Can Scuba Diving Cause Vestibular Neuritis?

Andy Derrow’s vestibular Story

Background

I am a 59-year-old man in excellent health. I take a statin to lower my cholesterol and a low-dose ACE inhibitor to maintain ideal blood pressure. I exercise both regularly and vigorously. My most significant prior medical event was a blood clot in my calf (DVT) and multiple pulmonary emboli (PE) in both lungs during the summer of 2000 that resulted in a two-year treatment with warfarin.

From January 14-21, 2017 I was in Belize with my son on a scuba diving trip. We did 14 dives of various depths, including two dives to 130-140 feet. All dives were done in strict accordance with the most conservative dive safety protocol. My last dive ended on Friday, January 20th at 11am. I flew home on Saturday January 21st feeling great. I did a hard workout on Sunday, the 22nd and felt fantastic.

Initial Onset

I woke up on Tuesday the 24th also feeling completely healthy. As I was sitting in my kitchen at around 9:30am drinking coffee, a sense of unease and dizziness came over me. As a 59 year old, I have had a number of common medical conditions during my life. I’ve had severe headaches, earaches, illnesses involving high fevers, etc. What I experienced on the morning of the 24th was different from anything I had ever experienced before.

There was something going on in my head that just wasn’t right. Something was off, and since I couldn’t associate what was going on with anything in my past it provoked a meaningful amount of anxiety. I felt progressively worse over the next hour, and eventually needed to lie down on the couch and cover my eyes, since this position best controlled the dizziness. Again, the unknown aspect of what I was feeling was frightening. I’m the furthest thing from a hypochondriac. I approach things logically and methodically, and what I was feeling at this time made me concerned.

I had an 11am appointment with a dermatologist to have a mole shaved off my head. Her office was across the street from our local hospital, so I kept my appointment in the event I decided to seek treatment for what I was experiencing. During my dermatology visit I had a very difficult time walking and my dizziness got worse (my wife drove and assisted me throughout). This is probably the first time I described to my wife what I was visually experiencing. I told her that as I moved my head there was latency, or lag, between my head movement and my vision. It was as if my eyes were trying to catch up with my head. This defect in my visual cues caused me to become somewhat nauseated, and I was very unsteady on my feet. I decided to seek treatment after the dermatologist appointment, so my wife and I walked to the hospital’s emergency room.

Hospital Experience

During the previous two days I had started to feel a little discomfort in my right calf. This level of discomfort was so insignificant I didn’t feel the need to treat it with any common over the counter pain medication. I do have a history of DVT, so I thought it made sense to mention my calf pain when I checked in at the ER. I was brought in very quickly and met with the doctor. I told him I was extremely dizzy and was having a hard time walking. I explained the latency in my vision. He asked about my calf pain and I told him it was very minor. He ordered a CAT scan of my head and chest. Both were negative. He then ordered an ultrasound of my calf. This was positive. I had a “near fully occluded” peroneal vein in my right calf (DVT).

So, I’m extremely dizzy and nauseated and I have a blood clot in my calf. The doctor was trying to connect the two, but as I soon learned, the clot in my leg is in the venous system and a problem in my head would be arterial. The only way they could be connected is if I have a patent foramen ovale (PFO), which is a hole in my heart. I don’t have a hole in my heart. I had an echocardiogram in 2000 when I had my first DVT, and I give myself the equivalent of a stress test five days a week when I ride the spin bike in my basement.

I was given heparin as the immediate treatment for the clot and was admitted overnight. The doctor also started me on Xarelto as a long-term anticoagulant to prevent blood clots in the future. The dizziness was still horrible.

When I awoke the next morning the dizziness was gone and I was totally asymptomatic. I was walking fine and had absolutely no issues with my head. A neurologist examined me on the morning of the 25th and had me do a number of balance tests (heel-toe walking, etc.). I passed them all easily. He ordered an MRI and MRA of my head/neck to check for any possible blood vessel issues. These tests were negative, so I was discharged from the hospital.

The rest of January 25th and 26th were normal days and I felt fine throughout. I saw my primary care physician on the 26th as a follow up for my blood clot. He confirmed that since this was my second blood clot, I would likely be anti-coagulated indefinitely. He then suggested I see one of the top otorhinolaryngologists (ENT) at the University of Pennsylvania regarding my dizziness. I left a message with this specialist’s office to make an appointment and I didn’t hear back.

Second Time

I woke up on Friday, January 27th also feeling fine, but at about 9am the exact same sensation I had felt on the morning of the 24th started creeping up on me again. This time it wasn’t an unusual or foreign feeling. I knew exactly what it was since it had just happened to me three days earlier. Within two hours I was totally incapacitated from a balance and comfort standpoint. I was reclining in my chair with my head stationary, and I felt miserable. This was worse than three days earlier. The nausea worsened, I vomited twice, and had a horrible night. I woke up on Saturday, hoping that, just like my night in the hospital, everything would be back to normal. Unfortunately, my symptoms were still severe. I had a difficult time walking and I noticed that I had begun to compensate for my balance issues by shuffling my feet and widening my stance as I walked. That morning I spoke with a local doctor friend of mine, who is a head and neck surgeon and, previously unknown to me, is a friend of the ENT doc I was trying to see. Connections matter and within 20 minutes I had an appointment with this ENT at Penn for Monday morning at 9am. As it turns out, his specialty is vertigo and balance issues involving the inner ear. Things were so bad on Saturday and Sunday that I didn’t eat anything either day. When I awoke on Monday I hadn’t had anything to eat since Thursday night because of my nausea and had lost eight pounds.

When I saw the ENT doctor on Monday morning, January 30th, the first thing he said was that I needed to eat since avoiding food wasn’t a viable long-term strategy. He performed the Dix-Hallpike test to determine if I had benign paroxysmal positional vertigo (BPPV) and that was negative. He reviewed the MRA/MRI report to confirm there were no abnormalities (there were none). He also stressed that I didn’t have vertigo at all since my symptoms did not involve visual rotation (spinning). I continued to use the words lag and latency to describe what I was seeing. He ordered a “Balance Function Test” (BFT) and fortunately, the senior audiologist who was assisting him had an opening at Penn for that Thursday, February 2nd. Perhaps the most perplexing aspect of my situation was the intermittent nature of how it presented. I had severe dizziness for 24 hrs, then I was fine for two days, then the dizziness came back for good. That, he said, was very unusual.

Each morning when I awoke I expected (hoped?) that my symptoms would be gone. Instead, it was my personal “Groundhog Day” because each morning I could instantly tell that my condition was unchanged. I began to adapt to how I was feeling as I started to eat normally, and could walk a little faster, albeit with a compensating gait.

Diagnosis

The audiologist who saw me on February 2nd mentioned that most people she sees don’t get in for testing until a few weeks after the onset of symptoms due to the difficulty of making an appointment. It was unusual for someone to be tested after only one week of balance-deficit symptoms. This turned out to be a very good thing since my comprehensive exam, lasting two hours and involving a series of vision, hearing, balance, and other tests, was irrefutably conclusive: vestibular neuritis of unknown origin damaged my right vestibular system. This damage caused a pronounced deficit of my right vestibulo-ocular reflex (VOR). The specific tests confirming my VOR deficit were the caloric test involving alternating warm and cool water in my ear canals and balance testing under changing sensory input conditions. I failed five out of six balance tests and my caloric test was “textbook” for unilateral VOR deficit.

The audiologist told me that my condition warranted vestibular therapy, and that with therapy there was a very good chance I would become asymptomatic within a few months. She stressed that while my deficit was likely permanent, the rest of my balance process, including my left VOR, vision, and brain, would compensate for my right-side deficit. She was very encouraging.

Cause

My ENT strongly believes there is a direct connection between the scuba diving and the vestibular neuritis that caused my VOR deficit. He thinks it is far too much of a coincidence that this happened so soon after returning from a week of extensive diving. While he can only speculate as to how it happened, he is confident there is a link.

Before I went on my trip, my son and I took out dive insurance (DAN) to protect us in the event of a medical emergency such as treatment in a decompression chamber. As a policyholder I was able to speak with the undersea medical specialist at the insurer. When I told her that my symptoms began four days after my last dive and that I was perfectly healthy between surfacing from my last dive and 96 hours later, she doubted there was a connection between the scuba diving and my vestibular neuritis. Fortunately, the experts she consults with on difficult cases are at the University of Pennsylvania. The same medical center where I had just been diagnosed has one of the world’s leading undersea medical teams as part of their Hyperbaric Medicine Department. I called the department and reviewed my case with the attending physician. He confirmed what the insurer’s expert said. If there is a connection between scuba diving and a nerve lesion in my inner ear, or any event involving air bubbles in tiny inner ear blood vessels, such a problem would have manifested itself shortly after surfacing from my last dive. He simply couldn’t mechanically connect an onset of symptoms to my last dive 96 hours earlier. He said that isn’t how excess nitrogen in the body works. He believed the vestibular neuritis was coincidental to my scuba diving.

The ENT strongly recommended that I give up scuba diving. He said that in most cases living with just one fully functioning VOR isn’t a problem, but living without either VOR is a real challenge. Scuba diving is not a big part of my life, so despite the uncertain connection between the diving and the nerve damage, I have decided to stick to snorkeling going forward. Unfortunately, given that I’m now on an anticoagulant indefinitely because of my second blood clot, my hematologist strongly advised that I also give up snowboarding (risk of head trauma leading to brain hemorrhage). I’ll miss snowboarding more than scuba diving.

I’m fine not knowing precisely what caused the damage to my vestibular system. Neither my treatment nor my prognosis is influenced by this uncertainty. The one nagging question I have is why it showed up for 24 hours, disappeared for 48 hours, and then returned for good. That too remains a mystery.

Recovery

Between my diagnosis on February 2nd and my first vestibular therapy session on February 21st, my ability to function continued to improve. As long as my head was still I had no trouble watching TV, reading a book, or looking at a computer monitor. The visual lag with head movement was still there, but it did not present any meaningful problems for me. I started to drive again by mid-February, since the only real issue I had was at stop signs and intersections where I needed to turn my head all the way left and right. In those instances, I needed to slow down and be more deliberate. I couldn’t simply rely on instinct or 43 years of driving experience.

I enjoyed working with my vestibular therapist over the following 10 weeks. I had four sessions with her. There is no way for me to know whether or not the VOR and balance exercises I was doing during the day were helping since I have no way to determine if I would have ended up in the same place without the exercises. I did feel that I had plateaued after just a couple of weeks since I couldn’t detect any meaningful improvement in the degree of lag I continued to experience. My symptoms with head movement were considerably less severe than they were at the onset of my VOR deficit, but they were still noticeable. As an automatic reflex, the VOR is not something we are aware of in our day-to-day lives. It’s something that only becomes noticeable when it is missing or defective. It’s also a reflex that when it’s off by just a tiny degree, it is still noticeable. After a month of therapy and treatment I became a little discouraged, since I was expecting to be completely asymptomatic, but I could still tell I had a VOR issue even though it had no impact on my quality of life. After reaching out to speak with experts in the field, I realized that my expectations were too high. I learned that almost nobody regains 100% and becomes totally asymptomatic. What happens is that people with a single compromised VOR usually adapt to the condition to such an extent that any residual symptoms are so insignificant they have absolutely no effect on one’s quality of life. I had reached that state within several weeks.

It’s been five months since my diagnosis and for the most part my life is totally back to normal. I can still tell I have a VOR deficit during the day since the most frequent reminder is simple walking. I learned through my research into the VOR that as we walk our heel strikes cause our eyes to vibrate slightly in our head. The VOR stabilizes the image we see on our retinas. Without the VOR it is like seeing things through the lens of a video camera lacking adequate image stabilization. I can still sense some slight vibration in my vision as I walk. It doesn’t bother me anymore since, for example, I can easily read street signs when I drive on bumpy roads. I’m an active cyclist, riding 30 or more miles at a time, and I have no problems with any aspect of my cycling. So, I can tell I have this deficit; it just doesn’t effect how I live my life.

Perhaps the best suggestion I heard over the last several weeks was that I shouldn’t be complacent with respect to continuing to work on balance techniques. I’m just shy of 60 years old, so maintaining balance, even under less than ideal conditions, is not challenging for me now. The issue however, is since this deficit is generally permanent, how will my VOR deficit influence my balance when I’m 80 years old, when a fall will be much more serious? That is something I’ll need to keep in mind.

I accept that this is simply one man’s experience with the onset of vestibular neuritis leading to a unilateral VOR deficit. I have no idea to what extent my experience is similar to other people who have received the same diagnosis. I wrote this because when I was first diagnosed, it would have been comforting to read something like this. I would have wanted to hear from someone who experienced what I was going through and who could provide some sense of what my recovery trajectory may look like. By memorializing my experience, it is my hope that this account is helpful to other people in the future.

Acknowledgements

I gratefully thank each of the following healthcare professionals, vestibular researchers, and therapists who helped me throughout my diagnosis, treatment, and recovery. I am fortunate to have had access to these exceptional people: Joshua Baron, DO; Matthew Miller, MD; Jason Bloom, MD; Michael Ruckenstein, MD; Sherrie Davis, AuD; Helena Esmonde, DPT; Lisa Kallenbach, MD; Susan Whitney, PhD; Michael Schubert, PhD. Most importantly, I thank my family and friends for their extraordinary love and support.