Correlating the cochleovestibular deficits with tumor size of acoustic neuroma.
CONCLUSIONS
The tumor size of acoustic neuroma correlates with cochleovestibular deficits. Those tumors with global frequency hearing loss, bilateral gaze nystagmus, or absent caloric and VEMP responses may indicate a tumor size >2.5 cm.


OBJECTIVE
This study aimed to investigate the correlation between cochleovestibular deficits and the size of acoustic neuroma.


METHODS
A total of 44 patients with acoustic neuroma were enrolled in this study. Pure tone audiometry, electronystagmography, caloric test, vestibular evoked myogenic potential (VEMP) test, and MRI were conducted.


RESULTS
There is a trend of correlation between tumor size and audiographic configuration, with small-sized tumor in normal and rising types, medium-sized tumor in mid- and high-frequency hearing loss, and large-sized tumor in flat and deafness types. Five patients with bilateral gaze nystagmus had significantly larger tumor size than those without nystagmus. When 1 and 0 are used to represent abnormal and normal responses, respectively, the relationship between tumor size and vestibular function can be expressed as: tumor size (cm)=1.43 (caloric response)+1.35 (VEMP response), indicating that the estimated tumor size for those with abnormal caloric or VEMP responses increased by 1.43 or 1.35 cm, respectively.
Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan.
An-Shiou
AS
Day
Chi-Te
CT
Wang
Chun-Nan
CN
Chen
Yi-Ho
YH
Young
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001299:Audiometry; D003051:Cochlea / Q000473:pathology / Q000503:physiopathology*; D003937:Diagnosis, Differential; D004584:Electronystagmography; D005071:Evoked Potentials; D005260:Female; D034381:Hearing Loss / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000473:pathology / Q000503:physiopathology*; D017120:Nystagmus, Optokinetic; D015835:Ocular Motility Disorders / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*; D011379:Prognosis; D012720:Severity of Illness Index; D014724:Vestibular Function Tests; D014722:Vestibule, Labyrinth / Q000473:pathology / Q000503:physiopathology*