BPPV (Benign Paroxysmal Positional Vertigo)
BPPV (Benign Paroxysmal Positional Vertigo)
BPPV is the most common cause of Vertigo, or spinning and is a problem within the inner ear. It typically gives patients a false sensation of spinning or movement, unless it is chronic and has been accomodated for, skewing it's typical presentation. The spinning sensation is caused by an excessive signal from the inner ear as the inner ear solution becomes more viscous and weight inappropriately, sending an excessive signal to the brain stem, causing quick movements of the eyes that give an illusory movement of your environment that results in spinning sensation. BPPV is easily diagnosed and treated at Portland Chiropractic Neurology.
What causes the spinning? Crystal become loose in the inner ear and travel into the parts of your inner ear that send acceleration information and direct eye movements.
Vertigo is defined as the subjective perception of rotational or translational movement int eh absence of an external stimulus (1). BPPV occurs when calcium carbonate crystals (otoconia) dislodge from their normal location, utricle/sacule (sensory organ) and travel into the semicircular canals. If they are freely floating in the SCC, we refer to this as canalithiasis. If they adhere to the cupula, we refer to this as cupulolithiasis. Posterior canal is most commonly affected due to its orientation lreative to gravity as the lowest portion of the inner ear The anterior and horizontal canals are affected to a lesser degree. Average onset is at 57 and women are twice as affected as men. BPPV may follow head trauma (concussion/TBI), viral neurolabyrinthitis, labyrinthine ischemia, infection, and prolonged or unusual head positioning (dentist, hairdresser, etc..). Age, dehydration, flying, intense exercise or pounding such as mountain biking on rough trails, and medication are also contributors to BPPV.
Symptoms of BPPV are very sudden and alarming and are often mistaken by patients for something more serious.
- Brief episodes of spinning, or vertigo when turning their head abruptly
- Certain head position is worse than others
- Spinning that fatigues or disappears with a minute or two
- Changing positions, or rolling over in bed that causes spinning
- Looking upwards or backing your vehicle up creates spinning
- Bending forward causes imbalance, unsteadiness or spinning
- People can often identify the head position that causes dizziness and tend to avoid activating
Clinical examination is performed after taking a careful history by rotating the patient’s head 45 deg to one shoulder, while keeping their eye open, and laying them backwards so that their head is hanging off the edge of the examiners table about 120 deg from upright. This is known as the Dix-Hallpike Maneuver. Expect a latent period from 2 seconds to 30 seconds before vertigo, nausea and nystagmus occurs. If necessary, we will utilize VideoNystagmography (VNG) to better visualize the nystagmus that may occur.
In posterior canal assessment, we are looking for a slow phase down and towards the nose with mixed upbeat and torsional nystagmus as the top poles of the eyes beat toward the ground. You may see more torsion when looking towards the affected ear, more vertical when looking towards the unaffected ear. It should lessen with the position after 30-60 seconds as the otoliths settle. Repeat this test as it should habituate, which is diagnostically important as central lesions do not dissipate.
Horizontal canal BPPV is tested by bringing the patient supine and rotating head 90 degrees to one side or the other. You are testing both canals in one position, so it is important observe whether the eyes are beating in a geotropic or apogeotropic pattern. Geotropic indicates affected ear is down, apogeotropic indicates affected ear is up. So, the nystagmus is greater towards the affected ear, which is synonymous with Ewald’s second law- ampulla movement in the excitatory direction elicits a brisker nystagmus than the opposing ampulla movement in the inhibitory direction. It is less susceptible to habituation through repeated testing (VSM is the culprit).
Anterior canal BPPV can be determined by the direction of the eye beating during dix-hallpike maneuver. They will be downbeat with the torsional component beating towards the affected ear with the affected ear up. This represents the relationship between canals, for example RALP. In our clinic we test the patient in the actual anterior canal with VNG goggles to allow for more accuracy.
Treatment of BPPV is through the Epley Manever, which is a repositioning maneuvers that relocates the otoconia out of the SCC and into the drainage system, it is a Four part maneuver as the patient is held in each position until nystagmus has dissipated before moving onto the following position. Patient is instructed to sleep in a reclined position that evening, staying as upright as possible for the remainder of the day to ensure drainage and limiting head movements.
It is important to understand that peripheral and central conditions may overlap and can be confused for one another. The hallmark for BPPV is positional induced and it is fatiguable. Peripheral abnormalities usually improve with fixation. If not in normal presentation of canals, consider Cardiovascular or CNS issues that can manifest as BPPV similarities are MS, cerebellar tumors, infarction, hematoma, vertebral artery compromise, brainstem ischemia or head injury.
(1) You Peng, MD, Instrum Ryan, MD, Parnes Lorne, MD, FRCSC. Benign paroxysmal positional vertigo. Laryngoscope Investigative Otolaryngology. 2019 Feb: 4 (1): 116-123.