Questions & Answers with Wouter Schievink, MD on spinalcsfleak.org
Early in 2014, Wouter Schievink, MD, neurosurgeon of Cedar-Sinai Medical Center in Los Angeles, California, kindly agreed to respond to questions regarding spinal CSF leaks and intracranial hypotension from members on spinalcsfleak.org. Here are those questions with his responses. We are deeply grateful to Dr. Schievink for sharing his time and expertise.
The questions and answers were grouped into sections:
General / Signs + Symptoms
Q: Do most people leak at one location or more than one location? How often do you see multiple leaks and under what circumstances does this occur?
A: Most patients with spontaneous intracranial hypotension have only a single CSF leak in the spine. Multiple leaks (at least simultaneous leaks) are quite rare, certainly less than 10% of patients. Multiple spinal CSF leaks do not occur under any specific set of circumstances and can be seen both in patients with a very obvious generalized connective tissue disorder as well as in patients who do not have any stigmata of a generalized connective tissue disorder.
Q: How often do you see both cranial and spinal leaks in the same patient?
A: I have seen only about a dozen patients who had both cranial and spinal CSF leaks, but symptoms are always due to the spinal CSF leak.
Q: What do you consider the biggest challenges or biggest problems when it comes to spinal CSF leaks?
A: There are many… we know little of the exact cause, risk factors, best treatments, outcomes, and long-term consequences of spinal CSF leaks.
Q: Is the intense feeling of downward pressure/intense pain accompanied with neurological symptoms that some leakers experience indicative of serious brain descent?
A: There is a poor correlation between severity of headache and presence or magnitude of brain decent on MRI. Some neurologic symptoms, such as hypersomnolence, dementia and cranial neuropathies are almost always associated with significant brain decent.
Q: When do our symptoms (in a known leaker) warrant a trip to the ER?
A: A trip to the ER should be considered with any sudden or significant change in headache or when new neurologic symptoms arise.
Q: Can you explain the physiology of elevated BP in patients with intracranial hypotension?
A: Usually, patients we see with intracranial hypotension have low blood pressure. I am aware that some patients with intracranial hypotension develop elevated BP but this isn’t well understood. There appears to be sympathetic activation (results in increased BP and heart rate) which may be due to pain and/or other factors.
Q: Do you have much understanding of how the body compensates physiologically after onset of a spinal CSF leak?
A: Many different reactions occur, for example to pain, but with regard to CSF physiology, we generally believe that intracranial hypotension is compensated for by an increase in CSF production, and also by venous dilatation. The venous dilatation is associated with a decrease in venous pressure, probably increasing the absorption of CSF which can create a vicious cycle.
Q: Why do some patients re-leak?
A: Usually, it is not clear why some patients develop a recurrent CSF leak, but a more or less trivial traumatic event certainly can precipitate recurrent symptoms. The development of rebound CSF hypertension also can contribute to a recurrent CSF leak.
Q: Have you ever seen a patient with a lumbar puncture leak relapse similar to how some spontaneous leakers relapse?
A: Yes, patients with an iatrogenic leak can relapse in a similar pattern as patients with a spontaneous CSF leak.
Q: In a person who has had repair of CSF leaks but imaging no longer reveals a leak, is it possible that instead of a slow CSF leak, the persistent positional headaches are triggered by dural sensitivity secondary to low CSF from months/years with CSF leaks?
A: Yes, that has been postulated but it is difficult to prove this theory.
Q: Are there many spinal leakers who DON’T have a headache?
A: The absence of a headache has been described in patients with spontaneous intracranial hypotension, rarely at the onset of symptoms, but more commonly in the chronic phase of a spinal CSF leak.
Q: Is the location of the headache/head pressure significant when differentiating between high or low pressure?
A: Many patients can differentiate a high pressure headache from a low pressure headache but not infrequently it becomes difficult to differentiate these two types of headaches.
Q: Approximately how many leakers images/records have you reviewed, over how many years?
Approximately how many leakers have you seen in your clinic, over how many years?
Approximately how many leakers have you and your team treated, over how many years?
What percent of your CSF leak patients are spontaneous leakers (versus iatrogenic or traumatic)?
A: I treated my first patient with a spontaneous spinal CSF leak in 1991 and between 1991 and 2001, I treated 22 patients.
Since 2001 I have treated 580 patients with spontaneous intracranial hypotension. These are only patients who meet strict diagnostic criteria.
I have also seen approximately 150 patients with symptoms suspicious for spontaneous intracranial hypotension (without meeting strict diagnostic criteria) during this time period as well as about 100 patients with iatrogenic spinal CSF leaks. I have seen just a few traumatic spinal CSF leaks.
These are patients I have personally seen. I have not collected data of those patients whose records and images I have reviewed but not seen myself.
Q: In patients with a known leak, is vertigo always due to the leak or can they also develop Benign Positional Vertigo?
A: Vertigo is a common symptom of a spinal CSF leak but patients with a known leak also can develop benign positional vertigo or vertigo from other causes.
Q: If the sinus has a small defect is it possible for CSF from a spinal leak to migrate there and cause positive cisternogram pledgets placed in the nose or ear?
A: No, that is not possible but false positive pledget counts can be caused by lymphatic drainage of injected radioactive tracer.
Q: Could a person be born with a CSF leak?
A: Possibly. I have reviewed scans with pediatricians where a congenital spinal CSF leak certainly appears possible, but it has never been documented.
Q: Have you heard of three generations of spinal leakers?
A: I have not encountered three generations of spinal leakers, but I do not include people with family members who have symptoms suggestive of a CSF leak but there is no documentation. Also, I do not include people with a family member who developed a CSF leak after spine surgery or a lumbar puncture.
Etiology / Associated Disorders
Q: With spontaneous or small injury leaks, how often would you estimate that EDS or other connective tissue disorder is present?
A: I estimate that slightly less than 100 percent of patients with spontaneous CSF leak have an underlying connective tissue disorder.
Q: Why does this happen to women more than men?
A: Spontaneous intracranial hypotension is definitely more common in women than it is in men, but the cause of this finding has not been established. It is likely that it involves hormonal factors.
Q: From one of your publications: “We propose that there is a clinical basis for considering spontaneous CSF leak as a clinical manifestation of heritable connective tissue disorders, and we suggest that patients with CSF leaks should be screened for connective tissue and vascular abnormalities.”
What type of screening for vascular abnormalities should be undertaken and what abnormalities should we be looking for in particular?
A: In one study, we found that about 10% of patients with spontaneous intracranial hypotension have an intracranial aneurysm. Therefore, we sometimes recommend a screening MR angiogram of the brain.
Some patients, such as those with Marfan syndrome or familial aortic aneurysms, are at risk for large arterial aneurysms and are screened with MRA of chest, abdomen and pelvis.
Q: In your experience, what percentage of leaks is caused by disc problems?
A: In patients with CSF leaks in front of the spinal cord, the level of the dural tear is usually at the level of the disc space and I commonly encounter calcified disc fragments associated with the dural tear at the time of surgery.
Q: Apart from EDS and other connective tissue disorders, are there any other common attributes in patients who come to see you with spinal leaks?
A: Patients with spontaneous intracranial hypotension often are tall and lanky, they are very healthy, and they often have low blood pressure.
Q: What other types of conditions are seen with intracranial hypotension that we should be aware of or have checked out?
A: Heritable connective tissue disorders are by far the most common conditions seen with spontaneous intracranial hypotension.
Q: What are your thoughts about a previous history of meningitis (viral, bacterial, other) in some spontaneous spinal CSF leakers? Could meningitis result in dural weakness?
A: Most forms of meningitis are actually risk factors for the development of intracranial HYPERtension, because the inflammation caused by meningitis interferes with the pathways of CSF absorption. However, it is certainly possible that some specific pathogens can cause dural weakness.
When a spinal tap shows an increase of white blood cells in the CSF which is also a common finding in CSF leak, a diagnosis of meningitis is often made erroneously in patients with spontaneous intracranial hypotension. I have seen a few patients that have a diagnosis of Lyme disease but we have not identified a relationship between Lyme disease and spontaneous CSF leaks.
Q: In your experience, are there cases where spontaneous spinal CSF leaking arises in the setting of pre-existing intracranial hypertension? (as in cranial CSF leaks) If so, is this an infrequent cause or a common cause?
A: Yes, preexisting intracranial hypertension can be related to the development of a spontaneous spinal CSF leak but this is not very common.
Q: Is there any observed relationship between spinal CSF leaks and AUTOIMMUNE connective tissue disorders?
A: This relationship is not well established but I do believe that it exists. Either it is the autoimmune disorder itself or it is related to its treatment.
Q: Can you explain what meningeal diverticula are ( i.e., are these cysts?) and what can cause them?
A: Meningeal diverticula are the same as arachnoid or dural cysts. They are congenital and are very unlikely to enlarge after adolescence.
Q: If a patient has a tethered cord, can that tether be at any area of the spine and give similar symptoms as leaks?
A: A tethered spinal cord is usually in the lumbosacral spine and indeed can cause symptoms similar to CSF leaks. It should be differentiated from spontaneous spinal cord herniation where the spinal cord is stuck to and eventually herniates through a ventral dural tear.
Diagnostics / Imaging
Q: How much weight do you place on opening pressures in diagnosis?
A: An opening pressure can be very important to confirm a diagnosis of spontaneous intracranial hypotension as it can be the only objective finding. Also, in countries where MRI is not readily available, an opening pressure can be the only diagnostic tool for cerebrospinal fluid leakage. Of course, not all patients with spontaneous intracranial hypotension have a low opening pressure.
Q: Is it possible to have a spinal leak with high pressure?
A: Yes, rarely patients with documented spinal CSF leak have a high CSF pressure.
Q: Is it possible to have high spinal pressure and low intracranial pressure? If so, how?
A: No, it is not possible to have high spinal CSF and low intracranial CSF pressures, except if there is a significant block of CSF flow at the craniospinal junction.
Q: The University of Miami is using MRI to check intracranial pressure. Do you have an opinion about the reliability of that method?
A: The University of Miami has by far the most experience with this MRI technology. It seems reliable in their hands.
Q: What should confirmed spinal CSF leakers do when they go to ER for severe headache relief and the physicians want to do a lumbar puncture? Are there other tests that can rule out meningitis?
A: It is important for patients with spinal CSF leak to educate their ER physician that these leaks are never associated with meningitis, unlike skull base (cranial) CSF leaks.
Q: When any patient needs a lumbar puncture, do you have specific recommendations on type and size of needle used to reduce risk of post-LP headache?
A: It has been well established that smaller gauge and certain types of spinal needles are less likely to cause post dural puncture headaches. One type of needle is the Gertie-Marx needle.
Q: Should patients who need a lumbar puncture be screened for inherited connective tissue disorders to reduce the risk of a long term spinal headache? If so, how?
A: A persistent post-LP headache should alert the physician to the possibility of a heritable disorder of connective tissue. While knowledge of a heritable disorder of connective tissue before an LP would be helpful in preventing this, the low prevalence in the general population may make routine screening of all patients about to have an LP impractical. The universal use of smaller gauge pencil-tip type needles is recommended since this is well-documented to reduce the risk of post-LP headaches.
Patients with a diagnosed heritable disorder of connective tissue that require an LP should inform the physician of an increased risk of persistent post-LP headache and request a smaller gauge pencil-tip needle for the procedure.
Q: Do you think that normal brain imaging in cases of spontaneous spinal leaks is more likely with increased chronicity of symptoms before imaging? If so, what do you think this might tell us about adaptive mechanisms?
A: Yes, normal brain imaging on MRI can occur at the time of the beginning of the CSF leak or more commonly it occurs over time and this may indicate that adaptive mechanisms fail these patients or that the leak is resolving.
Q: Can you speak a bit about the sensitivity of imaging modalities that you currently use and the various ways that you can increase the sensitivity of imaging?
A: MRI and MR myelography (as long as they are of outstanding quality) are almost as good in detecting the presence of CSF leak as conventional CT myelography.
Intrathecal gadolinium enhanced MRI can show a leak in about 5% of patients when these other tests are negative.
Q: What test is most reliable in finding small leaks such as those from an LP?
A: CSF leaks due to a lumbar puncture are rarely demonstrated on imaging except when is associated with a subcutaneous fluid collection.
Q: Can you tell us about the use (and results) of intrathecal saline infusion to increase sensitivity of imaging?
A: The main purpose of the intrathecal saline infusion is to see if replenishing CSF volume alleviates symptoms. The yield of finding a CSF leak after intrathecal saline infusion is similar to that of an intrathecal gadolinium enhanced MRI scan, about 5%.
Q: Do you ever recommend that patients perform a valsalva maneuver following contrast injection and before or during the CT portion of a CT myelogram to potentially increase the likelihood of finding the leak?
A: We have asked patients to perform a variety of tasks, including valsalva maneuvers prior to the CT portion of a CT myelogram but we have been disappointed with the results.
Q: Tell us more about when DSM is indicated?
A: DSM is indicated:
– for rapid leaks associated with intraspinal extradural CSF collections;
– for ventral leaks;
– to detect small CSF leaks not associated with obvious extradural CSF collections.
Q: Tell us when dynamic CTM is indicated?
A: Dynamic CT myelography is indicated for rapid CSF leaks associated with intraspinal extradural CSF collections.
Q: Any new developments or insights in imaging?
A: One recent development is that DSM may reveal a direct fistula between the intrathecal space and the epidural veins. Since the epidural space is bypassed, this would explain the failure of myelography to reveal a leak in such cases.
Q: What is the best type of MRI scanner, type of weighting etc. for detecting small spinal leaks?
A: Any 1.5 Tesla or greater MRI scan should be adequate for detecting small CSF leaks as long as there have been regular updates in hardware and software.
Q: What percentage of patients that you see with positional headache have no leaks identified on imaging? What percentage of those do you suspect CSF leaking versus not?
A: About 20% of patients with orthostatic headaches have normal or have had normal spinal imaging. In about half of those I had suspected a CSF leak.
Q: In what percentage of spontaneous spinal leakers is the leak site definitively identified?
A: A definitive leak site is identified in only a minority of patients. In a significant proportion of patients with spontaneous intracranial hypotension, resolution of symptoms occurs after one or more epidural blood patches so identification of the site of the CSF leak is not needed.
Q: What is the inter- and intra-observer variation in the interpretation of imaging for CSF leaks?
A: The inter- and intra-observer variation has not been studied very well. In our Medical Center, there is very little variation among the two neuroradiologists specializing in CSF leaks and myself. More commonly, a great deal of inter observer variation exists between different institutions. Particularly, many CT myelograms are being interpreted as showing CSF leaks while they actually demonstrate the presence of dilated nerve root sleeves.
Q: What are the most common differential diagnoses to spinal CSF leaks that you see?
A: The differential diagnosis of orthostatic headaches includes cervical spine disease (cervicogenic headache) and POTS but most commonly the cause remains unknown in those without evidence for a spinal CSF leak.
Q: What do you think about Canadian guidelines of deferring imaging until several EBPs have failed? Can this interfere with interpretation of imaging?
A: In patients who have clear evidence for spontaneous intracranial hypotension on brain imaging it is reasonable to defer spinal imaging until several blood patches have failed. This is a reasonable way to control healthcare costs. However, I am not in favor of proceeding with epidural blood patching without any brain imaging as is practiced in some other countries.
Q: Is it true that if a leak is at the very bottom of the spinal cord it is not possible to see with imaging?
A: No, that is an incorrect statement.
Q: When symptoms are known to be present / worse when upright, why are upright MRIs rarely carried out? Why would there be no reason to think that SEEPS, leaks and flow would not show more in this position?
A: Upright MRI’s have been shown not to be useful in the management of patients with spontaneous intracranial hypotension. We have studied a number of patients both in the recumbent and the upright position and have found no difference in MRI findings. It is likely that the MRI changes are related to CSF volume rather than pressure and CSF volume does not change much with a change in position.
Q: In the venous engorgement sign (cervical epidural venous dilation) of Spontaneous Intracranial Hypotension, will all of the head and neck veins eventually become involved in compensating? Are the veins actually helping to drain leaking CSF?
A: The dilated epidural veins increase absorption and drainage of CSF. Sometimes, intracranial veins are dilated but spinal epidural veins are not, or vice versa.
Q: What do we now know about the mechanisms of patches? I have heard of temporary mass effect causing an increase in pressure – how long would this be expected to last for say a 20 mL patch? Do we expect the dura to be capable of regenerating or scarring beneath a clot at the leak site or are we relying on some form of clot to remain in place to maintain the seal?
A: The immediate beneficial effect of epidural blood patching is due to replacement of the lost CSF volume with the volume of the blood that has been injected. After 2-5 days MRI scans generally do not show the presence of blood anymore in the epidural space. Patching could result in direct scab formation at the site of a dural rent, it could cause scarring in the epidural space, or it could alter the elasticity of the spinal dura. All of these mechanisms could provide symptom relief.
Q: Can you outline the protocol for high-volume epidural blood patching (for local physicians)? Has your team settled upon a standard recommended post-EBP recovery protocol involving a specific amount of time spent prone/supine in Trendelenburg position (at a specific angle, e.g., 20 degrees), then a specific amount of time spent lying flat on one’s back, etc?
A: For high volume multi level epidural blood patching, we usually place one epidural needle in the lower thoracic spine and one epidural needle in the mid lumbar spine. There is no predetermined blood volume to be injected. The volume of blood is only limited by symptoms. The post epidural recovery protocol is dependent on many factors, including site of the leak, the pressure during the injection, patient preference, etc.
Q: In cases where EBP works but relief is temporary, do you have any recommendations regarding timing of repeat EBP? (minimum wait before repeat and why) Are “high pressure rebound type symptoms” post EBP less likely or is permanent repair more likely if follow up EBP is done quickly after symptom return?
A: We usually wait 5 days between percutaneous procedures. This is based on the fact that we have not seen significant complications when this five-day period has been observed. High pressure rebound symptoms are more likely to occur when blood patching is performed at short intervals.
Q: At what point should you give up on blood patches and/or fibrin glue patches and consider surgery? Are there dangers to having too many epidural patching procedures?
A: Surgery should be considered when other treatments have failed or when a more durable result is desired.
Q: Can you “blow” a blood or fibrin glue patch?
A: Yes, it is possible to “blow” any type of CSF leak repair.
While post-patching or post-operative recommendations may vary somewhat from patient to patient, we generally suggest some physical restrictions for about 4 weeks. This includes avoiding lifting over about 10 lbs, minimizing bending, lifting and twisting, and avoiding constipation.
Q: Would you describe typical findings at surgery?
A: At the time of surgery for CSF leak repair, a variety of findings have been encountered ranging from small dural holes and tears to cysts with CSF seeping through the cyst wall or cysts pouring out large amounts of CSF. In some patients the spinal nerve roots have no dura at all.
Q: Would you describe materials in dural repair?
A: For repair of spinal CSF leaks I have used a variety of sutures, titanium aneurysm clips, the patient’s own muscle or fat, as well as artificial dura.
Q: Would you describe your surgical approach for anterior leaks?
A: For anterior leaks in the cervical spine, a standard approach with a corpectomy and discectomy is used. For anterior leaks in the thoracic spine I use a transdural and transpedicular approach. In the lumbar spine a direct approach between the nerve roots is used.
Q: Can you tell us about microscopic findings of dura?
A: Standard microscopy of the dura is usually normal but with electron microscopy markedly abnormal connective tissue structures can be observed.
Q: Can you describe your approach to patients with positional headache but negative imaging?
A: For patients with positional headaches but negative findings, we often proceed with an epidural blood patch, both for therapeutic and diagnostic purposes. Epidural blood patching can be repeated as can imaging.
Q: What treatment would you propose in a situation where imaging fails to identify the leak site and blind lumbar EBPs give full symptomatic relief but only temporarily
(1-2 months / patch)?
A: Under those circumstances consideration should be given to repeat epidural blood patching or even dural reduction surgery.
Q: When a patient cannot be permanently repaired, do you suggest any palliative treatments to help lessen the severity of the symptoms?
A: Many of these patients use caffeine liberally and even receive IV caffeine. Some find an abdominal binder helpful. Oral and IV theophylline has been tried with limited success. Supplemental Vitamin A, while not studied, can be attempted with knowledgeable medical supervision and lab monitoring. A few patients benefit from epidural saline infusion but this does carry some risk of infection.
Keep in mind that we are continually refining diagnostic and treatment approaches so patient should remain hopeful.
Q: One of the techniques you use is dural reduction surgery. When is this procedure indicated? Do you keep data on the success rate for that procedure? How would you define success?
A: Dural reduction surgery is indicated for patients with spontaneous intracranial hypotension who respond well to epidural blood patching with only transient benefit while no clear site of CSF leak can be identified. The surgery is successful in about 50-60% of patients. Success is defined as being symptom free or having minimum symptoms with no or only minimal need to alter activities of daily living.
Q: When do you choose to try epidural infusion via epidural PortaCath?
A: We consider an epidural PortaCath for patients when imaging fails to locate the suspected leak and response to EBP is temporary. They may or may not have had previous surgical repairs and/or lumbar dural plication. They must be comfortable with the requirements of meticulous sterile technique in accessing the port to minimize the risk of infection and have good local medical support.
Q: Can leaks secondary to a disc problem be treated successfully with blood patch or is surgery always required?
A: Disc related CSF leaks can be treated with blood patching but it is unlikely that these will cure the CSF leak.
Q: What physical activity would you recommend for a post-treatment spontaneous spinal CSF leaker as likely safe and what should he/she avoid?
A: Following treatment of a spinal CSF leak, walking is considered safe including going up and down stairs and walking on hard sand. I like to restrict lifting to less than 10-15 lbs and straining should also be avoided.
Q: Are you considering new approaches to epidural patching to include platelet rich plasma or MSCs (stem cells)?
A: Yes, we are in the process of evaluating those treatments but they have not started here yet.
Q: Why do we get relief by drinking coffee? What does coffee actually do? Can it potentially heal the leak?
A: The effects of coffee (caffeine) are poorly understood, but most likely it is due to caffeine causing an increase in CSF production. Caffeine withdrawal causes headache in some routine coffee-drinkers, again, not well understood. It would not be expected to heal a leak.
Q: Have you ever heard of or used infusion of adrenocorticotropic hormone (ACTH) prior to considering blood patching?
A: I would not recommend the use of ACTH prior to considering blood patching.
I am aware of other centers using ACTH to try to improve symptoms, however, I would not expect this to be curative.
Q: What can be done for intractable leakers with no known site of leak who cease responding to blood patches and who live outside of the US?
A: It is sensible to consider other causes of positional headache, such as POTS. If spinal CSF leaking is still suspected and repeat imaging is still unrevealing, then certainly patients unable to travel to see us in Los Angeles can have epidural saline infusions or lumbar dural plication done closer to home if their treating physician feels this is reasonable.
Q: Do you recommend the use of a TENS unit for neck and back pain
A: Sometimes a TENS unit can be helpful for neck and back pain.
Prognosis / Complications
Q: What is the possibility of healing this without medical intervention?
What are the key characteristics of a leak that heals without medical intervention?
A: It is impossible to answer that question with medical certainty, because there probably are many patients with spontaneous intracranial hypotension who have symptoms for only a few weeks, days, or even hours, who never seek any medical treatment.
Q: If a spontaneous leak is to heal naturally, what is the general length of time you would expect this to take?
A: I have seen spontaneous CSF leaks heal anywhere between hours to decades.
Q: Is there any correlation between the longer healing takes, the less likely full recovery may be?
A: Yes, the longer it takes for a CSF leak to heal without any medical intervention, the less likely it is that full recovery occurs.
Q: What percentage of patients with a spontaneous leak develops an additional or new leak related to the lumbar punctures for investigations or as a complication of blood patches?
A: For patients with SIH the risk of symptoms from a leak related to the lumbar puncture is very small, less than 1 or 2%, and it is even smaller as a complication of epidural blood patching.
Q: For the subgroup of spontaneous spinal leakers (with a proven diagnosis) without cysts, who have failed multiple blood patches, bed rest, caffeine etc., what is the true rate of complete recovery with surgery?
A: The success rate of surgery for patients with a cyst without a leak on spinal imaging is about 80% and for patients with a cyst associated with a CSF leak on spinal imaging it is about 90-95%.
The success rate of surgery for a ventral CSF leak is between 85-95%.
Q: In this group of patients:
What is the average number (and min-max range) of imaging procedures required to find the site of the leak?
A: The imaging for spontaneous CSF leaks continuous to evolve and some patients require only one test to find the site of the leak, while in others it is never found in spite of dozens of imaging procedures.
Q: What is the average number (and min-max range) of procedures required to seal the leak?
A: Some patients require only a single procedure to seal the leak while others have undergone dozens of procedures.
Q: Once sealed, what is the rate of recurrence?
A: Once a CSF leak is sealed, I estimate that the rate of recurrence is about 10% over 10 years.
Q: Are recurrences at the original leak site or at a different leak site?
A: Usually the leak recurrence is at a different site.
Q: While some get significant improvement, what percentage of patients in this sort of situation ever get their old normal lives back?
A: Among patients with a recurrent leak, the success of treatment appears to be the same as it is for initial leak.
Q: When dural reduction surgery is indicated, can it be performed outside of Cedars Sinai?
A: The technique of dural reduction surgery has been published in the literature and certainly can be performed outside of Cedars-Sinai.
Q: Is a leak more likely to be successfully treated in the first few weeks or months after onset, or does the passage of time have no effect on the probability of successful treatment?
A: CSF leaks that are treated early after their onset appear to have a better prognosis than those that are treated later on, but that reflects the more recalcitrant nature of chronic CSF leaks, rather than additional risk resulting from a delay in treatment.
Q: Any thoughts on why some people’s bodies try and heal themselves with this and some don’t?
A: Probably, there is a response to the dural tear in all patients with spontaneous CSF leaks, but some dural defects are larger and some patients repair mechanisms are less efficient than others.
Q: How often should a long-term leaker with residual symptoms have a follow-up MRI of the brain and/or spine? What would be the main goal of follow-up imaging?
A: Patients with chronic CSF leaks should probably consider follow up brain MRI scanning, at least for as long as abnormalities can be identified. The main goal of follow up imaging is the detection of complications of CSF leaks, such as subdural hematomas, and also the determination of a new baseline MRI study that can be compared to an MRI study performed when new symptoms develop.
Q: How common is rebound intracranial hypertension following patching or repairs?
A: Rebound intracranial hypertension occurs in 10-30% of patients depending on size and duration of the leak and also on the number and type of treatment.
Q: What is a typical clinical course of rebound intracranial hypertension?
A: The patient typically notices a reversal of the headache pattern, typically waking from sleep with the headache and improved with upright positioning. Most cases resolve uneventfully. Milder cases may not require treatment. If severe and left untreated, visual loss may occur but this is uncommon.
Q: How long can rebound intracranial hypertension persist?
A: Rebound intracranial hypertension usually only lasts for weeks or months but it can rarely persist for years.
Q: Does this increase the risk of new leaks where dura is attenuated elsewhere?
A: Rebound intracranial hypertension probably increases the risk of a new CSF leak but this has not been well-quantified.
Q: Is it more important to treat rebound intracranial hypertension (with Diamox) in some patients as compared with others?
A: When rebound intracranial hypertension is severe and causes some loss of vision, treatment is essential to reduce the risk of permanent loss of vision. Outside of that, we do not have research regarding outcomes of treating versus not treating with Diamox. For now, we individualize care.
Q: What treatment options do you use other than Diamox?
A: In addition to Diamox, intracranial hypertension can also be treated with diuretics, such as furosemide or hydrochlorothiazide, or by performing one or more lumbar punctures.
Q: Do you ever recommend VP or LP shunts for rebound intracranial hypertension?
A: I rarely recommend the placement of a shunt.
Q: Some suspected spinal CSF leakers have a hard time convincing their treating physician that rebound high pressure can occur after epidural patching and therefore are not offered Diamox. Are there published papers that might convince these doctors? Could this be improved, at least in the US, by writing guidelines that include Diamox after a blood patch?
A: There are a few papers published on the occurrence of rebound intracranial hypertension. Guidelines that include discussion of rebound intracranial hypertension would be helpful in this regard.
Q: Is it possible to fluctuate between high and low pressure on a daily basis? (i.e., low when standing/high when lying down)
A: Yes, it is possible to cycle between high and low pressure on a daily basis.
Q: You have published that a percentage of leakers have normal cranial MRIs and that this population tends to have poorer outcomes. Do you have any insights as to why this might be the case?
A: This really is not well understood at this point. Patients with the diagnosis of spontaneous intracranial hypotension and a normal cranial MRI may have different mechanisms to compensate than those with typical imaging findings. Some of these patients might not even have had a CSF leak.
In some patients with a longer history of leaking, often due to delay in diagnosis, those that are on opiate pain medications chronically also seem to have a poor prognosis.
Q: Are there leakers who can never be fixed permanently, and if so, why? (They have successful surgical interventions but the repairs are short-lived.)
A: Yes, some patients with spinal CSF leaks have persistent symptoms even though spinal imaging lumbar punctures and brain imaging are all normal. It is certainly possible that small CSF leaks remain under the level of detection of currently used imaging.
Q: What course would you follow after open surgery to find if in fact a patient re-leaked and in what sort of time-frame post-op would you say it was possible to determine a patient was still leaking?
A: Many factors play a role in determining the course of action after failed treatment for a CSF leak, including the findings on imaging, the type of procedure, the findings at the time of procedure, and patient’s expectations.
Q: When intracranial hypotension has been present for a long while, is a full recovery “back to normal” possible? probable?
A: Yes, even in patients who have had SIH for decades, a full recovery is certainly possible.
Q: What cognitive and/or neurological effects have been observed in sufferers of intracranial hypotension or hypertension?
A: Patients with SIH can have a myriad of neurological pathology.
Cognitive changes are commonly seen. Cognitive changes also can be a feature of intracranial HYPERtension.
Other common neurological effects include symptoms related to the various cranial nerves, change in balance, pain or tingling in upper limbs.
Less common neurological complications are mentioned in another question.
Q: How might low CSF affect the optic nerve, i.e. pulsing in eye, loss of vision?
A: Blurred vision is commonly seen in SIH while loss of vision or a visual field defect is quite rare. Probably, stretching of the optic nerve is the cause of these visual changes.
Q: Are you seeing many patients with neuroendocrine dysfunction from intracranial hypotension? If so, what are you seeing? Are you seeing a pattern of when this is more or less likely?
A: We intend to look at this more in the future. The most common neuroendocrine abnormality we have encountered in patients with spontaneous intracranial hypotension is hyperprolactinemia which is more common in patients with obvious brain sagging on MRI. Diabetes insipidus has been reported infrequently and treatment with DDAVP helps to prevent the associated dehydration which can exacerbate symptoms. Other neuroendocrine abnormalities can be more challenging to relate definitively to intracranial hypotension. For example, central hypocortisolism and central hypothyroidism may be the result of chronic use of opiates or other factors.
Q: How often do you see autonomic dysfunction, including, but not limited to, POTS?
A: Some patients with orthostatic symptoms have spontaneous intracranial hypotension, some have POTS (postural tachycardia syndrome), and a few have both. Other types of autonomic dysfunction, such as orthostatic intolerance without tachycardia and neurally mediated syncope are rare.
Q: Can you speak to the long term neurological effects on brain or spinal cord that may result (in cases where leaking persists)?
Is there any evidence of increased risk of diseases such as dementia, Parkinson’s disease or multiple sclerosis?
A: Long term neurologic effects of SIH include, but are not limited to, symptoms that mimic dementia, Parkinsonism, Meniere’s, superficial siderosis, and ALS (amyotrophic lateral sclerosis). We have discussed other neurologic signs and symptoms such as various cranial nerve palsies and imbalance, which usually resolve with treatment. We have not seen a relationship between CSF leaks and the development of multiple sclerosis.
Q: In someone who cannot be permanently repaired, is there anything that can help reduce the risk of long-term complications?
A: These long-term complications can really only be avoided by repair of the underlying CSF leak.
Q: The “brain sagging” that many CSF leakers experience has been reported to resolve in some cases once the CSF leak is fixed.
Can the herniation be too great for the brain to return to normal position?
A: The herniation associated with brain sagging in spontaneous intracranial hypotension indeed can be too extensive for the brain to completely return to a normal position but this is very rare.
Q: How long would you wait before doing follow up brain MRIs to see if the brain is going to move back up?
A: In patients who have recently had surgical repair of a leak, an MRI might be done soon after surgery.
For patients who are not undergoing active treatment for their CSF leak, I usually recommend yearly brain MRI’s to see if brain sagging gets better or worse. Of course if new symptoms develop then the brain MRI should be performed earlier.
Q: If the brain sag does not resolve, is it safe to repeat a CT myelogram?
A: It is safe to repeat the myelogram even if brain sagging persists.
Q: Is there often a need to proceed with Chiari decompression?
A: Performing a Chiari decompression in patients with brain sagging from spontaneous intracranial hypotension is rarely needed and actually can make symptoms worse.
Q: If patients push through the ‘minor’ symptoms (headache, nausea, neck stiffness, tinnitus, muffled hearing etc), they often develop significant neurological symptoms and signs (eg cranial nerve palsies, severe vertigo/balance problems, clouded and confused thinking, severe vomiting). Should patients limit their ‘up time’/activities so that they avoid this latter group of symptoms?
A: Patients with SIH should limit their activities if the activity seems to worsen symptoms or precipitate new symptoms.
Q: If they do persevere through these latter symptoms, what is the risk of major long term damage? What are they specifically at risk of (stroke, etc)?
A: The risk of major long-term damage, as discussed previously, is unknown. Patients should be educated about the early manifestations so that specific treatment of the underlying CSF leak can be undertaken when symptoms are still relatively mild.
Q: Do you have any specific recommendations for patients with recurrent spinal leaks before, during and after pregnancy? Do you necessarily recommend C-section delivery if there is no other indication for it?
A: Some patients feel better and others feel worse during pregnancy, but the risk of developing a CSF leak during or right after pregnancy is probably not very high. I recommend vaginal delivery for most women. If a C-section is done then I recommend spinal anesthesia over epidural or general anesthesia. When a leak occurs following spinal anaesthesia, the location of the leak is known and it is usually a simple puncture, more readily addressed with an EBP. When a leak occurs after an epidural catheter placement, the leak location may be less apparent and the leak may be a tear rather than a puncture.
Q: What is the incidence of myelopathy with SIH?
A: Myelopathy is seen in less than a few percent of patients with SIH.
Q: Will a leak-associated myelopathy ever improve if the leak site cannot be found or fixed?
A: It is unlikely for such a myelopathy to improve if the leak cannot be fixed.
Q: Is arachnoiditis a likely complication of blood patches?
A: Arachnoiditis is very rare after epidural blood patching because it implies that blood was injected through the dura into the arachnoid space.
Q: Is it possible to have chronic back pain 6 months after spinal surgery which includes laminectomy and eventually heal and not have pain?
A: Yes, it is certainly possible to have pain after spinal surgery or epidural blood patching for many months and then eventually become completely pain free.
Q: When a lumbar drain is used for intrathecal saline infusion, have you seen any long-term leak problems as a result?
A: Yes, I have seen quite a few patients with long-term CSF leaks following placement of a lumbar catheter, mainly when it is used during brain surgery but also when it is used for intrathecal saline infusion.
Training / Research / Future
Q: Are you currently training other neurosurgeons who are interested in doing more clinical work in spinal CSF leaking?
A: Yes, I am teaching neurosurgeons-in-training about evaluating and treating patients with spinal CSF leaks.
Q: We are aware of your clinical work with spinal CSF leaks. Are you engaged in any animal-model based research?
A: Currently, I am not involved in any basic science research, such as an animal model, with regards to CSF leaks.
Q: What is the most important progress that has happened during the last few years in the field of spinal CSF leaks?
A: The most important progress in the field of spinal CSF leaks revolves around different and more advanced imaging techniques.
Q: What do you think will be the biggest progress in the years to come?
A: Similarly, imaging will become more refined. Treatment techniques will be less invasive and more durable.
Q: What is highest on your wish list when it comes to spinal CSF leaks in the future (more money for research, new diagnostics, etc)?
A: My wish list really involves the entire spectrum of research, imaging and treatment for CSF leaks. Research should involve the causation, prevention, diagnostic imaging, best treatments and long term follow up of CSF leaks.
Q: Would you be willing to come to the UK or other countries without expertise to teach and share your diagnostic and treatment methods?
A: I have traveled to other countries to lecture on CSF leaks, but not to the UK.
Q: Is financial assistance (eg philanthropic) available to help people to be treated at Cedars Sinai?
A: Cedars Sinai Medical Center does provide charity care, but this is intended for individuals living in the community immediately surrounding the Medical Center.
Q: Would it be possible to establish a central facility available for patients worldwide where imaging could be sent for definitive expert interpretation?
A: We are always willing to review imaging for people with, or suspected of, spinal CSF leaks.
Q: Could you please publish a paper outlining all specific details of various imaging protocols for each type of imaging you use in diagnostics for spinal CSF leaks so that doctors in another country have a good chance of finding a leak site?
A: This is an excellent proposal, either as a paper or a web page.
Q: You have published papers about the increased prevalence of heritable disorders of connective tissue in patients with spontaneous spinal CSF leaks. Has a study been considered to perform whole genome sequencing on the population of spontaneous spinal leakers?
A: Yes, we are about to start a study involving whole genome sequencing in patients with spontaneous CSF leaks.