In most cases there are other neurological abnormalities, such as seizures and weakness of part of the body, but in 15–30% the headache is the only abnormality.Carotid artery dissection and vertebral artery dissection (together cervical artery dissection), in which a tear forms inside the wall of the blood vessels that supply the brain, often causes pain on the affected side of the head or neck. The pain usually precedes other problems that are caused by impaired blood flow through the artery into the brain; these may include visual symptoms, weakness of part of the body, and other abnormalities depending on the vessel affected. Diagnosis
The most important initial investigation is computed tomography of the brain, which is very sensitive for subarachnoid hemorrhage. If this is normal, a lumbar puncture is performed, as a small proportion of SAH is missed on CT and can still be detected as xanthochromia.If both investigations are normal, the specific description of the headache and the presence of other abnormalities may prompt further tests, usually involving magnetic resonance imaging (MRI). Magnetic resonance angiography (MRA) may be useful in identifying problems with the arteries (such as dissection), and magnetic resonance venography (MRV) identifies venous thrombosis. It is not usually necessary to proceed to cerebral angiography, a more precise but invasive investigation of the brains blood vessels, if MRA and MRV are normal. Epidemiology
Incidence of thunderclap headache has been estimated at 43 per 100,000 people every year. Approximately 75% are attributed to "primary" headaches: headache disorder, non-specific headache, idiopathic thunderclap headache or uncertain headache disorder.
Fosdenopterin (or cyclic pyranopterin monophosphate, cPMP), sold under the brand name Nulibry, is a medication used to reduce the risk of death due to a rare genetic disease known as molybdenum cofactor deficiency type A.The most common side effects include complications related to the intravenous line, fever, respiratory infections, vomiting, gastroenteritis, and diarrhea.Fosdenopterin was approved for medical use in the United States in February 2021,  It is the first medication approved by the U.S. Food and Drug Administration (FDA) for the treatment of molybdenum cofactor deficiency type A. and in the European Union in September 2022. Medical uses
Fosdenopterin is indicated to reduce the risk of mortality in people with molybdenum cofactor deficiency  (MoCD) type A. Mechanism of action
People with molybdenum cofactor deficiency type A cannot produce cyclic pyranopterin monophosphate (cPMP) in their body. Fosdenopterin is an intravenous medication that replaces the missing cPMP. cPMP is a precursor to molybdopterin, which is required for the enzyme activity of sulfite oxidase, xanthine dehydrogenase/oxidase and aldehyde oxidase. History
Fosdenopterin was developed at the German universities TU Braunschweig and the University of Cologne.The effectiveness of fosdenopterin for the treatment of MoCD-A was demonstrated in thirteen treated participants compared to eighteen matched, untreated participants. The participants treated with fosdenopterin had a survival rate of 84% at three years, compared to 55% for the untreated participants.The U.S. Food and Drug Administration (FDA) granted the application for fosdenopterin priority review, breakthrough therapy, and orphan drug designations along with a rare pediatric disease priority review voucher.