Publications by authors named "Agnete Jonsson"

5 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

The relationship between MRI and PET changes and cognitive disturbances in MS.

J Neurol Sci 2006 Jun 2;245(1-2):99-102. Epub 2006 May 2.

Department of Neurology 2082, Danish MS Research Center, Copenhagen University Hospital, Rigshospitalet, 9 Blegdamsvej, DK-2100 Copenhagen, Denmark.

Cognitive dysfunction in multiple sclerosis (MS) is present in approximately 50% of the patients. Only moderate correlations have been found between cognitive dysfunction and T(2) lesion load, black holes or atrophy. Cognitive dysfunction in MS is probably related to the overall disease burden of the brain including abnormalities in normal appearing white matter (NAWM) and cortical grey matter, which is undetected with conventional magnetic resonance imaging (MRI). Hence, imaging techniques that embrace such abnormalities are needed to achieve better correlation with cognitive dysfunction. MR spectroscopy (MRS) performed with multi-slice echo planar spectroscopic imaging (EPSI) and PET measurements of brain metabolism as the cortical cerebral metabolic rate of glucose are imaging methods that are able to provide information on axonal loss or dysfunction in both MS lesions and in NAWM and cortical grey matter. Measurements of global NAA using multi-slice EPSI is a new promising method for measurement of the global neuron capacity and can be repeated with only little discomfort and without any risk for the patient.
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http://dx.doi.org/10.1016/j.jns.2005.09.020DOI Listing
June 2006

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

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
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