TDCS as Augmentation Therapy to Cognitive Training in Mild Dementia

Official title

Randomized Controlled Trial of Transcranial Direct Current Stimulation (tDCS) as Augmentation Therapy to Cognitive Training (CT) in Individuals With Major Neurocognitive Disorder (MND) of Mild Severity

Overview

Due to increase in life expectancy, major neurocognitive disorder (MND) becoming increasingly important as reflected in the increasing number in dementia population, as well as in burden to health care system and to caregiver. Among current treatment, cognitive training has shown to have significant outcome in cognitive impaired patient. But the effect is reported to be small and might not be long-lasting. In consideration of the neuronal excitability effect in tDCS, it may consolidate the effect of cognitive training if used simultaneously. The study will investigate on efficacy of tDCS as combined intervention to cognitive training. The study aims to investigate the efficacy of 2-week (5 sessions per week) tDCS to augment cognitive training in subjects with MND with clinically mild severity. Patients with diagnosis of MND or dementia from HKWC will be recruited with inclusion and exclusion criteria listed. The eligible participants will be randomized to receive either active intervention (active tDCS) or sham (sham tDCS) as control with cognitive training simultaneously. Each session lasts for 20 minutes. The subjects will be allocated to either interventional or control group using block randomization. Block of 4 will be used to allocate subjects at 1:1 ratio between two groups. Both the participants and investigators responsible for assessment and data analysis will be blinded to the group allocation. Primary and secondary outcome will be assessed at baseline, week 2 (after course of intervention) and 4 weeks after the course of intervention. Baseline assessment assesses on demographic data (e.g. age, gender, years of education), clinical data with full psychiatric assessment and access to previous medical record, neuropsychiatric data (HK-MoCA and CNPI). Primary outcomes includes N-back (cognitive training) performance, forward and backward digit span. Secondary outcomes includes measurement on dementia rating and trail making test. In data analysis, any group differences in demographics and clinical profiles between the intervention and sham group at baseline will be assess. ANOVA will be performed to examine the effect of time and intervention on primary outcome and other cognitive assessment across time points. Potential confounders will be adjusted. Baseline assessments and outcome measures is either psychiatric assessment, clinician rating scales or cognitive assessment performed with investigator.

Detailed description

Due to increase in life expectancy, major neurocognitive disorder (MND) becoming increasingly important as reflected in the increasing number in dementia population, as well as in burden to health care system and to caregiver.

Among current treatment, cognitive training has shown to have significant outcome in cognitive impaired patient. But the effect is reported to be small and might not be long-lasting. In consideration of the neuronal excitability effect in tDCS, it may consolidate the effect of cognitive training if used simultaneously. The study will investigate on efficacy of tDCS as combined intervention to cognitive training.

The study aims to investigate the efficacy of 2-week (5 sessions per week) tDCS to augment cognitive training in subjects with major neurocognitive disorder with clinically mild severity. Patients with diagnosis of MND or dementia from HKWC will be recruited with inclusion and exclusion criteria listed. The eligible participants will be randomized to receive either active intervention (active tDCS) or sham (sham tDCS) as control with cognitive training simultaneously.

Each session lasts for 20 minutes. The subjects will be allocated to either interventional group or control group using block randomization. Block of 4 will be used to allocate subjects at 1:1 ratio between two groups. Both the participants and investigators responsible for assessment and data analysis will be blinded to the group allocation. Primary outcome and secondary outcome will be assessed at baseline, week 2 (after course of intervention) and 4 weeks after the course of intervention. Baseline assessment assesses on demographic data (e.g. age, gender, years of education), clinical data with full psychiatric assessment and access to previous medical record, neuropsychiatric data (HK-MoCA and CNPI). Primary outcomes includes N-back (cognitive training) performance, forward and backward digit span. Secondary outcomes includes measurement on dementia rating and trail making test. In data analysis, any group differences in demographics and clinical profiles between the intervention and sham group at baseline will be assess. ANOVA will be performed to examine the effect of time and intervention on primary outcome and other cognitive assessment across time points. Potential confounders will be adjusted.

Baseline assessments and outcome measures is either psychiatric assessment, clinician rating scales or cognitive assessment performed with investigator. No questionnaires will be given to participants.

Interventions

• Device transcranial direct current stimulation
  Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation by applying weak current through electrode. It can archive excitation by anode stimulation or inhibition by stimulating cathode. By inducing modification of membrane polarisation, it can modulate cerebral excitability. Literature suggested anode tDCS over the dorsolateral prefrontal cortex (DLPFC) improved cognitive function, in terms of responding faster and more accurate in cognitive tasks. tDCS was well tolerat

Primary outcome measures

• N-back task performance in terms of reaction time and % of correct [Time frame: Baseline, week 2 (after course of intervention) and 4 weeks after the course of intervention]
• Forward and Backward digit span [Time frame: Baseline, week 2 (after course of intervention) and 4 weeks after the course of intervention]

Secondary outcome measures (3)

• Clinical dementia rating - sum of boxes [Time frame: Baseline, week 2 (after course of intervention) and 4 weeks after the course of intervention]
• Chinese version of the neuropsychiatric inventory (CNPI) [Time frame: Baseline, week 2 (after course of intervention) and 4 weeks after the course of intervention]
• Trail making test [Time frame: Baseline, week 2 (after course of intervention) and 4 weeks after the course of intervention]

Eligibility criteria

Inclusion criteria

• 65 years of age or above
• Right-handedness Chinese as defined by Edinburgh handedness inventory
• Cantonese speaking
• Fulfil the criteria of Major neurocognitive disorder, as defined by the 5 th Edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM- 5)
• Clinical Dementia Rating Global score = 1

Exclusion criteria

• Active diagnosis of mood disorder or psychosis
• Alcohol or substance dependence
• Initiation or change in dose of cognitive enhancer within 6 months prior to the onset of the study 14
• Poor physical condition and mobility
• Having regular cognitive training (as defined by at least three 1-hour weekly structured and standardized cognitive training in recent 3 months) 15
• Receiving tDCS within 2 months prior to the onset of study 16
• Significant communication or visual impairment
• Having metal implant in area above upper back, or having metal crown or metal brace, or pacemaker

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Quadruple blind

Primary purpose

Treatment

Study locations

Hong Kong · 1 center

• Queen Mary Hospital — Hong Kong

Publications

• Kim HJ, Baek MJ, Kim S. Alternative type of the trail making test in nonnative English-speakers: the trail making test-black & white. PLoS One. 2014 Feb 13;9(2):e89078. doi: 10.1371/journal.pone.0089078. eCollection 2014. PMID 24551221
• Yeung PY, Wong LL, Chan CC, Leung JL, Yung CY. A validation study of the Hong Kong version of Montreal Cognitive Assessment (HK-MoCA) in Chinese older adults in Hong Kong. Hong Kong Med J. 2014 Dec;20(6):504-10. doi: 10.12809/hkmj144219. Epub 2014 Aug 15. PMID 25125421
• Gandiga PC, Hummel FC, Cohen LG. Transcranial DC stimulation (tDCS): a tool for double-blind sham-controlled clinical studies in brain stimulation. Clin Neurophysiol. 2006 Apr;117(4):845-50. doi: 10.1016/j.clinph.2005.12.003. Epub 2006 Jan 19. PMID 16427357
• Cruz Gonzalez P, Fong KNK, Chung RCK, Ting KH, Law LLF, Brown T. Can Transcranial Direct-Current Stimulation Alone or Combined With Cognitive Training Be Used as a Clinical Intervention to Improve Cognitive Functioning in Persons With Mild Cognitive Impairment and Dementia? A Systematic Review and Meta-Analysis. Front Hum Neurosci. 2018 Oct 16;12:416. doi: 10.3389/fnhum.2018.00416. eCollection 201 PMID 30386223
• Lampit A, Hallock H, Suo C, Naismith SL, Valenzuela M. Cognitive training-induced short-term functional and long-term structural plastic change is related to gains in global cognition in healthy older adults: a pilot study. Front Aging Neurosci. 2015 Mar 9;7:14. doi: 10.3389/fnagi.2015.00014. eCollection 2015. PMID 25805989
• Jones RW. Have cholinergic therapies reached their clinical boundary in Alzheimer's disease? Int J Geriatr Psychiatry. 2003 Sep;18(Suppl 1):S7-S13. doi: 10.1002/gps.936. PMID 12973745
• Hill NT, Mowszowski L, Naismith SL, Chadwick VL, Valenzuela M, Lampit A. Computerized Cognitive Training in Older Adults With Mild Cognitive Impairment or Dementia: A Systematic Review and Meta-Analysis. Am J Psychiatry. 2017 Apr 1;174(4):329-340. doi: 10.1176/appi.ajp.2016.16030360. Epub 2016 Nov 14. PMID 27838936
• Mintun MA, Lo AC, Duggan Evans C, Wessels AM, Ardayfio PA, Andersen SW, Shcherbinin S, Sparks J, Sims JR, Brys M, Apostolova LG, Salloway SP, Skovronsky DM. Donanemab in Early Alzheimer's Disease. N Engl J Med. 2021 May 6;384(18):1691-1704. doi: 10.1056/NEJMoa2100708. Epub 2021 Mar 13. PMID 33720637

Identifiers

NCT: NCT06559254 · UW 24-305

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗