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M Skalej

Publications and source records attributed to M Skalej.

At least 37 records · Page 2Linked to original sources
PubMed1999

Intracranial inflammatory tumors: a survey of their various etiologies by presentation of 5 cases.

Due to similar clinical and neuroradiological features, intracranial inflammatory tumors (IITs) are frequently misdiagnosed as brain neoplasms, from which they notably differ in respect to therapy and prognosis. In this article, five cases of such tumors are presented. Three of the patients with brain tumors (cases 3, 4 and 5) presented a history of 'pararheumatic' syndromes but no diagnosis of defined immunopathies. On the basis of radiological findings, all processes were classified as genuine brain neoplasms, but histology showed reactive inflammatory features. The possible etiologies of these 'tumors' are discussed on the basis of all clinical and histological data of the patients. The spectrum of diseases potentially leading to the manifestation of an IIT is reviewed. Additionally, the presentation of case 5, who developed a highly malignant B-cell-lymphoma 6 months after the removal of an IIT without any histological signs of atypia, shows that this differential diagnosis always has to be kept in mind.

Adult↗
PubMed1999

Detection and follow-up of homonymous visual field defects - perimetric essentials for evaluation of spontaneous recovery.

Clinical detection and follow-up of homonymous visual field defects require appropriate perimetric procedures: since postgeniculate lesions are usually characterised by absolute scotomata, time consuming threshold methods can be replaced by supraliminal strategies with comparatively high stimulus densities. Compared with equidistant rectangular grids, a centripetal stimulus condensation represents the physiological conditions more adequately and thus is more effective. It allows one to differentiate central changes of the visual field, like macular sparing or splitting, which also interfere with reading performance. This procedure requires test points to be located to either side of the vertical meridian, rather than directly on it. Multimodal assessment of visual subfunctions (using static, kinetic or colour test points, random dot patterns or optokinetic stimulation) specifies the effect of the lesion in different channels or regions of the visual pathways. Automation of perimetric procedures and continuous monitoring of fixation are important tools, enhancing the quality of examination and follow-up. The above mentioned psychophysical techniques for detection of functional defects and documentation of eventual recovery, as well as matching neuroimaging findings, are demonstrated by illustrative cases.

Journal Article↗
PubMed1999

Magnetic resonance imaging-based volumetry differentiates idiopathic Parkinson's syndrome from multiple system atrophy and progressive supranuclear palsy.

By using three-dimensional magnetic resonance imaging-based volumetry, we studied atrophy of the caudate nucleus, putamen, brainstem, and cerebellum in patients with idiopathic Parkinson's syndrome (IPS, n = 11), progressive supranuclear palsy (PSP, n = 6), and multiple system atrophy with predominant parkinsonism (MSA-P, n = 12) or ataxia (MSA-C, n = 17). Patients were compared with a total of 46 controls, of whom 16 were age matched. Mean striatal, cerebellar, and brainstem volumes were normal in patients with IPS. We found significant reductions in mean striatal and brainstem volumes in patients with MSA-P, MSA-C, and PSP, whereas patients with MSA-C and MSA-P also showed a reduction in cerebellar volume. On an individual basis, volumes of structures in patients with MSA and PSP showed an extensive overlap with the normal range with the exception of brainstem volumes in patients with MSA-C. Therefore, groups could not be discriminated on the basis of individual structure volumetry. Application of stepwise discriminant analysis, however, allowed discrimination of all 12 patients with MSA-P, 15 of 17 patients with MSA-C, and 5 of 6 patients with PSP from the normal and IPS cohorts. However, patients with IPS could not be separated from controls and patients with MSA-P could not be separated from patients with PSP. In conclusion, total intracranial volume-normalized magnetic resonance imaging-based volumetric measurements provide a sensitive marker to discriminate typical and atypical parkinsonism.

Adult↗
PubMed1998

A new semiautomated, three-dimensional technique allowing precise quantification of total and regional cerebellar volume using MRI.

A new method was developed to measure total and regional cerebellar volumes using MRI. Previously, the volumes of the cerebellum and its substructure had been studied planimetrically. The new method uses three-dimensional semiautomated volumetry with focus on reliability and performance. The method consists of a manual presegmentation using landmark-adjusted planes followed by region-growing segmentation and calculation of volume. The cerebellum is partitioned into 11 regions defined by planes, which are adjusted for internal cerebellar landmarks (three radial regions inside the vermis that extend into the medial hemisphere (one-fourth of the transverse diameter of the hemisphere); one region in the lateral hemisphere (remaining three-fourths)). Forty-six healthy volunteers were examined and the effects of age, gender, and symmetry were estimated. Shrinkage in the vermis (especially anterior superior compartment) was marked. Age effects diminished laterally and were not observed in the lateral hemisphere. Age effects on the total cerebellar volume were marginal. Effects of gender and symmetry were nonsignificant. Technique and results are discussed and related to methods and findings of others.

Adult↗
PubMed1998

Lesion location influences perception of homonymous scotomata during flickering random dot pattern stimulation.

An attempt was made to clarify whether the site of postchiasmal lesions affects subjective perception of homonymous visual field defects during stimulation with flickering random dot patterns (white noise-field). Out of 56 patients with homonymous hemianopia, 38 (68%) perceived scotomata in this situation, but 18 (32%) discerned none at all. Neuroradiologic superposition of cerebral lesions detected by computed tomography (CT) or magnetic resonance imaging (MRI) showed that nearly all patients who perceived their scotomata had lesions involving the primary visual cortex or the perigeniculate region, whereas those who received no scotoma had lesions centered within the optic radiation. Functional MRI of six normal subjects during stimulation with flickering random dot patterns indicated predominant activation of the primary visual cortex. Since noise-field defects were most frequently perceived by patients whose lesion involved the primary visual cortex, it appears that the sensitivity of noise-field campimetry depends on the site of damage in the visual pathway. The explanation for this may be that damage to long-range horizontal connections impairs filling-in processes.

Adolescent↗
PubMed1998

Image quality of spiral CT versus conventional CT in routine brain imaging.

OBJECTIVE: Aim of the study was to compare image quality of spiral (helical) versus conventional (sequential) routine brain scans obtained on a spiral CT scanner of the latest generation. MATERIALS AND METHODS: In a prospective study 60 patients scheduled for cranial CT were examined in spiral (27 cases) or conventional technique (33 cases) after randomization. Two blinded observers rated artifacts, gray--white-matter contrast and overall image quality. RESULTS: No significant differences in artifacts were detected. Concerning gray--white-matter contrast and overall image quality, none or small differences in favour of conventional scans were found depending on the observer. CONCLUSION: On a modern scanner image quality of spiral brain scans in adults is nowadays comparable to or only slightly less than that of conventional scans. On such a machine, spiral mode can be recommended if, for example, rapid scanning or high-quality secondary reconstructions are needed.

Artifacts↗
PubMed1998

Three-dimensional spiral CT angiography in the detection of cerebral aneurysm.

PURPOSE: The value of CT angiography in the detection and evaluation of aneurysms was compared to digital subtraction angiography (DSA). MATERIAL AND METHODS: Seventeen patients with acute subarachnoid hemorrhage (SAH) or with known or suspected aneurysm were investigated by means of spiral CT angiography, which included 3D reconstruction. These findings were compared with those at DSA. RESULTS: In 16 patients, 20 aneurysms were found; the remaining patient had an ectatic vessel that simulated an aneurysm. Seventeen of the angiographically proved aneurysms were detected at CT angiography (sensitivity 85%). One further aneurysm was identified retrospectively as the result of greater experience in the method. All the aneurysms that escaped detection at CT were 3 mm in size. All the vessels of the circle of Willis, except for the posterior communicating artery, were properly evaluated at CT angiography. Difficulties were encountered in assessing the posterior communicating artery and the extradural segment of the internal carotid artery owing to their close spatial relationship to the bony structures of the skull base and the cavernous sinus. CONCLUSION: CT angiography is a low-risk technique with a low level of invasiveness that is useful in following up known aneurysms. The 3D reconstruction yields further topographic information that helps in the planning of endovascular or surgical intervention. The facility for rotating the reconstructed vessels and displaying them from different angles is of particular value in cases difficult to assess at angiography.

Adult↗
PubMed1998

Autosomal dominant cerebellar ataxia type I. MRI-based volumetry of posterior fossa structures and basal ganglia in spinocerebellar ataxia types 1, 2 and 3.

Twenty-six patients suffering from autosomal dominant cerebellar ataxia type I were subjected to a genotype-phenotype correlation analysis using molecular genetic assignment to the genetic loci for spinocerebellar ataxia type 1, 2 or 3 (SCA1, SCA2, SCA3) and MRI-based volumetry of posterior fossa structures and basal ganglia nuclei. There was significant atrophy of the cerebellum and brainstem in all three SCA mutations compared with a group of 31 age- and sex-matched controls. Comparison between the SCA groups showed that cerebellar and brainstem atrophy was more severe in SCA2 than in SCA1 and SCA3. Putaminal and caudate volume was reduced only in SCA3, but not in SCA1 and SCA2. A set of three morphological criteria was defined that enabled us to assign all SCA2 and SCA3 patients correctly to the underlying genotype. In contrast, these criteria did not distinguish SCA1 from SCA2 and SCA3. Regression analysis failed to reveal a significant association between CAG repeat length and the volumes of the respective brain structures in any of the SCA mutant types. The present data provide in vivo evidence that SCA2 and SCA3 lead to distinct patterns of brain atrophy, while the atrophy changes in SCA1 overlap with both SCA2 and SCA3.

Adult↗
PubMed1998

Comparing motion- and imagery-related activation in the human cerebellum: a functional MRI study.

Cerebellar activation during execution and imagination of a finger movement was compared. Functional magnetic resonance imaging was used to detect cerebellar activation during execution and imagination of an untrained self-paced finger-to-thumb movement (left and right hand separately). The four fingers were opposed to the thumb in changing sequences freely chosen by the subjects. The activation maps of 10 right-handed healthy subjects were averaged after transformation into a common coordinate space. Averaged activation maps revealed strong motion-related bilateral activation in the anterior lobe of the cerebellum and in the paravermal regions of the posterior lobe. Ipsilateral activity predominated significantly. Compared to motion, imagination of the same task produced lower signal changes, and foci were more variable in position and strength. The averaged activation maps showed activity in the same regions as in motion. Activation in the posterior cerebellar lobe was more prominent extending into the lateral hemispheres. Ipsilateral dominance was significant for right-hand imagery. The left-hand task only showed marginally stronger ipsilateral activation. The activation pattern observed during execution of the finger-to-thumb movement is in agreement with theories of functional cerebellar topography. For imagery, activation at a comparable location may reflect common functionality, e.g., motor preparation and/or timing. Additional activation in the lateral hemispheres may be related to an imagery-specific function.

Adult↗
PubMed1998

Small rosarylike infarctions in the centrum ovale suggest hemodynamic failure.

BACKGROUND AND PURPOSE: Lesions in the centrum ovale may be classified as microangiopathic (lacunar) lesions and hemodynamic infarctions. To distinguish between them, a size of more than 2 cm has been postulated for hemodynamic infarctions. The reliability of this criterion was assessed with MR imaging. METHODS: In 16 patients with unilateral or bilateral occlusion or high-grade stenosis of the internal carotid artery (ICA), CO2 testing revealed an ipsilateral hemodynamic failure. Each hemisphere in these patients was assessed separately for the presence and size of centrum ovale lesions. RESULTS: Five of the 16 patients suffered from large cortical infarctions with a probable embolic pathogenesis. In the remaining 11 patients (22 hemispheres), a hemodynamic failure was found in 15 hemispheres, due to occlusion (13 hemispheres) or high-grade ICA stenosis (two hemispheres). MR imaging revealed centrum ovale infarctions with a size of more than 2 cm in three of the 15 hemispheres. In eight hemispheres, multiple small lesions (< 1.5 cm; three to 30 per hemisphere) could be found with a rosarylike or sickle-shaped distribution. In none of these eight cases did MR images show lacunar infarctions in the typical regions of the brain. CONCLUSION: Our results favor the assumption that the MR finding of multiple small (< 1.5 cm) rosarylike lesions in the centrum ovale seems to be typical in patients with hemodynamic failure due to severe ICA disease.

Adult↗
PubMed1997

CNS late effects after ALL therapy in childhood. Part I: Neuroradiological findings in long-term survivors of childhood ALL--an evaluation of the interferences between morphology and neuropsychological performance. The German Late Effects Working Group.

The effect of cranial irradiation on possible therapy-induced morphological central nervous system (CNS) side effects of children cured from acute lymphoblastic leukemia (ALL) is controversially discussed. In a retrospective multicenter study, 118 former ALL patients in first continuous remission were investigated using cranial computerised tomography (CCT) or magnetic resonance imaging (MRI) scans to evaluate CNS related impairments. Corresponding to the different kinds of CNS prophylaxis, the patient sample was divided: group A (n = 39) receiving intrathecal methotrexate (ITMTX) and systemical medium-high-dose methotrexate (SMHDMTX), group B (n = 41) cranial irradiated (in mean 16.8 Gy) and administering ITMTX and SMHDMTX, group C (n = 38) irradiated (in mean 17.1 Gy) and getting ITMTX. Pathologic scans showed atrophy, leukoencephalopathy, calcifications or grey matter changes. These findings were compared with the neuropsychological test results. Abnormal MRI or CCI scans were found in 61/118 patients (51.7%). Fifteen belonged to group A (38.5%), 23 to B (56.1%) and 23 to C (60.5%). Patients with definite CNS changes show reduced neuropsychological test results. The prevalence of brain alterations seems to appear twice increased after lengthening the posttherapeutic interval in irradiated patients as in nonirradiated patients. Irradiated patients as an age younger than 2 years at diagnosis may show a lower prevalence for developing CNS alterations. CNS alterations are not sex-related. Children treated with cranial irradiation in combination with SMHDMTX and/or ITMTX were at greater risk of developing morphological brain alterations than patients with chemotherapy alone. These alterations are partly correlated with reduced neuropsychological performances and seem to stay with a longer posttherapeutic interval.

Adolescent↗
PubMed1997

ICP monitoring with a re-usable transducer: experimental and clinical evaluation of the Gaeltec ICT/b pressure probe.

Intracranial pressure monitoring requires reliable transducers at a justifiable price. At present, transducers for single or repeated use are available. We examined the Gaeltec model ITC/b solid state miniature transducer experimentally and clinically. Measurement accuracy was assessed in vitro at increasing steps of 5 mmHg from 0 to 80 mmHg. While new and recently serviced probes revealed minimal deviations from the preset values, frequently used transducers differed up to 7 mmHg. This occurred especially in the high pressure range above 50 mmHg. Additionally the drift was investigated at different pressure levels. After 24 hours we already found drifts of 2 mmHg with new and serviced probes and up to 4 mmHg with used ones. In clinical practice we implanted 150 transducers in 121 patients from 1983 until 1995. The probes were re-used up to twelve times, the average time being 7 times. 32.7% of all measurements were regarded as not reliable. Dislocation (16.7%), inability to calibrate (3.3%) and defect pressure probes (3.3%) were the most common complications. Repeated use of the Gaeltec ICT/b probe also seemed to result in an additional decay of measurement quality. The strain of frequent cleaning and sterilizing may have caused changes of the physical properties of the probes with time. Whether these results also apply to other types of ICP probes for repeated use needs further evaluation.

Adolescent↗
PubMed1997

Clinical and genetic analysis of three German kindreds with autosomal dominant cerebellar ataxia type I linked to the SCA2 locus.

The detailed clinical, electrophysiological and imaging data of three German autosomal dominant cerebellar ataxia (ADCA) families are reported. Linkage to SCA2 was established using microsatellite markers D12S105, D12S1339(1328), D12S1304(1329) yielding a lod score exceeding +3.0 for the combined data. Analysis of the pedigree data provided evidence of anticipation as observed in other neurodegenerative disorders due to polyglutamine expansion encoded by a CAG repeat. This hypothesis was confirmed by the detection of the SCA2-specific pathological protein using the 1C2 monoclonal antibody which selectively recognizes large polyglutamine expansions and the characterization of a CAG expansion in the patients. Clinically, the families were characterized by progressive ataxia of stance, gait and limbs. Saccade velocity was markedly reduced in SCA2. Further oculomotor findings were gaze palsy, impaired smooth pursuit and reduced optokinetic reflex. Dementia and pyramidal tract signs were rather rare, while peripheral involvement (reduced or absent ankle reflexes, fasciculation-like movements, amyotrophy) was a prominent feature. Electrophysiological investigations provided evidence of sensory neuropathy of the axonal type and degeneration of the posterior columns. Imaging studies demonstrated severe shrinkage of brain-stem structures even in early stages of the disease.

Adult↗
PubMed1997

Saccade velocity in idiopathic and autosomal dominant cerebellar ataxia.

Slow saccades are often found in degenerative ataxia. Experimental studies have shown that horizontal saccades are generated in the paramedian pontine reticular formation and that lesions in this area produce slow saccades. Based on these findings, saccade slowing should be a frequent feature of olivopontocerebellar atrophy, a type of cerebellar degeneration with prominent involvement of the pons. To test this hypothesis, saccade velocity was measured in 31 patients with autosomal dominant cerebellar ataxia (ADCA) and 17 patients with idiopathic cerebellar ataxia (IDCA). Saccade velocity was reduced in most patients with ADCA whereas it was normal in IDCA although olivopontocerebellar atrophy occurred in both groups. Saccade velocities correlated with pontine size in ADCA but not in IDCA. The data disprove the hypothesis that saccadic slowing is a clinical hallmark of olivopontocerebellar atrophy. Instead, only patients with ADCA and morphological features of olivopontocerebellar atrophy have slow saccades.

Adult↗
PubMed1996

Autosomal dominant cerebellar ataxia type I clinical features and MRI in families with SCA1, SCA2 and SCA3.

Sixty-five patients suffering from autosomal dominant cerebellar ataxia-I(ADCA-1) were subjected genotype phenotype correlation analysis using molecular genetic assignment to the spinocerebellar ataxia type 1, 2 or 3 (SCA1, -2 or -3) locus, clinical examination, eye movement recording and morphometric analysis of MRIs. Pyramidal tract signs, pale discs and dysphagia were more frequent in SCA1 compared SCA2 and SCA3 patients. Saccade velocity was reduced in 56% of SCA1 and all SCA2, but only in 30% of SCA3 patients. MRIs of SCA2 patients showed atrophy changes typical of severe olivopontocerebellar atrophy (OPCA). The morphological changes in SCA1 were similar but less pronounced. In contrast, SCA3 patients had only mild cerebellar and brain stem atrophy distinct from typical OPCA. The principal finding of this study is that mutations of the SCA2 and SCA3 gene cause phenotypes which can be distinguished in vivo by recording of eye movements and morphometric MRI analysis. Correlative plotting of saccade velocity and diameter of the middle cerebellar peduncle yields a clear separation of SCA2 and SCA3. Spinocerebellar ataxia type I falls into an intermediate range that overlaps with both SCA2 and SCA3. However, the clinical syndrome observed in SCA1 patients is different from that in SCA2 and SCA3.

Adult↗