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

This study is currently recruiting participants. (see Contacts and Locations)
Verified March 2016 by Charite University, Berlin, Germany
Information provided by (Responsible Party):
Agnes Flöel, Charite University, Berlin, Germany
ClinicalTrials.gov Identifier:
First received: June 5, 2012
Last updated: March 15, 2016
Last verified: March 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
Endpoint Classification: Efficacy Study
Intervention Model: Crossover Assignment
Masking: Double Blind (Subject, Caregiver, 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 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 ] [ Designated as safety issue: No ]
    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 ] [ Designated as safety issue: No ]
    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 2016
Estimated Primary Completion Date: December 2016 (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
Genders Eligible for Study:   Both
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 ClinicalTrials.gov identifier: NCT01782391

Contact: Sven Paßmann, M.sc. 030/450 560 395 sven.passmann@charite.de
Contact: Nadine Külzow, PhD 030/450 560 140 nadine.kuelzow@charite.de

Charite CCM Neurologie Berlin Recruiting
Berlin, Germany, 10117
Contact: Sven Paßmann, M.sc.    +49/30/450560395    sven.passmann@charite.de   
Contact: Agnes Flöel, Prof. Dr.    +49/30/450560284    agnes.floeel@charite.de   
Sub-Investigator: Nadine Külzow, Dr.         
Sub-Investigator: Sven Paßmann, M.sc.         
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
ClinicalTrials.gov Identifier: NCT01782391     History of Changes
Other Study ID Numbers: Nighttime sleep-tSOS-MCI 
Study First Received: June 5, 2012
Last Updated: March 15, 2016
Health Authority: Germany: Ethics Commission

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

Additional relevant MeSH terms:
Cognition Disorders
Mild Cognitive Impairment
Mental Disorders
Neurocognitive Disorders

ClinicalTrials.gov processed this record on May 26, 2016