Ending Vertigo Today

Subjective vs. Objective Vertigo

Sometimes when discussing vertigo with a patient, providers try to decide if the vertigo the patient is experiencing is subjective or objective. What does this mean, and what are the implications for treatment?

“Subjective” means an internal feeling that only you experience and that is not visible to others. When referring to vertigo, it means a feeling of motion when you are otherwise still, usually a spinning sensation that you feel only in your head. The environment does not look like it is spinning or shifting.

“Objective” vertigo is not only feeling motion but also actually seeing the environment move. You might have to close your eyes because the visual illusion of spinning is so strong. If you can see the environment spinning, often an outside observer can see this too because you will have nystagmus. When your eyes are observed closely, they will be seen to move in a rhythmic jerking motion, as if panning and resetting over and over.

The problem with these two terms is that vertigo falls along a spectrum of severity. Subjective vertigo symptoms can simply mean shorter or milder vertigo, while objective vertigo is a more prolonged, more intense vertigo. As your vertigo disorder worsens, you can transition from subjective to objective.

The reason for this is that your eyes have the ability to focus away a lot of the spinning that you feel inside. Vision suppresses vertigo. If your vertigo is low-grade, staring at one spot or focusing strongly on an object that is not moving can make the vertigo slow down or stop. This means that if you are examined when feeling low-grade vertigo, the observer may not see any abnormal eye movements if they are looking at you in the light. If you are examined during testing in darkness you may have a low-grade nystagmus, since in the dark you will be unable to use vision to stop this drifting.

From a practical standpoint, then, the difference between subjective and objective vertigo is not all that helpful. They are merely either end of the same spectrum of vertigo. You can transition back and forth between them. For example, when I treat people with BPPV, they will often have very violent nystagmus when the first maneuver is being performed and will see the room spin crazily. After a couple of treatments this may improve to the point where I no longer see nystagmus and they don’t see the room spin, but they still might feel a mild spin inside. They’ve gone from objective to subjective vertigo. This just means that the remaining vertigo has become much milder but is not completely gone. I will do another maneuver in this situation.

Meniere’s disease also shows transitions like this. It can start with a mild spell felt only as a low, constant spin in the head. Later spells, though, can be quite much more intense, with the room spinning and nystagmus that is easily seen by others. Because subjective vertigo can transition to the more severe objective vertigo, it should be worked up with hearing and balance testing, rather than waiting to see if there is a visible progression.

Newsflash: Read our newest story

It’s been 250 years since the American Revolution began so I thought I would indulge something besides my vertigo interest. Here is a link to my new article on the American Revolution, for those history buffs out there!

Invading Canada: The First Scout of 1775 is a story of a scouting expedition at the start of the Revolution. It was shortly followed by Benedict Arnold’s invasion of Canada. This important scout had been essentially lost to history. I ran across mention of it while researching the inscriptions on an old powderhorn, and was able to put the story together from hints in many old sources. It’s a thrilling story to commemorate our past, enjoy!

What happens to BPPV crystals after maneuvers remove them?

After successful maneuvers, one of our readers wondered about the fate of the removed crystals. Do they go back to their original position in the gravity sensor, get washed away from the inner ear, or dissolve? If so, can they regenerate?

The otoconia are the crystals of calcium carbonate in the inner ear that are used to sense gravity. They are already forming in the fetus as early as two months of gestation. Calcium builds up on a collagen matrix to form each otoconium. They are embedded in a similar sticky protein matrix that holds them to the gravity sensors loosely enough that they and the membrane can shift as the head moves. This movement as you tilt your head allows you to sense gravity. They are designed to be permanent and to last throughout life.

Unfortunately, they do not always remain healthy. Calcium can erode from the crystals in some disorders, leaving a moth-eaten appearance. Older people often show cracks and furrows on the surface of the crystals, and pieces of broken crystals can be seen. Head trauma, lack of bloodflow, calcium disorders such as osteoporosis, and genetic defects in otoconia formation can all contribute to degeneration. Some antibiotics (aminoglycosides) can dissolve calcium from the crystals in addition to other serious effects on the inner ear.

When successful maneuvers are done for BPPV, the crystals are removed from the semicircular canals where they don’t belong, and return to the sac containing the utricle, a gravity sensor. However, they don’t necessarily re-attach. They may just settle down in the sac, waiting for an opportunity to go back into the canal and cause BPPV again. They always remain within the inner ear. If they do undergo slow degeneration, the calcium leaves but the collagen matrix may remain.

Unless you have been exposed to aminoglycoside antibiotics or have serious defects of the inner ear, there are dense piles of otoconia on the utricle that are still attached even when you have had BPPV. This means that the utricle continues to function, but with aging it will become a bit less effective. The damaged or wandering crystals do not get replaced once they are detached from the utricle, and no new ones form.

In experimental animals, otoconia can be removed from the utricle by centrifuging (spinning the animals at high acceleration). This is very similar to the movements in some spinning “G-force” amusement park rides. These rides are not a good idea if you want to keep your otoconia in place as long as possible.