[Recent-onset headache is a risk factor of intracranial lesion. A prospective study of 299 patients]

There is some controversy in the medical literature concerning the need to perform neuroimaging studies in neurologically normal patients complaining of headaches. The objective of the study is to determine the detection rate of intracranial abnormalities by computed tomography in patients with different headache durations.

Consecutive patients with the chief complaint of headache referred for neurological evaluation from January 1996 to April 1997 were studied both clinically and by computed tomography scanning. Brain magnetic resonance imaging was performed in 15 patients. Cerebrospinal fluid and/or blood analyses were performed when clinically indicated to rule out subarachnoid hemorrhage, meningitis or temporal arteritis.

15 (5%) out of the 299 patients available for study had significant intracranial lesion. 3 (1%) out of the 266 patients with headaches lasting for more than 1 month had computed tomography findings considered clinically significant and neurological examination was normal in 2 (0.7%) patients with abnormal scans. Patients with a headache duration of 1 month or less had the following case-finding rate: an overall significant intracranial abnormality of 36% (12/33) and significant intracranial abnormality in neurologically normal patients of 15% (5/33).

Patients with headache of recent onset (duration of 1 month or less), even with normal neurological examination, are at greater risk of significant intracranial abnormality than patients with long-lasting headaches. These patients at risk should be studied by cranial computed tomography and lumbar puncture if the computed tomography scan is normal and the cause of the headaches cannot be clinically determined.