• diseases

Common diseases are common. Rare diseases are rare. Or rather, rare diseases are individually rare, but taken together they are quite common, at least in neurology. Neurologists are often accused of having spanophilia (the love of the rare),1 as if it is inevitably a failing, but given the very large number of rare diseases in neurology it is almost a requirement for neurologists. And probably a good thing, as long as it does not get in the way of common sense. In this edition we let loose our inner spanophile and highlight why spanophilia is important for the practical neurologist—as well as for their patients.

Rare disease can be difficult to diagnose yet may respond to specific treatments, which clearly makes these diagnoses very important. Primary angiitis of the central nervous system illustrates this well, discussed by Shamik Battacharyya and Aaron Berkowitz (see page 195); in another …