High and Low Pressure Headache
Friedman DI. Headaches Due to Low and High Intracranial Pressure. Continuum (Minneap Minn). 2018 Aug;24(4, Headache):1066-1091.
Low Pressure Headache
Headache triggered by standing. In clinic, put patient in Trendelenburg (the body is laid supine, or flat on the back with the feet higher than the head by 15-30 degrees) 10 min, headache should resolve. Intracranial Spinal CSF leak, spontaneous or trauma (may be trivial) or valsalva. Ehlers-Danlos or joint laxity. Fragile dura. Brain MRI with contrast: dural thickening, brain sag. Do not confuse with Chiari malformation. Don't do LP routinely; if you do, use small needle, 24 gauge. Low pressure not always present: <60 mm. Cervical cord or thoracic cord. Identification of leak: CT and MR myelogram (intrathecal gadolinium, off label use).