[A case of congenital aqueductal stenosis from CT images taken for the differential diagnosis of a post-dural puncture headache].

We detected congenital aqueductal stenosis from CT images taken for the differential diagnosis of a post-dural puncture headache. A history of multiple spinal taps for anesthesia and the nature of headaches led us to a suspected diagnosis of headache caused by intracranial hypotension at variance with image findings diagnostic of hydrocephalus, perplexing us in the differential diagnosis. Hydrocephalus was of congenital type, having no causal relationship with past multiple spinal taps. Congenital aqueductal stenosis varies in severity from infancy-onset one to accidental one diagnosed from images like the current case. Since treatment may differ between hydrocephalus and intracranial hypotension which are diametrically opposite to each other in pathophysiology, it is essential to differentiate a headache in an overall view of a history, physical examination, and image findings.