It is specifically a derivative of testosterone in which an ethynyl group has been added at the C17α position and the methyl group at the C19 position has been removed; hence, it is a combined derivative of ethisterone (17α-ethynyltestosterone) and nandrolone (19-nortestosterone). These modifications result in increased progestogenic activity and oral bioavailability as well as decreased androgenic/anabolic activity. Derivatives
Norethisterone (NET) is the parent compound of a large group of progestins that includes most of the progestins known as the 19-nortestosterone derivatives. This group is divided by chemical structure into the estranes (derivatives of norethisterone) and the gonanes (18-methylgonanes or 13β-ethylestranes; derivatives of levonorgestrel) and includes the following marketed medications:

Several of these act as prodrugs of norethisterone, including NETA, NETE, etynodiol diacetate, lynestrenol, and quingestanol acetate. Noretynodrel may also be a prodrug of norethisterone. NETA is taken by mouth similarly to norethisterone, while NETE is given by injection into muscle. Non-17α-ethynylated
19-Nortestosterone (19-NT) progestins which are technically not derivatives of norethisterone (as they do not have a C17α ethynyl group) but are still closely related (with other substitutions at the C17α and/or C16β positions) include the following marketed medications:
The C17α vinyl (ethenyl) derivatives norgesterone (17α-vinyl-δ5(10)-19-NT) and norvinisterone (17α-vinyl-19-NT)
The C17α allyl derivatives allylestrenol (3-deketo-17α-allyl-19-NT) and altrenogest (17α-allyl-δ9,11-19-NT)
The C17α alkyl derivative normethandrone (17α-methyl-19-NT)
The C17α cyanomethyl derivative dienogest (17α-cyanomethyl-δ9-19-NT)
The C16β ethyl derivative oxendolone (16β-ethyl-19-NT)Many anabolic steroids of the 19-nortestosterone family, like norethandrolone and ethylestrenol, are also potent progestogens, but were never marketed as such. Synthesis
Chemical syntheses of norethisterone have been published.
A brainstem stroke syndrome falls under the broader category of stroke syndromes, or specific symptoms caused by vascular injury to an area of brain (for example, the lacunar syndromes). As the brainstem contains numerous cranial nuclei and white matter tracts, a stroke in this area can have a number of unique symptoms depending on the particular blood vessel that was injured and the group of cranial nerves and tracts that are no longer perfused. Symptoms of a brainstem stroke frequently include sudden vertigo and ataxia, with or without weakness. Brainstem stroke can also cause diplopia, slurred speech and decreased level of consciousness. A more serious outcome is locked-in syndrome. Syndromes
The midbrain syndromes (Significant overlap between these three syndromes)
Superior alternating hemiplegia or Webers syndrome
Paramedian midbrain syndrome or Benedikts syndrome
Claudes syndrome
Medial pontine syndrome or Middle alternating hemiplegia or Fovilles syndrome
Lateral pontine syndrome or Marie-Foix syndrome
Medial medullary syndrome or Inferior alternating hemiplegia
Lateral medullary syndrome or Wallenberg syndrome

History
A history of locked in syndromes. Jean-Dominique Bauby
Parisian journalist Jean-Dominique Bauby had a stroke in December 1995, and, when he awoke 20 days later, he found his body was almost completely paralyzed; he could control only his left eyelid. By blinking this eye, he slowly dictated one alphabetic character at a time and, in so doing, was able over a great deal of time to write his memoir, The Diving Bell and the Butterfly. Three days after it was published in March 1997, Bauby died of pneumonia.