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
Relatively compact subspace Relatively compact subspace In mathematics, a relatively compact subspace (or relatively compact subset, or precompact subset) "Y" of a topological space "X" is a subset whose closure is compact. Since closed subsets of a compact space are compact, every subset of a compact space is relatively compact. In the case of a metric topology, or more generally when sequences may be used to test for compactness, the criterion for relative compactness becomes that any sequence in "Y" has a subsequence convergent in "X". Some major theorems characterise relatively compact subsets, in particular in function spaces. An example is the Arzelà–Ascoli