Kidney Stones, also known as renal calculi, are hard masses that separate urine from the urinary tract. These stones can occur anywhere in the urinary tract, including the kidneys, bladder, ureters and urethra.
This fluid is called the cerebrospinal fluid (CSF). When it leaks out, the pressure around the brain and spinal cord drops. Causes of leakage through the dura include: 1  Certain head, brain, or spinal surgeries.  Head injury.
Spinal CSF Leak Foundation. Overview of Spinal CSF Leaks. The brain and spinal cord are bathed in fluid known as cerebrospinal fluid (CSF). This fluid is held inside layers of connective tissue called the meninges which surround the brain and spinal cord. There are three meningeal layers: pia mater; arachnoid mater; dura mater.