PubMed Health⌕ Search

Biomedical subjects

W Grodd

Publications and source records attributed to W Grodd.

At least 19 recordsLinked to original sources
PubMed1991

Superficial siderosis of the central nervous system. A 37-year follow-up of a case and review of the literature.

The course of a patient suffering from superficial siderosis of the central nervous system for 37 years is presented and diagnostic and therapeutic approaches are evaluated. The syndrome is clinically defined by slowly progressing deafness, cerebellar ataxia, myelopathy and neuropsychological deficits in combination with recurrent xanthochromia of the cerebrospinal fluid with siderophages. The diagnosis may be confirmed by computed tomography, which shows degeneration of the cerebellar vermis, and by magnetic resonance imaging, demonstrating iron deposits on the surface of brain, brain stem and spinal cord. Therapy should seek to identify and remove the source of bleeding, since pharmacotherapy with iron-depleting drugs is of limited effectiveness.

Brain Diseases↗
PubMed1991

Early onset cerebellar ataxia with retained tendon reflexes. Clinical, electrophysiological and MRI observations in comparison with Friedreich's ataxia.

Fourteen patients with the clinical diagnosis of early onset cerebellar ataxia with retained tendon reflexes (EOCA) were examined and compared with 11 patients with Friedreich's ataxia (FA). The mean age of onset in EOCA was 15.9 +/- 6.0 yrs (FA: 14.0 +/- 5.7 yrs). Annual progression rate and the percentage of patients who were wheelchair-bound was lower in EOCA as compared with FA, although the difference did not reach statistical significance. The latency until becoming wheelchair-bound, however, was significantly longer in EOCA than in FA. The segregation ratio in EOCA was significantly lower than 0.25. Clinically, EOCA and FA patients presented with a progressive cerebellar syndrome. Associated symptoms, such as muscle wasting, sensory disturbances, foot deformity, scoliosis and electrocardiographic abnormalities were encountered less frequently in EOCA than in FA patients. The electrophysiological findings in EOCA were variable and pointed to axonal degeneration in peripheral nerves and central pathways. Posturographic measurements revealed a higher incidence of anteroposterior sway direction in EOCA as compared with FA, suggesting a cerebellar type of ataxia in EOCA. Eleven out of the 14 EOCA patients had cerebellar atrophy in MRI. The characteristic MRI finding in FA was upper cervical cord shrinkage and only minor atrophy of the cerebellum. The demonstration of cerebellar atrophy in the majority of EOCA patients supports the view that EOCA is distinct from FA. It is uncertain, however, whether EOCA is a homogenous disease entity or a group of phenotypically similar syndromes.

Action Potentials↗
PubMed1991

Metabolic and destructive brain disorders in children: findings with localized proton MR spectroscopy.

The diagnostic potential of volume-selective proton magnetic resonance (MR) spectroscopy in vivo was evaluated in 20 children and young adults with various neurodegenerative brain disorders. All patients were examined with MR spectroscopy in conjunction with MR imaging of the brain on a whole-body imager at 1.5 T. Comparison of spectra in our patients with those of children with normal myelination (prominent signals from N-acetylaspartate [NAA], creatine/phosphocreatine, and choline) revealed a marked decrease of NAA in 12 of 17 patients with focal or generalized demyelination. In patients with Canavan disease, NAA signal intensity was markedly increased, but no choline signal was found. Increased signal intensity from lactate occurred in patients with Leigh disease, neuroaxonal dystrophy, Schilder disease, and Cockayne disease, which indicated a disturbed energy metabolism in the examined region. These results demonstrate that proton MR spectroscopy can be applied in a clinical environment to facilitate diagnosis of hereditary and acquired brain disorders in children.

Brain↗
PubMed1991

Myelinoclastic diffuse sclerosis (Schilder's disease): cliniconeuroradiologic correlations.

We report a 17-year-old boy with myelinoclastic diffuse sclerosis (Schilder's disease) presenting with left leg paresis, visual loss, and behavioral changes. CT and MRI showed two large lesions in the subcortical white matter of the occipital and parietal lobes of both hemispheres and increased intracranial pressure. Histology disclosed large areas of demyelination and perivascular infiltrates. The patient improved with coincident oral prednisolone treatment.

Adolescent↗
PubMed1990

Localized 1H in vivo NMR spectroscopy of small-volume elements in human brain at 1.5 T.

Localized in vivo proton NMR spectra of volume elements of minimal size (13 x 13 x 13 mm3) were obtained in human brain with a whole-body imager working at 1.5-T field strength. By use of an optimized version of the 90 degrees-180 degrees-180 degrees volume selection method, well-resolved proton spectra were acquired within 9 min and a comparison of spectra with different echo times (135 and 270 ms) was possible within 20 min.

Body Water↗
PubMed1990

Central spinal cord lesions in stenosis of the cervical canal.

34 patients suffering from cervical spondylotic myelopathy confirmed by myelography were examined by delayed CT 6-10 h after myelography. Twelve patients showed bilateral intramedullary collections of contrast medium, predominantly cranial to the stenosis. In these patients males predominated, the duration of clinical symptoms lasted longer although their age was lower. There was no correlation to the degree and the extension of the narrowing of the cervical spinal canal. Half of 20 patients undergoing consecutive decompressive surgery showed intramedullary contrast enhancement, and this was shown again by postoperative MRI in eight. The postoperative clinical and neurophysiological results revealed no change in the majority of patients, but three patients showing intramedullary contrast medium deteriorated in neurophysiological outcome, while only one of the patients in whom intramedullary contrast medium was not noticed got worse.

Adult↗
PubMed1990

MRI findings in medial temporal lobe structures in schizophrenia.

In an MRI volumetric study of 10 young male schizophrenics (DSM-III-R 295.9x) a temporal lobe segment, corresponding hippocampal formation and parahippocampal gyrus were found smaller as compared with healthy controls while temporal horn was enlarged. Temporal lobe segment and parahippocampal gyrus were larger on the right in patients and controls, reversed asymmetry was found for the hippocampus.

Adult↗
PubMed1990

Variation of contrast between different brain tissues with an MR snapshot technique.

The lack of tissue contrast in gradient-echo sequences with very short repetition times can be overcome by using a single inversion pulse prior to the entire imaging sequence. The contrast can be changed by variation of the time delay between the inversion pulse and the first excitation. This snapshot technique was introduced for very fast acquisition of images, but it also provides images with a strong contrast of gray to white matter and of brain tissue to cerebrospinal fluid. The authors designed a sequence that allows sufficient spatial resolution and good image quality. The measurement time is 1.2 seconds, and the in-plane resolution is 0.8 mm. A large variation in contrast with different inversion times was demonstrated on brain images of volunteers and patients.

Brain↗
PubMed1989

Cavernous angioma of the optic tract.

A cavernous angioma of the right optic tract in a 35-year-old man is presented. The patient suffered from headaches and had a left homonymous visual field defect after subarachnoid haemorrhage and an intracerebral haematoma in the right temporomedial region, revealed by computed tomography (CT). Follow-up CT showed a small contrast-enhanced lesion in the right suprasellar and parasellar cistern. Angiography on three occasions did not reveal a vascular lesion. Magnetic resonance imaging was helpful both for diagnosis and planning surgical therapy. It showed typical signs of a cavernous angioma of the right optic tract; the diagnosis was confirmed by surgery and histological examination. This appears to be the first reported case of a cavernous angioma of the optic tract.

Adult↗
PubMed1989

[Specific and non-specific contrast media for MRI of tumors. Experimental study of human breast carcinoma].

MRI has been shown as an adapted non-invasive modality for the detection of tumours in humans. The development of paramagnetic contrast agents could add to the MRI diagnosis. With an experimental model of human breast (MX-1) carcinoma developed in nude mice, two different classes of contrast medium were tested. The first class includes the well-known Gd-DTPA and a new nitroxide compound on going development, representing non specific contrast agents. The specific contrast agents are represented by a metalloporphyrin Mn-TPPS4. Non specific contrast agents can add to the differentiation between well vascularized viable tissue and necrotic areas of tumors. While specific contrast agents may specifically target tumorous tissue.

Animals↗
PubMed1989

[Magnetic resonance tomography (1.5 T) of traumatic extracerebral hematomas].

The advantages of magnetic resonance imaging (MRI) in the diagnosis of subacute and chronic traumatic extracerebral hematomas are described. The characteristic changes in signal intensity for hematomas depend on the magnetic properties of hemoglobin and its derivatives, which shorten the relaxation times and decrease the homogeneity of the local magnetic field. MRI is superior in detecting and depicting the extent of small hematomas adjacent to the skull. Changes in signal intensity with time allow rough estimation of the age of a hematoma. Small hemorrhages were often found (missed by CT) that were contralateral to chronic subdural hematomas.

Brain Injuries↗
PubMed1988

Sodium-MR-imaging of the brain: initial clinical results.

Twelve patients with different diseases of the brain were examined with sodium and proton MRI at 1.5 Tesla and the results of both studies compared. Due to the 1500-fold lower concentration in the body, the decreased sensitivity and the shorter relaxation times of sodium compared with hydrogen a sequence with gradient reversal and a volume imaging method was applied to achieve a short echo time (4.5 ms). As a result of the mainly extracellular distribution of sodium the CSF spaces are depicted by their high signal intensity while the normal parenchyma is not visible. Changes induced by encephalitis, ischemic infarction and tumors can also be detected by their increased sodium content. Different tumors provided different signal intensities, not always permitting a distinction between tumor, surrounding edema and CSF. The diagnostic impact of these findings is discussed.

Adolescent↗
PubMed1988

[Parameter-weighted MR images and their optimization: theory and example of images for the flash sequence compared to the spin-echo sequence].

In this paper the signal intensity and parameter-weighting zones of spin echo and gradient echo sequences (FLASH) have been analysed. Using information available in the literature, with additional analytical and numerical techniques, it is possible to determine parameters which maximise tissue contrast for T1, T2 and proton-weighted images. The technique is equally applicable to spin echo and FLASH sequences. The advantages of optimised gradient echo sequences compared with spin echo sequences with respect to its signal to noise ratio for short repetition times are analysed quantitatively. T2-weighted images can be generated as rapid as T1-weighted images, using the FLASH sequences when using a small angle of spin and relatively long echo. Illustrations are shown to demonstrate the numerical results (field strength 1.5 tesla). This is followed by a discussion of possible opposing effects.

Humans↗
PubMed1988

[Possibilities of using 3-dimensional computerized tomography for the spine].

A new computer programme that produces 3D reconstructions from sets of contiguous axial CT scans was used in evaluating a variety of spinal problems. The 3D images were easily correlated with plain radiographs and new views of high quality were obtained. Case reports illustrate the uniqueness of this perspective and its value in conveying new information to nonradiologist physicians who are unaccustomed to evaluating the numerous images of standard CT scans.

Adolescent↗
PubMed1987

Gadolinium-DTPA enhanced MR imaging of intramuscular abscesses.

Sterile, chemical and bacterial abscesses were induced in the paraspinal muscles of 16 rats before obtaining magnetic resonance (MR) images using a 0.35-T resistive system. Abscess intensity, T1 and T2 values were recorded before and after the intravenous administration of Gd-DTPA (0.2 mmol/kg). The MR appearances of the abscesses were correlated with histologic sections. Both sterile and bacterial abscess were detected on MR images without the use of contrast medium, particularly on the T2-weighted spin echo sequence (TE/TR 56/2000 ms). However, the inflammatory zones of abscesses markedly enhanced in intensity with a corresponding decrease in T1 values after the administration of Gd-DTPA (TE/TR 28/500 ms). A clear distinction between the necrotic center and the cellular periphery of each abscesses was evident only after contrast enhancement (TE/TR 28/500 ms). Thus paramagnetic Gadolinium-DTPA was beneficial for defining the histologic components of abscesses on spin echo MR images.

Abscess↗
PubMed1987

[Focal changes in the spleen. Ultrasonic morphological characteristics and their clinical significance].

Focal changes in the spleen were rare findings in a large clinical material (less than 1% of cases). In a prospective study, which included 580 patients, lesions in the spleen were found in 40. Four focal lesions were due to infiltrates from non-Hodgkin's lymphoma. Twenty-one lesions with low echoes consisted of twelve infiltrates from Hodgkin's disease (six patients) or non-Hodgkin's lymphoma (six patients), five were due to fresh splenic infarcts and one each to an abscess, a metastasis from a carcinoma of the stomach, sarcoid and a haemorrhage. In only three of ten highly echogenic foci was a diagnosis possible (one leukaemic infiltrate and two scars following splenic infarcts). The significance of the sonographic demonstration of focal splenic lesions for diagnosis and treatment is discussed. The advantages of a sector scanner for evaluation of the spleen and splenic size are mentioned.

Hodgkin Disease↗