first three years of the study using the Acuson 128 XP 10 system, equipped with a sector transducer with a 2.0/2.5 - MHz imaging frequency for the transcranial examination, and with a 7.0 MHz linear transducer fot the extracranial examination. During the second three years of the study, transcranial examination was performed with an Acuson Seqouia 512 ultrasound system equipped with a 2 - 4 MHz phased array transducer. RESULTS: In accordance with digital subtraction angiography, the intracranial AVMs could be visualized in 42 cases (77.8 %). The major feeding vessels of the AVMs could be easily identified due to typical hemodynamic parameters showing increased systolic and diastolic flow velocities and decreased pulsatility index. We failed to visualize AVMs localized near the cortex, i. e. in the parietal, frontal, occipital and cerebellar regions of the brain. In contrast, 88.9 % of AVMs localized in the basal regions were very easy to image. Additionally, TCCS was useful for postoperative or postinterventional follow-up, although only a limited number of patients could be examined by TCCS in the post-treatment period. CONCLUSION: TCCS is a noninvasive method for the diagnosis and possibly valuable in the long-term follow-up of intracranial AVMs. However, further research is needed to establish TCCS as an imaging modality in the follow-up after treatment of AVMs. The method can be regarded as a useful supplement to the palette of established, noninvasive diagnostic techniques such as MRI and MRA. However, since TCCS cannot rule out an AVM, angiography is still the method of choice for the definitive diagnosis.
Adult↗
[Spontaneous dissection of the internal carotid artery with ipsilateral Collet-Sicard syndrome].
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Accessory Nerve Diseases↗
A case of cerebral Whipple's disease initially presenting with isolated focal myoclonus.
Neurological manifestations in Whipple's disease are highly variable and tend to occur at later stages of the disease. However, isolated, focal neurological symptoms are reported to be rare. Here we describe the successful treatment of a case of cerebral Whipple's disease initially presenting solely with isolated myoclonic jerks of the left hand and forearm evolving to a segmental myoclonus at a later stage. Additionally, we present - to our knowledge - a novel treatment by administration of immunomodulatory therapy (IVIg) in addition to established antibiotics.
Adult↗
Creutzfeldt-Jakob disease: comparative analysis of MR imaging sequences.
BACKGROUND AND PURPOSE: MR imaging has played an increasingly important role in the diagnosis of Creutzfeldt-Jakob disease (CJD) since basal ganglia abnormalities on T2-weighted images have been described; thus, the aim of our study was to compare the value of different MR images in the diagnosis of CJD. METHODS: One hundred fifty-seven patients with CJD underwent MR imaging examinations. Ninety-two patients were neuropathologically confirmed, and 65 were clinically classified as having CJD through the CJD Surveillance Unit (probability of 95%). There was no standardized MR imaging protocol; thus, the examinations included 143 T2-weighted, 43 proton attenuation (PD)-weighted, 84 fluid-attenuated inversion recovery (FLAIR), and 44 diffusion-weighted images (DWI). The MR images were reviewed for pathologic changes of the basal ganglia, thalamus, and cerebral cortex. RESULTS: Cortical abnormalities were present in 70 patients (45%) and were visible in 80% (35/44) of all available DWI examinations. The basal ganglia were affected in 94 patients (60%), in particular in the caudate nucleus; the most sensitive sequences were DWI (64%) and PD-weighted (63%). A thalamic involvement was more frequently diagnosed on PD-weighted images (19%) and DWI (14%) than on FLAIR or T2-weighted images. CONCLUSION: PD-weighted images and DWI showed better results in the diagnosis of signal intensity changes in the basal ganglia compared with T2-weighted or FLAIR images; however, in the diagnosis of cortical changes, DWI was clearly superior. Our data suggest that DWI is the most sensitive MR imaging technique in the diagnosis of CJD.
Basal Ganglia↗
Hyperacute intracerebral hemorrhage complicating carotid stenting should be distinguished from hyperperfusion syndrome.
We describe a patient who experienced a fatal ipsilateral basal ganglia hemorrhage within an hour after carotid angioplasty and stent placement. In the few similar cases published there were no prodromata, but hyperacute onset of severe neurologic deterioration corresponding to intracerebral hemorrhage (ICH). Our findings suggest that besides the delayed ICH that is associated with hyperperfusion syndrome (HPS), a second type of hyperacute and usually fatal ICH exists that resembles hypertensive hemorrhage.
Aged↗
Sporadic Creutzfeldt-Jakob disease: clinical and diagnostic characteristics of the rare VV1 type.
BACKGROUND: Recently, six molecular subtypes of sporadic CJD (sCJD) have been identified showing differences regarding the disease course, neuropathologic lesion patterns, and sensitivity to diagnostic tools. Only isolated cases of the rare VV1 type have been reported so far. OBJECTIVE: To describe the clinical characteristics and neuropathologic lesion profiles in nine cases. METHODS: In the years 1993 until late 2003, 571 definite neuropathologically confirmed cases of sporadic CJD were identified in Germany. Of these, nine were homozygous for valine and displayed type 1 of the pathologic PrPSc in the brain (VV1 type). RESULTS: The authors describe eight men and one woman belonging to the VV1 type. All patients were relatively young at disease onset (median 44 years vs 65 years in all sCJD) with prolonged disease duration (median 21 months vs 6 months in all sCJD). During the initial stages, their main clinical signs were personality changes and slowly progressive dementia as well as focal neurologic deficits. None of the nine VV1 patients had periodic sharp-wave complexes (PSWCs) in the EEG. Only two out of seven displayed the typical signal increase of the basal ganglia on MRI, whereas signal increase of the cortex was seen in all patients. The 14-3-3 protein levels were elevated in CSF in all cases tested. CONCLUSIONS: The clinical diagnosis of the VV1 type of sCJD can be best supported by the 14-3-3 test and cortical signal increase on MRI. Because of the young age at onset vCJD is sometimes suspected as a differential diagnosis. MRI plays an important role in differentiating these two disease types and should be performed early during the disease course.
14-3-3 Proteins↗
Three-dimensional reconstruction and volumetry of intracranial haemorrhage and its mass effect.
Intracerebral haemorrhage still causes considerable disability and mortality. The studies on conservative and operative management are inconclusive, probably due to inexact volumetry of the haemorrhage. We investigated whether three-dimensional (3-D), voxel-based volumetry of the haemorrhage and its mass effect is feasible with routine computed tomography (CT) scans. The volumes of the haemorrhage, ventricles, midline shift, the intracranial volume and ventricular compression in CT scans of 12 patients with basal ganglia haemorrhage were determined with the 3-D slicer software. Indices of haemorrhage and intracranial or ventricular volume were calculated and correlated with the clinical data. The intended measures could be determined with an acceptable intra-individual variability. The 3-D volumetric data tended to correlate better with the clinical course than the conventionally assessed distance of midline shift and volume of haemorrhage. 3-D volumetry of intracranial haemorrhage and its mass effect is feasible with routine CT examination. Prospective studies should assess its value for clinical studies on intracranial space-occupying diseases.
Adult↗
Fatal subarachnoid hemorrhage after carotid stenting.
BACKGROUND AND PURPOSE: Cerebral hyperperfusion syndrome with intracerebral hemorrhage (ICH) following carotid angioplasty and stent placement (CAS) of the internal carotid artery (ICA) is well known. We report the occurrence of fatal subarachnoid hemorrhage in a patient undergoing CAS. CASE REPORT: A 77-year-old woman experiencing a left-hemispheric transient ischemic attack underwent CAS for a 95% stenosis of the left ICA. CAS was performed without acute complications. At 5 hours the patient suddenly deteriorated. Her level of consciousness changed and she developed neck stiffness. CT of the brain revealed diffuse SAH with acute hydrocephalus. CONCLUSIONS: Like ICH, SAH may develop as a severe complication after CAS. There are no reliable clinical symptoms preceding this fatal complication. However, several factors such as long-standing severe carotid stenosis with contralateral occlusion and increasing blood pressure after CAS accompanied by the extensive use of antithrombotic agents may predispose to this fatal complication.
Aged↗
[Current use and possible future applications of the magnetization transfer technique in neuroradiology].
Magnetization transfer (MT) imaging is a special MR technique used for selective suppression of the MR signal of protons bound on macromolecules. The most important applications in neuroradiology are (1) detection of subtle changes in otherwise normal-appearing cerebral white matter, for instance in multiple sclerosis (MS), Wallerian degeneration, and hydrocephalus, (2) differentiation of white matter lesions with high signal on T (2)-weighted MR-images, like MS plaques, brain infarctions, and brain edema, (3) follow-up of cerebral white matter diseases using volumetric MT techniques, and (4) improvement in delineating of contrast enhancing brain lesions, such as cerebral metastases. We describe the physical rationale of the MT technique and present the most important current and possible future applications of MT imaging to answer clinical and scientific questions in neuroradiology.
AIDS Dementia Complex↗
Pronounced arterial collateralization was induced after permanent rat cerebral four-vessel occlusion. Relation to neuropathology and capillary ultrastructure.
The present study investigates chronic changes in cerebral arterial vessel system, microvasculature, and brain histopathology using an adult rat model based on permanent and stepwise occlusion of four cerebral vessels. Digital subtraction angiography (DSA) was performed to study chronic changes in arterial cerebral vessel system after permanent vessel occlusion. Long-lasting functional changes such as NMDA-, AMPA- and GABA(A)-receptor binding were detected in hippocampus and dentate gyrus using autoradiography. Structural changes in cerebral capillaries were investigated using light- and electron microscopy. Chronic cerebral oligemia did not cause any significant changes in the densities of excitatory glutamate and inhibitory GABA(A) receptors. By electron microscopy we could document, however, that most capillaries in vessel-occluded animals shrank, the endothelial cells were prominent with enlarged nuclei and increased cytoplasm, and the basal membrane was thickened. In contrast to the degenerative changes in brain capillaries, pronounced arterial collateralization was disclosed by DSA after chronic brain vessel occlusion. The model of chronic occlusion of four cerebral vessels is characterized by capillary degeneration and arterial collateralization proceeding in parallel. Thus, this rat model may be useful in investigations of long-lasting compensatory mechanisms contributing to cerebrovascular or neurodegenerative disorders.
Angiography, Digital Subtraction↗
Precocial diving and patent foramen ovale in bearded seal (Erignathus barbatus) pups.
In this study we used a Doppler ultrasonic device, in combination with a sonographic contrast medium, to test whether free-living bearded seal (Erignathus barbatus) pups have a closed (anatomically or functionally) foramen ovale. A total of 17 examinations were performed on 12 individual pups with a body mass range of 29-103 kg (0-21 days old). These examinations showed that young bearded seal pups dive with a patent foramen ovale (PFO), and that this structure starts to close, at least functionally, during the 2nd week of life. The wide range in the timing of closure (one animal 21 days old still had a PFO) indicates that a closed foramen ovale is not crucial for the diving that these seals perform at this age. The primary function of diving during the 1st week of life is to avoid surface predation and only moderate diving ability is sufficient to achieve this goal. However, some of the diving performed by bearded seal pups with a PFO would likely be sufficient to create intravenous bubble formation during breath-hold diving in humans. Special adaptations in the seals, such as collapsible lungs and diving with minimal lung air volume, probably prevent this from happening.
Animals↗
CT and diffusion-weighted MR imaging in randomized order: diffusion-weighted imaging results in higher accuracy and lower interrater variability in the diagnosis of hyperacute ischemic stroke.
BACKGROUND AND PURPOSE: Diffusion-weighted MRI (DWI) has become a commonly used imaging modality in stroke centers. The value of this method as a routine procedure is still being discussed. In previous studies, CT was always performed before DWI. Therefore, infarct progression could be a reason for the better result in DWI. METHODS: All hyperacute (<6 hours) stroke patients admitted to our emergency department with a National Institutes of Health Stroke Scale (NIHSS) score >3 were prospectively randomized for the order in which CT and MRI were performed. Five stroke experts and 4 residents blinded to clinical data judged stroke signs and lesion size on the images. To determine the interrater variability, we calculated kappa values for both rating groups. RESULTS: A total of 50 patients with ischemic stroke and 4 patients with transient symptoms of acute stroke (median NIHSS score, 11; range, 3 to 27) were analyzed. Of the 50 patients, 55% were examined with DWI first. The mean delay from symptom onset until CT was 180 minutes; that from symptom onset until DWI was 189 minutes. The mean delay between DWI and CT was 30 minutes. The sensitivity of infarct detection by the experts was significantly better when based on DWI (CT/DWI, 61/91%). Accuracy was 91% when based on DWI (CT, 61%). Interrater variability of lesion detection was also significantly better for DWI (CT/DWI, kappa=0.51/0.84). The assessment of lesion extent was less homogeneous on CT (CT/DWI, kappa=0.38/0.62). The differences between the 2 modalities were stronger in the residents' ratings (CT/DWI: sensitivity, 46/81%; kappa=0.38/0.76). CONCLUSIONS: CT and DWI performed with the same delay after onset of ischemic stroke resulted in significant differences in diagnostic accuracy. DWI gives good interrater homogeneity and has a substantially better sensitivity and accuracy than CT even if the raters have limited experience.
Acute Disease↗
Acute disseminated encephalomyelitis: a follow-up study of 40 adult patients.
OBJECTIVES: To describe the clinical, CSF, and radiologic findings and long-term follow-up in a cohort of patients with acute disseminated encephalomyelitis (ADEM), and to determine possible prognostic factors for progression to MS. METHODS: Forty adults (28 women, mean age 33.5 years) diagnosed with ADEM were analyzed. Clinical symptoms, cranial MRI and CSF findings, and the response to a standardized treatment during the acute phase of the disease were analyzed by chart review. The final diagnosis of ADEM or clinically definite MS was established upon follow-up examination after 8 to 137 months. The patients with ADEM and MS were compared to detect differences between the two groups. RESULTS: Fifteen patients had a preceding infection (n = 14) or immunization (n = 1). The most frequent clinical signs were motor deficit (80%), followed by sensory deficits, brainstem signs, and ataxia. CSF findings were highly variable; normal results were present in 20% of patients. Oligoclonal bands were positive in 65% of patients. Ninety-five percent of all patients improved during the acute phase of the disease. Upon follow-up, 14 patients had developed clinically definite MS. Of the 26 patients with the final diagnosis of ADEM, two patients had died, nine had minor deficits, three had moderate deficits, and 12 patients had no remaining symptoms. Patients with the final diagnosis of ADEM were older, and more often had a preceding infection, clinical signs of brainstem involvement, a higher CSF albumin fraction, and infratentorial lesions. CONCLUSIONS: Many patients initially diagnosed with ADEM develop clinically definite MS upon long-term follow-up. The authors found no useful diagnostic criteria for the differentiation of a first episode of MS from monophasic ADEM. The term ADEM may still be employed as a description of a clinical syndrome, but should not be used as a distinct entity until reliable diagnostic criteria have been developed.
Adult↗
Comparison of intraoperative MR imaging and 3D-navigated ultrasonography in the detection and resection control of lesions.
OBJECT: The authors undertook a study to compare two intraoperative imaging modalities, low-field magnetic resonance (MR) imaging and a prototype of a three-dimensional (3D)-navigated ultrasonography in terms of imaging quality in lesion detection and intraoperative resection control. METHODS: Low-field MR imaging was used for intraoperative resection control and update of navigational data in 101 patients with supratentorial gliomas. Thirty-five patients with different lesions underwent surgery in which the prototype of a 3D-navigated ultrasonography system was used. A prospective comparative study of both intraoperative imaging modalities was initiated with the first seven cases presented here. In 35 patients (70%) in whom ultrasonography was performed, accurate tumor delineation was demonstrated prior to tumor resection. In the remaining 30% comparison of preoperative MR imaging data and ultrasonography data allowed sufficient anatomical localization to be achieved. Detection of metastases and high-grade gliomas and intraoperative delineation of tumor remnants were comparable between both imaging modalities. In one case of a low-grade glioma better visibility was achieved with ultrasonography. However, intraoperative findings after resection were still difficult to interpret with ultrasonography alone most likely due to the beginning of a learning curve. CONCLUSIONS: Based on these preliminary results, intraoperative MR imaging remains superior to intraoperative ultrasonography in terms of resection control in glioma surgery. Nevertheless, the different features (different planes of slices, any-plane slicing, and creation of a 3D volume and matching of images) of this new ultrasonography system make this tool a very attractive alternative. The intended study of both imaging modalities will hopefully allow a comparison regarding sensitivity and specificity of intraoperative tumor remnant detection, as well as cost effectiveness.
Brain Neoplasms↗
Low-field interventional MRI in neurosurgery: finding the right dose of contrast medium.
MRI is increasingly being used as an interventional tool in neurosurgery. The field strength of "intraoperative" MR systems is usually lower than that of imagers commonly used for diagnostic purposes. However, lesion enhancement and apparent lesion extent depend on field strength. The aim of this study was to compare the contrast between intracranial, contrast-enhancing space-occupying lesions and the surrounding white matter obtained with low-field (0.2 T) and high-field (1.5 T) MR imaging and to find the contrast medium dosage for low-field MRI that produces the same lesion-to-white-matter contrast as the one obtained with high-field MRI after the administration of a standard dose of the contrast medium. A total of 38 patients with intracranial metastases or high-grade glioma were enrolled in this study. T1-weighted spin-echo sequences were acquired. High-field (1.5 T) studies were performed after the i.v. administration of 0.1 mmol gadolinium-DTPA/kg body weight. For low-field MRI (0.2 T) a dose escalation technique was used. T1-weighted sequences were repeated after each of three i. v. injections of 0.1 mmol gadolinium-DTPA/kg body weight. Thus, at the low-field examinations three T1-weighted sequences with a contrast medium dosage of 0.1, 0.2 and 0.3 mmol gadolinium-DTPA/kg body weight were obtained. Lesion-to-white-matter contrasts were calculated and compared. The average lesion-to-white-matter contrast obtained with high-field MR examinations was 1.63 (standard deviation 0.32). In the low-field MR examinations the average lesion-to-white-matter contrast was 1.34 (0.2) after a single dose, 1.57 (0.2) after a double dose, and 1.71 (.19) after a triple dose of contrast medium. The lesion-to-white-matter contrast of the high-field MR examination after a single dose of contrast medium was significantly higher than that of the low-field study after a single dose (P < 0.0001), but did not differ significantly from the low-field studies after a double (P = 0.28) or a triple dose (P = 0.17) of contrast medium. In a series of patients with contrast-enhancing space occupying brain lesions low-field MRI (0.2 T) after a double dose of contrast medium yielded the same lesion-to-white-matter contrasts as high-field MRI (1.5 T) after a standard dose. This is an important finding to avoid errors in intraoperative MRI due to the immanently lower degree of lesion enhancement in low-field MR imaging.
Adult↗