Introduction: Chiari malformation has a prevalence of 0.1-0.5% and is associated with cerebellar symptoms, headaches, vestibular symptoms, and apnea. Sleep apnea affects 9%-25% of the middle aged population and symptoms overlap with CM. Patients with these other conditions and CM present a diagnostic dilemma, since decompression may not provide relief if symptoms are due to these more-common disorders. For this reason, we refer these patients for neuro-otologic and vestibular evaluation with videonystagmography to determine if pathologic nystagmus is consistent with CM.

Methods: We present a case of a 61-year-old female with CM presenting with dizziness, imbalance, migraines, nystagmus, and severe sleep apnea diagnosed by polysomnography.

Results: She underwent operative decompression. At her 3 month follow-up she reported improvement in gait, general well-being and sleep apnea. She had discontinued nighttime oxygen. A post-operative pulse oximetry on room air demonstrated improvement with an SpO2 < 89% for 3 mins 8 secs (a 93% improvement); there were 5.3 desaturation events per hour (a 55% improvement. At 5 months post op she reported that her constant “swimming” feeling had resolved. Her central nystagmus was no longer present on exam. AT 1 year post-op she continued to endorse improvement in her vestibular symptoms and gait.

Conclusions: Dizziness and headache due to CM are difficult to differentiate from similar symptoms due to sleep apnea, migraine, or peripheral vestibular disorders. In this case the patient experienced positional nystagmus, dizziness, migraine headaches and sleep apnea, all of which improved after decompression, suggesting that all of her symptoms were secondary to the malformation. If a patient is determined to have sleep apnea without other causes in the setting of a Type I malformation, suboccipital decompression should be considered as a viable treatment option. Formal evaluation of nystagmus with vestibular testing was useful in determining that the source of the nystagmus was the CM.

Patient Care: If a patient is determined to have sleep apnea without other causes in the setting of a Type I malformation, suboccipital decompression should be considered as a viable treatment option. Formal evaluation of nystagmus with vestibular testing can be useful in determining that the source of the nystagmus was the CM.

Learning Objectives: By conclusion of this session, participants should be able to 1) discuss the utility of chiari decompression in the treatment of central sleep apnea and 2)describe the importance of vestibular testing in concluding that the CM is the source of symptoms

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