Frequently missed BPPV diagnosis can be avoided with two simple bedside tests
Two retrospective studies looked upon here suggests that although BPPV entails simple and straightforward pathophysiology the diagnosis is frequently missed and clinicians may not reliably screen for it. Both studies suggest that CT and MRI of the head are not helpful in identifying the cause of dizziness of vertigo. Only 0.74% of CT and 12.2% of MRI scans revealed a possible cause of the dizziness in an emergency department setting whereas in an otoneurology clinic receiving patients referred by external physicians, 70.6% of patients undergone previous diagnostic tests, of which none met the criteria for the clinical diagnosis (BPPV). A focused evaluation guided by history, physical examination with the use of a specific test for positional nystagmus, should improve diagnostic timeliness and reduce cost. Mechanical clinical tests are a better go to ahead of diagnostic imaging for ruling out or confirming BPPV.
Two major bedside test used to diagnose for BPPV (to be done with eyes open in order to observe nystagmus):
Dix Hallpike Test unilateral Posterior - contralateral anterior canals:The patient is seated in the long sitting position on a plinth, with the head turned 45° toward the side to be tested. The patient is then moved briskly into a supine position with the head hanging 30° below body level/ plinth. Observe for eye nystagmus. Caution while patient might have symptoms returning from test position. When symptoms stop the test can be repeated to the other side.
Head Roll Test horizontal canals - Patients lies supine with head supported on pillow (20° above body level) head is moved briskly 90° to one side, keep position up to 1 minute, inspect for nystagmus and vertigo. Slowly return head to midline, hold head in midline until symptoms resolve. Test the other side. If cervical ROM is limited, test can be done with rolling the patient to the side lying position. The affected side will provoke most symptoms, horizontal canal BPPV is usually more severe than that of anterior or posterior canal involving balance problems and nausea.
Differentiating symptoms of BPPV vs other common vertigo causes:
• Vestibular Neuritis: (viral infection of the vestibular nerve) presents with continuous vertigo, nausea, spontaneous nystagmus, disequilibrium and no hearing loss that improves within days.
• Labyrinthitis: (fluid in the labyrinth) entails similar symptoms with hearing loss/ tinnitus.
• Canalithiasis BPPV: (common) Intermittent symptoms, on testing present with latency before onset of symptoms (1-40 seconds) and short duration (less then 60 seconds).
• Cupulolithiasis BPPV: (rare) Intermittent symptoms, on testing will present without latency and a persistant nystagmus over a minute.
• CNS associated vertigo nystagmus will be persistent (not altered by posture), will have no torsional component, will not accommodate over time and will likely have some other CNS test positive.
Assessment and treatment of dizziness and vertigo is commonly and effectively done in select physiotherapy clinics. Clinicians at Parkway Physiotherapy + Performance Centre are receiving, diagnosing and effectively treating dizziness and vertigo associated patients on a daily basis.
Polensek SH, Tusa R. Unnecessary diagnostic tests often obtained for benign paroxysmal positional vertigo. Med Sci Monit. 2009 Jul;15(7):MT89-94. PubMed PMID: 19564834.
Ahsan SF, Syamal MN, Yaremchuk K, Peterson E, Seidman M. The costs and utility of imaging in evaluating dizzy patients in the emergency room. Laryngoscope. 2013 Sep;123(9):2250-3. doi: 10.1002/lary.23798. PubMed PMID: 23821602.