Focused Issue of This Month Gyu Cheol an, MD Department of Otolaryngology ead & Neck Surgery, Gachon University of College Medicine E - mail : han@gilhospital.com Won-o Jung, MD Department of Otolaryngology ead & Neck Surgery, Sungkyunkwan University School of Medicine E - mail : whehung@skku.edu J Korean Med Assoc 2008; 51(11): 975-983 Basically laboratory vestibular function testing use the vestibular ocular reflex and vestibular spinal reflex like as bedside examination or outpatients' evaluation. Such vestibular laboratory testing can aid diagnosis and can be used to document an abnormality suspected at bedside evaluation. The ability to perform serial vestibular evaluations allows an assessment over time of patients who are undergoing treatment for dizziness or treatment with potentially ototoxic medication. Generally speaking, it includes spontaneous nystagmus, some kinds of evoked nystagmus, ocular eye movement testing, Caloric's testing, rotational chair testing, vestibular evoked myogenic potential, subjective visual vertical, posturography and so on. Those testing have been developed with biomedical engineering based on the proven scientific facts together. Keywords: estibular function testing Abstract 975
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Positional-ead - Right Positional-ead - Center Positional-ead - Left 14s 48s 94s 14s 48s 94s Positional-ead - Right Positional-ead - Center Positional-ead - Left 6s 29s 47s 6s 29s 47s Figure 1. The results of positional test. It shows two types of horizontal canal benign positional paroxysmal vertigo. The ageotrophic horizontal direction changing positional nystagmus is shown on the top and it means the cupulolithiasis. Otherwise the geotrophic horizontal direction changing positional nystagmus is shown on the bottom and it means the canalithiasis. The lesion sides are right (top) and left (bottom) each. 977
an GCJung W Figure 2. The results of oculomotor testing. It shows saccadic (top) and pursuit (the middle) tests on left vestibulopathy patient, and then optokinetic (bottom) test on right vestibulopathy patients. Whole graphic data are affected by right beating (top and the middle) and left beating (bottom) spontaneous nystagmus. 978
Figure 3. The result of bithermal caloric test. It shows right acute vestibuopathy. The canal paresis and directional preponderance are 78%, 45% each. isual fixation test is done on left side only and the value is not significant. 979
an GCJung W Figure 4. The results of sinusoidal harmonic acceleration test. It shows gain (top right), symmetry (top left), phase (bottom) on right acute vestibulopathy patients. 980
Figure 5. The results of step velocity test. It shows decreasing time constant on clockwise rotation (top) as 1 sec. Otherwise it is longer than that at counterclockwise rotation as 5 sec. It means the right acute vestibulopathy. 981
an GCJung W 0 SOM IS EST PREF Figure 6. The results of dynamic posturograhy. The patient was fall down at condition 5 and 6 (right). Those condition means vestibular sensory organized condition (left). 11. Michael Fetter. Assessing vestibular function: which tests, when? J Neurol 2000; 247: 335-342. 12. erman Kingma. Function tests of the otolith or statolith system. Curr Opin Neurol 2006; 19: 21-25. 13. Thomas Brandt, Michael Strupp. General vestibular testing. Clinical Neurophysiology 2005; 116: 406-426. 982
Peer Reviewers Commentary 983