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BPPV is one of the commonest causes of vertigo that we see in our clinic. It is often under-diagnosed, especially in the elderly.
It is characterized by brief episodes of vertigo (the room spinning) that occur on position change, especially on looking up, lying back, turning quickly or turning over in bed.
The condition is caused by tiny crystals in one of the three semi-circular (balance) canals of the inner ear. On certain movements, as the head position changes, so the low point of the canal changes and the crystals will drift down following gravity. This has a plunger effect in the fluid-filled canal. The movement of fluid stimulates nerve endings at the end of the canal, resulting in vertigo. As the crystals settle in their new position the vertigo resolves but may recur on more position changes and chronic symptoms of imbalance may result. The crystals originate from a gravity-sensing organ (called an otolith) in the adjacent utricular sac . The three semi-circular canals lead off from this sac so it is easy for the crystals to find their way into one of the canals.
Diagnosis:
It is diagnosed in the office by a simple position test, the Dix-Hallpike maneuver, in which the patient's head, whilst sitting upright, is turned to one side and then the patient is moved back quickly to lie flat with the head hanging off the end of the couch with the head still to one side. This will produce vertigo after a latent period of a few seconds (while the crystals pick up some speed, relatively speaking) and then, as the crystals settle towards the new bottom of the canal, the vertigo will resolve. The examiner watches the patient's eyes very closely and, during the vertigo, will see fine rhythmic eye movements called nystagmus, (because the role our inner ears play in stabilizing our gaze, despite head movements, is disturbed).
Above: the Dix-Hallpike test. Note that, in the reclined position, the tester is observing the eyes for nystagmus as well as when the patient has returned to the sitting position.
Management: the Epley maneuver:
This maneuver re-positions the head, and therefore the canal, so that the crystals will drift on out of the canal into the adjacent (utricular) sac where they came from and where they are harmless. It is performed as follows: after the vertigo has completely settled in the reclining position of the Dix-Hallpike test, the patient turns their head to the opposite side and then follows this with the whole body turning onto that opposite side with the head looking down towards the floor, (see below). The patient remains in this position for at least three minutes before returning to the sitting position, but without turning onto their back in doing so. The procedure can be performed by the patient at home but only with assistance, as it may occasionally precipitate quite severe vertigo. It is frequently successful, although it may need to be repeated and sometimes additional physical therapy is required. In the following images the patient had vertigo on lying back with her right ear down (first image). When the vertigo has settled she turns her head to other side and then follows this by turning her whole body to the opposite side with the head looking down as shown in the final photograph. After three minutes the patient should come back to the sitting position, without turning onto their back, and should avoid lying on their back for 24 to 48 hours.
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BPPV is usually an isolated disorder. However it may occur in other inner ear conditions and further tests of the two functions of the inner ear may be advised, namely hearing (audiology) and the balance system, (videonystagmography for example), to clarify the diagnosis. |
