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 Formally étale morphism In commutative algebra and algebraic geometry, a morphism is called formally étale if it has a lifting property that is analogous to being a local diffeomorphism. Let "A" be a topological ring, and let "B" be a topological "A"-algebra. "B" is formally étale if for all discrete "A"-algebras "C", all nilpotent ideals "J" of "C", and all continuous "A"-homomorphisms , there exists a unique continuous "A"-algebra map such that , where is the canonical projection. Formally étale is equivalent to formally smooth plus formally unramified. Since the structure sheaf of a scheme naturally carries only the discrete