What’s your favourite bodily fluid?

This picture has been used for representational purpose

I have these drops of liquid trickling from my right nostril for the past week," expressed Sheila, a concerned, visibly overweight 45-year-old business executive. She leaned slightly forward and bent her head to elucidate what she was saying. Crystal clear driblets trickled down, one every few seconds, like they do from a tightly shut, but slightly leaky tap, whose washer needs to be replaced. I collected a few bubbles in a sterile glass bottle to test. "Initially, I thought that this was just a runny nose, but then, I have no other symptoms apart from a headache and this just felt odd, so here I am," she gestured with animated hands, in a way used by most people when something unexpected shows up.

"Do you feel a slight salty sensation at the back of your throat when you lie down?" I asked, to confirm my suspicion of this being no ordinary liquid, but sacrosanct cerebrospinal fluid (CSF). "Yes, yes, yes!" she interjected, relieved to know that I'd already diagnosed her problem. After a detailed assessment, I emphasised that she was lucky not to have had any fever; if the fluid got infected, it could lead to meningitis. I ordered a specialised MRI and CT scan to be able to exactly pinpoint the specific defect in the base of the skull from where the brain fluid was likely to be leaking from, and had her see me back at the earliest.

CSF is a colourless, odourless liquid that bathes the brain and spinal cord. About half a litre of this fluid is produced daily and gets recycled, nourishing the brain, and washing away all the toxins that get absorbed via a drainage system curated flawlessly by nature. A slightly higher content of sodium and chloride gives it its saliferous taste. It also protects the brain by acting like a shock absorber for the central nervous system. A tear or hole in the covering of the brain (meninges), coupled with even a tiny bony defect in the base of the skull, could cause CSF to seep out from the nose as it's all inter-connected. In health, the nose is a "stairway to heaven" as far as the journey of breath to the brain is concerned; in disease, however, when directions are swapped and there is an egress of CSF, it can potentially be a "highway to hell".

Sheila returned with her reports a few days later, and as expected, one could easily trace the exodus from a tiny defect in the base of the skull into the right nostril. "We must seal the leak before you develop an infection that could be calamitous," I forewarned. "We'll do it through the nose itself, so we don't have to open up the head."

"I'm ready when you are," she replied resolutely.

The next day, alongside my ENT colleague, we navigated into her cavernous nostrils, an endoscope in one hand, and an instrument in the other, to flatten out the nasal turbinates against the lateral wall of the nose. Navigating through the nose with an endoscope is like driving a car. I remember my days as an assistant doctor: my chief would honk, "Peep,peep!" which was an indicator for me to move the scope ahead or out of the way without bumping into any structure to avoid fogging the lens. We did a little drilling along Sheila's nose to smoothen out bumps and edges. After searching a fair bit,we could identify clear CSF weeping from a 3mm defect in the base of the skull. A little bit of redundant brain was also trying to push itself out unsuccessfully.

Every surgeon has their cardinal body liquid, which often dictates the specialty they choose. Being fascinated and mesmerised by blood is not enough; that is simply a basic denominator. For ENT surgeons, it's mucus and phlegm. The ophthalmologists are busy with tears. Dentists only have access to saliva. Hepato-biliary surgeons love bile. Cardio-thoracic surgeons enjoy the pericardial fluid that cushions the heart. General surgeons are attracted to pus. Orthopaedic surgeons make do with synovial fluid that lubricates joints. Cancer surgeons deal with lymph quite a bit. For nervous surgeons, their own sweat suffices. Gynaecologists are smitten by amniotic fluid. Urologists have urine, but they are also enamoured by prostatic fluid - the yellowish straw-coloured sticky juice that nourishes the sperm. Colorectal surgeons, unfortunately, need to be satisfied with diarrhoea. I, for one, am blessed to work with CSF.

CSF is the most angelic liquid present in the human body - spotless, sanctified, and seraphic. It is, however, both the boon and bane of neurosurgeons. When handled tenderly and released gently, it relaxes the brain, allowing for surgery to proceed virtuously. When CSF flows over the tips of tiny metallic instruments, it looks like an immaculate waterfall inside the brain, under the microscope. Rarely, when it isn't possible to create a watertight seal of the meninges, CSF seeps out from a cranial or spinal wound like a ghoulish adversary one has to fight till the very end for the patient's survival. Any infection of the CSF can turn into a lethal rampage. The sight of CSF within the brain or spinal cord is resplendent, but when you see the same fluid outside, it can be utterly demoralising. After a valiant operation, to see a postoperative wound leak CSF is disheartening. Only another neurosurgeon can fathom the joy and exultation of a CSF leak ceasing.

In Sheila's case, we delineated the defect and sealed it using some fat, glue, and a flap we had harvested from the nose itself. We injected fluorescein dye to see if there was any further leak, and inspected the entire panorama to ensure that it was dry. "The first chance is always the best chance for any surgery," I coached my assistant, "Revisions and re-dos are never pleasant." I concluded by reminiscing about two cases where I had needed to go back a second time to seal the defect. "Sir, every surgery of yours has a take-home message," my assistant added wryly, cheekily imitating what I often say after each operation. We packed the nose with nasal packs, similar to tampons, and kept them in for 48 hours. When we removed them, there was no further leakage. She walked around merrily, and was discharged a few days later.

The writer is practicing neurosurgeon at Wockhardt Hospitals and Honorary Assistant Professor of Neurosurgery at Grant Medical College and Sir JJ Group of Hospitals.