November 4, 2009
October 29, 2009
A few days after my 3rd son Brennan was born, I suffered from classic benign positional vertigo. Looking back on the course of events, I had a eureka moment last night that literally kept me up in bed.
Benign Positional Vertigo (or BPV) is a well-described inner ear condition that otolaryngologists like myself treat all the time. The classic description is when you feel dizzy, like the room is spinning, just after a sudden head movement, either up or down, or side to side. The spinning will usually last a few seconds, and you may have residual nausea and imbalance for hours to days. It’s typically preceded by an infection, head trauma, stress, or in many cases, no significant events at all (50%).
The Dix-Hallpike maneuver is performed to make the diagnosis and the Modified Epley is then continued on to cure the problem if the Dix-Hallpike is positive. In my experience, the Epley maneuver works about 80-90% of the time to cure the problem instantly if the Dix-Hallpike is strongly positive. It’s one of the more gratifying maneuvers/procedures that I perform.
When I developed BPV, I didn’t have an infection, or had any kind of head trauma. The only thing I can remember is that I was severely sleep-deprived the prior few days with all the excitement surrounding Brennan’s birth. I had the classic symptoms: spinning lasting a few seconds aggravated by sudden head turns, particularly every time I lay down in bed or rolled over to the left. After performing the Dix-Hallpike and Epley maneuver on myself, the condition got better.
The explanation for BPV is as follows: Your inner ear has three semicircular canals in three different planes, each filled with fluid and a sensor that sways back and forth, depending on which direction you turn your head. Essentially, these three paired semicircular canals tell your brain your head position. At the ends of each of these canals, there’s a sensor that sways back and forth, depending on which direction your head moves. Small calcium carbonate stones are stuck to the top of these sensors, making them sway easier.
The theory is that if one of these stones falls off, and as you move your head into a certain position, the stone moves to the top of the semicircle. Then the stone takes a few seconds to slowly move down the canal, until it reaches the bottom-most/gravity dependent position in the semi-circle. During movement of the stone, fluid waves are transmitted to the sensor which sends a one-sided signal to the brain, which thinks you’re moving your head.
Various models and even surgical findings (of otoliths, or ear stones) confirm this theory. But here’s a more plausible explanation, based on my own experience. Stones are constantly regenerated and some fall off the sensor occasionally. However, if you suffer head trauma, more stones may become dislodged and produce the symptoms. But why would a viral infection cause a stone to become dislodged? In most cases, there’s no history of infection or head trauma at all.
Any infection, whether a common cold or sinusitis, causes swelling in the nose and throat which narrows the upper airway, which narrows the throat even further, leading to more obstructions, causing more reflux, leading to more throat inflammation and narrowing. (I discuss my sleep-breathing paradigm in much more detail in my book, Sleep, interrupted.)
What’s probably happening is that sleep deprivation of any kind, including that period after a new baby is born, sleep apnea, upper airway resistance syndrome, or insomnia, can all heighten your nervous system, leading to hypersensitive sensors. It’s like when you get a migraine and certain noises or bright lights can make you cringe. In the same way, a hypersensitive inner ear sensor can over-react to any extra form of stimulation, including otoliths.
If you take this concept even further, if the other parts of the inner ear are also extra sensitive, then you can have anything from hyperacusis (sensitivities to certain sounds or voices) to ringing. This could apply to Meniere’s as well.
So ultimately, it may not be the free-floating stone, per se, that causes your symptoms, but that if your nervous system is extra sensitive to stimulation due to various forms of sleep deprivation or added stress, then you can suffer classic BPV symptoms.
Am I completely out of line, or am I on to something? Please give me your opinion in the box below.