Non-Invasive Brain Stimulation: the Influence of Gender and Menstrual Phase

An Investigation of the Impact of Gender and the Menstrual Cycle on the Effects of tDCS and rTMS on Cortical Excitability in Healthy Controls.

Status

Completed

Phases

Unknown

Study type

Interventional

Source

ANZCTR

Registry ID

ACTRN12615000720516

Enrollment

Registered

2015-07-13

Start date

2015-04-01

Completion date

2016-03-03

Last updated

2020-01-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

None listed

Brief summary

Non-invasive brain stimulation is emerging as a therapeutic tool for many brain related conditions. There are numerous non-invasive brain stimulation techniques that apply electrical or electromagnetic stimulation to the brain in different ways to alter neural activity. The most researched, and consequently best developed, of these are transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS). Both TMS and tDCS has been shown to have varying degrees of therapeutic efficacy for major depression. Research efforts are currently focused on identifying factors that modulate individual differences in the way the brain response to TMS which could lead to development of optimised protocols for stimulation delivery. There is evidence that sex hormones may modulate the effect of TMS and tDCS. However very few studies have investigated this and none have focused on the dorsolateral prefrontal cortex, the site that both methods are most often applied in a clinical context. The current project is an investigation of the impact of gender, and within female gender of menstrual phases associated with high and low estrogen, on the effect of TMS and tDCS to the dorsolateral prefrontal cortex.

Interventions

Participants will either take part in the transcranial direct current stimulation (tDCS) or repetitive transcranial magnetic stimulation (rTMS) rTMS arms of the study. They will not be required to engage in both. tDCS study arm: 1 mA tDCS. The anodal stimulation will be applied to the left dorsolateral prefrontal cortex and the cathode over the right orbit. Stimulation will be delivered for for 15 minutes using a neuroConn GBH/Eldith DC stimulator. rTMS study arm: Fifty trains of 10 Hz rTMS delivered at 120% of resting motor threshold. rTMS will be delivered using the MagPro R30 to the left DLPFC. Trains will be 4.5 second in duration with a 20.5 second inter-train interval (2250 pulses over 20.8 minutes). Males will take part in one testing session only. Females will take part in two testing sessions: once during an early phase of the menstrual cycle when endogenous estrogen is low, and once more during a later phase when endogenous estrogen level are high.

Study design

Allocation

Non-randomised trial

Primary purpose

Treatment

Eligibility

Sex/Gender

All

Age

18 Years to 40 Years

Healthy volunteers

Yes

Inclusion criteria

1. Are voluntary and competent to consent, 2. Are right handed , 3. Have no history of endocrine disorder, traumatic brain injury or neurological or mental illness.

Exclusion criteria

General Exclusion Criteria: 1. Are a professional driver, 2. Have epilepsy or a history of seizure, 3. Currently taking any psychoactive medications, 4. Have metal anywhere in the head, except the mouth. This includes metallic objects such as screws and slips from surgical procedures. Female Specific Exclusion Criteria 1. Are currently pregnant or lactating, 2. Currently taking the oral contraceptive pill, 3. Have an irregular menstrual cycle.

Outcome results