Thunderclap headache

A 43 year old woman addressed to us due to a "violent headache." The patient, who already suffered sporadically from "migraine without aura", complained of the sudden onset of a headache that had quickly reached the maximum pain intensity. The pain made her totally unfit and every change in posture caused vertigo, nausea and vomiting. Nevertheless, the neurological exam was substantially negative and the CT scan, performed in emergency, did not indicate hemorrhage or lesions detectable through this method; besides, there was no fever and inflammatory markers were not significant. We started forthwith the investigation in accordance with the 2004 IHS guidelines on suspicion of "thunderclap headache". [1] During the hospitalization, there was an attenuation of pain but not of postural dizziness, so we planned a lumbar puncture (PL). [2] Before doing the PL, we subjected the patient to a brain MRI and MRA. This time the images showed intracranial hypotension due to the presence of a diffuse, symmetric and bilateral thickening of the pachymeninges. The caution used before doing the PL was providential. An MRI of the spinal CSF excluded secondary causes of hypotension. The patient was treated with rehydration with about four liters of physiological solution daily for three days with rapid improvement of symptoms. The brain MRI control showed no more signs of CSF hypotension. Final diagnosis is: Headache attributed to idiopathic low CSF pressure.[1