Persistent Postural Perceptual Dizziness
The first thing patients need to know about dizziness is that it is very complex. The most complex thing about dizziness is that the word has so many potential meanings. In medical training they emphasize that the two main types of dizziness are vertigo (room spinning) and presyncope (lightheadedness) and that they are the main two branching points that differentiate different causes of the dizziness. Medical school never prepared me for how many hispanic fathers would get referred to me for dizziness with the story “every time my kid breaks a dish, I get SOOO DIZZZY”. For these men, dizzy meant rage. The truth is that these terms, spinning, light headed, dizzy, and others have no meaning in and of themselves, and they don’t help me understand what is happening to a patient.
In this article, I will generally focus on other types of dizziness besides the ones that typically cause a light headedness (often due to a drop in blood pressure or conditions like low blood sugar) since they are caused by problems outside the nervous system. I need to consider them when I meet a patient since even a heart rhythm problem can lead to a feeling of room spinning and there are many neurologic conditions that have a fainting component. Even if we don’t consider those in our discussion, dizziness is still extremely complex.
The brain takes in a lot of information constantly. There is the vision signal coming from the eyes, position signals coming from the inner ears, very specialized signals coming from the muscles of the eyes and the neck, and sensation coming from the rest of the body. All of these signals have to line up perfectly or the brain starts to get very uncomfortable. There are three very common disorders (and a few uncommon ones) that every medical student is taught to call the “peripheral vertigos”. They are called peripheral because they originate in the inner ear or in the nerve that carries signals from the inner ear to the brain.
The most common of these is called “benign paroxysmal positional vertigo” or BPPV and it is often anything but benign. It is caused by little crystals that form in a tube within the inner ear. That tube holds fluid that shifts whenever the head turns, sending a specialized signal to to the brain. With those crystals mucking up the signal, the brain starts getting very mixed messages from each ear and from the brain about what is happening and suddenly the room starts to spin. This usually starts with infrequent waves of room spinning that can be consistently brought on by certain head positions. The trick is to see if you can bring on the dizziness each time you go from sitting to laying flat on one ear (with the head turned sideways the whole time). If the wave of dizziness always happens when the right ear is down, then those crystals are in the right inner ear. This is important because there is a very easy (often very uncomfortable) physical therapy that can get the crystals to fall out, but it is a bit different depending on which ear is having the problem. Dizziness may become more consistent over time, but at least at first, it is a big wave of room spinning that only lasts a few seconds to a minute, and settles down as soon as you stop moving.
The second most common “peripheral vertigo” is called vestibular neuritis (and a similar condition called Labyrinthitis). This happens when there is inflammation in the nerve carrying signals from the inner ear. This is rarely due to an active infection, but commonly caused when the immune system spikes up to fight off an infection. This syndrome is one of the worst forms of vertigo because it will often last a week or two and other than steroids to reduce the inflammation, there isn't much that can be done to treat it. It also doesn’t get better when you stop moving. The only thing we can do is to sedate a patient with meclizine or benzodiazepines so that their brain doesn’t care that a crazy signal is being sent to the brain.
The third most common type of peripheral vertigo is called Meniere disease. This is caused by a problem with fluid build up in part of the inner ear and happens unpredictably, causing a severe spinning sensation like vestibular neuritis, but typically only lasting a few hours. Often the same ear that causes the dizziness will have loss of hearing or tinnitus, and there is often ear pain. It isn’t fully understood what causes a Meniere spell, but reducing salt intake and a few other simple measures can significantly reduce how frequently they occur. After a spell starts, just like the vestibular neuritis, the best thing to do is to take a sedative, lay back, and wait until it ends.
The most dangerous causes of room spinning are related to damage in the area of the brain that receives the signals from the nerve in the ear, or the areas that process that information deep in the brainstem and cerebellum. In the Emergency Room, there will often be worries about a stroke. There is a simple test for dizziness related stroke, even more sensitive and specific than MRI, but most people just get the MRI, are told the tests all came back normal, and are sent home with an unclear diagnosis (or a firm but inaccurate one) and a prescription for meclizine. Meclizine is a medicine that sedates the brain so it isn’t bothered by the dizziness, but it can have some dire consequences.
See, most people with dizziness have had one or another contributor in the past that was untreated, or where treatment was delayed. Often the dizziness was covered up by the meclizine but the crystals were never properly removed or they were left on the sedative long after the Meniere spell or the neuritis had resolved. In those cases, as well as some cases of migraine and concussion related dizziness, a long term condition is created called “persistent postural perceptual dizziness” or PPPD. This is likely the most common diagnosis I see related to dizziness other than lightheadedness from low blood pressure. PPPD is a network problem, where the signals are coming in from the eyes, the ears, and all of those muscles, but the brain has difficulty lining them up properly. Just like people get dizzy on a boat when they feel the room moving but their vision disagrees, when signals get mixed up it can cause a whole host of strange feelings. People sometimes feel like the room, themselves, or other objects are spinning around. They may feel light headed or drunk, or like everything is in slow motion or their depth perception is off. Others feel like they are on a boat or their legs just feel uneven or wobbly. It tends to fluctuate but is always present to some degree.
This is the most common diagnosis I see when someone was diagnosed with BPPV in the hospital. They did the test where they lay the person back and it made them dizzy, so they blame it on ear crystals. What they don’t document is that the dizziness also happens when they stand, when they sit up, when they turn in either direction, and when they just move their eyes from left to right. If the problem were from ear crystals, then just moving the eyes would have no effect at all. Did the patient also have BPPV in the ER? Difficult to know, since most ER docs won’t document the exact eye movements they see during the testing. Regardless, in my office I cannot find any evidence of the inner ear crystals, and their exam shows no stroke or evidence of the inflamed vestibular nerve. Now they truly have PPPD.
How is PPPD treated? Since it is a brain network problem, it is treated like any other brain network problem. First, they must be treated for any other condition that is contributing such as migraine or one of the primary vertigos we discussed. After those problems have been resolved, the only way to get networks to behave properly is to practice using them. When people sit on a couch for a year, even if they keep the legs strong, they often have to practice balancing with physical therapy to feel steady on their feet again. When someone develops an anxiety syndrome, medications can help a little but they really need psychotherapy to “rewire” those networks and replace anxiety responses with more adaptive responses. In PPPD, they have to practice integrating complex information from visual, inner ear, and other sensory inputs if those networks are going to have any chance of returning to normal. Sedating the networks with Meclizine or a benzodiazepine will only delay recovery and often make the network degenerate further.
What does this therapy look like? The simplest version is to sit comfortably, stare at an object about 6 feet away, and slowly turn the head left and right. That sends signals from vision, eye muscles, the inner ear, and the neck muscles up to the brain to let it “recalibrate” those networks. If that is too easy, the head can turn faster, or begin including up and down movements as well as side to side. This can get more and more complex with different types of positions, looking at closer objects and switching to farther objects, and even while standing on one foot to practice integrating body movements as well. Importantly, doing exercises that are too easy probably won’t help much, but doing exercises that are too complex will often make the situation worse. The best exercise is one that causes a small amount of discomfort, and it should be done over and over until it no longer causes any discomfort. Then a harder exercise must be done and so on and so forth until patients can do the most complex maneuvers without discomfort. Many people can figure this out on their own with a small amount of guidance, but others benefit from a formal physical therapy where the therapist helps them discover what exercises are best and when.
While this vestibular-ocular therapy is the key to treatment, there are some other things to consider. For unclear reasons, certain types of antidepressants can make the vestibular therapy more effective and speed recovery. The most well studied are SSRIs like zoloft and SNRIs like venlafaxine. It is also important to work on body strength, flexibility, and coordination as well since the sensations from the body can also lead to balance disorders that will worsen the “mixed signals” the brain gets that cause PPPD. Lastly, it is vital to keep an eye out for other contributors to dizziness like the vertigos since many of them can recur and must be treated if possible, or vestibular therapy should be delayed if there is no curative treatment.
Do you suffer from dizziness and feel that no one has offered a clear diagnosis or treatment, or if they did the symptoms persisted despite treatment? If so, request a consult today if you’d like to discuss your symptoms with a Practical Neuropsychiatrist.
