Chronic paroxysmal hemicrania Chronic paroxysmal hemicrania Chronic paroxysmal hemicrania (CPH), also known as Sjaastad syndrome, is a severe debilitating unilateral headache usually affecting the area around the eye. It normally consists of multiple severe, yet short, headache attacks affecting only one side of the cranium. It is more commonly diagnosed in women than in men, but, unlike a migraine, has no neurological symptoms associated with it. CPH headaches are treated through the use of non-steroidal anti-inflammatory drugs, with indomethacin found to be usually effective in eliminating symptoms. Paroxysmal hemicrania is classified by the frequency and duration of attacks experienced by patients. Episodic paroxysmal
Formally étale morphism topology, the notion of formally étale for schemes is analogous to formally étale for the discrete topology for rings. That is, a morphism of schemes is formally étale if for every affine "Y"-scheme "Z", every nilpotent sheaf of ideals "J" on "Z" with be the closed immersion determined by "J", and every "Y"-morphism , there exists a unique "Y"-morphism such that . It is equivalent to let "Z" be any "Y"-scheme and let "J" be a locally nilpotent sheaf of ideals on "Z". Formally étale morphism In commutative algebra and algebraic geometry, a morphism is called formally étale if it