Frequency of focal cerebral transient ischemic attacks during a 12 month period. The Copenhagen city heart study.

As an offshoot of a larger prospective cardiovascular population study, the present study aimed to determine the 12 months frequency of focal cerebral transient ischemic attacks (TIAs) in persons randomly selected after age stratification from the Copenhagen city population register. A questionnaire of 5 questions pertaining to cerebrovascular attacks sustained within the last 12 months was distributed to 2,357 persons. The TIA-questionnaire was returned by 88%, of whom 22% responded affirmatively to one or more questions. The positive responders were interviewed by phone, and when suspected of having TIAs they were examined by a neurologist. A total of 11 persons proved to have had TIAs, which for the age group of 60 years and over gives o 12 months frequency of 8/1000. Dizziness, ophthalmologic problems and migraine were the most frequent causes of a "false" positive response.