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Effects of Brain Stimulation During a Daytime Nap on Memory Consolidation in Patients With Mild Cognitive Impairment

This study is ongoing, but not recruiting participants.
Information provided by (Responsible Party):
Agnes Flöel, Charite University, Berlin, Germany Identifier:
First received: January 31, 2013
Last updated: July 4, 2017
Last verified: July 2017
The beneficial effect of nocturnal as well as daytime sleep on memory consolidation is well-documented in young, healthy subjects. Slow wave sleep (SWS), in particular, with its slow oscillating activity have shown to enhance declarative, hippocampus-dependent memory representations. This impact of sleep on memory performance can be additionally enhanced by exogeneous induction of transcranial slow oscillating stimulation (tSOS) within the frequency range of SWS in humans (0,7- 0,8 Hz) during sleep, as has been demonstrated in young, healthy subjects. If patients with amnestic mild cognitive impairment (MCI)- usually characterized by initial difficulties in hippocampus dependent memory functions - benefit from transcranial slow oscillatory stimulation (tSOS) during sleep as well has not been studied so far. The primary goal of the study is therefore to investigate the impact of oscillating current stimulation (tSOS) during a daytime nap on declarative memory consolidation in MCI patients.

Condition Intervention
Mild Cognitive Impairment, So Stated Device: SHAM stimulation Device: 0,75 Hz stimulation

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 Slow Wave Sleep of a Daytime Nap in Patients With Mild Cognitive Impairment(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.

Enrollment: 16
Study Start Date: April 2013
Estimated Study Completion Date: December 2017
Primary Completion Date: August 2016 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: 0,75 Hz stimulation
transcranial slow oscilliating stimulation (tSOS)during periods of SWS
Device: 0,75 Hz stimulation
Other Name: oscillating direct current brain stimulation
Sham Comparator: SHAM stimulation
SHAM stimulation during periods of SWS
Device: SHAM stimulation
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
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Please refer to this study by its identifier: NCT01782365

Charite CCM Neurologie Berlin
Berlin, Germany, 10117
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: NCT01782365     History of Changes
Other Study ID Numbers: Nap-tSOS-MCI
Study First Received: January 31, 2013
Last Updated: July 4, 2017

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

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