None listed
Conditions
Brief summary
Amnestic mild cognitive impairment (a-MCI) is believed to represent a transition period between normal aging and Alzheimer's disease. People with a-MCI experience problems with their memory without it impacting on their daily functioning. As a-MCI represents a stage prior to irreversible neurodegeneration, it is important from a therapeutic perspective that neural changes occurring in a-MCI are determined in order to see if there remains potential for response to treatment. Neuroplasticity refers to the brains ability to re-organize its function in response to the environment. One aspect of this is known as long-term potentiation (LTP), which is imperative in learning and memory. LTP-like plasticity can be induced through brain stimulation techniques including transcranial direct current stimulation (tDCS). Application of tDCS through a gentle electrical current can increase brain activity as measured through electroencephalography (EEG) and behavioural outcomes. When transcranial magnetic stimulation (TMS) is applied in combination with EEG, the cortical excitability of the stimulated and surrounding brain regions can be determined. This provides information about the LTP-like plasticity that is present. Recent evidence has shown that spaced application of tDCS may be more beneficial in enhancing cognitive performance and neural plasticity compared to only a single session. Therefore the aim of our study is to investigate whether LTP can be induced in a-MCI and if there are differences in LTP-like plasticity and cognitive performance with spaced application of tDCS compared to a single active tDCS condition.
Interventions
Transcranial direct current stimulation (tDCS) involves the application of a weak electric current to the scalp to non-invasively increase cortical excitability. Two surface electrodes are attached to the scalp. The anode is placed on the left dorsolateral prefrontal cortex and the cathode on the right forehead. Participants sit upright in a chair and are awake and alert for the period of stimulation.
Participants will be asked to attend for two sessions, spaced at least one week apart, with e
Transcranial direct current stimulation (tDCS) involves the application of a weak electric current to the scalp to non-invasively increase cortical excitability. Two surface electrodes are attached to the scalp. The anode is placed on the left dorsolateral prefrontal cortex and the cathode on the right forehead. Participants sit upright in a chair and are awake and alert for the period of stimulation. Participants will be asked to attend for two sessions, spaced at least one week apart, with each session lasting approximately 2 hours. In each session tDCS will be applied by a trained researcher for two 13 minute blocks with a 20 minute break between. The first block of tDCS will be either active (2mA) or sham stimulation, with the second block active. Sessions will be counterbalanced across participants.
Sponsors
Monash University
Study design
Allocation
Non-randomised trial
Primary purpose
Treatment
Eligibility
Sex/Gender
All
Age
18 Years to 80 Years
Healthy volunteers
Yes
Inclusion criteria
a) Subjective and objective memory complaints. Objective memory complaints are defined as >1.5SDs below the mean on visual or verbal memory tasks, OR b) Healthy adults aged between 18 - 35 years OR 56 - 80 years with no cognitive complaints.
Exclusion criteria
* History of seizures or neurological disorders * Current psychiatric diagnoses, alcohol or substance dependence * Left-handed * Presence of metal in head * Women who are currently pregnant or lactating * Individuals taking benzodiazepines or acetyl cholinesterase inhibitors
Outcome results
None listed