Some new info on the Dix-Hallpike manoeuvre:
- Stand in front of the patient (not behind as I’ve been doing)
- Look at them for 30s first. (Why? Must ask DNUK.)
- After the patient is lain down, the nystagmus usually appears within 5 to 20 secs, but may take up to a minute, so possibly worth looking for that long.
Note that positional nystagmus may also be associated with cerebellar dysfunction, so isn’t exclusive to inner-ear problems. Here are the features associated with BPPV:
- Delayed by a few seconds
- Rotatory and directed towards the ground
- Slowed then stopped
- Much less severe if manoeuvre repeated.
Note that BPPV is self-limiting; it will frequently resolve in a few months.
The triad is of vertigo, hearing loss and tinnitus. Patients may not have all the symptoms, especially in the early stages; however, all three are officially needed to make the diagnosis, as no confirmatory test (‘perception of aural fullness’ can substitute for tinnitus):
- At least two spontaneous episodes of rotational vertigo lasting at least 20 minutes.
- Sensorineural hearing loss confirmed with audiometry
- Tinnitus and/or perception of aural fullness
(American Association of Otolaryngology and Head and Neck Surgeons)
There actually isn’t any evidence that any of the treatments used for Meniere’s are helpful. Best advice is to refer to an ENT surgeon with a special interest in balance disorders.
I thought this referred to recurrent vestibular neuronitis, but apparently it’s actually something different; it refers to recurrent episodes of spontaneous vertigo (between five minutes and 24 hours in duration) with no auditory or neurological symptoms or signs. The episodes are not triggered by movement and have no prodromes. There is very little understanding of how to treat them, although the prognosis is quite good; in one study, 70% of diagnosed cases resolved spontaneously. (20% were rediagnosed as something else, leaving only 10% of the original group with active RV.) As with Meniere’s, the best bet is to refer the patient to an ENT surgeon who specialises in balance disorders.
Red flags and cautions
- Unremitting vertigo (as opposed to dysequilibrium) for more than a few days
- Brainstem or cerebellar signs
- Associated unilateral tinnitus or hearing loss.
- Downbeat nystagmus – this is a good sign of pathology at the cranio-cervical junction. (When arranging imaging, sufficient views of the cerebellar tonsils are required to rule out Arnold-Chiari malformation.)
These signs or symptoms can indicate cerebellar or brainstem pathology such as a CVA or tumour. Audiogram and MRI within two weeks, including imaging of the cerebellopontine angle, is advised (or CT if MRI contraindicated).
Note that if this is malfunctioning unilaterally, it causes vertigo (due to the asymmetrical sensory input). However, if it is malfunctioning bilaterally, it usually doesn’t cause vertigo, but instead causes a problem where the person can’t read signs while walking. This is rare; causes include syphilis and gentamicin toxicity.
(BMJ learning module)