Things that go bump in the night: diagnosing sleep-related movement disorders without a sleep laboratory.

It is common for general physicians to experience diagnostic doubt and trepidation whenever faced with patients who exhibit abnormal nocturnal behaviours or excessive movements at night. There is also a perception that expensive and often poorly available overnight tests are usually required for diagnostic precision. In fact, the majority of conditions, whether they be parasomnias or, more rarely, nocturnal seizures, can be reliably diagnosed from a directed history, if available. Although the evidence base for treating parasomnias and sleep-related movement disorders remains minimal, accurate recognition is important for a variety of reasons. This review covers the diagnostic features of the full range of parasomnias and movement disorders that might present to a multidisciplinary adult sleep clinic. Throughout, it will be argued that the recognition of key or salient features obtained from a good history is the most important diagnostic tool. Indeed, when diagnostic doubt remains after a thorough sleep history, it is relatively rare for detailed tests to add much in the way of useful information.