Table 2.

Summary of Studies Examining the Impact of Sex Hormones in Measures of Cortical Excitability and Clinical Outcomes

Author	Subjects	Design	Outcomes Measures	Sex hormone	TMS Protocol	Measure of Cortical Excitability	Adjustment for Mentrual Cycle	Findings
Huang et al. (2008)9	31HF (17 pre-menopausal 14 post-menopausal) 16 HM	Observational	50% HAMD reduction	Estradiol, Progesterone	5Hz TMS over the left DLPFC	Not applicable	Not applicable	Higher E/P ratio associated with a greater improvement in HAMD scores in premenopausal women
Zogui et al. (2015)28	10 HF/10 HM	Observational	Manual Dexterity Performance	Estradiol, Progesterone	Paired-pulse TMS	ICI, ICF	Hormone levels were meausured during follicular and mid-luteal phases	ICI and ICF remained unchanged during the menstrual cycle. Manual dexterity was lower during mid-luteal phase.
Ansdell et al. (2019)32	15 HF on OCPs and 14 HF w/o OCPs	Observational	Motor performance of knee extensors	Estradiol, Progesterone	Single and Paired-pulse TMS	MT, MEP, SP, ICI	Measures obtained at day 2, 14 and 21 of the menstrual cycle	Increase progesterone concentrations was associated with increased ICI during day 21 in HF w/o OCPs
He et al. (2021)33	57 M with severe TBI and disorders of consciousness	Placebo Controlled RTC	Improvement in LOC	Estradiol	10Hz rTMS over left DLPFC	None	Not applicable	Improvement in LOC in patients receiving rTMS. Higher estradiol levels correlated with clinical response.

Abbreviations: DLPFC: dorsolateral prefrontal cortex, E/P: estrogen-progesterone, HAM-D: Hamilton depression rating scale, HF: healthy females, HM: healthy males, ICF: intracortical facilitation, ICI: intracortical inhibition, LOC: level of consciousness, M: males, MEP: motor evoked potential, MT: motor threshold, OCPs: oral contraceptive pills, RCT: randomized control trial, rTMS: repetitive transcranial magnetic stimulation, SICI: short interval cortical inhibition, SP: silent period, TBI, traumatic brain injury, TMS: transcranial magnetic stimulation