Publications by authors named "Thomas Tscherning"

4 Publications

  • Page 1 of 1

Cerebral metabolism, magnetic resonance spectroscopy and cognitive dysfunction in early multiple sclerosis: an exploratory study.

Neurol Res 2012 Jan;34(1):52-8

Department of Neurology, Copenhagen University Hospital, Copenhagen, Denmark.

Objectives: Positron emission tomography (PET) studies have shown that cortical cerebral metabolic rate of glucose (CMRglc) is reduced in multiple sclerosis (MS). Quantitative magnetic resonance spectroscopy (MRS) measures of N-acetyl-aspartate (NAA) normalized to creatine (NAA/Cr) assess neuronal deterioration, and several studies have shown reductions in MS. Furthermore, both PET and MRS reductions correlate with cognitive dysfunction in MS. Our aim was to determine if changes in cortical CMRglc in early MS correlate with NAA/Cr measurements of neuronal deterioration, as well as cognitive dysfunction and neurological disability.

Methods: We studied 20 recently diagnosed, clinically definite, relapsing-remitting MS patients. Global and cortical CMRglc was estimated using PET with 18-F-deoxyglucose and NAA/Cr ratio was measured using multislice echo-planar spectroscopic imaging. All subjects were neuro-psychologically tested and a cognitive dysfunction factor (CDF) was calculated.

Results: Cortical CMRglc correlated with cortical NAA/Cr (r = 0.45; P < 0.05), but there were no correlation between CMRglc and other NAA/Cr measurements, conventional magnetic resonance imaging measurements, or CDF. Stepwise regression analysis showed association between cortical NAA/Cr and CMRglc of the left ventrolateral prefrontal cortex (P < 0.001), left putamen (P = 0.010), and left hippocampus (P = 0.011). Furthermore, CDF was related to CMRglc in the left cerebellum (P = 0.001) and the left caudate nucleus (P = 0.013). The results of the statistical analysis should be regarded as exploratory, since we did not correct for multiple comparisons.

Conclusion: Our findings suggest that reductions in cortical CMRglc are associated with reductions in cortical NAA/Cr in early MS. These changes affect cortical and subcortical neural circuits of importance to cognitive function.
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http://dx.doi.org/10.1179/1743132811Y.0000000059DOI Listing
January 2012

Cognitive impairment in newly diagnosed multiple sclerosis patients: a 4-year follow-up study.

J Neurol Sci 2006 Jun 27;245(1-2):77-85. Epub 2006 Apr 27.

Department of Neurology, Section 6131, Danish Multiple Sclerosis Centre, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, DK-2100 Copenhagen, Denmark.

Cognitive impairment occurs in early multiple sclerosis (MS), may decline over time, and has major impact on social functioning. The objectives of this study were to examine cognitive functioning in newly diagnosed MS, and to follow up over a period of 5 years. The results of the first three yearly re-examinations are reported. Eighty newly diagnosed (<1 year) MS patients participated (male/female: 19:61, mean age: 35 years, mean EDSS 2.7, course: 75 relapsing-remitting, 3 primary progressive, 2 secondary progressive). Seventy-five healthy persons served as controls. The neuropsychological (NP) test battery comprised 30 test measures and was grouped into seven cognitive domains. A residual score of -1.5 SD as cut-off point was used to diagnose cognitive impairment. At the first examination, 44-48% had cognitive impairment. None of the patients were clinically depressed, 51% had no signs of depression on Beck Depression Inventory (BDI), and none had severe signs. Sixty-four patients completed four examinations, and a significant linear improvement over time was seen in three cognitive domains, no change in two domains, and deterioration in one domain. At the time of the fourth examination, 4.3 years since diagnosis, 33-34% of the patients had cognitive impairment. Thirty percent of the patients were on disablement pension, 34% received social services in relation to work and 13% had home care. Methodological problems are discussed, especially the practice effect and the importance of identifying sensitive and stable test measures.
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http://dx.doi.org/10.1016/j.jns.2005.09.016DOI Listing
June 2006

Correlation of global N-acetyl aspartate with cognitive impairment in multiple sclerosis.

Arch Neurol 2006 Apr;63(4):533-6

Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital Hvidovre, Kettegaard Alle 30, DK-2650 Hvidovre, Denmark.

Background: Whole-brain N-acetyl aspartate (NAA), a measure of neuronal function, can be assessed by multislice echo-planar spectroscopic imaging.

Objective: To test the hypothesis that the global brain NAA/creatine (Cr) ratio is a better predictor of cognitive dysfunction in multiple sclerosis than conventional magnetic resonance imaging measures.

Design: Survey.

Setting: Research-oriented hospitals.

Patients: Twenty patients, 16 women and 4 men (mean age, 36 years), with early relapsing-remitting multiple sclerosis (mean Expanded Disability Status Scale score, 2.5).

Main Outcome Measures: Correlation between the global NAA/Cr ratio and a cognitive dysfunction factor comprising 16 measures from an extensive neuropsychological test battery that best distinguished patients with multiple sclerosis from healthy control subjects.

Results: A significant partial correlation between the global NAA/Cr ratio and the cognitive dysfunction factor was found (partial r = 0.62, P = .01), and 9 cognitively impaired patients had significantly lower global NAA/Cr ratios than 11 unimpaired patients (P = .04). No significant correlations were found between the cognitive dysfunction factor and conventional magnetic resonance imaging measures (ie, brain parenchymal fraction and lesion volume).

Conclusions: Multislice echo-planar spectroscopic imaging provides global metabolic measures that distinguish between cognitively impaired and unimpaired patients with multiple sclerosis and correlate with a global cognitive measure. Standardization of the technique is needed, and larger-scale studies that include healthy controls are suggested.
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http://dx.doi.org/10.1001/archneur.63.4.533DOI Listing
April 2006

Multi-slice echo-planar spectroscopic MR imaging provides both global and local metabolite measures in multiple sclerosis.

Magn Reson Med 2005 Apr;53(4):750-9

Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital, Kettegaard Allé 30, DK-2650 Hvidovre, Denmark.

MR spectroscopy (MRS) provides information about neuronal loss or dysfunction by measuring decreases in N-acetyl aspartate (NAA), a metabolite widely believed to be a marker of neuronal viability. In multiple sclerosis (MS), whole-brain NAA (WBNAA) has been suggested as a marker of disease progression and treatment efficacy in treatment trials, and the ability to measure NAA loss in specific brain regions early in the evolution of this disease may have prognostic value. Most spectroscopic studies to date have been limited to single voxels or nonlocalized measurements of WBNAA only, and longitudinal studies have often been hampered by standardization and reproducibility problems. Multi-slice echo-planar spectroscopic imaging (EPSI) is presented as a promising alternative to single-voxel or nonlocalized spectroscopy for obtaining global metabolite estimates in MS. In the same session, measurements of metabolites in specific brain areas chosen after image acquisition (e.g., normal-appearing white matter (NAWM), gray matter (GM), and lesions) can be obtained. The identification and exclusion of regions that are inadequate for spectroscopic evaluation in global assessments can significantly improve quality and reproducibility, as demonstrated by a low within-subject variance in healthy controls. The reproducibility of the technique makes it a promising tool for future longitudinal spectroscopic studies of MS.
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http://dx.doi.org/10.1002/mrm.20407DOI Listing
April 2005
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