1. Otolaryngologic Manifestations of Arnold-Chiari Malformation Syboney Zapata, M.D., F.A.A.P. Pediatric Otolaryngology Austin Ear, Nose, & Throat Clinic

2. Objectives Recognize symptoms of ACM pertinent to ENT Discuss differential diagnosis Review diagnostic studies

3. Arnold-Chiari Malformation Herniation of cerebellar tonsils through foramen magnum Neuronal impairment of brainstem, upper spinal cord, & cranial nerves

4. Symptoms of ACM Pertinent to the Otolaryngologist Auditory/vestibular dysfunction Vocal cord paralysis Sleep apnea

5. Vestibular Symptoms in Cerebellar Disorders Cerebellum largely involved in COORDINATION Cerebellar dysfunction presents as unsteadiness, clumsiness, and difficulty with stabilizing eye movements

6. Vestibular Findings in Cerebellar Disorders CEREBELLAR SYNDROMESPHYSICAL EXAM MIDLINE (“Imbalance”)Romberg Tandem gait Truncal ataxia Titubation Abnormal eye movements HEMISPHERIC (“Incoordination of Limbs”) Dysdiadochokinesis Finger-to-nose/Heel-to-shin

7. Mechanism of Auditory/Vestibular Symptoms Direct pressure on vestibular areas Increased fluid pressure throughout the brain Increased pressure of inner ear via cochlear aqueduct

8. Mechanism of Auditory/Vestibular Symptoms Further stretching of elongated nerves Bending of 8 th nerve over bony edge of porus acousticus Compression of brainstem nuclei

9. Auditory/Vestibular Symptoms in ACM Sensorineural hearing loss Vertigo & Dizziness Nystagmus (Downbeating) and Poor Pursuits

10. Diagnostic Evaluation of Auditory/Vestibular Symptoms in ACM Electronystagmography (ENG) Rotational chair testing Vestibular Evoked Myogenic Potential Testing (VEMP) Electrocochleography testing (ECOG) Fistula testing Moving platform posturography

11. Diagnostic Evaluation of Auditory/Vestibular Symptoms in ACM Electronystagmography (ENG) Rotational chair testing Vestibular Evoked Myogenic Potential Testing (VEMP) Electrocochleography testing (ECOG) Fistula testing Moving platform posturography

12. Electronystagmography

13. Determines whether or not dizziness is due to inner ear disease Excellent for diagnosis of unilateral ear disorders 4 main parts: - Calibration test - Tracking test - Positional test - Caloric test Intended to diagnose CNS disorders

14. Rotational Chair Testing

15. Determines whether or not dizziness is due to inner ear or brain disorder Obtained in addition to ENG 3 main parts: - Chair test - Optokinetic test - Fixation test

16. Vocal Cord Paralysis Flexible laryngoscopy demonstrates bilateral vocal cords in the paramedian position and no mobility with vocalization

17. Vocal Cord Paralysis Congenital TVC paralysis ACM accounts for most central neurologic causes of bilateral TVC paralysis Tracheostomy often necessary

18. Sleep Apnea Central Apnea: Cessation of both airflow and respiratory effort Obstructive Apnea: Cessation of airflow in the presence of continued respiratory effort Mixed Apnea

19. When to Order a Sleep Study in the Pediatric Population Symptoms in morbidly obese patient Apnea in absence of snoring Apnea without adenotonsillar hypertrophy Underlying neurologic disorders Craniofacial abnormalities

20. Central Sleep Apnea

21. Dysfunction of medullary centers of respiratory control Cranial nerve dysfunction involving laryngeal nerves or bulbar muscles, which mediate airway patency

22. Central Sleep Apnea

24. Anticipate immediate improvement after decompression surgery Reports of recovery taking up to 6-12 months

25. Conclusions Physical exam in combination with diagnostic studies may indicate central cause of imbalance and hearing loss ACM should be considered in bilateral TVC paralysis High index of suspicion of ACM in central/mixed sleep apnea

26. Thank You

27. Ada M, et al. Congenital vocal cord paralysis. J Craniofac Surg. 2010 Jan;21(1):273-4 Dauvilliers Y, et al. Chiari malformation and sleep related breathing disorders. J Neurol Neurosurg Psychiatry 2007;78:1344-1348 Hain TC. www.dizziness-and-balance.comwww.dizziness-and-balance.com Hershberger ML and Chidekel A. Arnold-Chiari Malformation Type I and Sleep-Disordered Breathing: Review of Literature. J Pediatr Health Care. 2003;17(4) Kuma A, et al. The Chiari I malformation and the neurologist. Otol Neurotol. 2002 Sep;23(5):727-35 Murray C, et al. Arnold Chiari type I malformation presenting with sleep disordered breathing in well children. Arch Dis Child. 2006 April;91(4):342-343 Rowley JA. Obstructive Sleep Apnea-Hypopnea Syndrome: Multimedia. www.emedicine.com. Updated May 14, 2010www.emedicine.com