Michael Schocke

The purpose of the present study was to evaluate the potential of multimodal MR imaging including mean diffusivity (MD), fractional anisotropy (FA), relaxation rates R2 and R2* to detect disease specific alterations in Parkinson's Disease (PD). We enrolled 82 PD patients (PD-all) with varying disease durations (≤5 years: PD≤5, n = 43; >5 years: PD>5, n = 39) and 38 matched healthy controls (HC), receiving diffusion tensor imaging as well as R2 and R2* relaxometry calculated from multi-echo T2*-weighted and dual-echo TSE imaging, respectively. ROIs were drawn to delineate caudate nucleus (CN), putamen (PU), globus pallidus (GP) and substantia nigra (SN) on the co-registered maps. The SN was divided in 3 descending levels (SL 1–3). The most significant parameters were used for a flexible discrimination analysis (FDA) in a training collective consisting of 25 randomized subjects from each group in order to predict the classification of remaining subjects. PD-all showed significant increases in MD, R2 and R2* within SN and its subregions as well as in MD and R2* within different basal ganglia regions. Compared to the HC group, the PD≤5 and the PD>5 group showed significant MD increases within the SN and its lower two subregions, while the PD≤5 group exhibited significant increases in R2 and R2* within SN and its subregions, and tended to elevation within the basal ganglia. The PD>5 group had significantly increased MD in PU and GP, whereas the PD≤5 group presented normal MD within the basal ganglia. FDA achieved right classification in 84% of study participants. Micro-structural damage affects primarily the SN of PD patients and in later disease stages the basal ganglia. Iron contents of PU, GP and SN are increased at early disease stages of PD.

Recently published studies have elucidated alterations of mitochondrial oxidative metabolism during ageing. The intention of the present study was to evaluate the impact of ageing on cardiac high-energy phosphate metabolism and cardiac function in healthy humans. 31-phosphorus 2-dimensional chemical shift imaging (31P 2D CSI) and echocardiography were performed in 196 healthy male volunteers divided into groups of 20 to 40 years (I, n = 43), 40 to 60 years (II, n = 123) and >60 years (III, n = 27) of age. Left ventricular PCr/β-ATP ratio, myocardial mass (MM), ejection fraction and E/A ratio were assessed. Mean PCr/β-ATP ratios were significantly different among the three groups of volunteers (I, 2.10±0.37; II, 1.77±0.37; III, 1.45±0.28; all p2 = −0.25; p<0.001) with a decrease from 2.65 by 0.02 per year of ageing. PCr/β-ATP ratios further correlated with MM (r = −0.371; p<0.001) and E/A ratios (r = 0.213; p<0.02). Moreover, E/A ratios (r = −0.502, p<0.001), MM (r = 0.304, p<0.001), glucose-levels (r = 0.157, p<0.05) and systolic blood pressure (r = 0.224, p<0.005) showed significant correlations with age. The ejection fraction did not significantly differ between the groups. This study shows that cardiac PCr/β-ATP ratios decrease moderately with age indicating an impairment of mitochondrial oxidative metabolism due to age. Furthermore, MM increases, and E/A ratio decreases with age. Both correlate with left-ventricular PCr/β-ATP ratios. The findings of the present study confirm numerous experimental studies showing an impairment of cardiac mitochondrial function with age.

Ziele: Rezent konnte eine erniedrigte Fraktionale Anisotropie (FA) im dorsolateralen Anteil der Substantia nigra (SN) bei Patienten mit Morbus Parkinson (MP) nachgewiesen werden, während frühere Studien erhöhte Eisendepositionen in der SN zeigen konnten. Das Ziel der Studie war es mithilfe der Parameter R2, R2*, ADC und FA Eisenablagerungen und neuronale Integrität in der Substantia nigra und anderen Hirnregionen von MP Patienten zu bestimmen. Methode: In diese Studie wurden 32 MP Patienten und 24 altersentsprechende Kontrollpersonen inkludiert. Alle inkludierten Personen erhielten eine Magnetresonanz Tomographie an einem 1.5 Tesla System (Magnetom Avanto, Siemens Erlangen). Das Protokoll umfasste eine TSE Doppelechosequenz, eine Multiecho (8 TEs) Gradientenecho Sequenz sowie eine EPI Sequenz mit Diffusionsgradienten in 12 Richtungen und b-Faktoren von 0 und 1000s/mm2. Es wurden die Parameter R2, R2*, ADC und FA berechnet. Ergebnis: Die MP Patienten zeigten erhöhte R2 Werte im Globus pallidus und in der SN, während R2* nur im Globus pallidus signifikant war. Die MP Patienten zeigten in der SN signifikant erhöhte ADCs und signifikant erniedrigte FA Werte im Vergleich zu den Kontrollpersonen. Eine genauere Analyse zeigte, dass ADCs und FA Werte haupsächlich im unteren SN Abschnitt verändert waren. Schlussfolgerung: Ein etwas unerwartetes Ergebnis war, dass die R2* Werte in der SN bei MP Patienten nicht signifkant erhöht waren, während die R2 Werte einen signifikanten Unterschied ergaben. Das dürfte wohl dadurch bedingt sein, dass bei R2* noch weitere Faktoren eine Rolle spielen dürften, wie zum Beispiel Überlagerungen durch Flussartefakte und durch die Nähe zur Schädelbasis. Die ADC Erhöhungen und FA Erniedrigungen in der Substantia nigra von MP Patienten passen zur Pathologie und dürften auf die Degeneration von Neuronen hinweisen. Interessant wäre es, diese Veränderungen im zeitlichen Verlauf zu messen. Keywords: Morbus Parkinson, Substantia nigra, Eisen, Apparent Diffusion Coeffiient, Fractional Anisotropy Korrespondierender Autor: Schocke M Universitätsklinik für Radiologie, Annichstraße 35, 6020, Innsbruck E-Mail: michael.schocke@i-med.ac.at

Elevated plasma fibrinogen levels are a well known finding in acute infectious diseases, acute stroke and myocardial infarction. However its role in the cerebrospinal fluid (CSF) of acute and chronic central (CNS) and peripheral nervous system (PNS) diseases is unclear.

Am besten untersucht ist die Hippocampusatrophie, die bereits bei leichten kognitiven Störungen nachweisbar sein kann und um einige Prozent pro Jahr zunimmt. Darüber hinaus gibt es neuere Methoden zur Bestimmung der kortikalen Dichte als weitere Verfahren in der Diagnose der Alzheimer-Demenz. So kann auch die Corpus callosum-Atrophie als ein Maß für den regionalen neokortikalen Zelluntergang genommen werden. Aufgrund der leichten und reliablen Vermessung eignet sich die Methode zur Verlaufsbeobachtung bei mittleren und schweren Graden der Alzheimer-Demenz. Korrespondierender Autor: Schocke M Universitätsklinik für Radiologie, Annichstraße 35, 6020, Innsbruck E-Mail: michael.schocke@i-med.ac.at

Functional magnetic resonance imaging (fMRI) studies investigating the neural mechanisms underlying developmental dyscalculia are scarce and results are thus far inconclusive. Main aim of the present study is to investigate the neural correlates of nonsymbolic number magnitude processing in children with and without dyscalculia.

Friedreich ataxia (FRDA) is characterized by GAA expansions in the intron 1 of the frataxin gene correlating with disease onset and progression as well as cardiac affection. Accordingly, FRDA patients with early disease onset show a clear impairment of mitochondrial function in the myocardium. The purpose of this study was to investigate cardiac function and high-energy phosphate metabolism in FRDA patients with late disease onset. Using a 1.5 T magnetic resonance scanner, cardiac phosphorus-31 two-dimensional chemical shift imaging was performed in ten patients (seven male, three female) with a late onset of FRDA and in 35 healthy, male controls. Ejection faction (EF) and interventricular septum thickness (IST) were determined by echocardiography. The differences in left ventricular phosphocreatine (PCr) to β-adenosine triphosphate (β-ATP) ratios between both groups were not significant. FRDA patients had increased ISTs (10.8 ± 1.6 vs. 9.7 ± 0.9 mm; p = 0.048), which correlated significantly with the left ventricular PCr to β-ATP ratios (r = −0.644; p = 0.04), and decreased EFs (52.24 ± 7.72% vs. 64.09 ± 4.25%; p = 0.001) compared to normal controls. In contrast to FRDA patients with early disease onset, our patients collective exhibited a normal, probably compensated cardiac mitochondrial function, whereby IST and EF were mildly altered.

To investigate the relationship between the atherosclerotic lesion load determined on magnetic resonance angiography (MRA) and phosphocreatine (PCr) kinetics during incremental, exhaustive calf exercise in patients with bilateral, symptomatic peripheral arterial disease (PAD). Using a 1.5 Tesla MR scanner, 26 patients with bilateral symptomatic PAD and 24 healthy male controls underwent serial phosphorus-31 MR spectroscopy (31P MRS) during incremental exercise at 2, 3, 4, and 5 Watts. For each increment and recovery, PCr time constants, amplitudes of PCr changes and pH values were calculated from the MR spectra. In patients, the run-off resistance (ROR) was determined on MRA. The patients exhibited significantly (p ≤ 0.002) increased PCr time constants at the first (36.7, 13.8–360.3 vs. 22.9, 9.2–60.7 s), at the second (68.1, 4.2–757.2 vs. 18.3, 5.2–57.6 s), at the third (65.3, 14.7–277.7 vs. 29.0, 4.48–97.2 s), the fourth increment (64.1, 34.2–548.8 vs. 34.6, 4.9–106.2 s), and during recovery (53.2, 11.1–353.2 vs. 41.4, 15.1–122.4 s) compared to the normal controls. The PCr on-kinetics during the increments correlated significantly with the pH levels (r = −0.39 to −0.66, p ≤ 0.005) at the end of the corresponding increments, but not with the RORs. The correlation between PCr on-kinetics and end-increment pH values might indicate remodelling processes within the muscle that probably affect mitochondrial performance, diffusion of oxygen, and muscle fiber distribution. These parameters could be improved by exercise training.