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.
Cerebrospinal fluid can leak if there is a tear or hole in the membrane (thin tissue) that surrounds the brain and spinal cord. The most common reasons for the membrane to tear include: 1  Certain head, brain, or spinal surgeries.  Head injury.