Pain Perception during Menstrual Cycle

Abstract

Sexual hormones influence complex brain function and pain perception. Many psychophysical studies attempted to establish pain perception changes across menstrual cycle in animal models and healthy women or those with chronic pain. General results are quite uncertain in regard to consistent menstrual-related fluctuations of pain perception. The few studies applying neurophysiological procedures to test pain-related changes during menstrual cycle suggested a fluctuation of central modulation of pain across phases, with a prevalence of excitatory versus inhibitory control in the premenstrual period, which may explain the cyclic worsening of many syndromes, such as migraine. Whatever is the relevance of menstrual cycle on individual painful symptoms, it should be accepted as one of the numerous factors influencing mechanisms of neuromodulation.

Evaluation of sensitivity, motor and pain thresholds across the menstrual cycle through medium-frequency transcutaneous electrical nerve stimulation

“…The data collected in this study indicated that nervous thresholds vary systematically during the different phases of the menstrual cycle (MC), which is in accordance with the findings of several other studies (1-5),.…”

“…Behavioral, biochemical and physiological data obtained from animal studies indicate that beyond their reproductive function, ovarian hormones can influence sensory, motor and pain responses, depending on the menstrual cycle (MC) phase of the woman. As such, these hormones could account for certain responses that are specific to females (1-5). …”

“…This variation makes it difficult to compare and reproduce previously reported findings (4). Moreover, most studies have only assessed pain response across MC phases (1,2,4,7,8), without evaluating other parameters, such as sensitivity and motor responses.…”

Using a Menstrual Emotional Stroop Task Test (MEST) to Measure Emotional Responses to Menstrual Cycle Pain

“…Menstrual pelvic pain severity has been reported to be greatest during early follicular (menstruation) and premenstrual (late luteal phase) compared to late follicular and early luteal phases [8]. Increased pain correlates with other indicators of emotional arousal during the luteal phase such as increased levels of stress hormones after a stressful task, higher amygdala activity when anticipating pain, and increased negative daily moods [34].…”

“…If pain is not managed over time it can become chronic and difficult to endure leading to conditions such as Post-Traumatic Stress Disorder (PTSD) [7]. Moreover, pain is a complex function, depending on cognition, emotions, context, and biological status of neuronal structures [8]. Pain has much broader implications for health as an integrated framework compared to mood and behavioral syndromes alone [9,10].…”