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Biomedical subjects

H Przuntek

Publications and source records attributed to H Przuntek.

At least 91 records · Page 5Linked to original sources
PubMed1999

Delayed motor response correlates with striatal degeneration in Parkinson's disease.

OBJECTIVE: Studies on reaction time have suggested a selective deficit of slowness in motor readiness and motor programming in Parkinson's disease (PD). Objective of this study was the putative relation between delayed initiation and execution of movement and the striatal dopamine deficiency in PD. MATERIAL AND METHODS: We investigated 32 idiopathic, previously untreated parkinsonian patients to evaluate dopaminergic nigrostriatal degeneration by single photon emission tomography in combination with the radiotracer [123I]-beta-CIT and performed a simple reaction time paradigm on the same day. RESULTS: Significant relations between the [123I]-beta-CIT-SPECT-ratio striatum/cerebellum and reaction--and movement time appeared. Reaction time and movement time of parkinsonian patients were significantly longer compared to age-matched controls. CONCLUSIONS: We conclude that reaction- and movement-time is related to the dopaminergic nigrostriatal degeneration in untreated parkinsonian subjects.

Adult↗
PubMed1999

Basal ganglia alterations and brain atrophy in Huntington's disease depicted by transcranial real time sonography.

OBJECTIVES AND METHODS: Transcranial real time sonography (TCS) was applied to 49 patients with Huntington's disease and 39 control subjects to visualise alterations in the echotexture of the basal ganglia. For comparison T1 weighted, T2 weighted, and fast spin echo MRI was performed in 12 patients with Huntington's disease with and in nine patients without alterations of the basal ganglia echotexture as detected by TCS and T1 weighted, T2 weighted, and fast spin echo MRI. Furthermore, the widths of the frontal horns, third ventricle, and the lateral ventricles were depicted in TCS examinations and correlations examined with corresponding CT slices. RESULTS: Eighteen out of 45 (40%) of the patients with Huntington's disease with adequate insonation conditions showed hyperechogenic lesions of at least one basal ganglia region. In 12 patients TCS depicted hyperechogenic lesions of the substantia nigra; in six patients the head of the caudate nucleus was affected. The lentiform nucleus (n=3) and the thalamus (n=0) were less often affected or spared. Hyperechogenic lesions were significantly more frequent in patients with Huntington's disease than in 39 control subjects, who had alterations of the echotexture in 12.8% (4/39) of the examinations. The number of CAG repeats and the clinical status correlated with the identification of hyperechogenic lesions of the substantia nigra (p<0.01). Hyperechogenic lesions of the caudate nucleus were associated with an increased signal intensity in T2 weighted MR images (p<0.05). All TCS parameters indicating brain atrophy correlated with CT findings (p<0.0001). CONCLUSIONS: TCS detects primarily abnormalities of the caudate nucleus and substantia nigra in Huntington's disease. These changes in the echotexture may represent degenerative changes in the basal ganglia matrix and are partially associated with CAG repeat expansion and the severity of clinical findings.

Adult↗
PubMed1999

Impaired visual function in focal idiopathic dystonia.

Visual dysfunctions have previously been reported in Parkinson's disease and Huntington's chorea. To further characterize the pathophysiology of vision in basal ganglion diseases, we studied visual functions in focal dystonic syndromes. Colour discrimination and visual contrast perception were investigated in 37 patients with focal idiopathic dystonia (ID; 20 spasmodic torticollis, 17 blepharospasm) and in age- and sex-matched healthy volunteers using the Farnsworth-Munsell 100-hue test and stationary contrast targets (Vistech plates). The mean total error score as well as the partial scores for the 'red-green' and the 'blue-yellow' axes in the Farnsworth-Munsell 100-hue test of the patients with ID were significantly elevated as compared to controls (spasmodic torticollis mean total error score 90.9 +/- 67.6, controls: 16.6 +/- 10.2; blepharospasm mean total error score 119.4 +/- 78.6, controls: 22.7 +/- 7.9). Additionally, the spatial contrast sensitivity was impaired in patients as compared to controls. The results indicate that the visual system is affected in ID. The visual disorder may be related to an imbalance of certain neurotransmitters in the visual system of patients, e.g. in the catecholaminergic pathways.

Adult↗
PubMed1999

Second harmonic imaging In acute middle cerebral artery infarction. Preliminary results.

BACKGROUND: Second harmonic imaging (SHI) is a new ultrasound technique that is able to detect microbubbles in the tissue vascular space. The aim of this pilot study was to prove that this technique may detect focal abnormalities of cerebral echo-contrast enhancement in acute hemispheric stroke. CASE DESCRIPTIONS: Two male patients (aged 72 and 64 years) were included who presented with acute onset of severe hemiparesis and no established demarcation of the ischemic area in CT scans. After bolus application of galactose-based microbubbles, axial SHI examinations in a diencephalic plane of sections were performed using the transtemporal approach. Ultrasound investigations were recorded and evaluated offline. In both individuals demarcated focal abnormalities of cerebral contrast enhancement were detectable: in patient 1 the region of the lentiform nucleus and the adjacent parts of the temporoparietal lobe was affected, and in patient 2 a large region including the lentiform nucleus and cortical white matter was involved for at least 24 hours. Follow-up CT scans demonstrated a striatocapsular infarct in patient 1 and complete MCA infarction in patient 2, correlating with the presumed ischemic area in acute ultrasound examinations. The patient with complete MCA infarction showed missing contrast enhancement in the entire hemisphere of the affected side in follow-up SHI examinations. He died of malignant space-occupying brain edema. In the patient with the striatocapsular infarction, reappearance of echo-contrast enhancement in the ischemic area was assessable after 1 week. CONCLUSIONS: SHI may identify focal abnormalities of cerebral echo-contrast enhancement in acute hemispheric stroke. Furthermore, this technique helps to determine size, localization, and prognosis of the ischemic region and could be useful for bedside assessment of echo-contrast agent distribution related to brain tissue perfusion.

Acute Disease↗
PubMed1999

Contrast-enhanced transcranial color-coded sonography in acute hemispheric brain infarction.

PURPOSE: The aim of the present study was to investigate the diagnostic potential of contrast-enhanced transcranial color-coded real-time sonography (CE-TCCS) in otherwise ultrasound-refractory acute stroke patients with an ischemia in the territory of the middle cerebral artery (MCA). Furthermore, correlations of CE-TCCS findings with clinical, angiographic, and CT results were investigated. METHODS: In 90 acute stroke patients with inadequate insonation conditions in unenhanced transcranial color-coded real-time sonography (TCCS) examinations, CE-TCCS, clinical, angiographic, and CT examinations were performed within 12 hours, 36 hours (CE-TCCS only), and 1 week after onset of clinical symptoms. A CT angiography (CTA) as reference method was available in 39 individuals. After application of a galactose-based echo-enhancing agent, the portion of conclusive ultrasound examinations of the MCA, as manifested by an MCA occlusion, decreased or increased flow velocity (FV), and symmetrical MCA FV, was evaluated. CE-TCCS findings on admission and during follow-up were correlated with infarction size as demonstrated on follow-up CT, and clinical findings were assessed by use of the European Stroke Scale. RESULTS: Adequate diagnosis was achieved in 74 of 90 patients (82%) by the use of echo contrast agents. MCA occlusion or reduction of MCA FV was found in 20 and 27 patients, respectively. MCA occlusion was confirmed by CTA in 17 cases. In one individual, false-positive diagnosis of MCA occlusion was made according to ultrasound criteria. In 5 patients with MCA occlusion, vessel recanalization was observed during follow-up; 15 of 27 patients with decreased flow velocities showed normalization after the third examination that was associated with a significantly better clinical outcome (P<0.0001). Furthermore, MCA occlusion or decreased FV in the first 12 hours were associated with significantly larger infarctions in the MCA territory compared with normal CE-TCCS findings (P<0.0001). CONCLUSIONS: CE-TCCS enables adequate diagnosis in approximately 80% of acute hemispheric stroke patients with insufficient unenhanced TCCS examinations. It is a reliable diagnostic tool regarding MCA mainstem and branch occlusions. Because this method conveys useful information concerning cerebral tissue and clinical prognosis, it may be useful to identify those patients who benefit most from local or intra-arterial thrombolytic therapy.

Acute Disease↗
PubMed1998

Neural structures associated with recognition of facial expressions of basic emotions.

People with Huntington's disease and people suffering from obsessive compulsive disorder show severe deficits in recognizing facial expressions of disgust, whereas people with lesions restricted to the amygdala are especially impaired in recognizing facial expressions of fear. This double dissociation implies that recognition of certain basic emotions may be associated with distinct and non-overlapping neural substrates. Some authors, however, emphasize the general importance of the ventral parts of the frontal cortex in emotion recognition, regardless of the emotion being recognized. In this study, we used functional magnetic resonance imaging to locate neural structures that are critical for recognition of facial expressions of basic emotions by investigating cerebral activation of six healthy adults performing a gender discrimination task on images of faces expressing disgust, fear and anger. Activation in response to these faces was compared with that for faces showing neutral expressions. Disgusted facial expressions activated the right putamen and the left insula cortex, whereas enhanced activity in the posterior part of the right gyrus cinguli and the medial temporal gyrus of the left hemisphere was observed during processing of angry faces. Fearful expressions activated the right fusiform gyrus and the left dorsolateral frontal cortex. For all three emotions investigated, we also found activation of the inferior part of the left frontal cortex (Brodmann area 47). These results support the hypotheses derived from neuropsychological findings, that (i) recognition of disgust, fear and anger is based on separate neural systems, and that (ii) the output of these systems converges on frontal regions for further information processing.

Adult↗
PubMed1998

Kleine-Levin syndrome and Parkinsonian symptoms--a case report.

We report the case of a 54-year-old male patient, who developed the symptoms of Kleine-Levin syndrome (KLS) at the age of fifty. Four years later Parkinsonian symptoms (PS) appeared. The possible relationship between both KLS and PS, e.g. regarding neuroendocrinological similarities, will be discussed to explain the subsequent onset of PS after the manifestation of KLS in this patient.

Humans↗
PubMed1998

Selegiline as immunostimulant--a novel mechanism of action?

In clinical studies the MAO-B inhibitor selegiline appears to slow the progression of neurological deficits in Parkinson's disease (PD) and the cognitive decline in Alzheimer's disease (AD). The mechanisms of action remain unclear. Several lines of evidence indicate an immune-mediated pathophysiology of PD and AD. According to animal trials, selegiline increases the survival rate of immune suppressed mice. Stimulation of the immune response to bacterial or viral infection or in chronic inflammatory processes in managed by an increased synthesis of the cytokines interleukin-1 beta (IL-1 beta) and subsequent interleukin-6 (IL-6). Outcome of viral or bacterial infections in the brain highly correlates with levels of the cytotoxic cytokine tumor-necrosis-factor-alpha (TNF). The aim of our study was to characterize the influence of selegiline on the biosynthesis of IL-1 beta, IL-6 and TNF in human peripheral blood mononuclear cells (PBMC) from healthy blood donors. After isolation and washing PBMC were cultured without and with selegiline in three different concentrations (0.01 mumol/l, 0.001 mumol/l, 0.0001 mumol/l) in a humidified atmosphere (7% CO2). Then cultures were centrifuged and supernatants were collected for IL-1 beta, IL-6 and TNF ELISA-assays. Treatment of cultured PBMC with various concentrations induced an increased synthesis of IL-1 beta (ANOVA F = 9.703, p = 0.0007), IL-6 (ANOVA F = 20.648, p = 0.0001) and a reduced production of TNF (ANOVA F = 3.770, p = 0.040). These results indicate, that the influence of selegiline on the cytokine biosynthesis may also contribute to its putative neuroprotective properties.

Adjuvants, Immunologic↗
PubMed1998

[Promoting remyelination as a future therapeutic principle in multiple sclerosis?].

Multiple sclerosis (MS), the most common neurological autoimmune disorder diagnosed in young adults, is characterised by the repeated occurrence of demyelinating lesions within the central nervous system (CNS). Promotion of remyelination in the brain and spinal cord constitutes a potential strategy for therapeutic intervention in MS and other demyelinating diseases. Three different principles are known to promote remyelination in the CNS of different animal models: Application of growth factors, transplantation of myelin-forming cells and intravenous immunoglobulin (IVIg) therapy. However, the systemic application of growth factors could be limited by effects on unaffected tissue. For successful transplantation we still have the problem of homologous cells not tolerated by a immunological different organism. Currently the required combination of growth factors needed to cultivate human homologous cells is not known, so that cells suitable for transplantation are still not available. Nevertheless, there is increasing evidence for beneficial effects of IVIg therapy on the promotion of remyelination in humans. In this review we summarise recent findings on the regulation of myelin sheath development and oligodendrocyte differentiation, and discuss the presented strategies in the context of possible clinical application for the therapy of MS.

Adult↗
PubMed1998

Colour vision abnormalities do not correlate with dopaminergic nigrostriatal degeneration in Parkinson's disease.

Sensory disturbances such as olfactory or visual dysfunctions are common in Parkinson's disease (PD). A possible relationship between distorted colour discrimination and the nigrostriatal dopamine deficit is still a matter of debate. We examined 31 de novo Parkinsonian patients with [123I]beta-CIT single photon emission tomography (SPECT). We used a single-head gamma-camera and calculated the binding ratio striatum/cerebellum (specific/nonspecific binding) of [123I]beta-CIT uptake. On the same day, we performed the Farnsworth-Munsell 100 Hue Test (FMT) in these patients and estimated the total error score, in order to investigate abnormalities of colour vision. Parkinsonian patients' total error score was higher compared with an age- and sex-matched control group (P = < 0.0001), whereas disability scores of the Hoehn and Yahr scale (P = 0.019, Spearman r = 0.419) and the Unified Parkinson's Disease Rating Scale (P = 0.039, Spearman r = 0.373) correlated with total error score. No significant association appeared between total error score (Spearman r = -0.119, P = 0.525) and [123I]P-CIT-SPECT ratio. Thus both total error scores of the FMT and [1231]beta-CIT-SPECT binding ratios have been found to reflect the severity of PD. However, only [123I]beta-CIT SPECT reflects degeneration of dopaminergic neurons of the basal ganglia, but does not reflect alterations of the visual system and/or extranigral lesions in PD. From our results, we speculate that FMT may be a valuable clinical method to measure extranigral lesions of the visual system in PD.

Adult↗
PubMed1998

Plasma levels of R- and S-salsolinol are not increased in "de-novo" Parkinsonian patients.

An augmented synthesis of tetrahydroisoquinolines, such as salsolinol (SAL) or an increased N-methylation of these compounds has been addressed by various investigators as putative pathophysiologic mechanisms in Parkinson's disease (PD). Aim of this study was (1) to investigate putative relations between plasma levels of dopamine and R- and S-enantiomers of SAL and (2) whether these metabolic precursors of the neurotoxic N-methylated-SAL (NMSAL) are elevated in untreated "de-novo" Parkinsonian patients compared to age- and sex-matched healthy controls. Plasma levels of R- and S-SAL and dopamine did not significantly (R-SAL: p=0.61, S-SAL: p=0.51, dopamine: p=0.84) differ in both groups. Parkinsonian patients' R-SAL plasma levels were inversely related to intensity (p=0.03, r =-0.42) and duration of PD (p=0.03, r=-0.43) in contrast to S-SAL and dopamine. Dopamine levels were not associated to R-SAL (p=0.88, r2=0.0008) and S-SAL (p=0.088, r2=0.12) neither in Parkinsonian patients nor in controls. We conclude, that an upregulation of N-methylation of tetrahydroisoquinolines takes place in PD by enzymes such as neutral N-methyltransferase specific for R-SAL. The activity of this enzyme has been found elevated in parkinsonian lymphocytes. This increased N-methylation by the N-methyltransferase specific for R-SAL leads to the known augmented levels of neurotoxic R-NMSAL in Parkinsonian patients compared to controls in the cenral nervous system especially in the beginning of PD.

Adult↗
PubMed1998

Diagnosis and monitoring of middle cerebral artery occlusion with contrast-enhanced transcranial color-coded real-time sonography in patients with inadequate acoustic bone windows.

Transcranial color-coded real-time sonography (TCCS) is an emerging diagnostic technique that allows noninvasive imaging of intracranial vessels within parenchymal structures. However, in some patients, transcranial ultrasound is particularly hindered by insufficient ultrasound penetration through the temporal bone. The present study evaluates whether or not application of an echo-contrast agent in ultrasound-refractory patients with middle cerebral artery (MCA) trunk occlusion enhances image acquisition enough to yield accurate diagnoses. Contrast-enhanced (CE) TCCS examinations, computed tomography scans and angiographic studies were performed in 20 patients with clinical symptoms suggestive of MCA occlusion within 12 h of the onset of symptoms. For comparison, 20 control persons without history or clinical signs for cerebrovascular diseases were examined using CE-TCCS. In none of the patients or control subjects did unenhanced TCCS investigations depict any color-coded vascular signal of an intracranial vessel. After application of 9 mL of 400 mg/mL galactose-based microbubbles, CE-TCCS was performed. In subjects with MCA occlusion, CE-TCCS examinations were repeated within 24 h, 48 h and 5 days after stroke. In stroke patients (n = 20), CE-TCCS showed an occluded MCA main stem in 11 patients, and this vessel was clearly demonstrable on the unaffected side. On the affected side, the posterior cerebral artery (PCA) and anterior cerebral artery (ACA) could be visualized in 8 of 11 subjects; in 3 patients, at least 1 of these vessels was detectable. Angiographic studies confirmed the diagnosis of MCA trunk occlusion in all 11 individuals. In follow-up investigations, 3 stroke patients had angiographic and CE-TCCS examinations consistent with vessel reperfusion. Nine stroke patients had a patent MCA shown in angiographic and CE-TCCS examinations. In the control group, the MCA trunk could be visualized in all subjects by CE-TCCS. CE-TCCS is a sensitive and specific ultrasound method for the diagnosis of MCA trunk occlusion that overcomes the anatomical hindrance of inadequate acoustic bone window. This technique may help to identify patients suitable for thrombolytic therapies and monitor their response.

Aged↗
PubMed1998

Echo contrast-enhanced three-dimensional power Doppler of intracranial arteries.

The purpose of this study was to evaluate the potential of contrast-enhanced three-dimensional (3-D) power Doppler (CE3DPD) in the assessment of intracranial vascular structures, and to compare the results with unenhanced 3-D power Doppler (3DPD) and magnetic resonance angiography (MRA) findings. We insonated 25 patients without cerebrovascular diseases through the temporal bone window using 3DPD and CE3DPD; for comparison, 13 patients underwent MRA. Identification rates of vascular segments and of small branches of intracranial vessels were evaluated by two independent investigators blinded to MRA results. In 21 patients with adequate insonation conditions, CE3DPD significantly improved identification rates compared to 3DPD for the complete visualization of the P1 segment (80.9 vs. 19.0%, p < 0.005, P2 segment (80.9 vs. 42.8%, p < 0.05 and A1 segment (85.7 vs. 38.1%, p < 0.005). Furthermore, CE3DPD depicted, in significantly more examinations, branches of the middle (MCA) and posterior cerebral artery (PCA). Interobserver agreement was higher than 95% for the main intracranial segments and branches of the MCA, but relatively low (80.1-85.7%) for branches of the PCA. In comparison to CE3DPD, MRA identified only parieto-occipital branches of the PCA, temporal branches of the MCA, frontal branches of the anterior cerebral artery and the MCA bifurcation more frequently and accurately. In 4 patients with inadequate acoustic temporal bone windows, the application of a galactose-based microbubble suspension allowed clear 3-D visualization of almost all major intracranial vascular segments and some branches of the large arteries. In conclusion, CE3DPD is a more sensitive ultrasonic tool compared to unenhanced 3-D reconstructions. It makes 3-D ultrasound imaging of the basal cerebral circulation easier to perform and interpret, by providing an improved spatially oriented display of image position. As such, this method may increase operator diagnostic confidence level under pathologic conditions.

Adult↗
PubMed1998

Interleukin-6 levels in cerebrospinal fluid inversely correlate to severity of Parkinson's disease.

INTRODUCTION: Several lines of evidence suggest that neuroimmune mechanisms may also be involved in neurodegeneration in Parkinson's disease (PD). The potential role of cytokines such as interleukin 6 (IL-6), in the interaction between neurons and immune system has been emphasized by recent findings. IL-6 induces acute phase protein synthesis, differentiation of neuronal cells and improves catecholaminergic and cholinergic cell survival in the brain. SUBJECTS AND METHODS: We determined levels of IL-6 in cerebrospinal fluid (CSF) of untreated parkinsonian patients and age- and sex-matched controls. Intensity of disease was evaluated by the Unified Parkinson's Disease Rating scale. RESULTS: Significantly elevated levels of IL-6 were found in the CSF of parkinsonian patients. Moreover a significant inverse correlation between severity of PD and IL-6 CSF levels appeared. DISCUSSION: Elevated IL-6 levels in the CSF of untreated parkinsonian patients may reflect the original condition in the course of disease. We speculate that an endogenous upregulation of IL-6 synthesis occurs in order to regenerate lesioned neurons probably at an early phase of the degenerative process in PD.

Adult↗
PubMed1998

Spinocerebellar ataxia type 6: genotype and phenotype in German kindreds.

OBJECTIVE: Spinocerebellar ataxia type 6 (SCA6) is an autosomal dominant cerebellar ataxia (ADCA) of which the mutation causing the disease has recently been characterised as an expanded CAG trinucleotide repeat in the gene coding for the alpha1A-subunit of the voltage dependent calcium channel. The aim was to further characterise the SCA6 phenotype METHODS: The SCA6 mutation was investigated in 69 German families with ADCA and 61 patients with idiopathic sporadic cerebellar ataxia and the CAG repeat length of the expanded allele was correlated with the disease phenotype. RESULTS: Expanded alleles were found in nine of 69 families as well as in four patients with sporadic disease. Disease onset ranged from 30 to 71 years of age and was significantly later than in other forms of ADCA. Age at onset correlated inversely with repeat length. The SCA6 phenotype comprises predominantly cerebellar signs in concordance with isolated cerebellar atrophy on MRI. Non-cerebellar systems were only mildly affected with external ophthalmoplegia, spasticity, peripheral neuropathy, and parkinsonism. Neither these clinical signs nor progression rate correlated with CAG repeat length. CONCLUSIONS: This study provides the first detailed characterisation of the SCA6 phenotype. Clinical features apart from cerebellar signs were highly variable in patients with SCA6. By comparison with SCA1, SCA2, and SCA3 no clinical or electrophysiological finding was specific for SCA6. Therefore, the molecular defect cannot be predicted from clinical investigations. In Germany, SCA6 accounts for about 13% of families with ADCA. However, up to 30% of SCA6 kindreds may be misdiagnosed clinically as sporadic disease due to late manifestation in apparently healthy parents. Genetic testing is therefore recommended for the SCA6 mutation also in patients with putative sporadic ataxia.

Adult↗