Diagnostic approaches to vestibular disorders.pptx

Diagnostic approaches to vestibular disorders.

1. Diagnostic approaches to vestibular disorders By Prof. Enass Sayed Mohamed Professor of Audiology ENT Department Assiut University

2. Vestibular Labyrinth Anatomy : Semicircular Canals •Detect rotation in the different planes •3 canals •Superior, Horizontal, Posterior • Otolith Organs: contain otoconia (“ear rocks”) in a gelatinous membrane to stimulate hair cells to detect linear accelerations •Utricle: horizontal plane (side-to-side) • Saccule : vertical plane (up and down, front to back)

3. Balance *The human vestibular system is made up of three components: peripheral sensory apparatus, central processor,& mechanism for motor output Complex interaction of visual, vestibular and proprioceptive inputs that the CNS integrates as motion and spatial orientation to keep balance

4. History taking A complete history taking is still the fundamental part in diagnosing patients with dizziness, subsequent examination and investigations are used to confirm the diagnosis Vertigo: sensation of self-rotation or rotation of the surroundings Unsteadiness, imbalance or disequilibrium describes a loss of equilibrium on movement Dizziness or light headedness describes any vague sensation or discomfort in the head Syncope: episodic loss of consciousness due to diffuse CNS dysfunction produced by reduced cerebral blood flow

5. a. The neurotological history: Chief complaint: The most important feature in the patient's history of current complaint is what patient feels. Vertigo is a spinning or rotatory sensation of the patient or his or her surroundings, and is often in keeping with a vestibular event. It is necessary to distinguish vertigo from sensation of unreality or vague dizziness . Patients who feel faint ( presyncope ) or actually have had syncopal attacks are more likely to have a cardiovascular problem such as orthostatic hypotension, cardiac ischemia, or arrhythmia

6. Analysis of the vestibular related symptoms: Onset: acute, gradual Course: regressive, intermittent, continuous Duration: History characteristic of current episode: Vertigo lasting seconds and induced by positional change such as rolling over in bed is likely to be due to BPPV. Vertigo lasting seconds and induced by loud sounds or coughing may be due to semicircular canal dehiscence. Vertigo lasting seconds with a history of trauma may be secondary to a perilymphatic fistula

7. Vertigo lasting minutes to hours is suggestive of migraine, Meniere's disease, or cardiovascular disease such as a transient ischaemic attack. Vertigo lasting hours-to-days is suggestive of labyrinthitis , vestibular neuritis, central pathology such as multiple sclerosis or a stroke, or an anxiety disorder   Unsteadiness or sense of imbalance may be episodic and could last for seconds, hours or more. For seconds may arise from minor inadequacies from visual, vestibular, and propioceptive systems, aging , & after attack of BPPV Episodic of unsteadiness lasting for hours may be associated with drug intake as tranquilizers or anticonvulsants, perilymph fistula. Prolonged unsteadiness is consistent with central nervous system lesion, anticonvulsants, ototoxic drugs and psychogenic disorder.

8. Subsequent dizzy spells should be documented if they are similar or difference from the initial attack : BPPV occurs on head movement (e.g., rolling over in bed, bending down, or looking up quickly) Uncompensated unilateral vestibular loss may cause unsteadiness on head movement. Otologic symptoms 1-Hearing loss. 2-Tinnitus. 3-Earache. 4-Aural discharge. 5-Sense of fullness in the ear. 6-Autophony. 7-Intolerance to loud sounds. Meniere’s disease, labyrinthitis , acoustic neuroma , SSCD, perilymph fistula, Cholesteatoma . Previous otologic surgery

9. . General neurological symptoms: 1-Double vision. 2-Numbness of the face or extremities. 3-Blurred vision or blindness. 4-Weakness of arms or legs. 5-Confusion or loss of consciousness. 6-Speech difficulty. 7-Swallowing difficulty. 8-Convulsions. Patients with vertebrobasilar insufficiency present with episodic vertigo lasting 1 to 15 minutes, with diplopia , dysarthria , ataxia, drop attack, gait disturbance, may indicate neurological pathology, such as cerebellar infarction or cerebellar pathology. Tongue weakness with limb weakness may be a feature of a cerebral stroke. Changes in vision, motor and sensory functions could be additional manifestation of neoplastic , demyelinating , vasculitis within the central nerves system.

10. . Systemic illness: It is important to consider a history of associated chest pain, exertion syncope, and dyspnoea that may be related to a cardiovascular etiology. Vestibular migraine may be associated with aura, visual disturbance, phonophobia , or photophobia, with or without headaches . Diabetes mellitus associated with hypoglycemic episodes, thyroid dysfunction Rheumatoid arthritis or systemic lupus erythematosis   may also be associated with dizziness

11. History of trauma or surgery History of psychogenic disorders Family history Medication and drug history

12. Physical examination General examination : General appearance, unsteadiness or drowsiness. Mental and emotional state. Irregular pulse or carotid bruits. Lying and standing blood pressure in patients with postural symptoms. It may demonstrate a fall in systolic or diastolic blood pressure in orthostatic hypotension. Neck examination for thyroid enlargement. Examination of neck blood vessels for diagnosis of cerebrovascular occlusive diseases. Pallor for anemia of any cause that may present with throbbing headache, dizziness and fainting Clubbing and cyanosis of fingers help in diagnosis of congenital heart disease which may be present with dizziness and syncopal attacks

13. Otological examination: Ear examination The fistula test Audiological evaluation: Pure tone audiometery Speech audiometery Tympanometery and acoustic reflex measurments

14. Neurological examination: Cranial nerve palsies such as facial weakness or numbness may occur with cerebellopontine angle tumors. Tongue weakness with limb weakness may be a feature of a cerebral stroke. Examination of cerebellar function is usually tested with the finger-to-nose test and rapid alternating hand movements, Dysdiadochokinesia Testing Abnormalities seen in patients with cerebellar dysfunction . Poor sensitivity and specificity . Gait, Tandem Gait Test: Patients are asked to walk heal to toe in a straight line or in a circle . Complex function evaluates many aspects of balance . Poor performance seen in cerebellar lesions, but can be seen in many disorders . Poor sensitivity and specificity Motor and sensory functions Wallenberg's syndrome (lateral medullary infarction caused by occlusion of the ipsilateral vertebral artery that supplies the posterior inferior cerebellar artery) causes prolonged vertigo, abnormal eye movements, ipsilateral Horner's syndrome, ipsilateral limb ataxia, and loss of pain and temperature sensation of the ipsilateral face and contralateral trunk

15. . Clinical balance tests Assessment of vestibulo -ocular function: The vestibulo -ocular reflex (VOR) functions are responsible to maintain steady gaze during head rotation. Ocular nystagmus : which may be - Congenital or infantile nystagmus : This is present at birth or soon after or Acquired nystagmus : Which occurs secondary to some inducing factor (neurological disease or drug toxication ) Vestibular nystagmus which may be spontaneous, gaze –evoked or induced.

16. Examination of spontaneous and gaze evoked nystagmus Examination of induced nystagmus : * Optokinetic nystagmus *Head-shaking nystagmus *Fistula test *The Dix- Hallpike test *Positional Nystagmus *Minimal ice water calorics

17. Dix- Hallpike Maneuver Dix- Hallpike maneuver (used to diagnose benign paroxysmal positional vertigo). This test consists of a series of two maneuvers: With the patient sitting on the examination table, facing forward, eyes open, the physician turns the patient's head 45 degrees to the right (A). The physician supports the patient's head as the patient lies back quickly from a sitting to supine position, ending with the head hanging 20 degrees off the end of the examination table. The patient remains in this position for 30 seconds (B). Then the patient returns to the upright position and is observed for 30 seconds. Next, the maneuver is repeated with the patient's head turned to the left.

18. Head Shake Nystagmus Evaluates unilateral vestibular weakness , Head tilted back 30 degrees , Shake back and forth for 30 seconds as quickly as possible , Unilateral vestibular deficit causes slow phase nystagmus to the side of lesion , Low sensitivity (27%) ,Good specificity (85%)

19. Dynamic Visual Acuity Used for bilateral vestibular weakness. Visual acuity checked on Snellen chart. Re-checked while rotating head back and forth at 1-2 Hz. Loss of 2-3 lines considered abnormal

20. Static versus dynamic visual acuity test

21. Head impulse test

22. Head Thrust Test Inhibitory response not as robust as the stimulatory response to stimulate VOR Movements that overcome the inhibitory response of vestibule will result in VOR lag Head tilted 30 degrees Rapid head movements to either side with focus on examiner’s nose. Patients have catch-up saccade when rotated to side of weakness Sensitivity 75%, Specificity of 85%

23. Assessment of vestibulospinal function: Vestibulospinal reflex produce postural stability through appropriate displacement of the center of the body mass over the base of support. Balance is achieved by the complex integration and coordination of multiple body systems including the vestibular, visual, somatosensory cues.

24. Head impulse test & evaluation of nystagmus

25. Romberg tests: Romberg test perform by asking the subject to stand erect with feet together and eyes closed and fold the arm in front the chest. Romberg's test is positive if the patient sways or falls while the patient's eyes are closed. When vision is absent, there is only one remaining functioning system, either the vestibular or propioceptive system. When there is no evidence of propioceptive or cerebellar dysfunction by neurotological examination, a positive Romberg test indicts that patient has loss of vestibular function

26. Fukuda test: The test is suggested to identify the weaker of the labyrinth not necessarily the side with the lesion by the direction of the rotation of a patient while walking in place with eyes closed. In the original work by Fukuda, subjects were blind folded and asked to extend both arms and march in place for 50 to 100 steps. The maximum rotation noted was 30 degree to either side with 50 steps. A deviation of greater than 30 degree about the vertical axis suggested asymmetrical labyrinthine function with the weaker side identified by the direction of rotation

27. Fukuda stepping test

28. Tests for otolith organ dysfunction Cover- uncover test With the subject viewing an object at least 18 inches away, cover one eye while observing the other for a vertical adjustment. Then perform the same test covering the other eye Subtle skew deviation is detected if the uncovered eye adjusts vertically when the other eye is covered Skew deviation indicates dysfunction in the otolithic input from the peripheral end-organ or in the brain stem’s interpretation of the otolith input. This is part of the ocular tilt reaction that may result from either peripheral or central dysfunction.

29. Cover uncover test

30. Subjective visual vertical For measurement of the SVV, the patient remained sitting in an upright position and looked into a hemispheric dome 60 cm in diameter. The surface of the dome extended to the limits of the observer’s visual field and was covered with a random pattern of colored dots; 30 cm in front of the observer was a circular target of 14° visual angle with a straight line through the centre. The patient had to adjust the central test edge to the vertical. SVV was determined by means of 10 adjustments of the target disk from a random offset position to the SV (normal range (2SD): ±2.5° 1 ).

31. Videonystagmography (VNG) Most common tool to assess vestibular function. Consists of 3 subtests: Oculomotor testing: the patient follows a visual target with their eyes : Saccade, smooth pursuit, OPK. Looking for abnormal patterns. Positional testing: checking for BPPV, positional nystagmus Caloric testing: irrigate ears with water of calibrated temperature, which stimulates the horizontal SCC. COWS- cold water opposite side, warm water same side, direction of nystagmus The GOLD STANDARD for identifying the affected ear in a vestibular disorder.

32. Electronystagmograghy Positive potential between the cornea and retina recorded as eyes move from straight ahead gaze Test includes different head positions, eyes open, closed and caloric tests

33. Important Instructions For VNG or ENG Testing Certain medications must be avoided for 48 hours before the test, including: sleeping pills, diuretics, tranquilizers, sedatives, antihistamines, muscle relaxants, anti-dizzy medications, barbiturates, anti-depressants, anti-anxiety medications, pain medication. No food or beverages (except water) for 3 hours before the test. No smoking for 3 hours before the test. Females – no eye make-up of any sort (no eyeliner or mascara, especially) should be worn to the test.

34. Spon. Nystagmus. Gaze test: Right horizontal gaze left horizontal gaze

35. Oculomotor tests:

36. Saccade test. Saccade test.

37. Smooth pursuit test Saccadic pursuit Normal

38. Optokinetic nystagmus test (OPK) Normal OPK. Abnormal OPK.

39. Positional tests Positional test. Tests for nystagmus in static head positions Positioning test. Tests for nystagmus in dynamic head positions Vertical or ageotropic, direction changing in same positions, may suggest central disorder Positioning test used to determine presence of BPPV by Dix-Hallpike maneuver

40. BPPV

41. Apogeotropic positional nystagmus Right positional Left positional test

42. Caloric Testing Established and widely accepted method of vestibular testing Most sensitive test of unilateral vestibular weakness Patient positioned 30 degrees from prone (HSCC vertical allowing max stimulation) Cold and warm water/air flushed into EAC COWS (cold opposite, warm same) – direction of the nystagmus Stimulation in 0.002-0.004 Hz range Visual fixation should reduce strength of caloric responses 50-70% % caloric paresis = 100 [(LC + LW) – (RC + RW)/(LC + LW + RC + RW)]

43. VEMP (vestibular-evoked myogenic potential) Loud click sound in test ear and we measure resulting muscle reflex in neck Abnormal VEMP in patient’s with Meniere’s , perilymph fistula, SSCD

44. Rotary Chair Testing * Preferred test method for children *Cannot provide ear specific information

45. Computerized Dynamic Posturography *Sensory Organization Test Varying inputs to the 3 systems: vision, vestibular, proprioception *Motor Control Test Measures reaction time to disturbance of the platform (pulling the rug out from under them) Assesses fall risk

46. Commn vestibular disorders

47. Meniere’s Disease Due to cochlear hydrops =over accumulation of endolymph in the cochlea Usually characterized by 4 symptoms: Periodic episodes of rotary vertigo or dizziness (lasts minutes to 24 hours) Fluctuating, progressive, low-frequency hearing loss (SNHL) Tinnitus (often a “roar” or “buzz”) A sensation of "fullness" or pressure in the ear

48. *In the early stages of Meniere’s , the hearing loss effects only the low frequencies *As the disease progresses, the hearing loss will flatten

49. Causes of Meniere’s disease

50. Incidence 2/1000 persons Most commonly unilateral (~75%) Affects men and women equally Most common in the patient’s 40s and 50s Diagnosed based on case history, audiogram, other specialized tests that look specifically at vestibular function ↑ SP/AP ratio in ECochG

51. Two Subvarieties of Meniere’s Disease Cochlear Meniere’s disease No vertigo Fluctuating and progressive SNHL Aural fullness/pressure May or may not have tinnitus Vestibular Meniere’s disease Spells of vertigo No hearing loss May have aural pressure

52. Benign Paroxysmal Positional Vertigo Extremely common Otoconia displacement No hearing loss or tinnitus Positions that elicit vertigo: turning head in bed, bending down, head extention Horizontorotary nystagmus, after slight latency period Less pronounced with repeated stimuli Typically can be reproduced at bedside with positioning maneuvers

53. 1.Posterior canal BPPV ( canalithiasis or cupulothiasis ) 2 .Anterior canal BPPV ( canalithiasis or cupulothiasis ) 3. Latreal canal BPPV ( canalithiasis or cupulothiasis ) Diagnosis by: 1.Dix-Hallpike test. 2. Side lying test. 3. Roll test.

54. Rt. Posterior canal BPPV

55. Lf. Posterior canal BPPV

56. Vestibular Neuronitis Suspected viral etiology Inflammation of the nerve Acute vestibular crises improving over 1-4 days Nausea and vomiting No hearing loss Common to have Posterior canal BPPV as a sequel

57. Labyrinthitis Acute vestibular crises, may improve 1-4 days Associated hearing loss and tinnitus Involves the cochlear and vestibular systems (inflammation of the inner ear) Usually continuous vertigo Viral Labyrinthitis Bacterial Labyrinthitis

58. Labyrinthitis

59. Vestibular migraine Migraine diagnosed by IHS criteria, dizziness may related to headache or independent, may presented with peripheral or central vestibular involvement, can have hearing loss, mild and NOT progressive. Very common cause of dizziness Approximately 35% of migraine patients have some vestibular syndrome at one time or another May not get a physical headache, but instead the migraine manifests itself as vestibular symptoms (vertigo, ear pressure, tinnitus, nausea) Commonly misdiagnosed as Meniere’s disease

60. Acoustic Neuroma Tumor of the Schwann cells around the 8 th CN *Can appear as brief spells of imbalance or vertigo, typically HL& persistent tinnitus, Unilateral hypo function, +/- CNS; VEMP + ve in inferior vestibular n. division involvement. With tumor enlargement, it encroaches on the cerebellopontine angle causing neurologic signs Earliest sign is decreased corneal reflex Later trunkal ataxia Most occur in women during 3 rd and 6 th decades

61. CNS Neoplasm MRI scanning of the brain showing posterior fossa cystic lesion, involving the fourth(FV) ventricle. The lesion measured 5x7cm, insinuating through the foramina of FV into both cerebellopontine angles and below the vermis .

62. Vascular events VBI: AICA, PICA→ episodic vertigo, imbalance& other brainstem signs and symptoms(D’s): Diplopia, dysphasia, dysarthria, dysmetria , dysphagia. Or asymmetrical muscle weakness, numbness of the face or extremities. Vertical nystagmus is characteristic of a (superior colliculus) brain stem lesion Cerebellar and cerebral hemispheric ischemic events→ loss of coordination and balance, ocular abnormality and postural control and gait abnormality

63. Anterior Vestibular artery occlusion. Presence of risk factors( age, DM, Hypertension, hyperlipidemea , cardiovascular diseases, smoking ) impaired flow velocity of vertebrobasilar circulation, showed by TCD May be impaired ABR. MRA

64. 2 MRI scanning of the brain showing multiple bilateral small focal lesions, scattered along the periventricular white matter of both fronto -parietal regions, suggesting multiple lacunar infarctions.

65. Multiple sclerosis Usually central, INO→ discongiogate eye movement, gaze evoked nystagmus Saccadic dysmetria , pursuit abnormalties , abnormal OPK, impaired visual suppression May have peripheral hypofunction from VIII nerve involvement, abnormal ABR. exacerbation and remission.

66. Multiple sclerosis MRI scanning of the brain showing MS plagues in cerebellar hemispheres, brainstem and cerebral hemisphere , related to the ventricular system.

67. Psychogenic disorders Depression and anxiety screening scales. May or may not have a past history of classic vestibular event Symptoms are the same lying, sitting, standing, may increased with walking Sensitive to high visual complex environment, Change by different situations( exmp : ↑at work, grocery store, but not at home) Anxiety disorders(likely a neurotransmitter problem) can produce positional vertigo complaint but no nystagmus.

68. Thank You