[Diagnostic approach to the patient with stroke].

In the case of a patient with sudden-onset focal neurological deficit, clinicians must answer three fundamental questions: is it a stroke? is it ischemia or hemorrhage? and what kind of ischemic stroke is it? Clinical information (i.e., history and examination) is available in any situation, and its role in answering these questions is extremely important, even though certainty can only be achieved from instrumental diagnostic tools. In fact, when diagnosis is based on properly designed clinical criteria, the percentage of mistakes is quite low. Clinical methods are still the best way to orient topographic and etiologic diagnosis, as well as estimate prognosis. In addition, time might be saved if randomization in clinical trials were performed using clinical methods before initiating complex investigations.