A guide to parasomnias

• Many of the parasomnias have distinguishing features that can be gleaned from the clinical history and occasionally from the physical examination and investigative studies. • It may be necessary to differentiate parasomnias from each other and from sleep related epilepsy. • Specialist investigation may be required in some circumstances, such as when sleep behaviours are complicated, injurious or threatening, and sometimes in medicolegal circumstances. • For straightforward cases of sleep walking in childhood, providing explanation and reassurance may be all that is necessary. • Simple safety precautions should be advised when parasomnia behaviour is potentially harmful. • Most parasomnias will respond favourably to pharmacotherapy, if required.