Dizziness and Balance Disorders: An Investigative Overview

1. Investigating a Dizzy patientDizzy Battery at a Glance Mohammad, S Asghar The Ear Institute Audiology Clinic, Scarborough General Hospital, Scarborough, ON

2. Some statistics about dizziness/balance disorders • Prevalence: Young adults: 1.8% Older Adults: 30% All Population: 25% will have dizziness in there lifetime at least once Causing considerable morbidity and utilization of health services. • In an other study Older adults above 60: 65% experience dizziness or loss of balance, often on a daily basis.

3. Some statistics about dizziness/balance disorders • 7 million people in US seek medical help for disequilibrium/vertigo every year. • 30 % of US population has experienced at least one episode of vertigo by age 65

4. Definitions • Dizziness: It is a nonspecific term that describes a sensation of altered orientation in space. • Almost half of the patients complaining of dizziness usually have a disorder of vestibular system. • Vertigo:It is defined as an illusion of movement, and it always indicates an imbalance within the vestibular system.

5. Balance Disorder • A balance disorder is a condition that makes you feel unsteady or dizzy. • If you are standing, sitting, or lying down, you might feel as if you are moving, spinning, or floating. • If you are walking, you might suddenly feel as if you are tipping over.

6. The symptoms of vestibular disease . • Illusions of rotational motion (i.e., vertigo) • Illusions of linear motion (e.g., mal de debarquement) • Illusions of spatial disorientation (e.g., tilt illusion) . • Oscillopsia • Imbalance • Drop attacks • Lateropulsion • Autonomic accompaniments: malaise, nausea, vomiting .

7. Which patients are appropriate for testing? www.natus.com

8. Anatomic and Basic Medical considerations

9. Anatomic and Basic Medical considerations: Multiple sensory inputs contribute to balance function. • Vestibular end organ • Visual system • And Somatosensory system/proprioceptive system The information is integrated at the level of brainstem and cerebellum with influence from cerebral cortex including frontal, parietal and occipital lobes. The integrated input information results in various motor and perceptual outputs.

10. Balance system

11. Balance System

12. Dynamic Equilibrium(The concept) Sensory Motor Initiate Automatic/ Voluntary Movements Central integration Determine Body Position Compare, Select and Combine Senses Select and Adjust Muscle Contractile Patterns Ankle Muscles Visual System Vestibular System Somato- Sensation Thigh Muscles Trunk Muscles Environmental Interaction Generation of Body Movement www.natus.com

13. Motor System Outputs Dynamic Control of the COG • Reflexes • Automatic and adaptive postural responses • Anticipatory postural set • Voluntary movements Select and Adjust Muscle Contractile Patterns Ankle Muscles Thigh Muscles Trunk Muscles Generation of Body Movement www.natus.com

14. Balance disorder/Different perspective • Audiologist/ENT: Generally look at peripheral vestibular system • Neurologist: Look at mainly central integration and Motor part. • Geriatricians & Orthopedic specialists: Look at motor part and coordination

15. International Classification of Functioning, Disability, and Health – ICF Health condition (Disorder or Disease) Body Structure & Function Activity (Limitations) Participation (Restrictions) Environmental Factors Personal Factors ICF International Classification of Functioning, Disability and Health http://www3.who.int/icf/icftemplate.cfm Jette AM. Toward a common language for function, disability, and health. Phys Therapy 2006;86:726-734. www.natus.com

16. International Classification of Functioning, Disability, and Health – ICF Health condition (Dizziness/Imbalance) Vestibular system/Vision & Somatosensory system Difficulty in focusing while moving head/Cannot walk straight Cannot participate in daily activities like reading while moving (oscillopsia) Unstable and unpredictable environment Psychological and personal gain factors ICF International Classification of Functioning, Disability and Health http://www3.who.int/icf/icftemplate.cfm Jette AM. Toward a common language for function, disability, and health. Phys Therapy 2006;86:726-734. www.natus.com

17. Anatomy of the vestibular system

18. Inner Ear: Bony and Membranous Labyrinths Medial View

19. Anatomy of Vestibular System

20. Blood supply of Inner Ear

21. Irrigation ParallelsInnervation Blood supply Innervation Basilar A VIIIth N AICA Labyrinthine A Common Cochlear Artery Main Cochlear Artery Cochlea Auditory Nerve Vestibulo Cochlear artery Vestibular N Post Vest A Post SCC Ampulla Inferior division Majority of Saccule Ant Vestibular A Anterior SCC Ampulla Superior Division Horizontal SCC Ampulla Utricle Minority of Saccule

22. Arterial Blood supply

23. Vertebro-basilar arteries

24. Vertebro-basilar arteries

25. Lateral Medullary syndrome

26. Vestibular system: central connections

27. Central connections.(Important for rehab) • First order afferents : These are bipolar cells located deep in the internal auditory meatus. • In children the number of cells is around 80000. In elderly it is 11000. • So you can Imagine the incidence of imbalance in elderly

28. Mechanism of Vestibular lesions • Direct insult to peripheral vestibular system like Vestibular neurinitis/labyrinthitis • Blood supply interruptions Like Ant Inf. cerebellar art infarcts • Diseases affecting vestibular nerve like schawnoma. • Central lesions: cerebrovascular accidents, tumours and generalised diseases like MS • Motor system disorders: • Like spinal cord injuries, muscle and joint diseases

29. Neurological Causes of Dizziness. • Mixed peripheral and central lesion • Anxiety and psychogenic dizziness. • Emergency room: Acute Cerebellar infarction. • Migraine associated dizziness. • Disequilibrium of age. • Labyrinthine concussion • Vertebrobasillar insufficiency. • Multisensory disequilibrium

30. Neurological Causes of Dizziness • Cerebellar degeneration • Multiple scleroses. • Head Trauma (combined CNS, Labyrinthine and cervical injury • Migraine related dizziness and anxiety disorder. • Walenberg syndrome (posterior Inferior cerebellar artery syndrome) • Anterior Inf cerebellar artery infarction • Drop attacks • Convergence spasm.

31. Neurological Causes of Dizziness • Occular tilt reaction. • Chiari malformation • Progressive supranuclear palsy. • Wernicks encephalopathy • Vestibular epilepsy • Cervicogenic dizziness • Vascular cross compression syndrome.

32. Rational for Dizzy test Battery

33. Rationale of dizzy test battery approach • The ear has 10 sensory structure controlling the balance; • Three semicircular canals (SCC) in each ear. • Two Otolith organsSaccule and Utricle in each ear.

34. Rationale of dizzy test battery approach • Innervated by Vestibular Nerve which divides in Sup and Inf vestibular Nerves. • Sup Vest N supplies: Sup and Lateral SCC and Utricle. • Inf Vest N supplies: Post SCC and the Saccule.

35. Dizzy test battery: • Includes • Complete Audiological Assessment (PTA, ABR & Ecoch.G) • And Complete vestibular assessment (ENG, vHIT, VAT, Rotary chair test, VEMP, CDP & DVAT)

36. Vestibular Tests What do we look for

37. Audiological Evaluation.

38. Vestibular Function Tests.

39. Vestibular Function Tests.

40. Vestibular Function Tests.

41. Vestibular Functional Assessment

42. Why Dizzy Battery • As we can See no single test looks at all the vestibular sensory organs completelyso the Test battery approach is recommended to completely evaluate the Balance function in a dizzy patient. • This battery of tests performed together completely evaluates hearing and balance part of the ear (VIII N) including Superior and Inferior Vestibular Nerve.

43. What is the best test for balance assessment? Horak FB. Postural orientation and equilibrium: what do we need to know about neural control of balance to prevent falls? Age and Ageing. 2006;35(2):ii7-ii11. Horak FB, Wrisley DM, Frank J. The Balance Evaluation Systems Test (BESTest) to differentiate balance deficits. PhysTher. 2009;89:484-498. www.natus.com

44. Cost analyses • MRI/CT Cost = $ 1300 Only diagnose cause of dizziness in .04% of cases. • Where as dizzy battery of test: Cost 50% less at least Can detect cause of dizziness in 50% of patients

45. Team Work • Although testing has become more and more automated but you still need a qualified person behind the computer to accurately interpret the results. • That is why team work is important. • We work closely with our group of ENT doctors to interpret the test results and help our physician properly manage the patients balance issues.

46. Final word • If you are not sure what could be real issue, just ask for a “Dizzy Test Battery” Because ear is the cause of vertigo in almost 50% of patient.