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.
Causes and Risk Factors. Some CSF leaks occur spontaneously and the cause is unknown, while others are a result of trauma such as a head injury, brain or spinal surgery, an epidural, a lumbar puncture (spinal tap) or skull base tumor.