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

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

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

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

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

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

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

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

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

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

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

Electronystagmography

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

Rotational Chair Testing

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

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

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

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

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

Central Sleep Apnea

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

Central Sleep Apnea

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

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

Thank You

Ada M, et al. Congenital vocal cord paralysis. J Craniofac Surg Jan;21(1):273-4 Dauvilliers Y, et al. Chiari malformation and sleep related breathing disorders. J Neurol Neurosurg Psychiatry 2007;78: Hain TC. 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 Sep;23(5): Murray C, et al. Arnold Chiari type I malformation presenting with sleep disordered breathing in well children. Arch Dis Child April;91(4): Rowley JA. Obstructive Sleep Apnea-Hypopnea Syndrome: Multimedia. Updated May 14, 2010www.emedicine.com