PubMed Health⌕ Search

Biomedical subjects

B Tomandl

Publications and source records attributed to B Tomandl.

At least 19 recordsLinked to original sources
PubMed2006

Identifying the affected hemisphere by (1)H-MR spectroscopy in patients with temporal lobe epilepsy and no pathological findings in high resolution MRI.

Up to 30% of patients with temporal lobe epilepsy (TLE) remain without remarkable changes in MRI. In this study we investigated the role of (1)H-MR spectroscopy ((1)H-MRS) in lateralizing the affected hemisphere in the mentioned patient group. Twenty-two consecutive patients diagnosed with TLE were investigated by high resolution MRI and (1)H-MRS. We examined the incidence and diagnostic accuracy of temporal metabolite alterations determined by Linear Combination of Model Spectra (L C Model) via water reference. Metabolite values of each hemisphere of TLE patients were compared with healthy controls. Results of metabolite alterations were related to intensive video EEG focus localization. Reduction of N-acetylaspartate + N-acetylaspartyl-glutamate (tNAA) in the affected hemisphere revealed identification in six of nine patients (66%) with unilateral TLE. Group comparison revealed a significant reduction of tNAA (6.1+/-0.8*) in the involved temporal lobe compared with controls (6.67+/-0.4*, P=0.026). Choline levels were significantly increased in the affected hemisphere (1.42+/-0.17*) compared with healthy controls (1.22+/-0.17*, P=0.035). The results of our study show that (1)H-MRS is able to identify the affected hemisphere of MRI negative TLE patients and can be used as an additive tool in multimodal focus localization.

Adult↗
PubMed2005

Short TE single-voxel 1H-MR spectroscopy of hippocampal structures in healthy adults at 1.5 Tesla--how reproducible are the results?

The purpose of our study was to evaluate inter- and intra-subject variability and scan-rescan reproducibility of single-voxel 1H-MR spectroscopy (1H-MRS) in hippocampal structures at 1.5 T field strength. Thirty healthy adults were studied bilaterally by optimized, standardized short echo time single-voxel 1H-MRS (PRESS, TE=30 ms, TR=3000 ms, oblique voxel orientation, voxel size 2 cm3). Spectral analysis and absolute metabolite quantitation of N-acetylaspartate+N-acetylaspartyl-glutamate (tNAA), choline (Cho), creatine (Cr), total glutamate plus glutamine (Glu+Gln) and myo-inositol (Ins) were carried out by LCModel. Inter- and intra-individual reproducibility of these metabolite values were investigated by calculation of mean, standard deviation, coefficient of variation (CV), and by analysis of variance for repeated measurements. The smallest CV in intersubject variability was obtained for tNAA, followed by Cr, Cho, Ins and Glu+Gln. The results of the analysis of variance for repeated measures in inter-subject variability showed a marginal effect of scan repetition for Cr (p=0.063) and Glu+Gln (p=0.082); the rescan of both metabolites showed slightly higher concentrations. No statistical significant effect of scan repetition was seen for tNAA (p=0.913), Cho (p=0.857), and Ins (p=0.826). Rescan led to the same results and gave proof of good reproducibility. Scan-rescan testing in one subject showed comparable results: tNAA (CV=4.8%), followed by Cr, Ins, Glu+Gln and Cho (all CV above 10%).

Adult↗
PubMed2005

[Cranial imaging and serology tests are not helpful in tonic pupil. A retrospective study].

BACKGROUND: Tonic pupil (TP) is a common disorder of parasympathetic innervation. In contrast to textbook recommendations, cranial imaging is still being performed in most of the patients with TP. The intention of the present study is to show that cranial imaging is of no benefit. PATIENTS AND METHODS: The medical records of 33 patients with TP were analyzed retrospectively. All patients had undergone a complete ophthalmological, orthoptic, and neurological investigation. Cranial imaging was performed by computed tomography or magnetic resonance imaging. Serology tests were carried out in some of the patients. RESULTS: Diagnostic imaging provided no additional data revealing the underlying cause of TP. CONCLUSIONS: Cranial imaging in isolated tonic pupil is not helpful. Because of therapeutic implications, diagnostic evaluation can be recommended only in patients older than 50 years to exclude giant cell arteritis and syphilis.

Adolescent↗
PubMed2003

1H-MR spectroscopy: a promising method in distinguishing subgroups in temporal lobe epilepsy?

Proton MR spectroscopy offers an additional noninvasive method of supporting focus lateralization in patients with intractable temporal lobe epilepsy. In this study involving 57 patients, the ability of multivoxel 1H-MRS to differentiate between mesial and lateral TLE was investigated in addition to its ability to lateralize the epileptogenic focus. Temporal lobe epilepsy (TLE) was classified into mesiobasal or lateral temporal lobe epilepsy according to the results of preoperative diagnostics including neurological and neuropsychological examinations, video-EEG monitoring and high resolution MRI. 1H-MR-spectroscopy (1H-MRS) showed that pathological changes in the mesial temporal lobes indicate a predominance in different parts of the ipsilateral temporal lobe (hippocampal and parahippocampal areas) correlating to the clinically defined groups. In addition, mesiobasal TLE tends to have higher concomitant contralateral abnormalities. Our results reveal that 1H-MRS is able to distinguish between mesiobasal and lateral pathologies in patients with TLE and represents a useful tool for noninvasive TLE classification.

Adult↗
PubMed2003

Upregulation of CD40-CD40 ligand (CD154) in patients with acute cerebral ischemia.

BACKGROUND AND PURPOSE: Inflammation and hypercoagulability contribute to the development of acute cerebral ischemia. Both can be mediated by the CD40 system. This study investigated whether the CD40 system and related mediators are upregulated in patients with transient ischemic attack (TIA) or stroke. METHODS: Seventeen patients with TIA, 60 patients with complete stroke, and 15 control subjects were investigated. CD154 and P-selectin were analyzed on platelets and CD40 on monocytes during and 3 months after acute cerebral ischemia by double-label flow cytometry. Blood concentrations of soluble CD154 and monocyte chemoattractant protein-1 (MCP-1) were evaluated. RESULTS: Our main findings are as follows: (1) patients with acute cerebral ischemia showed a significant increase of CD154 on platelets and CD40 on monocytes compared with controls; (2) plasma levels of soluble CD154 were significantly higher in these patients; (3) these patients had significantly higher numbers of prothrombotic platelet-monocyte aggregates; (4) the chemoattractant MCP-1 was significantly elevated in cerebral ischemia; and (5) at 3 months' follow-up, upregulation of CD154 still persisted in patients with previous acute cerebral ischemia. CONCLUSIONS: Patients with acute cerebral ischemia show upregulation of the CD40 system, which might contribute to the known proinflammatory, proatherogenic, and prothrombotic milieu found in these patients.

Acute Disease↗
PubMed2003

[Time consumption and quality of an automated fusion tool for SPECT and MRI images of the brain].

AIM: Although the fusion of images from different modalities may improve diagnostic accuracy, it is rarely used in clinical routine work due to logistic problems. Therefore we evaluated performance and time needed for fusing MRI and SPECT images using a semiautomated dedicated software. PATIENTS, MATERIAL AND METHOD: In 32 patients regional cerebral blood flow was measured using (99m)Tc ethylcystein dimer (ECD) and the three-headed SPECT camera MultiSPECT 3. MRI scans of the brain were performed using either a 0,2 T Open or a 1,5 T Sonata. Twelve of the MRI data sets were acquired using a 3D-T1w MPRAGE sequence, 20 with a 2D acquisition technique and different echo sequences. Image fusion was performed on a Syngo workstation using an entropy minimizing algorithm by an experienced user of the software. The fusion results were classified. We measured the time needed for the automated fusion procedure and in case of need that for manual realignment after automated, but insufficient fusion. RESULTS: The mean time of the automated fusion procedure was 123 s. It was for the 2D significantly shorter than for the 3D MRI datasets. For four of the 2D data sets and two of the 3D data sets an optimal fit was reached using the automated approach. The remaining 26 data sets required manual correction. The sum of the time required for automated fusion and that needed for manual correction averaged 320 s (50-886 s). CONCLUSION: The fusion of 3D MRI data sets lasted significantly longer than that of the 2D MRI data. The automated fusion tool delivered in 20% an optimal fit, in 80% manual correction was necessary. Nevertheless, each of the 32 SPECT data sets could be merged in less than 15 min with the corresponding MRI data, which seems acceptable for clinical routine use.

Automation↗
PubMed2002

[CT and MRI of the petrous bone].

Diseases of the petrous bone should now be diagnosed by means of high-resolution multislice spiral computed tomography (MSCT) and/or magnetic resonance imaging (MRI). The first step in the process of diagnosis, however, must be conventional X-ray photographs (according to Schüller, Mayer, Stenvers) for screening purposes, because of the high cost of the other procedures mentioned. Because of the excellent imaging of bone structures with MSCT, this technique is especially suitable for the diagnosis both of acquired pathologies and of congenital abnormalities of the external auditory meatus, the middle ear and the mastoid, of trauma-induced pathologies of the entire petrous bone, and of osteogenic diseases. MRI is the method of choice for examination of the labyrinthine system, the interior auditory meatus and the cerebellopontine angle because it gives much the best depiction of soft tissue. Sometimes when questions remain unsolved after computed tomography (CT) examination of the middle ear MRI can be applied to complement CT, and it can yield additional information. Lesions affecting the apex of the petrous pyramid should be examined by MRI. High-resolution CT through the bone window and thin-layer MRI are both components of the presurgical diagnosis before cochlear implant (CI) surgery. For postoperative monitoring a conventional transorbital X-ray of the petrous bone is sufficient; CT is indicated only in complicated cases, and MRI is absolutely contraindicated after CI.

Artifacts↗
PubMed2001

Ictal fear in temporal lobe epilepsy: surgical outcome and focal hippocampal changes revealed by proton magnetic resonance spectroscopy imaging.

BACKGROUND: Ictal fear (IF) is most frequently associated with epileptic discharges from mesial temporal areas. OBJECTIVES: To determine whether patients with IF were more likely to become seizure free after anteromesial temporal lobe resection compared with those without IF and whether they show more anteriorly pronounced metabolic changes assessed by means of multivoxel magnetic resonance spectroscopy (MRS) along the hippocampal axis. METHODS: Surgical outcome was assessed in 33 consecutive patients with temporal lobe epilepsy after a mean follow-up of 25 months (range, 12-38 months). Proton multivoxel MRS of the hippocampal formation was applied to detect regional differences along the axis of the hippocampus in patients with and without IF. Magnetic resonance tomography showed typical features of hippocampal sclerosis in all patients. RESULTS: Twelve (36%) of the 33 patients reported fear at the beginning of their habitual seizures. Eleven of these patients were seizure free postoperatively. In contrast, only 11 of 21 patients without IF had a favorable outcome. Results of MRS revealed significantly higher pathologic N-acetylaspartate-choline ratios in the anterior portion of the hippocampal formation in patients with than in those without IF, indicating focal metabolic and/or morphologic changes in the head of the hippocampus. CONCLUSIONS: These results indicate the importance of diagnosing auras with IF to provide a more detailed prognosis of the surgical outcome. In addition, our data emphasize that multivoxel MRS is a valuable tool in the presurgical evaluation, as it may reveal different topographical patterns of hippocampal sclerosis.

Adult↗
PubMed2001

Cerebral vein thrombosis and prothrombin gene (G20210A) mutation.

Recently, prothrombin gene mutation G20210A has been associated with elevated thrombosis risk and rarely with cerebral vein thrombosis (CVT). Three patients are described who had this genetic predisposition and who developed CVT in an unusual constellation with other factors. In the first patient, the intake of valproic acid (VPA) may have played an aggravating role in the development of CVT; in the second patient diagnosis of coagulation disorder was made during pregnancy consultation 6 years after CVT; in the third patient the CVT occurred at the age of 78 years. In patients with CVT, coagulation-examinations should include tests for the prothrombin gene (G20210A) mutation.

Adult↗
PubMed2001

[Orbito-palpebral emphysema due to ethmoidal fracture].

BACKGROUND: Orbito-palpebral emphysema is a frequent pathological entity due to head injury. We report on a patient and correlate the clinical view and computer tomography findings. CASE REPORT: A 17-year-old male was referred to our hospital after a blunt trauma to his head. Visual acuity was 1,0. Diplopia, restricted motility and exophthalmus about 4 mm were found. CONCLUSION: If swelling of the lid is found orbito-palpebral emphysema should be thought of to initiate appropriate therapy to avoid possible severe complications, for example, occlusion of the retinal central artery.

Adolescent↗
PubMed2000

2D and 3D visualisation of head and neck tumours from spiral-CT data.

PURPOSE: This paper intends to demonstrate the possibilities of two- and three-dimensional visualisation methods from spiral-CT data sets in the head and neck region and demonstrates their value based on various studies. MATERIAL AND METHODS: The scanner was a Somatom PLUS 4 (Siemens, Forchheim/Germany). The patients were scanned using a slice thickness of 3 mm and a table feed of 5 mm (pitch 1,6). The images were reconstructed with an increment of 1 mm. Contrast agent (150 ml) was applied intravenously with a flow of 2.5 ml/s and a start delay of 80 s. In one study the start delay was 20 s in order to visualise the carotid arteries (extracranial aneurysm). Volumetric data sets were postprocessed with 'Vitrea' and 'VoxelView' (Vital Images) volume rendering software on a Silicon Graphics O2 workstation (virtual laryngoscopy). Multiplanar reformation and colour-coded 3D-reconstruction were done on a Prominence workstation (Siemens/Forchheim/Germany). RESULTS: In every region of the head and neck MPRs are useful as additional planes (with the exception of the hypopharynx and the larynx), SSDs are always useful if there is extensive bony destruction (skull, spine, skeleton larynx). Colour-coded three-dimensional reformations may be done for extensive tumours and before multi-specialty surgery. Perspective volume rendering is already in use for virtual endoscopy of the paranasal sinuses and the virtual laryngoscopy. In temporal bone evaluation, perspective volume rendering is a new and promising method of the future to assess the inner ear. SUMMARY: Two- and three-dimensional displays are used to visualise pathological findings in their topographic relation to anatomical leading structures. Thus, the radiologist can point out to the clinician the pathological findings by some essential images without having to demonstrate all axial slices.

Aneurysm↗
PubMed2000

[Diplopia as first symptom of a bronchogenic carcinoma].

BACKGROUND PATIENTS: In about 30% of patients with orbital metastases, these metastases are detected before the primary tumour is known. Less than 5% of orbital metastases are located in extraocular muscles. We report on a patient with diplopia caused by diminished abduction of the left eye as first symptom of a bronchogenic carcinoma. PATIENT: A 86-year-old patient presented with a newly developed diplopia. On examination, the left eye showed a diminished abduction, ptosis and miosis. Pharmacological testing revealed peripheral Horner's syndrome. On cranial magnet resonance tomography, the lateral rectus muscle belly was enlarged. A chest X-ray showed a large tumour (6 cm in diameter) of the left upper lobe with multiple metastases to the lungs. Further examinations revealed a large cell bronchogenic carcinoma with metastases to the lungs, adrenal glands, and the lateral rectus muscle. CONCLUSIONS: Diplopia caused by metastases to extraocular muscles is rare as first sign of a bronchogenic carcinoma. The combination of peripheral Horner's syndrome with diminished abduction of the homolateral eye primarily suggests a lesion of the cavernous sinus. The bronchogenic carcinoma could not be causative for Horner's syndrome in the patient presented here, however an undetected tumor-infiltration of the postganglionic region cannot be excluded. This case demonstrates that in all patients with newly developed diplopia and Horner's syndrome, even in absence of orbital signs, apart from a ophthalmological examination detailed radiographic or magnetic resonance tomographic imaging is necessary of both skull base and orbita.

Aged↗