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Effects of Brain Stimulation During Nocturnal Sleep on Memory Consolidation in Patients With Mild Cognitive Impairments

This study is currently recruiting participants.
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Verified December 2016 by Agnes Flöel, Charite University, Berlin, Germany
Information provided by (Responsible Party):
Agnes Flöel, Charite University, Berlin, Germany Identifier:
First received: June 5, 2012
Last updated: December 20, 2016
Last verified: December 2016
The beneficial effect of nocturnal sleep on memory consolidation is well-documented in young, healthy subjects. Especially, periods rich in slow-wave sleep (SWS) have shown a memory enhancing effect on hippocampus-dependent declarative memory. Slow oscillatory activity typically occuring during SWS has been implicated in the consolidation effect. Recent evidence in young healthy subjects suggest that the sleep-associated consolidation effect can be amplified by the application of a weak transcranial oscillatory electric current within the frequency range of SWS in humans (0,7-0,8 Hz) during SWS. If patients with amnestic mild cognitive impairments (MCI)- usually characterized by initial difficulties in hippocampus dependent memory functions - benefit from transcranial slow oscillatory stimulation (tSOS) during nocturnal sleep as well has not been studied so far. The primary aim of the present study is to investigate the influence of a weak slow oscillating brain stimulation (tSOS) on declarative memory consolidation applied during periods of nocturnal SWS in MCI patients.

Condition Intervention
Mild Cognitive Impairment, So Stated Device: Stimulation Device: SHAM

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Primary Purpose: Treatment
Official Title: Impact of Transcranial Slow Oscillating Stimulation on Memory Consolidation During Nocturnal Slow Wave Sleep in Patients With Mild Cognitive Impairments(MCI)

Resource links provided by NLM:

Further study details as provided by Agnes Flöel, Charite University, Berlin, Germany:

Primary Outcome Measures:
  • Retention of declarative memories after 0.75 Hz stimulation during SWS, vs after sham stimulation during SWS [ Time Frame: 4 weeks ]
    Retention between stimulation conditions (0.75 Hz during SWS, vs sham stimulation during SWS) in the declarative memory task.

Secondary Outcome Measures:
  • Amount of Slow wave Sleep, spindels, eeg-correlates, further memory systems [ Time Frame: 4 weeks ]
    1. Amount of slow wave sleep assessed by standard polysomnographic criteria in 0,75 Hz vs SHAM stimulation during SWS.
    2. Spindel activity during sleep indicated via several spindel parameters like number, duration, frequency of spindles; compared between 0,75 Hz and SHAM stimulation during SWS.
    3. Neuronal correlates (EEG-power in slow oscillation frequency bands induced by 0,75 Hz vs SHAM stimulation during SWS; EEG-correlates of encoding and retrieval of a declarative memory task).
    4. Performance in further memory systems (procedural), compared between 0,75 Hz and SHAM stimulation during SWS.

Estimated Enrollment: 22
Study Start Date: April 2013
Estimated Study Completion Date: December 2017
Estimated Primary Completion Date: December 2017 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: 0,75 Hz stimulation
slow transcranial oscillating stimulation (~0,75Hz) during periods of Slow Wave Sleep
Device: Stimulation
Other Name: oscillating direct current brain stimulation
Sham Comparator: SHAM stimulation
SHAM stimulation during periods of Slow Wave Sleep
Device: SHAM
no stimulation


Ages Eligible for Study:   50 Years to 90 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • amnestic and amnestic plus MCI-patients:

    1. Concern reflecting a change in cognition reported by patient or informant or clinician (i.e., historical or observed evidence of decline over time)
    2. Objective evidence of memory impairment; additional cognitive domains may be affected as well;
    3. Preservation of independence in functional abilities
    4. no dementia
  • age: 50-90 years

Exclusion Criteria:

  • untreated severe internal or psychiatric diseases
  • epilepsy
  • other severe neurological diseases eg., previous major stroke, brain tumour
  • dementia
  • contraindications to MRI
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01782391

Contact: Sven Paßmann, 030/450 560 395
Contact: Nadine Külzow, PhD 030/450 560 140

Charite CCM Neurologie Berlin Recruiting
Berlin, Germany, 10117
Contact: Sven Paßmann,    +49/30/450560395   
Contact: Agnes Flöel, Prof. Dr.    +49/30/450560284   
Sub-Investigator: Nadine Külzow, Dr.         
Sub-Investigator: Sven Paßmann,         
Principal Investigator: Agnes Flöel, Prof. Dr.         
Sponsors and Collaborators
Charite University, Berlin, Germany
Study Chair: Agnes Flöel, Professor Charite Universitätsmedizin Berlin - Neurologie
  More Information

Responsible Party: Agnes Flöel, Prof. Agnes Flöel, MD, Charite University, Berlin, Germany Identifier: NCT01782391     History of Changes
Other Study ID Numbers: Nighttime sleep-tSOS-MCI
Study First Received: June 5, 2012
Last Updated: December 20, 2016

Keywords provided by Agnes Flöel, Charite University, Berlin, Germany:
mild cognitive impairment
brain stimulation
memory consolidation

Additional relevant MeSH terms:
Cognition Disorders
Mild Cognitive Impairment
Neurocognitive Disorders
Mental Disorders processed this record on September 21, 2017