Thunderclap headache from complicated sinusitis.

We report a case of complicated pansinusitis presenting with thunderclap headache. The patient quickly developed left ophthalmoplegia and imaging demonstrated extension of inflammation from the sphenoid sinus into the sellar region. Thunderclap headache is well known to occur from a variety of intracranial events, but complicated sinusitis presenting this way is seldom described. The patient recovered completely with appropriate treatment.