CAUSES OF VERTIGO & VESTIBULAR FUNCTION TESTS

1. CAUSES OF VERTIGO & VESTIBULAR FUNCTION TESTS

2. Definition of vertigo • A sensation of rotation or imbalance of one's self or of one's surroundings in any plane

3. Causes for vertigo A. Peripheral: lesions of vestibular end organs & vestibular nerve. Account for 85% of all cases of vertigo. B. Central:lesions of central nervous system. Account for 15% of all cases.

4. Peripheral causes  B.P.P.V. (commonest)  Temporal bone #  Meniere’s disease  Syphilis  Vestibular neuronitis  Cholesteatoma  Labyrinthitis  Vestibulotoxic drugs  Vestibular schwannoma  Perilymph fistula

5. Central causes for vertigo Vascularcauses:Vertebro basilar insufficiency, PICA synd, basilar migraine Epilepsy RoadTraffic Accident: Head trauma Tumor:of brainstem, 4th ventricle & cerebellum Infection: Meningitis, Encephalitis Glialdiseases:Multiple sclerosis Others: Cervical vertigo, ocular vertigo, psychogenic

6. History Taking

7. Important history questions • Confirmation of vertigo:rotatory sensation • Absence of syncope or light headedness • Onset:sudden or gradual • Episodic (isolated / recurrent) or continuous • Duration of each episode of vertigo • Associated symptoms • Provoking or aggravating factors • Systemic illness for vertigo

8. Associated symptoms • Decreased hearing: symmetric or asymmetric • Ear discharge • Tinnitus • Aural fullness • Nausea & vomiting • Imbalance

9. Provoking or aggravating factors

10. 1. Specific head position 2. Sudden standing up from sitting position 3. Sudden head & neck movement 4. Recent U.R.T.I. 5. Trauma to ear or head 6. Stress 7. Change in ear pressure 8. Headache 9. Drug intake

12. Drugs causing vertigo Aminoglycosides Antihypertensives Estrogen preparations Diuretics Antimicrobials Antimalarials

13. Routine ENT OPD tests for vertigo evaluation

14. Clinical test • Laboratory test

15. Clinical tests • 1. Spontaneous nystagmus • 2. Fistula test • 3. Romberg test • 4.Gait • 5. Positional test • 6. Tests of cerebellar dysfunction

16. Nystagmus • Involuntary, rhythmical oscillatory movement of eye • Horizontal, vertical or rotatory • slow & fast phase • Direction of nystagmus given by its fast phase • Vestibular nystagmus gets enhanced by looking in direction of faster phase & diminished by looking away from it (Alexander’s law)

17. How do you elicit nystagmus

18. Alexander’s Classification Intensity grading of vestibular nystagmus: 1°  only present while looking towards fast phase 2°  present while looking towards fast phase & also while looking straight 3°  present while looking towards fast phase, looking straight & looking towards slow phase

19. Nystagmus • Vestibular lesion nystagmus gets suppressed by optic fixation & gets enhanced with removal of optic fixation (with Frenzel glasses or in dark) • Irritative vestibular labyrinthine lesion:Ipsilateral nystagmus • Paralytic vestibular labyrinthine lesion:Contralateral nystagmus

21. Fistula test • Transmission of increased air pressure in E.A.C., via middle ear, into inner ear through a labyrinthine fistula causes vertigo + nystagmus towards affected ear • E.A.C. pressure is increased by intermittent tragal pressure or Siegelization

22. Fistula Test

23. Sites of labyrinthine fistula 1. Horizontal semicircular canal  Cholesteatoma destruction  Fenestration operation 2. Oval window  Post-stapedectomy 3. Round window membrane rupture

24. Hennebert’s sign False positive fistula sign in absence of labyrinthine fistula. Seen in: 1. Meniere's disease: fibrosis b/w stapes footplate & utricle 2. Hyper mobile stapes footplate  Congenital syphilis  Idiopathic

25. False negative fistula sign Negative fistula sign in presence of labyrinthine fistula. Seen in: 1. Cholesteatoma matrix / granulation covering labyrinthine fistula 2. Dead Labyrinth 3. Total E.A.C. obstruction (impacted wax)

26. Hallpike maneuver(Nylen – Barany maneuver)

27. Steps 1 to 3

28. Step 3 to 4

29. Dix-Hallpike Manoeuvre 1. Pt in sitting position on a couch looking ahead 2. Pt’s head turned 45° towards diseased ear 3. Pt moved rapidly into supine position with head hanging 30° below couch. Pt’s eyes observed for nystagmus for 1 minute 4. Pt moved rapidly back into sitting position 5. Manoeuvre repeated for opposite ear

30. Latency • Duration • Direction • Fatiguability

31. Frenzel glasses

32. Video attachment

33. Other tests • Romberg’s test • Gait • Tests of cerebellar function

34. Laboratory tests of vestibular function • 1. Caloric test • 2.Electronystagmography • 3. Optokinetic tests • 4. Rotation test • 5.Galvanic test • 6. Posturography

35. Caloric testing

36. Thermal stimulation of vestibular system causes nystagmus • Each labyrinth can be tested separately

37. Mechanism of caloric stimulation

38. Convection current formation in endolymph due to temperature gradient → ampullo-petal flowfor warm water activation of Vestibulo-Ocular Reflex OR ampullo-fugal flowfor cold water inhibition of Vestibulo-Ocular Reflex vertigo + horizontal nystagmus (slow phase away from side of VOR activation & toward side of VOR inhibition)

40. Fitzgerald-Hallpike Bithermal Caloric Test • Pt supine + 30° head elevation. Each ear irrigated in turn for 40 sec with warm water at 44°C & then cold water at 30°C. • Duration of nystagmusis from start of irrigation to end point of nystagmus. Normal =90–140 sec • Direction of fast component:Cold → Opposite ear; Warm → Same ear

41. Normal Calorigram

42. Canal Paresis Duration of nystagmus with both 44°C & 30°C irrigations in one ear is 30 % less than opposite ear. Seen in same sided peripheral vestibular lesion. Eg: Meniere’s disease, AN, post labyrinthectomy C. P. (%) = (R30 + R44) – (L30 + L44) X 100 R30 + R44 + L30 + L44

43. Right Canal Paresis

44. Left Canal Paresis

45. Directional Preponderance Duration of nystagmus in one direction is 30 % more than opposite direction. Seen in same sided central vestibular lesion & opposite peripheral vestibular lesion. D.P. (%) = (L30 + R44) – (R30 + L44) X 100 R30 + R44 + L30 + L44

46. Right Directional Preponderance

47. Left Directional Preponderance

48. Special cases Same sided canal paresis + same sided directional preponderance: • Acoustic Neuroma Same sided canal paresis + opposite sided directional preponderance: • Meniere’s disease

49. Modified Kobrak's Test E.A.C. irrigated for 60 sec with ice cold water in increasing quantity (5, 10, 20 & 40 ml) till nystagmus is noticed If nystagmus noticed with: • 5 ml = Normal vestibular labyrinth • 10 / 20 / 40 ml = Hypoactive labyrinth • No nystagmus (40 ml) = Dead labyrinth

50. Dundas Grant Cold Air Caloric Test • Done in T.M. perforation as water syringing is contraindicated • Air in coiled copper tube is cooled by pouring ethyl chloride in it • Effluent cool air is blown into E.A.C. to produce vertigo + nystagmus