ABSTRACT
BACKGROUND: Leiomyomas are usually easily identifiable on routine imaging. However, there is increasing difficulty with diagnosing leiomyomas following degeneration. Subserosal leiomyomas that undergo cystic degeneration can imitate ovarian pathology. CASE: We present the case of a 39-year-old nulligravid woman who underwent surgery for a large pelvic mass originally suspected to be of ovarian origin. Intraoperatively, the mass was found to originate from the uterus and determined to be a large pedunculated, fluid-filled cyst arising from a fibroid which had undergone cystic degeneration. The mass was successfully removed laparoscopically through a single, two-centimeter port. CONCLUSION: Gynecologists and radiologists should take into account this presentation when encountering suspected enlarged ovarian cysts without clearly identifying an origin. Laparoscopic intervention should be considered as the first line of management.
ABSTRACT
UNLABELLED: Animal models of neuropathic pain in which a peripheral nerve is damaged result in spontaneous activity in primary afferents that can be inhibited by intravenous administration of sodium channel blockers. Many of these compounds exhibit use-dependent block of sodium current, leading to the prediction that they should more readily inhibit neurons that fire at higher frequencies. This prediction was tested in 2 rat models of nerve injury, L5 spinal nerve section and sciatic nerve section. Sciatic nerve section produced average firing frequencies that were higher than spinal nerve section and often manifested as high-frequency bursting. Inhibition of firing by intravenous sodium channel blockers was longer lasting in this model. Within each model, higher frequency of firing did not translate into more effective block. In the spinal nerve section model, there was a robust inverse correlation between frequency and inhibition. Within the sciatic section model, only neurons that fired in rhythmic bursts were inhibited, and again, those firing at lower mean frequencies were more effectively inhibited. These results indicate that the efficacy of sodium channel blockers depends on the nature of the injury and the pattern of the resulting activity rather than simply the frequency of action potentials generated. PERSPECTIVE: This study examines the ability of frequency-dependent sodium channel blockers to inhibit spontaneous firing of injured peripheral nerves in vivo. It outlines the conditions under which inhibition is more and less effective and will provide insight into conditions under which sodium channel blockers are likely to be therapeutically useful.
