Pathophysiology
Testicular torsion occurs when there is mechanical twisting of the spermatic cord, which suspends the testicle within the scrotum and contains the testicular artery and vein. Twisting of the cord reduces or eliminates blood flow to the testicle. The degree of arterial and venous obstruction depends on the duration and severity of the torsion event. Typically, venous blood flow is compromised first. The increase in venous pressure subsequently causes decreased arterial blood flow, leading to decreased oxygen supply to the testicle, and if untreated, testicular infarction.It is also believed that torsion occurring during fetal development can lead to so-called neonatal torsion or vanishing testis, and is one of the causes of an infant being born with monorchism (one testicle). Intermittent testicular torsion
Intermittent testicular torsion (ITT) is a less serious but chronic variant of torsion. It is characterized by intermittent scrotal or testicular pain, followed by eventual spontaneous detorsion and resolution of pain. Nausea and vomiting may also occur. : 150  Though less pressing, such individuals are at significant risk of complete torsion and possible subsequent orchiectomy and the recommended treatment is elective bilateral orchiopexy. Ninety-seven percent of patients who undergo such surgery experience complete relief from their symptoms. : 316

Extravaginal testicular torsion
Torsion occurring outside of the tunica vaginalis, when the testis and gubernaculum can rotate freely, is termed an extravaginal testicular torsion. This type occurs exclusively in newborns, however, newborns can be affected by other testicular torsion variants as well.
Metreleptin, sold under the brand name Myalept among others, is a synthetic analog of the hormone leptin used to treat various forms of dyslipidemia. It has been approved in Japan for metabolic disorders including lipodystrophy and in the United States as replacement therapy to treat the complications of leptin deficiency, in addition to diet, in patients with congenital generalized or acquired generalized lipodystrophy.The most common side effects include hypoglycaemia (low blood glucose) and weight loss. Medical uses
In the European Union, metreleptin is indicated in addition to diet to treat lipodystrophy, where people have a loss of fatty tissue under the skin and a build-up of fat elsewhere in the body such as in the liver and muscles. It is used in adults and children above the age of two years with generalised lipodystrophy (Berardinelli-Seip syndrome and Lawrence syndrome); and in adults and children above the age of twelve years with partial lipodystrophy (including Barraquer-Simons syndrome), when standard treatments have failed.In the United States, it is indicated as an adjunct to diet as replacement therapy to treat the complications of leptin deficiency in people with congenital or acquired generalized lipodystrophy. Research
Metreleptin is currently being investigated for the treatment of diabetes and/or hypertriglyceridemia, in patients with rare forms of lipodystrophy, syndromes characterized by abnormalities in adipose tissue distribution, and severe metabolic abnormalities.