scholarly journals Transcranial stimulation enhances memory-relevant sleep oscillations and their functional coupling in mild cognitive impairment

2016 ◽  
Author(s):  
Julia Ladenbauer ◽  
Josef Ladenbauer ◽  
Nadine Külzow ◽  
Rebecca de Boor ◽  
Elena Avramova ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Memory Consolidation ◽  
Declarative Memory ◽  
Activity Patterns ◽  
Functional Coupling ◽  
Dependent Manner ◽  
Sleep State ◽  
Sleep Physiology ◽  
Spindle Power

AbstractAlzheimer’s disease (AD) not only involves loss of memory functions but also prominent deterioration of sleep physiology, already evident in the stage ofmild cognitive impairment(MCI). Cortical slow oscillations (SO, 0.5-1 Hz) and thalamo-cortical spindle activity (12-15 Hz) during sleep, and their temporal coordination, are considered critical for memory formation. We investigated the potential of slow oscillatory transcranial direct current stimulation (so-tDCS), applied during a daytime nap in a sleep state-dependent manner, to modulate these activity patterns and sleep-related memory consolidation in 16 patients with MCI.Stimulation significantly increased overall SO and spindle power, amplified spindle power during SO up-phases, and led to stronger synchronization between SO and spindle power fluctuations in electroencephalographic recordings. Moreover, visual declarative memory was improved by so-tDCS compared to sham stimulation, associated with stronger synchronization. These findings indicate a well-tolerated therapeutic approach for disordered sleep physiology and deficits in memory consolidation in MCI patients.

scholarly journals Applying time series analyses on continuous accelerometry data – a clinical example in older adults with and without cognitive impairment

2020 ◽  
Author(s):  
Torsten Rackoll ◽  
Konrad Neumann ◽  
Sven Passmann ◽  
Ulrike Grittner ◽  
Nadine Külzow ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Brain Stimulation ◽  
Memory Consolidation ◽  
Activity Patterns ◽  
Accelerometer Data ◽  
Activity Data ◽  
Link Type ◽  
Early Afternoon ◽  
The Impact

AbstractIntroductionCurrent analysis approaches of accelerometry data use sum score measures which do not provide insight in activity patterns over 24 hours, and thus do not adequately depict circadian activity patterns. Here, we used a functional approach to analyze accelerometer data that models activity pattern and circadian rhythm. As a test case, we demonstrated its application in patients with mild cognitive impairment (MCI) and age-matched healthy older volunteers (HOV). Moreover, we assessed the impact of chronotype on distribution of activity data.MethodsData of two studies were pooled for this analysis. Following baseline cognitive assessment participants were provided with accelerometers for seven consecutive days. A function on scalar regression (FoSR) approach was used to analyze 24 hours accelerometer data. In a second step, analyses were controlled for chronotype using the German version of the morningness-eveningness questionnaire (d-MEQ).ResultsInformation on 47 HOV (mean age 66 SD 6 years) and 13 patients with MCI (mean age 69, SD 8 years) were available for this analysis. MCI patients displayed slightly higher activity in the morning hours as compared to HOV (maximum relative activity at 7:35 am: 75.6%, 95% CI 2.6 to 200.4%, p = 0.031). After controlling for d-MEQ, disturbed activity patterns were found in MCI of intermediate or evening chronotype, compared to HOV, i.e., MCI presented with higher activities in the morning hours (peak at 8:40 am: 357.6%, 95% CI 92.9 to 985.1, p < 0.001) and early afternoon hours (peak at 1:40 pm: 401.8%, 95% CI 63.9 to 1436.4, p < 0.001).DiscussionUsing a novel approach of FoSR, we found timeframes with higher activity levels in MCI patients compared to HOV which were not evident if sum scores of amount of activity were used. In addition, we found that previously described activity patterns as a function of chronotype swere altered in MCI patients, possibly indicating that changes in circadian rhythmicity in neurodegenerative disease are detectable using easy-to-administer accelerometry.Clinical TrialsEffects of Brain Stimulation During Nocturnal Sleep on Memory Consolidation in Patients With Mild Cognitive Impairments, https://clinicaltrials.gov/ct2/show/NCT01782391?term=NCT01782391&rank=1,ClinicalTrial.gov identifier: NCT01782391Effects of Brain Stimulation During a Daytime Nap on Memory Consolidation in Patients With Mild Cognitive Impairment,https://clinicaltrials.gov/ct2/show/NCT01782365?term=NCT01782365&rank=1,ClinicalTrial.gov identifier: NCT01782365

scholarly journals Promoting Sleep Oscillations and Their Functional Coupling by Transcranial Stimulation Enhances Memory Consolidation in Mild Cognitive Impairment

2017 ◽  
Vol 37 (30) ◽  
pp. 7111-7124 ◽  
Author(s):  
Julia Ladenbauer ◽  
Josef Ladenbauer ◽  
Nadine Külzow ◽  
Rebecca de Boor ◽  
Elena Avramova ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Memory Consolidation ◽  
Functional Coupling ◽  
Transcranial Stimulation

scholarly journals Applying time series analyses on continuous accelerometry data—A clinical example in older adults with and without cognitive impairment

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0251544
Author(s):  
Torsten Rackoll ◽  
Konrad Neumann ◽  
Sven Passmann ◽  
Ulrike Grittner ◽  
Nadine Külzow ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Brain Stimulation ◽  
Memory Consolidation ◽  
Activity Patterns ◽  
Relative Activity ◽  
Lower Activity ◽  
Activity Levels ◽  
Accelerometer Data ◽  
Link Type

Introduction Many clinical studies reporting accelerometry data use sum score measures such as percentage of time spent in moderate to vigorous activity which do not provide insight into differences in activity patterns over 24 hours, and thus do not adequately depict circadian activity patterns. Here, we present an improved functional data analysis approach to model activity patterns and circadian rhythms from accelerometer data. As a use case, we demonstrated its application in patients with mild cognitive impairment (MCI) and age-matched healthy older volunteers (HOV). Methods Data of two studies were pooled for this analysis. Following baseline cognitive assessment participants were provided with accelerometers for seven consecutive days. A function on scalar regression (FoSR) approach was used to analyze 24 hours accelerometer data. Results Information on 48 HOV (mean age 65 SD 6 years) and 18 patients with MCI (mean age 70, SD 8 years) were available for this analysis. MCI patients displayed slightly lower activity in the morning hours (minimum relative activity at 6:05 am: -41.3%, 95% CI -64.7 to -2.5%, p = 0.031) and in the evening (minimum relative activity at 21:40 am: -48.4%, 95% CI -68.5 to 15.4%, p = 0.001) as compared to HOV after adjusting for age and sex. Discussion Using a novel approach of FoSR, we found timeframes with lower activity levels in MCI patients compared to HOV which were not evident if sum scores of amount of activity were used, possibly indicating that changes in circadian rhythmicity in neurodegenerative disease are detectable using easy-to-administer accelerometry. Clinical trials Effects of Brain Stimulation During Nocturnal Sleep on Memory Consolidation in Patients With Mild Cognitive Impairments, ClinicalTrial.gov identifier: NCT01782391. Effects of Brain Stimulation During a Daytime Nap on Memory Consolidation in Patients With Mild Cognitive Impairment, ClinicalTrial.gov identifier: NCT01782365.

The heterogeneity of mild cognitive impairment: A neuropsychological analysis

2009 ◽  
Vol 16 (1) ◽  
pp. 84-93 ◽  
Author(s):  
DAVID J. LIBON ◽  
SHARON X. XIE ◽  
JOEL EPPIG ◽  
GRAHAM WICAS ◽  
MELISSA LAMAR ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Executive Control ◽  
Declarative Memory ◽  
Community Dwelling ◽  
Lexical Retrieval ◽  
Memory Clinic ◽  
Delayed Recognition ◽  
Single Versus ◽  
Normal Controls

AbstractA group of 94 nondemented patients self-referred to an outpatient memory clinic for memory difficulties were studied to determine the incidence of single versus multi-domain mild cognitive impairment (MCI) using Petersen criteria. Fifty-five community dwelling normal controls (NC) participants without memory complaints also were recruited. Tests assessing executive control, naming/lexical retrieval, and declarative memory were administered. Thirty-four patients exhibited single-domain MCI, 43 patients presented with multi-domain MCI. When the entire MCI sample (n = 77) was subjected to a cluster analysis, 14 patients were classified with amnesic MCI, 21 patients with dysexecutive MCI, and 42 patients were classified into a mixed/multi-domain MCI group involving low scores on tests of letter fluency, “animal” fluency, and delayed recognition discriminability. Analyses comparing the three cluster-derived MCI groups versus a NC group confirmed the presence of memory and dysexecutive impairment for the amnesic and dysexecutive MCI groups. The mixed MCI group produced lower scores on tests of letter fluency compared with the amnesic MCI and NC groups and lower scores on tests of naming and memory compared with the NC group. In summary, multi-domain MCI is quite common. These data suggest that MCI is a highly nuanced and complex clinical entity. (JINS, 2010, 16, 84–93.)

Brain Activity Patterns in Stable and Progressive Mild Cognitive Impairment During Working Memory as Evidenced by Magnetoencephalography

2011 ◽  
Vol 28 (2) ◽  
pp. 202-209 ◽  
Author(s):  
Fernando Maestú ◽  
Raquel Yubero ◽  
Stephan Moratti ◽  
Pablo Campo ◽  
Pedro Gil-Gregorio ◽  
...  
Keyword(s):  
Working Memory ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Brain Activity ◽  
Activity Patterns

scholarly journals 0696 Memory Consolidation and Cerebral Oxygenation during Afternoon Naps in Older Adults with Amnestic Mild Cognitive Impairment

SLEEP ◽  
2018 ◽  
Vol 41 (suppl_1) ◽  
pp. A258-A259
Author(s):  
B W Carlson ◽  
K R Jones ◽  
M A Craft ◽  
J R Carlson ◽  
K Deardeuff ◽  
...  
Keyword(s):  
Older Adults ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Memory Consolidation ◽  
Cerebral Oxygenation ◽  
Amnestic Mild Cognitive Impairment

Global Functional Coupling of Resting EEG Rhythms is Abnormal in Mild Cognitive Impairment and Alzheimer’s Disease

2009 ◽  
Vol 23 (4) ◽  
pp. 224-234 ◽  
Author(s):  
Claudio Babiloni ◽  
Giovanni Frisoni ◽  
Fabrizio Vecchio ◽  
Roberta Lizio ◽  
Michela Pievani ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Brain Networks ◽  
Elderly Subjects ◽  
Functional Coupling ◽  
Eeg Rhythms ◽  
Eyes Closed ◽  
Global Cognition

Alzheimer’s disease (AD) is typically associated with an impairment of brain networks and global cognitive function in aging. In this vein, the present study tested the hypothesis that the functional coupling of resting cortical electroencephalographic (EEG) rhythms is progressively abnormal in amnesic mild cognitive impairment (MCI) and AD subjects. Eyes-closed resting EEG data were recorded (10–20 system) in 33 mild AD, 52 amnesic MCI, and 47 normal elderly subjects (Nold). EEG rhythms of interest were delta (2–4 Hz), theta (4–8 Hz), alpha1 (8–10 Hz), alpha2 (10–13 Hz), beta1 (13–20 Hz), beta2 (20–30 Hz), and gamma (30–40 Hz). The global functional coupling of the EEG rhythms was indexed by means of spectral coherence for all combinations of electrode pairs (i.e., total coherence). The main results showed that the total coherence of delta rhythms was higher in the AD than the MCI group. It was also higher in the MCI than the Nold group. Furthermore, the delta total coherence was negatively correlated with global cognition (Mini Mental State Examination score) across the Nold, MCI, and AD subjects. Finally, the alpha1 total coherence was lower in the AD group than in the MCI and Nold groups. These results suggest that in the AD process an impairment of brain networks and global cognition is associated with a frequency-specific modulation of the global functional coupling of resting EEG rhythms.

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