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Microstate connectivity alterations in patients with early Alzheimer's disease.

Hatz F, Hardmeier M, Benz N, Ehrensperger M, Gschwandtner U, Rüegg S, Schindler C, Monsch AU, Fuhr P - Alzheimers Res Ther (2015)

Bottom Line: Networks were reduced to 22 nodes for statistical analysis.The domain score for verbal learning and memory and the microstate segmented PLI between the left centro-lateral and parieto-occipital regions in the theta band at baseline differentiated significantly between the groups.Combining neuropsychological and quantitative EEG test results allows differentiation between subjects with aMCI remaining stable and subjects with aMCI deteriorating over 30 months.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, University Hospital of Basel, Petersgraben 4, 4031, Basel, Switzerland. florian.hatz@usb.ch.

ABSTRACT

Introduction: Electroencephalography (EEG) microstates and brain network are altered in patients with Alzheimer's disease (AD) and discussed as potential biomarkers for AD. Microstates correspond to defined states of brain activity, and their connectivity patterns may change accordingly. Little is known about alteration of connectivity in microstates, especially in patients with amnestic mild cognitive impairment with stable or improving cognition within 30 months (aMCI).

Methods: Thirty-five outpatients with aMCI or mild dementia (mean age 77 ± 7 years, 47% male, Mini Mental State Examination score ≥24) had comprehensive neuropsychological and clinical examinations. Subjects with cognitive decline over 30 months were allocated to the AD group, subjects with stable or improving cognition to the MCI-stable group. Results of neuropsychological testing at baseline were summarized in six domain scores. Resting state EEG was recorded with 256 electrodes and analyzed using TAPEEG. Five microstates were defined and individual data fitted. After phase transformation, the phase lag index (PLI) was calculated for the five microstates in every subject. Networks were reduced to 22 nodes for statistical analysis.

Results: The domain score for verbal learning and memory and the microstate segmented PLI between the left centro-lateral and parieto-occipital regions in the theta band at baseline differentiated significantly between the groups. In the present sample, they separated in a logistic regression model with a 100% positive predictive value, 60% negative predictive value, 100% specificity and 77% sensitivity between AD and MCI-stable.

Conclusions: Combining neuropsychological and quantitative EEG test results allows differentiation between subjects with aMCI remaining stable and subjects with aMCI deteriorating over 30 months.

No MeSH data available.


Related in: MedlinePlus

Links (microstate segmented phase lag index [msPLI]) in theta band with significant differences between groups. Plot: p < 0.05 (violet); p < 0.01 (red) (corrected for multiple comparisons). Box plot: axes indicate raw msPLI values. FP frontal parieto-occipital left, FM frontal midline, FL frontal lateral, CM central midline, CL central lateral, TA temporal anterior, TP temporal posterior, PL parietal lateral, PM parietal midline, PO parieto-occipital, O occipital, L left, R right, CLL_POL link centrolateral to parieto-occipital left, CLL-OL link centrolateral to occipital left, PLL-POL link parietolateral to parieto-occipital left, AD Alzheimer’s disease, MCIstable patients with stable or improving cognition within 30 months, HC healthy control subjects
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Fig4: Links (microstate segmented phase lag index [msPLI]) in theta band with significant differences between groups. Plot: p < 0.05 (violet); p < 0.01 (red) (corrected for multiple comparisons). Box plot: axes indicate raw msPLI values. FP frontal parieto-occipital left, FM frontal midline, FL frontal lateral, CM central midline, CL central lateral, TA temporal anterior, TP temporal posterior, PL parietal lateral, PM parietal midline, PO parieto-occipital, O occipital, L left, R right, CLL_POL link centrolateral to parieto-occipital left, CLL-OL link centrolateral to occipital left, PLL-POL link parietolateral to parieto-occipital left, AD Alzheimer’s disease, MCIstable patients with stable or improving cognition within 30 months, HC healthy control subjects

Mentions: After correction for multiple comparisons, no significant differences were found in connectivity calculated without splitting by microstates. Using connectivities from microstates, significant differences in theta-band connectivity were detected (Fig. 4). The theta-band link between the left centrolateral and parieto-occipital regions differentiated most significantly between all three groups and between AD and MCI-stable with a sensitivity of 77 % and a specificity of 78 %. Connectivities were higher in the AD group than in the MCI-stable and HC groups. No significant differences were found for the connectivities in the alpha1, alpha2, and beta bands. Only a few links in the theta band correlated significantly with one of the six domain scores after correction for multiple comparisons. For results, see Fig. 5.Fig. 4


Microstate connectivity alterations in patients with early Alzheimer's disease.

Hatz F, Hardmeier M, Benz N, Ehrensperger M, Gschwandtner U, Rüegg S, Schindler C, Monsch AU, Fuhr P - Alzheimers Res Ther (2015)

Links (microstate segmented phase lag index [msPLI]) in theta band with significant differences between groups. Plot: p < 0.05 (violet); p < 0.01 (red) (corrected for multiple comparisons). Box plot: axes indicate raw msPLI values. FP frontal parieto-occipital left, FM frontal midline, FL frontal lateral, CM central midline, CL central lateral, TA temporal anterior, TP temporal posterior, PL parietal lateral, PM parietal midline, PO parieto-occipital, O occipital, L left, R right, CLL_POL link centrolateral to parieto-occipital left, CLL-OL link centrolateral to occipital left, PLL-POL link parietolateral to parieto-occipital left, AD Alzheimer’s disease, MCIstable patients with stable or improving cognition within 30 months, HC healthy control subjects
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4697314&req=5

Fig4: Links (microstate segmented phase lag index [msPLI]) in theta band with significant differences between groups. Plot: p < 0.05 (violet); p < 0.01 (red) (corrected for multiple comparisons). Box plot: axes indicate raw msPLI values. FP frontal parieto-occipital left, FM frontal midline, FL frontal lateral, CM central midline, CL central lateral, TA temporal anterior, TP temporal posterior, PL parietal lateral, PM parietal midline, PO parieto-occipital, O occipital, L left, R right, CLL_POL link centrolateral to parieto-occipital left, CLL-OL link centrolateral to occipital left, PLL-POL link parietolateral to parieto-occipital left, AD Alzheimer’s disease, MCIstable patients with stable or improving cognition within 30 months, HC healthy control subjects
Mentions: After correction for multiple comparisons, no significant differences were found in connectivity calculated without splitting by microstates. Using connectivities from microstates, significant differences in theta-band connectivity were detected (Fig. 4). The theta-band link between the left centrolateral and parieto-occipital regions differentiated most significantly between all three groups and between AD and MCI-stable with a sensitivity of 77 % and a specificity of 78 %. Connectivities were higher in the AD group than in the MCI-stable and HC groups. No significant differences were found for the connectivities in the alpha1, alpha2, and beta bands. Only a few links in the theta band correlated significantly with one of the six domain scores after correction for multiple comparisons. For results, see Fig. 5.Fig. 4

Bottom Line: Networks were reduced to 22 nodes for statistical analysis.The domain score for verbal learning and memory and the microstate segmented PLI between the left centro-lateral and parieto-occipital regions in the theta band at baseline differentiated significantly between the groups.Combining neuropsychological and quantitative EEG test results allows differentiation between subjects with aMCI remaining stable and subjects with aMCI deteriorating over 30 months.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, University Hospital of Basel, Petersgraben 4, 4031, Basel, Switzerland. florian.hatz@usb.ch.

ABSTRACT

Introduction: Electroencephalography (EEG) microstates and brain network are altered in patients with Alzheimer's disease (AD) and discussed as potential biomarkers for AD. Microstates correspond to defined states of brain activity, and their connectivity patterns may change accordingly. Little is known about alteration of connectivity in microstates, especially in patients with amnestic mild cognitive impairment with stable or improving cognition within 30 months (aMCI).

Methods: Thirty-five outpatients with aMCI or mild dementia (mean age 77 ± 7 years, 47% male, Mini Mental State Examination score ≥24) had comprehensive neuropsychological and clinical examinations. Subjects with cognitive decline over 30 months were allocated to the AD group, subjects with stable or improving cognition to the MCI-stable group. Results of neuropsychological testing at baseline were summarized in six domain scores. Resting state EEG was recorded with 256 electrodes and analyzed using TAPEEG. Five microstates were defined and individual data fitted. After phase transformation, the phase lag index (PLI) was calculated for the five microstates in every subject. Networks were reduced to 22 nodes for statistical analysis.

Results: The domain score for verbal learning and memory and the microstate segmented PLI between the left centro-lateral and parieto-occipital regions in the theta band at baseline differentiated significantly between the groups. In the present sample, they separated in a logistic regression model with a 100% positive predictive value, 60% negative predictive value, 100% specificity and 77% sensitivity between AD and MCI-stable.

Conclusions: Combining neuropsychological and quantitative EEG test results allows differentiation between subjects with aMCI remaining stable and subjects with aMCI deteriorating over 30 months.

No MeSH data available.


Related in: MedlinePlus