KISEP Otology Korean J Otolaryngol 2000;43:7-14 청신경종의크기에따른어지러움의양상및전정기능검사의특징 정원호 홍성화 조양선 김성민 장병찬 최재연 이승진 Characteristics of Vertigo Manifestations and Vestibular Function Tests in Patients with Acoustic Neuroma according to the Tumor Size Won-Ho Chung, MD, Sung Hwa Hong, MD, Yang-Sun Cho, MD, Sung-Min Kim, MD, Byung-Chan Chang, MD, Jae-Yeon Choi and Seung-Jin Lee Department of Otorhinolaryngology-Head and Neck Surgery, Sungkyunkwan University School of Medicine, Seoul, Korea ABSTRACT Background and ObjectivesAcoustic neuromas ANs usually manifest ipsilateral peripheral vestibulopathies with various degrees of compensation in vestibular function tests VFTs. As the tumor grows, the cerebellum and brain stem are compressed and various central signs may develop. However, the clinical usefulness of VFTs in ANs, especially in the early diagnosis, treatment, and rehabilitation, is not yet fully studied. The objective of this study was to evaluate the characteristics of clinical manifestations and VFTs according to the tumor size in ANs. Material and MethodsWe reviewed the medical records of 33 patients who were pathologically diagnosed as ANs. We divided the patients into 5 groups according to the tumor size Tos, 1992 and analyzed the relationship between the tumor size and the characteristics of clinical manifestations and VFTs. ResultsSeventy percent of patients had experienced dizziness. True vertigo was more common in patients with smaller tumorsin contrast, unsteadiness or dysequilibrium was manifested more frequently in larger tumors. Most patients 94% showed peripheral vestibulopathies and among them, 42% of patients were compensated functionally and physiologically. ConclusionClinical manifestations regarding dizziness and the results of VFTs, especially the degree of compensations, might be helpful in diagnosing early ANs. Further investigations will be needed to confirm these assumptions. Korean J Otolaryngol 2000;43:7-14 KEY WORDSAcoustic neuroma Vestibular function tests. 7
8 Table 1. Chief complaints of the patients with acoustic neuroma Chief complaints Progressive unilateral hearing loss Tinnitus Dizziness Headache Facial numbness Incidentally detected Total N % 14 42 6 18 6 18 3 9 3 9 1 3 33 100 Korean J Otolaryngol 2000;43:7-14
Table 2. History associated with dizziness in the patients with acoustic neuroma Tumor size mm IC 110 1125 2640 40 Total % True vertigo 3 0 2 1 1 7 21 Unsteadiness or dysequilibrium 0 1 5 3 7 16 48 No vertigo 0 0 6 3 1 10 30 Total 3 1 13 7 9 33 100 Table 3. Electronystagmography findings in the patients with acoustic neuroma Tumor size mm IC n3 110 n1 1125 n13 2640 n7 40(n9 Total % n33 Spontaneous N. 1 0 0 0 0 1 3 Gaze N. Bruns N. 0 0 0 3 7 4 10 30 Impaired Smooth pursuit 0 0 0 3 7 10 30 Impaired Saccade 0 0 1 3 2 6 18 Impaired OKN Bilateral 0 0 0 3 7 10 30 Unilateral 1 0 2 1 1 5 15 ICintracanalicular, N.nystagmus Table 4. Caloric test in the patients with acoustic neuroma Tumor size mm IC 110 1125 2640 41 Total % CP25% 2 0 0 0 0 2 21 25%CP99% 1 0 4 2 0 7 48 CP100% 0 1 7 3 7 18 56 Bilateral weakness 0 0 1 2 2 5 16 Total 3 1 12* 7 9 32* 100 ICintracanalicular, CPcanal paresis *In one patient, caloric test was not done due to tympanic membrane perforation 9
청신경종의 크기에 따른 어지러움의 양상 및 전정기능 검사의 특징 있었던 경우가 2예(6%) 있었다(Fig. 2A, B and C). 보상의 정도 종양의 크기별로 보면 초대형 종양은 9예 중 2예(22%)에 보상의 기준을 자발안진이 없고, 회전의자검사에서 비대 서만 정상소견을 보인 반면, 중형에서는 13예 중 8예(62%), 칭성을 보이지 않으며, 동적자세검사상 전정기능장애의 소 내이도에 국한된 종양에서는 3예 모두 정상소견을 보였다. 견을 보이지 않는 경우로 하였을 때 보상이 이루어진 경우 A B C D E Fig. 1A-E. Patterns of vestibulo-ocular reflex in patients with acoustic neuroma. A. It shows normal vestibulo-ocular refex. B. It shows slightly low gain and greater-than-normal phase lead at frequencies of 0.01 and 0.02 Hz, but no asymmetry is found. C. It shows low gain, greater-than-normal phase lead and asymmetry to left. D. It shows asymmetry only at low frequencies. E. It shows low gain and greater-than-normal phase lead at all frequencies, but no asymmetry is found. 10 Korean J Otolaryngol 2000;43:7-14
Table 5. Rotating chair test in the patients with acoustic neuroma Tumor size mm Total % IC 110 1125 2640 41 Normal 2 0 1 1 0 4 13 Low gain and/or phase lead VOR with asymmetry 0 0 2 3 5 10 31 without asymmetry 0 0 6 1 1 8 25 Asymmetry only 1 1 2 0 1 5 16 Bilateral weakness 0 0 1 2 2 5 16 VVOR Normal 3 1 9 3 1 17 53 Abnormal 0 0 3 4 8 15 47 VFX Normal 3 1 12 7 8 31 97 Abnormal 0 0 0 0 1 1 3 Total 3 1 12* 7 9 33 100 ICintracanalicular, VORvestibulo-ocular reflex, VVORvisual vestibulo-ocular reflex, VFXvestibulo-ocular reflex with fixation *Rotary chair test could not be done due to incorporation Table 6. Dynamic posturography sensory organization test in the patients with acoustic neuroma Tumor size mm Total % IC 110 1125 2640 41 Normal 3 0 8 3 2 16 48 Abnormal SOMVISVEST 0 0 1 0 1 2 6 VISVEST 0 0 1 4 1 6 19 VEST 0 1 3 0 5 9 27 Total 3 1 13 7 9 33 100 ICintracanalicular, SOMsomatosensory, VISvisual, VESTvestibular 11
청신경종의 크기에 따른 어지러움의 양상 및 전정기능 검사의 특징 병력상 청력소실이나 이명을 동반하지 않더라도 반복적인 자발안진은 말초성 또는 중추성 장애에 의하여 동안신경 회전성의 어지러움을 경험하는 경우에는 감별진단에 청신 에 도달하는 긴장신호의 부조화로부터 나타나는 것으로 청 경종을 포함시켜야 할 것이다. 신경 종양에서의 자발안진은 일측 전정장애로 인하여 종양 A B C Fig. 2A-C. Patterns of sensory organization test in patients with acoustic neuroma. A. It shows abnormal postural stability under condition 5 and vestibular dysfunction on sensory analysis. B. It shows normal postural stability under conditions 1 to 3, but marked instability under conditions 4 to 6 and visual and vestibular dysfunction on sensory analysis. C. It shows abnormal postural stability under all conditions and somatosensory, visual, vestibular dysfunction on sensory analysis. Table 7. Status of compensation in the patients with acoustic neuroma Tumor size (mm) Total (%) IC 1-10 11-25 26-40 > 40 Compensated 2 0 8 3 2 15 ( 45) Uncompensated 1 1 5 4 7 18 ( 55) 3 1 13 7 9 33 (100) Total IC intracanalicular 12 Korean J Otolaryngol 2000;43:7-14
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