Head injury or whiplash can create fractures in the Otolith crystals. Over time pieces of the otolith can break off. If they stay in the vestibule then there are no symptoms. If they end up in the semicircular canals then vertigo can occur.
The Cause of Vertigo
When our head stops moving the endolymph or fluid in our semicircular canals settles. The sensing organ, the cupula, stops its deflection telling the brain that there is no longer any acceleration changes to the head.
What happens next is the cause of vertigo.
A crystal starts to sink stimulating the cupula or sensing organ of it’s canal to fire while the other 5 canals are telling the brain that there is no movement of the head. It is this abnormal information that causes vertigo. The cool thing is this! As we continue to stimulate the cupula we see a blunting of the cupular response. A lot of cases of vertigo get better week by week without treatment as our vestibular nuclei shift their input to ignore this problem creating a unilateral vestibular hypo-function.
This can be helpful but does not ‘fix’ the problem.
How to fail with your vertigo treatment
If you are unsure of the canal or side (remember there are 3 on each side) you can shift the crystal further down the semicircular canal, getting it stuck. You or your patient will feel better but not fully, and now this problem is more difficult to find and to treat. It will also return and can cause other symptoms in the meantime.
Treatments that will NOT treat positional vertigo are a Brandt-Daroff exercise as well as Gyrostim. These treatments do not follow the physics of moving a small crystal in a curved, fluid filled tube. I especially love Dr. Chang’s, Dr. Christopher Chang, ENT comments on treatment of positional vertigo. If you do not properly position the canal in a dependent position with gravity and allow the crystal to fall and settle your treatment “will fail”. Head position is CRITICAL in treating positional vertigo.
If your position changes of the head are too slow then the crystal settles back where it was.
A lack of liberating maneuvers for an anterior canal or horizontal canal problem will fail to clear a crystal. These maneuvers are necessary to successfully treat these canals.
Reasons why positional vertigo treatments fail
The Wrong Canal or Side
The Wrong Treatment - Gyrostim
It's Not Positional Vertigo
Tips for success
Head position is critical in treating vertigo
Know which canal and side as each treatment needs to be specific to the involved canal
Most horizontal and anterior canal positional vertigo problems are ‘sticky’ and require liberating techniques. Without them treatment fails to work.
Maybe the dizziness is coming from a vision or neck problem? Or a combination of these systems?
So you have a vertigo patient in your clinic…what do you do?
- Do the Dix Hallpike Test
- Look for nystagmus
- Treat the most symptomatic side with an Epley maneuver (Over half of positional vertigo problems are a posterior canal. Play the odds!)
- Hold each position 45 seconds (30 – 60 seconds) with quick head turns
- Give instructions of sleeping more upright over the next two nights
- If this doesn't work? Get imaging!