Q&A with Dr Ian Carroll - Anaesthetist

There is no one best way, however an MRI of the brain and spine can show signs of fluid outside the dura. Abnormalities can often be seen in the area around a leak rather than the leak itself. We are not sure what percentage of people with leaks show nothing on an MRI scan, and a clear MRI doesn't rule out a leak - although it can confirm a leak. Enough research hasn't been carried out on this.

CT Myelogram

Can be used to measure CSF pressure but higher readings do not rule out leak. Fluid is tested and protein is often found to be elevated. The patient will be tilted head down for 30-60mins to spread the contrast. Images are much better/ clearer on myelogram than MRI. Better for seeing bone spurs that might cause leak.

Radionuclide Cisternogram

Some places favour this method of imaging. It can be used to detect skull based leaks - more on this below.

If brain sagging is small then a LP may be carried out. But if the Chiari is severe a myelogram may not be carried out because of the risk of the LP and the neurosurgeon's advice sought. If they are concerned they sometimes go ahead but will patch hole from LP that day to make sure no extra leak/ brain sag.

Spinal fluid can leak from spine OR skull base. But what's less clear is if a skull based leak whether the patient will suffer with symptoms of intracranial hypotension. It does not seem to - spinal leaks are orthostatic in nature because of the position of the leak. If a leak is from the skull, pressure is not affected as greatly.

Even when someone seems to have a skull based leak they may well have a spinal leak too. The orthostatic symptoms will be from the spinal leak.

Dr Carroll patches many people who have fluid coming out of nose and ears and when successfully patched in spine the fluid also stops. So the spinal leak seems to aggravate sinuses or something similar.

There are 3 tests for skull based leaks:

• CT myelogram up to skull base
• Collect spinal fluid from nose/ ear and test
• Radionuclide Cisternogram - inject radioactive contrast into spinal fluid and scan and do pledget study too up the nose.

When someone has been leaking for a long time some develop RHP (Rebound Hypertension) when patched. Not sure if this is because they are overproducing spinal fluid or other reasons.

Papers written suggest this is a benign or temporary problem over days to months.

Fibrin glue is better at sealing leaks permanently but much more RHP is seen with glue patching.

Some have RHP for months and months without going away or easing. It's less of a problem with blood than glue. But with blood they often have to keep patching and patching and patching. But on other hand glue means more RHP.

They use Diamox to treat RHP. Extended release is better. Start 500mg then up to 1000mg twice a day if needed. Lasix is better to add to Diamox but if with Diamox then loose too much potassium . So then need diuretic that doesn't loose potassium to add to Diamox.

Fibrin Glue: concentrated blood clotting. So body should clean up like a clot. Not sure if lasts from 2 weeks to 2 months.

They will often see very small areas of clot on images after 1 month whether with blood or glue.

Glue is better and more permanent. But more RHP. And glue clots quickly but doesn't spread well so only really use for small targeted patches. 2-3ccs but with blood x8-10 that.

Always try blood first. If not last try glue.

Often if imaging is ambiguous the hospital are happier with the use of blood.

So for those cases they decided try 3 patches then stop if imaging ambiguous - if no progress from patches then stop. So start with blood. Maybe second blood or glue. Then finally try glue. To give patients the best chance with 3 patches. (3 patches might include multiple (up to 3 suspicious sites) patches in different spots at a time.)

He has not seen deafness resulting from a leak, but has seen hearing affected. Often a reduction in hearing in one or both ears.

Some people are wrongly diagnosed with Menieres & chronic dizziness.

If dementia with a story that is suggestive of a leak / could be in line with leak/ connective tissue disorder / Chiari/ POTS then worth looking into. Even with negative MRI.

Very little written about it.

Dr Carroll has discussed with wife - Obs Dr.

He had a patient who had leak and got much better but not fully. They then got pregnant and leak got much worse.

There may well be a much higher risk in pregnancy of leaking if have weakness/ chronic leak already - patient will need to think carefully about conceiving.

If do get pregnant/ decide want a family and some leak issues in past or current you will need better support and pushing to deliver would probably be a problem so might need assisted or C-section.

If pregnant somewhat limited in scans and fluoroscopy patches etc. But things can be done.

Pregnant lady needs to talk to OBS Dr and ask them to read up on it.

His opinion on this may well differ from other Drs.

EDS is connected to POTS and leaks.

POTS often connected to connective tissue disorders as well as leaks.

Leaks often cause tachycardia.

When they found patients with POTS diagnosis. And patched them their dizziness and tachycardia improved or fully went away too.

Is POTS caused by leaks sometimes or do they have both? etc they have not done enough research but a leak should be considered.

More than one location may be patched if anything looks suspicious. Willing to try 3 areas per patch.

No more than 45cc total volume split between areas.

For blind patching the volume may start with 30cc but will increase if patient can tolerate up to 45cc. But no more.

Some people can pass out if pressure in head gets too high. Not if pressure felt in spine or leg but in head it can be a problem.

If people have big leaks and very depleted CSF Dr Schievink has been known to try up to 100cc in special cases.

Stanford never went over or had case they felt needed more than 45cc.

If patients travel for treatment, it is advisable to wait for 5-6 days post patch before flying. If they're local this is ideal. After being patched they should stay flat at home or in local accommodation for 3 days/ However there is no data on this, but we suggest 3 days to give the patch the best chance of working - procedures take time and energy and carry a risk so we tend to err on the side of caution.

For the first six weeks we recommend no stretching, lifting, no gym etc - just normal light activities, but without staying flat for too long because of the risk of DVT.