Satoshi Sonoda

Traction of lateral cricoarytenoid muscle for unilateral vocal fold paralysis: comparison with Isshiki' s original technique of arytenoid adduction.

Between 1995 and 1997, we performed Isshikis original method of arytenoid adduction alone or as an adjunct to type I thyroplasty for the treatment of unilateral vocal fold paralysis. From 1997 onward, we performed arytenoid adduction by traction of the lateral cricoarytenoid muscle (Iwamuras method), because it reduces discomfort to the patient and avoids rotation of the thyroid cartilage. Preliminary experiments and surgical procedures involving traction of the lateral cricoarytenoid muscle are described. Of 21 patients with a maximum phonation time of less than 9 seconds, 14 underwent type I thyroplasty as an adjunct to our method of arytenoid adduction and 7 underwent arytenoid adduction alone. Sixteen patients (76%) were able after surgery to extend their maximum phonation time beyond 10 seconds; this result compares favorably with the results of Isshikis original adduction technique. We describe useful anatomic landmarks for approaching the lateral cricoarytenoid muscle in the hope that more voice surgeons will adopt this approach in the treatment of unilateral vocal fold paralysis.

A Case of Earpick Injury with Delayed Facial Paralysis

We reported a rare case of ear trauma with delayed facial paralysis, ossicular chain dislocation and perilymph fistula caused by an earpick. A 36-year-old male consulted our clinic with a complaint of left otalgia, hearing loss, tinnitus and dizziness after left ear trauma with an earpick. Otoscopic examination showed perforation of the left ear-drum and pure tone audiometory demonstrated a mixed hearing loss with an average air conduction threshold of 53dB on the initial examination. He was diagnosed as having a traumatic ear-drum perforation. Left facial paralysis occurred 6 days after the trauma, then recovered after the intravenous steroid treatment. Hearing impairment did not improve after spontaneous closure of the ear-drum perforation, and exploratory tympanoplasty was performed. At surgery, the incus was dislocated and the anterior and posterior crura of stapes were fractured. Perilymphatic leakage from the fractured footplate was noted. The footplate was covered with temporal fascia and ossicular chain reconstruction was performed using the incus on the foot plate as a columella. Post operationally, the hearing threshold improved with an average air conduction threshold of 31.7dB.

Auditory cortical response to monaural stimulation detected by functional magnetic resonance imaging

Abstract Few reports have characterized auditory processing in monaural listening, which is important for the understanding of auditory brain activity in subjects with hearing loss. We measure regional brain activity in response to monaural audition of 95 dB sound pressure level (SPL) monosyllables using functional magnetic resonance imaging (fMRI) in the 10 subjects with normal hearing and four subjects with unilateral deafness as controls for “cross-hearing”. Images were analyzed by statistical parametric mapping software. In subjects without hearing loss, the stimuli elicited cortical activation in the primary auditory and auditory association regions, particularly contralaterally where extent of activation was approximately 2.5 times the ipsilateral extent. All patients with profound unilateral deafness showed no statistically apparent response in the primary auditory and auditory association regions, ruling out an important influence from cross-hearing. We found fMRI to be a useful technique for analysis of auditory processing that should be applicable to patients with various hearing abnormalities.