THE WEATHER AND MY IIH/ICPDD:
WHAT I KNOW…
The latest installment in my ongoing narrative of the effects that barometric pressure has on my condition, and presumably, others as well. The reason I have time to do this today is, of course, a rapidly dropping barometer accompanying a strong weather front. December 23, 2017.
I was recently surprised during a visit with a new neurosurgeon to discover that he was not aware that changes in barometric pressure, or even weather, were issues for his ICPDD patients. He seemed as knowledgeable as a physician could be about this new class of disorders, and he eagerly and actively accepted patients into his care. Thus, when I brought up the issue of barometric pressure and its effects on my personal disorder, it surprised me when he related that changes in barometric pressure were not a problem for the patients he saw.
Thinking about it afterwards, I can see how that impression could be an honest error, although having conducted polls of members of various support groups I belong to, it seems that almost everyone knows there is something about weather that affects their ICPDD symptoms for better or worse. Most seem to relate impending stormy weather with a change in their symptoms, usually for the worse*. Based on the information that most ICPDD patient are given to work with, I’m sure some know that some days they are better or worse than others. Another group may associate impending weather with a change, usually worsening in their symptoms. Some have discussed changes in altitude, which translates into changes in barometric pressure, as affecting their symptoms. Perhaps patients aren’t questioned about they notice any factors that trigger their symptoms.
Then there’s me, who is so tuned in to my disorder that the neurosurgeon asked the fair question “Do you think your attention and management to your symptoms is making them worse?”
Really, a very fair question, and I was impressed with this doc’s diagnostic thought processes. My answer is “No; I only started managing my own symptoms to the degree I’m able after months of study of my own disorder. Since starting to manage those symptoms based on my study, I have more “good” days, fewer days when I can’t get out of bed, and have been able to formulate theories about ICPDDs when unfortunately, consensus amongst medical professionals is rare (note that I said “consensus”, or “agreement”; the docs I see are desperately trying to get a handle on ICPDDs. The problem is that none of them suffer from one. That’s where I’ trying to help.).
Is my attention to and management of my ICPDD symptoms making my condition worse? Only if swimming to the surface and taking a breath when you realize you’re drowning makes your “drowning disorder” worse.
Disclaimer: I don’t know that my ICPDD is the same as somebody elses. Even if the cause is the same (I believe mine is Venous Outflow Insufficiency), it’s not likely that each patient shares exactly the same physiology. BUT: there are immutable laws of physiology that apply to everyone, and as such, probably bear consideration. I don’t know if I’m 100% right, but I’m definitely onto something; I’m not trying to get credit for anything except maybe to get people talking instead of just telling us how much medicine doesn’t know about ICPDDs. Remember this as you read the following:
BAROMETRIC PRESSURE/WEATHER: For the purposes of this segment, we’ll consider them one and the same, as I know that barometric pressure changes accompanying changes in weather and changes in altitude definitely affect my symptoms in a predictable manner. Short version: increases in barometric pressure cause and increase in symptoms that I associate with increased ICPs. Before I was treated with a VP shunt, high pressure systems made my head feel like it was going to explode. Extremely low barometric pressures as seen in hurricanes and severe storm fronts very simply put me in bed, barely able to function. My best days were overcast, but not rainy days. After I was shunted, barometric pressure still affects me in the same manner, but my symptoms are different because of the shunt. That last part took me three months to figure out, but it is fact. A couple of stories:
The first one I love to tell. I hate that my surgeon had stopped ICP monitoring during shunt placement, because I (and a lot of others) would love to have know what that monitoring might have told them. The day I had my diagnostic Lumbar Puncture (LP), my opening pressure (OP) was only 17mm H2O; it took nearly an hour to drain 30 cc of CSF, whereupon my closing pressure (CP) was 16. Most would look at the OP/LP values and say “That’s too low for a diagnosis of “IIH”.” However, the truth is that the numbers currently used to designate “high” and “low” ICPs have not basis in science.** I had great relief from my symptoms of pain, cognitive difficulties, etc. Based on the positive response, my surgeon recommended that I might benefit from a shunt; on the day of that consultation, I was feeling very uncomfortable with increased symptoms I associated with increased ICPs.
Fast forward five weeks to March 23rd: I was counting the days till the shunt; it seemed that the onset of unstable spring weather was making my ICPDD symptoms swing wildly, and I felt I was deteriorating exponentially. On the morning of the shunt surgery, I was particularly uncomfortable, my head feeling as if it was going to explode. “If this doesn’t work,” I told my neurosurgeon, “we’re going to have to scramble to find another solution.” When I woke up in postop, I was groggy, but the sensation that my head was going to explode had seeming disappeared. My surgeon came by to check on me and related that “I appeared to have had some pretty high pressures, because when (he) opened my dura for the proximal catheter of the shunt, my CSF literally shot across the room.”. Contrast that to the day of my LP, when I was actually pretty comfortable, despite feeling lousy after my angiogram. Could what I emailed to my surgeon as “Post-Angiogram Blues” been a result of the procedure, or the fact that the day between the angiogram and the LP was a near record low pressure for the area, and the lowest in the months of February and March 2017? Maybe a little of both?
Look for yourselves. These are screenshots of barometric pressure for Charlottesville, Virginia, with dates of procedures shown:
BAROMETRIC PRESSURE GRAPH 2/1/2017 – 3/31/2017, COURTESY WWW.WUNDERGROUND.COM
BAROMETRIC PRESSURE GRAPH 2/16/2017, DAY OF DIAGNOSTIC LP – OPENING PRESSURE 17mm H2O, CLOSING PRESSURE 16mm
BAROMETRIC PRESSURE GRAPH 3/23/2017, DAY OF VP SHUNT PLACEMENT – “YOUR CSF SHOT ACROSS THE ROOM.”
What these graphs show is that on the days of my Angiogram and LP, the area was experiencing a near record low barometric pressure. I always associated an extremely low barometer with feelings of “weakness”, leaving me bedridden. I’d further postulate that the this also explains the fact that it took nearly an hour to drain 30 cc of CSF, and that there was no significant difference in the Opening/Closing Pressures because…wait for it…
…ICPs are proportionally affected by barometric pressure. This theory is given further merit by the fact that on the day of the shunt, I was experiencing possibly the worst high pressure symptoms I’d had to that point, and the fact that I hosed the OR with my CSF, under increased pressure due to increased barometric pressure.
Why? It turns out that barometric pressure units are very significant compared to the units used to measure ICP. One millibar, or hectopascal, is the equivalent of almost 10mm H2O. Thus, the difference in barometric pressure of 28-30 mb between the days of my LP and Shunt translate into 280-300mm H2O. Normally not a problem unless you suffer from and ICPDD; now, it seems to be a big problem.
I believe this is one of those physiologic commonalities we all share. Interestingly, after I received my shunt, my symptoms changed. Now, instead of the severe pressure, I had a feeling of “lightheadedness” that I now, thru bitter experience, associate with “overdrainage”, or excessive loss of CSF. The problem now was that I felt that way 95% of the time. When the barometer was low, I still felt drained, but when the barometer rose sharply to high levels, I had a paradoxical “sensation” of pressure in my head and at the base of my skull, but still had the overdrainage symptoms. As it turns out, the barometer is still affecting me in the same manner, but because I have a shunt (“an extra hole for CSF to drain through”), my symptoms are different, but no less debilitating.
My shunt has been like trying to balance a marble on top the end of a sewing needle with the other end on a granite slab. The tendency has been to require ever-increasing pressure settings on my shunt to achieve ever shorter periods of “stability”, until in early July, the whole business went sideways and the shunt could not be turned up further. I’ve been managing my symptoms by managing my cerebral perfusion and Mean Arterial Pressures in response primarily to symptoms, and the nature of those symptoms always follow certain stimuli such as barometric pressure. Now, I believe my shunt is causing CSF Hypo-tension in the following manner:
When blood flow to my brain (cerebral perfusion) is at the low end of the scale I use to measure it, I feel very lightheaded, sleepy, weak. I know it’s due to lack of CSF because these are the same symptoms for which I was hospitalized in mid-June due to lowered a “neurologic wane/depressed state of consciousness”, symptoms that resolved with in 8 hours of turning the shunt up to its max setting. Remember, CSF is made from blood, and the amount of CSF produced and absorbed depends on the amount of blood flowing into and out of the brain. In my case, at low perfusion, I don’t make enough CSF to make up for both the normal losses of my venous outflow AND the seepage/leakage through my shunt.*** During these periods, the flexible components of my shunt are soft and shrunken as if there is not a lot of pressure in them. I believe a more appropriate term for this condition is Shunt-Dependent Underperfusion as opposed to Overdrainage.
I have a right jugular vein that has been described as between 60 and 80% stenosed at the level of C2. Venous drainage from the brain favors one side, usually the right, for reasons I don’t know. At any rate, one of the main veins that drain my brain is badly narrowed. I’ve discovered that if my cerebral perfusion exceeds a certain limit, I start todevelop sensations of pressure at the base of my skull and inside the right side of my head. My right ear turns red and swells noticeably compared to the right side (see pic). Most significantly, my shunt swells up; the catheters and antechamber become tight and enlarged, and at times the skin over the shunt is painful to touch. Why?
Simple. The pinched/narrowed jugular. At a certain point, more blood can flow into my brain than can flow out. I’ve discussed this as the “Cerebrovascular Theory of ICPDD”; blood backs up in the blood vessel of the brain, the vessels swell, displacing brain tissue and causing the brain itself to swell. The only place the brain can swell towards is where there is CSF: the ventricles inside the brain and the subarachnoid space surrounding it. Because the area inside the skull is fixed, CSF is now pressurized, blood is now more pressurized, brain tissue swells and….
…in my current condition, CSF is forced out of my shunt under high pressures, accounting for the swelling of its components. CSF is only made at ~.35cc/minute; my shunt drains at .5 cc/minute under “normal” ICP. Now, however, I have higher ICP, greater flow out of the shunt in addition to CSF absorption by normal venous pathways, and I still have a CSF deficit. This explains the feeling of pressure (due to cerebrovascular edema) as well as the “overdrained” feeling due to excessive CSF loss. This is also referred to as secondary intracranial hypotension, or iatrogenic hypotension.
This all leads me to believe that my shunt is only treating a symptom of my disorder – CSF pressurized as a result of restricted blood flow out of my brain. Maybe this is why my particular condition is so unstable. I believe the cause is the narrowed jugular, and treatment of that narrowing with a stent, then assessing its impact on my stability with the possible need to intervene by adjustment, removal, or replacment of my shunt is the next course of action. All I want for Christmas….
My first neurosurgeon told me he was confused by my symptoms. The low LP values. The apparently odd instability of my shunt treatment. I’ve actually been told (paraphrasing) that I am the “unicorn” of ICPDD cases. Here’s the thing: when I was in practice, I learned the most from the cases that fell outside of the normal curve. Cases that didn’t turn out as anticipated despite following all the accepted procedures. Those cases got under my skin, and I took it as a personal challenge to figure out what happened so I might be able to avoid putting a patient into the same situation in the future. I always became a better doctor/dentist/surgeon for the effort. That’s all I’m doing here. It’s a peculiar blessing to have a particularly challenging form of a disorder shared by others AND have the modicum of knowledge necessary to at least draw basic conclusions from observing my own condition in as scientific a fashion as possible. At first it was solely to tell the story of my treatment so that others might not be as…”surprised”…if they experienced the challenging outcomes I’ve had. Then, when my wife Trina was diagnosed (hello…rare condition…a married couple both have it…what are the odds, and more importantly, what is the reason? I believe I know….), I changed mission to find out how to alleviate her suffering and hopefully prevent her from going through what I did, possibly prevent her from getting a shunt. Tragically, help did not come fast enough. Now, having lost my career and my wife/best friend, soul mate to this…disorder…my teeth are sunk in and I will not let go until somebody somewhere listens and for the sake of everyone suffering and ICPDD and being told “medicine doesn’t know why….”. I’m grateful for everything that has been done for me up to this point, but as it turns out, it seems that the a combination of the misfortune of having a New and Exciting Medical Disorder along with the fortune of having a neurosurgeon in the right place at the right time who was at least willing to try this shunt (which I admit likely saved my life despite its unstable nature) has left me with a polar opposite bag of blessings, losses and opportunities. I miss my Leloo; Christmas will never be the same again; but as long as I have a story to tell, I’ll continue to Whisper in the hopes that the right person/people listen….
The Shunt Whisperer
December 23, 2017
ASTERISKY THINGS (Trina’s Humor):
*It is my belief based on observation and recordkeeping of my own ICPDD that ICP increases with increasing barometric pressure and vice versa. For lack of any other explanation, I believe that increasing barometric pressure compresses skin against unyielding objects such as bone and cartilage, compressing blood vessels. This blood is forced into the only structures where the atmospheric pressure changes do not affect their inner pressures. Hard structures with hollow inner cavities filled with blood vessels. The are the long bones, the teeth, and the skull. Interestingly enough, the next time somebody complains about a joint hurting when weather is changing, you can impress them with this knowledge.
**The values currently used to decide if ICPs are “high” or “low” are arbitrary numbers plucked from 30 year old research papers. There is no scientific evidence to support them; further, to say that a value of “24” is “normal” but “25” is “high” makes no sense in this system. ICPs vary widely due to a number of factors, often with a few hours. A patient’s symptoms are a far more important indicator of a disease process; ICP values are merely a snapshot of pressure for that patient, under the conditions observed, at that moment.
***The current generation of shunts are exquisitely manufactured examples of inefficient, analog devices that were originally intended for the treatment of true hydrocephalus in children. They have no active control of valve mechanisms beyond simple springs or weights, and the ball valve design lends itself to “seepage” of fluid below specified “opening” values due to accumulations of proteins or brain cells that prevent the valve from closing fully. When they do actually “open” at designated pressure setting, the valves don’t pop open, but rather creep open to “allow” CSF to flow based on the difference in pressure on either side of the valve – ranging from a slight seep to a full-on gush, again depending on pressure. This process continues until pressure differentials are within specified limits again. Further, at this time, there is no method of non-invasively measuring Intracranial Pressures, and thus determine if a shunt is functioning or not beyond patient symptoms. While inclusion of electronics to monitor intracranial pressures is definitely possible, the challenge of using them in devices that must be subjected to MRI examination has yet to be overcome. They are the best option available if regulation of CSF pressure is necessary.