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.
See below: Spinal fluid may leak following a spinal tap, surgery or trauma to the head and sometimes without known cause. See this site for more info. http://www.nlm.nih.gov/medlineplus/ency/article/001068.htm. ...Read more.