Otolaryngology– Head and Neck Surgery Volume 119 Number 6 689 Air in the vestibule: Computed tomography scan finding in traumatic perilymph fistula DAVID J. MALIS, MD, ANTHONY E. MAGIT, MD, SETH M. PRANSKY, MD, DONALD B. KEARNS, MD, and ALLAN B. SEID, MD, San Diego, California CASE REPORT A 13-year-old boy was involved in a bicycle accident and sustained a closed head injury with 5 minutes of loss of con- sciousness and seizure activity. The patient was stabilized in the emergency department; findings of a CT scan of the brain were normal. The patient was admitted to the hospital, and the otolaryngology service was consulted the following day for evaluation of the patient’s dizziness symptoms. On examination, the patient reported decreased hearing in the left ear with associated high-pitched tinnitus. Additionally, the patient reported dysequilibrium at rest and severe vertigo with any head motion; he could not walk without assistance. From the Department of Pediatric Otolaryngology (Drs. Malis, Magit, Pransky, Kearns, and Seid), Children’s Hospital of San Diego; and the Division of Otolaryngology (Dr. Magit), University of California at San Diego Medical Center. The opinions expressed herein are those of the authors and do not necessarily reflect those of the Departments of the Army or Defense. Reprint requests: David J. Malis, MD, Otolaryngology–Head & Neck Surgery Service, Brooke Army Medical Center, San Antonio, TX 78234. Otolaryngol Head Neck Surg 1998;119:689-90. 23/4/81225 Physical examination revealed third-degree nystagmus (with- out Frenzl lenses), intact facial function, and a Weber tuning fork lateralizing to the left ear at 512 and 1024 Hz. The left ear canal and tympanic membrane were normal. There was, however, a small meniscus of serosanguinous effusion in the middle ear. An audiogram was performed and demonstrated a conductive hearing loss through 2000 Hz and a steep, pro- found, mixed hearing loss through 8000 Hz. A CT scan of the temporal bones was obtained and demonstrated a transverse fracture line lateral to the cochlea extending through the vestibule. Of note was the finding of air bubbles in the vestibule and lateral and superior semicircular canals (Fig. 1). Because a traumatic perilymph fistula (PLF) was suspected, the patient was placed on bed rest; the symptoms of vertigo completely resolved, although the tinnitus persisted. Serial audiograms demonstrated resolution of the low-frequency conductive hearing loss; however, the mixed hearing loss improved to only 50 dB (masked bone conduction) through 6000 Hz. DISCUSSION The clinical signs and symptoms in suspected PLF make the existence of this entity an enigma. Objective evidence to support the diagnosis of a PLF has relied on individual surgeons’ observations at the time of exploratory tympan-