Transcript Otolaryngologic Manifestations of Arnold

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 SYNDROMES
PHYSICAL 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 8th 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
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
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
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
Central Sleep Apnea
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. 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.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, 2010