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Biomedical subjects

M Warmuth-Metz

Publications and source records attributed to M Warmuth-Metz.

At least 37 records · Page 2Linked to original sources
PubMed2000

Lesion pattern in patients with multiple sclerosis and depression.

To assess if a specific lesion pattern or changes of the basal limbic system as seen in primary depression and depression associated with neurodegenerative disorders might be identified in depressive multiple sclerosis (MS) patients, we submitted 78 MS patients to a MRI examination consisting of a quantitative measurement of lesions and of hyperintense signals from the pontomesencephalic midline (raphe). Furthermore relaxometry of the pontomesencephalic midline, a transcranial ultrasound examination rating its echogenicity semiquantitatively and a standardized neurological, neuropsychiatric and neuropsychological assessment were obtained. Thirty-one patients fulfilled the DSM-IV criteria for depression. Depressed MS patients had a significantly larger temporal lesion load than non-depressed MS patients, especially on the right side. A trend of difference was detected for lesions of the right parietal lobe, the right frontal lobe, the cerebellum and the total lesion load. Neither hyperintense signals or relaxometry nor echogenicity of the region at the level of the pontomesencephalic midline were significantly different between the groups. We conclude that depression in MS patients is not associated with an alteration of the basal limbic system at the brainstem as seen in Parkinson's disease or unipolar depression but with an increased lesion load of the projection areas of the basal limbic system.

Adult↗
PubMed2000

Phase-contrast MR imaging of the cervical CSF and spinal cord: volumetric motion analysis in patients with Chiari I malformation.

BACKGROUND AND PURPOSE: Most previous MR studies of the dynamics of Chiari I malformation have been confined to sagittal images and operator-dependent measurement points in the midline. To obtain a deeper insight into the pathophysiology of the Chiari I malformation, we performed a prospective study using axial slices at the level of C2 to analyze volumetric motion data of the spinal cord and CSF over the whole cross-sectional area. METHODS: Eighteen patients with Chiari I malformation and 18 healthy control subjects underwent cardiac-gated phase-contrast imaging. Cross-sectional area measurements and volumetric flow/motion data calculations were made for the following compartments: the entire intradural space, the spinal cord, and the anterior and posterior subarachnoid space. RESULTS: The most striking feature was an increased early systolic caudal and diastolic cranial motion of the spinal cord in the patients. CSF pulsations in the anterior subarachnoid space were unchanged at systole but showed an impaired diastolic upward flow. In the posterior compartment, the CSF systole was slightly shortened, with an impairment of diastolic upward flow. Fourteen of the 18 patients had associated syringeal cavities. This subgroup showed an increased systolic downward displacement of the cord as compared with patients without a syrinx. CONCLUSION: Obstruction of the foramen magnum in patients with Chiari I malformation causes an abrupt systolic downward displacement of the spinal cord and impairs the recoil of CSF during diastole.

Adolescent↗
PubMed2000

Efficacy of trisacryl gelatin microspheres versus polyvinyl alcohol particles in the preoperative embolization of meningiomas.

BACKGROUND AND PURPOSE: Trisacryl gelatin microspheres are a new, commercially available nonabsorbable embolic agent. The purpose of this study was to evaluate their efficacy in the preoperative embolization of meningiomas as compared with polyvinyl alcohol (PVA) particles of various sizes. METHODS: In 30 consecutive patients, trisacryl gelatin microspheres (150-300 microm) were used for the preoperative superselective embolization of meningiomas (group 1). Thirty other consecutive patients had embolization with PVA particles of 45 to 150 microm (n = 15, group 2) and of 150 to 250 microm (n = 15, group 3). Extent of devascularization, intraoperative blood loss, blood transfusion, and hemostasis at the time of surgery were recorded for every patient. The inflammatory reaction, the extent of necrotic areas, and the most distal intravascular location of the embolic agent (arterial, arteriolar, precapillary, capillary) were recorded. RESULTS: There was no significant difference in the extent of angiographic devascularization among the groups. Intraoperative blood loss differed significantly between groups 1 and 2 and groups 1 and 3, but not between groups 2 and 3. The trisacryl gelatin microspheres were located more distally in tumor vessels than were the PVA particles of either size. The extent of intratumoral necrosis was not significantly different between the two embolic agents. In all groups there was a mild inflammatory tissue reaction in the vicinity of the embolic agent. CONCLUSION: Trisacryl gelatin microspheres may be effective in the preoperative embolization of meningiomas, producing significantly less blood loss at surgery than seen with PVA particles of either size, possibly because of the significantly more distal vascular penetration of the microspheres.

Acrylates↗
PubMed2000

MR spectroscopy in gliomatosis cerebri.

BACKGROUND AND PURPOSE: The diagnosis of gliomatosis cerebri with MR imaging is known to be difficult. We report on the value of MR spectroscopy in the diagnosis, grading, and biopsy planing in eight patients with histopathologically proved gliomatosis cerebri. METHODS: Patients underwent MR imaging and MR spectroscopy (single-voxel point-resolved spectroscopy [PRESS] at 1500/135, and chemical-shift imaging [CSI] PRESS at 1500/135) before open (n = 4) or stereotactic (n = 4) biopsy. In six patients who underwent CSI, biopsy samples were taken from regions of maximally elevated levels of choline/N-acetylaspartate (Cho/NAA). RESULTS: All patients showed elevated Cho/creatine (Cr) and Cho/NAA levels as well as varying degrees of decreased NAA/Cr ratios, which were most pronounced in the anaplastic lesions. In low-grade lesions, there was a maximum Cho/NAA ratio of 1.3, whereas in anaplastic tumors, the maximum Cho/NAA level was at least 2.5. Spectra in two patients with grade III lesions revealed a lactate peak; lactate and lipid signals were seen in two patients with grade IV lesions. Biopsy specimens from regions with maximally elevated levels of Cho/NAA showed dense infiltration of tumor cells. CONCLUSION: MR spectroscopy might be used to classify gliomatosis cerebri as a stable or a progressive disease indicating its potential therapeutic relevance.

Adolescent↗
PubMed2000

MR imaging- and MR spectroscopy-revealed changes in meningiomas for which embolization was performed without subsequent surgery.

We describe our experience with follow-up MR imaging and MR spectroscopy in two patients after embolization of meningiomas without subsequent surgery. In both patients there was a marked reduction in tumor size and a decrease in contrast enhancement associated with spectroscopic signs of fatty degeneration. We did not observe regrowth; however, in one patient with incomplete angiographic devascularization, residual vital tumor tissue was seen at follow-up examinations.

Aged↗
PubMed2000

Is there a benefit of preoperative meningioma embolization?

OBJECTIVE: To evaluate the effect of preoperative embolization of meningiomas on surgery and outcomes. METHODS: In a prospective study, 60 consecutive patients with intracranial meningiomas who were treated in two neurosurgical centers were included. In Center A, embolization was performed for none of the patients (n = 30). In Center B, 30 consecutive patients with embolized meningiomas were treated. Preoperatively, tumor size and location, neurological status, and Barthel scale score were recorded. In Center B, the extent of tumor devascularization was evaluated using angiography and postembolization magnetic resonance imaging. Intraoperatively, blood loss, the numbers of blood units transfused, and the observations of the neurosurgeon concerning hemostasis, tumor consistency, and intratumoral necrosis were recorded. Postoperatively, the neurological status and duration of hospitalization were recorded. Six months after surgery, the outcomes were assessed using the Barthel scale and neurological examinations. RESULTS: The mean tumor sizes were 22.9 cc in Center A and 29.6 cc in Center B (P > 0.1). The mean blood losses did not differ significantly (646 ml in Center A versus 636 ml in Center B; P > 0.5). However, for a subgroup of patients with subtotal devascularization (>90% of the tumor) on postembolization magnetic resonance imaging scans in Center B, blood loss was less, compared with the entire group in Center A (P < 0.05). The observations of the neurosurgeon regarding hemostasis, tumor consistency, and intratumoral necrosis did not differ significantly. There were no surgery-related deaths in either center. The rates of surgical morbidity, with permanent neurological worsening, were 20% (n = 6) in Center A and 16% (n = 5) in Center B. There was one permanent neurological deficit (3%) caused by embolization. CONCLUSION: In this preliminary study, only complete embolization had an effect on blood loss. The value of preoperative embolization for all meningiomas must be reconsidered, especially in view of the high costs and risks of embolization.

Adult↗
PubMed1999

Silent embolism in diagnostic cerebral angiography and neurointerventional procedures: a prospective study.

BACKGROUND: Cerebral angiography is associated with a small but definite risk of neurological complications with an unknown incidence of clinically silent embolism. We assessed the neurological complication rate compared with the frequency of silent embolism after angiography METHODS: We used diffusion-weighted magnetic resonance imaging (MRI) before and after angiography to assess embolic events. 100 consecutive angiographies (66 diagnostic and 34 interventional procedures) were done on 91 patients. Patients underwent neurological assessment before, immediately after, and 1 day after angiography. FINDINGS: Before angiography, no abnormalities were seen on diffusion-weighted MRI. Diffusion-weighted MRI showed 42 bright lesions in 23 patients after 23 procedures (17 diagnostic, six interventional) in a pattern consistent with embolic events. There was no new neurological deficit after any angiographic procedure. After diagnostic angiography in patients with a history of vasculopathy, the frequency of lesions was significantly higher than in patients without vascular risk factors (12 [44%] of 27 vs five [13%] of 39 patients, p=0.03). In diagnostic angiography, the appearance of lesions was significantly correlated with whether vessels were difficult to probe (p=0.01), amount of contrast medium needed (p<0.01), fluoroscopy time (p<0.01), and use of additional catheters (p=0.02). INTERPRETATION: After diagnostic and interventional cerebral angiography, embolic events are more frequent than the apparent neurological complication rate. In diagnostic procedures, the incidence of embolism is closely related to a vascular risk profile.

Adolescent↗
PubMed1999

[Agenesis septum pellucidum in a schizophrenic patient].

Absence of the septum pellucidum is a rare developmental disorder of the human brain. Previous reports focused on the association with other cerebral anomalies. We present MRI scans showing an isolated absence of the septum pellucidum. The patient was suffering from a schizophrenic psychosis. Mental retardation or epileptic seizures, which are often found in more complex developmental brain disorders, were not observed. The septal area is part of the limbic system and aplasia of the septum pellucidum could indicate developmental anomalies of the limbic system. The concept of cerebral maldevelopment and the limbic system in schizophrenic psychosis is discussed.

Adolescent↗
PubMed1999

[Cerebral aneurysms in the posterior circulation. Treatment results in 44 consecutive cases].

PURPOSE: Evaluation of clinical and morphological results in 44 consecutive patients with 45 aneurysms of the posterior circulation. METHODS: Retrospective analysis of patient charts and angiograms of all vertebrobasilar aneurysms diagnosed in our department between 10/95 and 08/99. All aneurysms were treated. RESULTS: 36/44 pts had a hemorrhage. Hunt/Hess (HH) gradings were as follows: HH1 in 10, HH2 in 6, HH3 in 9, HH4 in 10 cases, and HH5 in 1 case. 38 pts with 39 aneurysms were treated exclusively in the endovascular way, 3 pts with 3 aneurysms were operated on. 3 patients had to be operated upon following insufficient endovascular treatment. Endovascular treatment resulted in 63% total and 27% subtotal occlusions, results being stable in 85%. For our pts as a whole, the grading according to the Glasgow Outcome Scale (GOS) was GOS1 in 4, GOS3 in 8, GOS4 in 7, and GOS5 in 25 cases. CONCLUSION: Despite a less favourable clinical status of pts pre-treatment, the results of our interdisciplinary concept compare favourably with those of other surgical or interventional groups.

Adult↗
PubMed1999

Isolated absence of the septum pellucidum.

Absence of the septum pellucidum in the human is a rare congenital anomaly. Previous reports suggest it is almost always associated with other brain anomalies. However, MRI in two patients with absence of the septum pellucidum presented here, indicates that this anomaly may occur without associated anomalies. It may be one manifestation of a spectrum of developmental anomalies. One patient presented with schizophrenic psychosis; developmental disturbances in limbic areas are believed to be associated with schizophrenia. Agenesis of the septum pellucidum may indicate abnormal development of limbic structures and it may be associated with anomalies, such as cytoarchitectural disturbances of cortical layers, as yet undetectable by MRI.

Adolescent↗
PubMed1999

[MRI in funicular myelosis].

The MRI morphology in combined subacute degeneration has only rarely been reported. We describe two patients suffering from subacute combined degeneration of the spinal cord on the basis of a deficiency of vitamin B12. In both patients characteristic hyperintense areas on T2-weighted images in the posterior columns of the cervical and thoracic cord without contrast enhancement were demonstrated by MRI.

Demyelinating Diseases↗
PubMed1999

Central neurocytoma of the fourth ventricle. Case report.

The authors report on a 17-year-old boy who suffered from slowly progressive and long-standing symptoms of ataxia, neck pain, and headache. Computerized tomography (CT) and magnetic resonance (MR) imaging revealed a tumor arising from the floor of the fourth ventricle that resulted in a moderate hydrocephalus. A partial resection was performed. Histological and immunohistological findings led to the diagnosis of an atypical central neurocytoma of the fourth ventricle. The imaging features on CT scanning, MR imaging, and proton MR spectroscopy studies, the clinical picture, and the prognosis of this very unusual tumor are discussed. Three cases of neurocytomas in the posterior fossa have been described to date; however, in all three cases some atypical aspects were present. In the present case, with the exception of the very unusual location, both imaging findings and clinical history perfectly met the definition of this rare tumor.

Adolescent↗
PubMed1998

1H magnetic resonance spectroscopy of the lentiform nucleus in primary focal hand dystonia.

Several radiologic findings point toward the lentiform nucleus as a possible site of lesion in primary dystonia. Histologic examinations, however, have shown inconsistent results. 1H-magnetic resonance spectroscopy (MRS) has proved helpful to assess neuronal degeneration in a variety of basal ganglia disorders. MRS data of dystonia patients are, however, lacking so far. 1H-MRS centered on the lentiform nuclei was performed in 14 patients with primary focal hand dystonia and in 12 healthy control subjects using a 1.5-T MR imager. No statistically significant differences of N-acetylaspartate/creatine and lactate/creatine ratios were found between patients and control subjects. Based on these data, the authors found no evidence that primary focal dystonia was associated with a conspicuous loss of lentiform nucleus neurons or a marked disturbance of the aerobic metabolism, although minor abnormalities cannot be excluded because of the possibly limited sensitivity of the method.

Adult↗
PubMed1998

[Recurrent transverse myelitis. 2 cases and review of the literature].

Recurrent transverse myelitis is a rare inflammatory demyelinating disorder, which is distinguished from acute monophasic transverse myelitis and from MS. We present two patients with recurrent transverse myelitis, who developed an acute remitting tetraparesis and sensible deficits with a cervical level. They were followed for 4 and 5 years. MRI showed an isolated lesion with contrast enhancement in the spinal cord but no pathological cranial findings. Oligoclonal bands were negative in repeated lumbar punctures. One patient showed lymphocytic pleocytosis during the first and second attack. Somatosensory and motor evoked potentials were abnormal during relapses while visually and brainstem acoustically evoked potentials (VEP and BAEP) stayed within limits. Laboratory examinations for bacterial, viral or parasitic infections, antinuclear antibodies, Angiotensin-converting enzyme and the sedimentation rate were also normal. The differential diagnosis will be discussed in view of previously reported series. We give a review of the current literature and discuss the differential diagnoses.

Adult↗
PubMed1998

The corticospinal tract in amyotrophic lateral sclerosis: an MRI study.

Cortical motor neurone loss and corticospinal tract (CST) degeneration are typical of amyotrophic lateral sclerosis (ALS). It is a matter of debate whether qualitative assessment of the CST by MRI is useful in the diagnosis. It is also an open question whether quantitative determination of the T2 relaxation times can improve its value. Signal intensity along the CST on 14 consecutive slices was assessed using arbitrary visual rating on double-echo T2-weighted and proton-density spin-echo images of 21 patients with ALS and 21 age- and sex-matched controls. T2 was determined quantitatively. On the T2-weighted images the patients' ratings did not differ from that of controls. The T2 of patients and controls showed no statistical difference in any slice. There was no correlation between T2 and patient age, duration of the disease, or predominant bulbar, lower or upper motor neurone signs. The only correlation between MRI findings and disease was on the proton-density images: all cases in which the CST was poorly seen were controls; a clearly high-signal CST was seen only in the patients. High conspicuity of the CST was thus specific but not sensitive for the diagnosis of ALS. T2-weighted images and measurement of T2 were not useful for diagnosis.

Amyotrophic Lateral Sclerosis↗
PubMed1998

A possible role for somatostatin receptor scintigraphy in the diagnosis and follow-up of children with medulloblastoma.

The surgical resection of medulloblastoma (MB), the most frequent malignant brain tumor in children, often remains subtotal. To estimate the response to further treatment the residual tumor is monitored by CT or MRI. The interpretation of both imaging techniques is complicated by disturbances resulting from surgery and radiation. Our study searched for alternative imaging techniques and asked the following questions. 1) Do MB express somatostatin receptors (SSTR), 2) is SSTR scintigraphy a sensitive imaging technique for the follow-up and the detection of vital tumor tissue in children with MB, and 3) do the results of SSTR scintigraphy correlate with the in vitro analysis of MB tissue by SSTR autoradiography. We analyzed the SSTR status in 20 children with MB, aged 1 to 15 years. Sixteen SSTR scintigraphies using Indium-111-DTPA-D-Phel-pentetreotide were performed in 14 children. MB tissue of 14 children was analyzed by SSTR autoradiography using Iodine-125-Tyr3-octreotide. In 8 cases SSTR were measured by both methods in vivo and in vitro. In comparison with conventional imaging, results of SSTR scintigraphy were true positive in 7 of 7 patients, true negative in 9 of 9 patients, including one patient with false positive findings in MRI, false negative in only one patient with small spinal metastases (diameter < 3 mm) and false positive in none of the analyzed patients. In all cases with residual tumor (n = 3) and suspected relapse (n = 4) the diagnosis could be confirmed (n = 4) or excluded (n = 3), consistent with the results of MRI and tumor histology. All MB tissues analyzed by SSTR autoradiography (n = 14) showed an extremely high density of SSTR ranging from 4047 to 15526 dpm/mg MB tissue. MB (n = 8) which were analyzed by SSTR scintigraphy and autoradiography demonstrated consistent results in evaluation by both methods. In cases where the integrity of the blood-brain barrier was tested by Tc-99m-DTPA scintigraphy (n = 10), the SSTR-to-brain scintigraphy index confirmed the tumor specificity of radionuclide uptake. We conclude that 1) MB tissue expresses a particularly high density of SSTR, 2) the high density of SSTR in autoradiography correlates with a sensitive imaging of these tumors by SSTR scintigraphy, 3) SSTR scintigraphy might be a valuable imaging method for detection of vital MB tissue in patients with residual tumor or relapse.

Adolescent↗
PubMed1997

MRI T2 relaxation times of brain regions in schizophrenic patients and control subjects.

In this MRI investigation T2 relaxation times were studied in schizophrenic patients compared to normal control subjects. Approximate T2 relaxation times were calculated using signal intensity at two echo times in several brain regions of 25 male schizophrenic patients and 25 age-matched, normal male control subjects. The schizophrenic patients showed significantly longer T2 relaxation times as compared to normal control subjects in the left anterior column of the fornix. This is a small structure, prone to partial volume effects and this may account for these findings. There was a trend towards longer T2 times in the left frontal cortex and shorter T2 times in [corrected] right temporal cortex in schizophrenic patients as compared to control subjects. There were right/left differences in relaxation times within each group. In both patients and control subjects, frontal lobe white matter T2 was longer on the right than on the left side. This finding is probably due to brain asymmetry and unrelated to the presence or absence of psychiatric illness. In schizophrenic patients only the left temporal cortex showed longer T2 times than the right side. This observation could indicate left sided temporal lobe pathology in schizophrenia.

Adolescent↗