A modified o VEMP test to elicit the

Vestibulo-ocular reflex Visuomotor reflex (VOR) circuit ri MLF Otolithic reflex III VI IV MLF

Patients (2012 -2017) Case no. : 26 / 13, 026 (0. 2%) with bil.

Methods Electronystagmography Ocular and cervical VEMPs Head shaking reading test Cervico-ocular reflex test ¡

Clinical manifestation 100 Group A oscillopsia (+) (%) 77 54 54 Tinnitus Headache 0

I. Visuomotor reflex tests Abnormality 100 (%) 77 46 62 Group A oscillopsia (+)

II. Otolithic reflex test o. VEMP 88% : Normal : Abnormal 73% p>0. 05

III-1. Cervico-ocular (COR) test via head vibration method • • The The electrodes were

III-2. Cervico-ocular (COR) test via neck vibration method • • The electrodes were placed

Characteristic parameters of COR 30 10 21. 0 (ms) 5. 7 (μV) 15. 9

COR prevalence : Presence : Absence 0% Group A Group C 58% Group B

Conclusion The COR serves as a powerful compensatory mechanism for bilateral VOR loss. The

World heritage: Pieta of S. Maria de Flore Neck rotation Gaze upward (Michelangelo, 1547

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A modified o. VEMP test to elicit the cervico-ocular reflex 修飾o. VEMP檢查方法來誘發頸眼反射許碩彥楊怡和臺大醫院耳鼻喉部

Vestibulo-ocular reflex Visuomotor reflex (VOR) circuit ri MLF Otolithic reflex III VI IV MLF VIII N Cervico-ocular reflex (COR)

Patients (2012 -2017) Case no. : 26 / 13, 026 (0. 2%) with bil. VOR loss Group A Group B Group C Oscillopsia (+) Oscillopsia (-) Caloric normal Case no. : 13 Sex : M/F = 5/8 Sex : M/F = 7/6 Sex : M/F = 6/7 Age : 39 -87 (69)Y Age: 38 -83 (66) Y Age: 62 -67 (65) Y p>0. 05

Methods Electronystagmography Ocular and cervical VEMPs Head shaking reading test Cervico-ocular reflex test ¡ head vibration method ¡ neck vibration method

Clinical manifestation 100 Group A oscillopsia (+) (%) 77 54 54 Tinnitus Headache 0 Vertigo 0 15 31 Fullness p >0. 05 15 62 (%) 100 77 Group B oscillopsia (-)

I. Visuomotor reflex tests Abnormality 100 (%) 77 46 62 Group A oscillopsia (+) 0 Pursuit Abnormality 0 (%) 100 Saccade 31 85 OKN 46 p >0. 05 Group B oscillopsia (-)

II. Otolithic reflex test o. VEMP 88% : Normal : Abnormal 73% p>0. 05 c. VEMP 77% Group A: oscillopsia (+) 62% Group B: oscillopsia (-)

III-1. Cervico-ocular (COR) test via head vibration method • • The The electrodes were placed below the lower eyelids. head rotated to activate the neck muscles. eyes looked upward during recordings. vibrator tapped the forehead.

Ipsilateral vs. cross-over COR

COR vs. c. VEMPs o. VEMPs

III-2. Cervico-ocular (COR) test via neck vibration method • • The electrodes were placed below the lower eyelids. The vibrator tapped at the mid-dorsal neck. The eyes looked upward. Without head rotation.

COR: head vs. neck vibration

Characteristic parameters of COR 30 10 21. 0 (ms) 5. 7 (μV) 15. 9 0 10 c. I latency c. I-c. II amplitude

COR prevalence : Presence : Absence 0% Group A Group C 58% Group B (by sides) p< 0. 001 85% Group B (by subjects) p< 0. 001

Conclusion The COR serves as a powerful compensatory mechanism for bilateral VOR loss. The COR responses could be elicited by modifying o. VEMP test without changing procedural settings.

World heritage: Pieta of S. Maria de Flore Neck rotation Gaze upward (Michelangelo, 1547 -55)