A rare condition in which cerebrospinal fluidThis clear, water-like fluid forms, for the most part, within the brain, more specifically inside the ventricles of the ... leaks, spontaneously, from the thecaThis Latin word means a sheath, or sleeve. It refers to the tube of dura that lines the spinal canal, retaining within i... which lines the spinal canalThe individual bones that comprise the spinal column are made up of a weight-bearing “body” and other components whi.... The fluid that drains out of the spine and the head causes the brain to lose buoyancy. The brain slumps downwards and pulls on the arteries that supply it with blood. It also presses on the membranes that line the skull. These structures contain nerve fibres which then send pain signals to the brain itself and which are perceived as headaches. The headaches of spontaneous intracranial hypertension characteristically develop or are made worse when the affected individual is upright for a period and are relieved by lying down. In this respect they are similar to the low-pressure headaches that develop after a lumbar punctureA long needle is passed into the lower part of the spine, in order to remove some cerebrospinal fluid. This may be to re....