Making the diagnosis in patients with blackouts: it's all in the history.

The distinction between the different causes of blackouts is an important and challenging clinical task. Given that treatment is very diagnosis-specific, therapeutic success depends entirely on the correct categorisation of the problem. However, despite impressive technological advances in brain imaging and improved access to tests such as video-EEG monitoring and tilt-table testing, the act of taking and interpreting the patient's history is still the most important diagnostic tool in the evaluation of patients presenting with blackouts; in many if not most cases it provides the only diagnostic pointers. Here we discuss the potential and limitations of using factual information (what patients say about their attacks) and summarise the findings of a number of recent studies which suggest that taking note of how patients talk can help get the diagnosis right.