Early post-laser stapedotomy hearing thresholds.

OBJECTIVE: Auditory testing is not routinely performed within 4-6 weeks after stapedotomy, because hearing acuity is thought to be transiently depressed. In rare circumstances, postsurgical auditory and vestibular complaints may lead one to test hearing soon after stapedotomy. The early postoperative effects of carbon dioxide (CO2) and potassium titanyl phosphate (KTP) lasers, which now are routinely used to perform stapedotomies, have not been reported. The purpose of this report is to present normative data for auditory thresholds measured within 2 weeks of laser stapedotomy. STUDY DESIGN: The study design was a prospective, unblinded study. SETTING: The study was conducted at three academic medical centers. PATIENTS: Thirty-six subjects undergoing 38 stapedotomies for otosclerosis by 5 surgeons participated. MAIN OUTCOME MEASURES: Behavioral audiometry was performed using standard techniques beginning before surgery and continuing through > 1 year after surgery. RESULTS: The CO2 laser was used in 26 stapedotomies and the KTP laser was used in 12. Nine cases were revision procedures. Bone conduction pure-tone averages and speech discrimination scores did not worsen during the early postoperative period. Bone conduction at 250 and 4,000 Hz dropped slightly within the first 2 weeks (-4.3 and -6.7 dB) but recovered thereafter. Bone conduction at 1,000 Hz actually improved within the first week after surgery (+6.2 dB, p = 0.021). Significant improvements in air conduction thresholds (and air-bone gap) were seen at the second week and late audiometry. The results for CO2 and KTP laser-treated groups were not significantly different. CONCLUSIONS: Cochlear function is not significantly depressed in the early postoperative period after laser (CO2 or KTP) stapedotomy.

Sac-vein decompression for intractable Meniere's disease: two-year treatment results.

Surgical intervention has been offered to patients with Meniere's disease who have failed medical treatment and have disabling symptoms. Surgical options have included labyrinthectomy (mechanical and chemical), vestibular neurectomy, and endolymphatic sac surgery with or without shunting. We present a modification of endolymphatic sac decompression surgery that includes wide decompression of the sigmoid sinus, posterior cranial fossa dura, and endolymphatic sac (sac-vein decompression). Thirty-five patients underwent 37 primary procedures with 2 years of follow-up. Patients were evaluated according to the 1985 American Academy of Otolaryngology-Head and Neck Surgery criteria for assessing Meniere's disease. Vestibular symptom severity was resolved or mild in 92% and disability severity was none or mild in 95% of patients at 2 years after surgery. Vertigo control was complete or substantial in 85% and 100% of patients at 1 and 2 years after surgery. Audiologic data showed stable or improved hearing in 86% and 85% of patients at 1 and 2 years after surgery. In summary, wide decompression of the sigmoid sinus, posterior cranial fossa dura, and endolymphatic sac offers improved control of vertigo and hearing stabilization for intractable Meniere's disease compared with simple endolymphatic sac decompression or shunt surgery.

Temporal bone encephalocele and cerebrospinal fluid leaks.

Nineteen cases of temporal bone brain herniation and cerebrospinal fluid (CSF) leaks in 17 adult patients since 1987 are reviewed. Of these 19 cases, 11 were spontaneous CSF leaks, 6 were related to chronic otitis media, and 2 were posttraumatic. Among the 10 women and 7 men, the average age was 51.2 years, with average follow-up time of 2 years, 7 months. Two cases were repaired by a middle fossa craniotomy approach, 1 case by a transmastoid approach, and 16 by a combined transmastoid and middle fossa approach. Ten cases utilized the preferred technique of fascia-bone-fascia to repair the defects. The diagnosis was made on clinical grounds in 18 of the 19 cases, with ancillary diagnostic test providing little useful information. There were no postoperative surgery-related complications, and definitive repair was accomplished in one stage in all cases.

Surgical treatment of Ménière's disease.

Several reliable surgical procedures aimed to control the vertigo associated with Meniere's disease exist. Vestibular preservation and ablative procedures are available with the latter divided between hearing preservation and destructive operations. Factors to consider prior to choosing a surgical option include the age, health, and employment status of the patient; the degree of hearing loss in the involved ear; and the status of the contralateral ear.

Pulsatile tinnitus associated with a laterally placed sigmoid sinus.

We describe a case of subjective pulsatile tinnitus associated with a laterally placed sigmoid sinus. CT showed an enhancing eroding through the medial wall of the right mastoid. Two-dimensional time-of-flight MR angiography and conventional cerebral angiography revealed the tortuous and laterally deviated sinus.

Carcinoma metastatic to both cerebellopontine angles masquerading as acoustic neuromas.

Metastases to the cerebellopontine angles (CPAs) are rare. Typically, the clinical course is one of rapid onset and progression of crarial nerve deficits. The clinical presentation and course of carcinoma metastatic to the CPAs are reviewed. We report a case of bilateral CPA metastases with a radiographic appearance similar to neurofibromatosis type 2 presenting with rapidly progressive bilateral hearing loss followed by unilateral facial nerve palsy.

Facial nerve outcome in acoustic tumor surgery.

Seventy-three procedures involving 70 acoustic tumors were carried out over 3 years. The majority of tumors (65) were removed by the translabyrinthine approach. Tumor size ranged from 0.5 through 5.0 cm. All patients underwent intraoperative facial nerve monitoring: 22 patients developed immediate facial palsy (House-Brackmann grades II-VI); 11 patients recovered completely; 11 patients (15.7%) had persistent paralysis. The incidence of long-term, poor outcome (H-B grade IV-VI) was 5.7 percent. The overall incidence of facial palsy was not found to be related to tumor size; however, facial paralysis associated with large tumors exhibited a poorer House-Brackmann grade compared to small and medium lesions. The use of intraoperative facial monitoring has enhanced the surgeon's ability to preserve facial nerve function by reducing the overall incidence of postoperative facial paralysis.

Selective embolization of glomus jugulare tumors.

Four patients with grade C or D(1) glomus jugulare tumors who underwent preoperative highly selective embolization followed by infratemporal fossa removal of their tumors were compared to three patients undergoing surgery alone with respect to intraoperative blood loss, operative time, cranial nerve palsy, length of hospitalization, and perioperative complications. Embolized patients demonstrated a marked reduction in blood loss (650 vs 1375 cc) compared with the nonembolized group. Operative time was shortened (by 51 minutes). Facial nerve function did not appear related to embolization but was directly related to intraoperative nerve manipulation. Hospital stay, perioperative complications, and lower cranial nerve palsies were not related to embolization.

Titration streptomycin therapy in Menière's disease: current concepts.

Soon after its discovery, streptomycin sulfate was found to be beneficial in the treatment of tuberculosis. However it also was found to have toxic effects, primarily vestibular and typically sparing the auditory nerve until higher doses were administered. The first reported use of streptomycin in the treatment of vertigo was in 1948. This was soon followed by its use for treating Menière's disease. Although excellent control of vertigo was achieved significant post-treatment oscillopsia was experienced by these completely ablated patients. A protocol of titration streptomycin therapy was established that effectively controls vertigo while decreasing the incidence of oscillopsia. This report presents three patients with Menière's disease treated with this protocol.

The effect of pentoxifylline on cochlear blood flow.

Pentoxifylline, a phosphodiesterase inhibitor and hemorrheologic agent has been found to increase oxygen delivery to ischemic tissue. Intravenous pentoxifylline was administered to normal guinea pigs in order to assess the effect of pentoxifylline on cochlear blood flow and to elucidate its mechanism of action. Intravenous pentoxifylline was found to acutely increase cochlear blood flow in a dose-dependent manner. In normal animals, the effect appeared strongly related to the rheologic properties of this agent rather than a vasodilative action. Normovolemic hemodilution with 75% dextran resulted in no increase in cochlear blood flow during infusion of pentoxifylline, whereas the application of nitroprusside over the round window failed to abolish the effect of pentoxifylline.

The effects of Carbogen, carbon dioxide, and oxygen on noise-induced hearing loss.

An investigation into the effect of Carbogen (95% O2/5% CO2), 5% CO2/air, and 100% oxygen on cochlear threshold shifts caused by noise was undertaken. Five groups of eight pigmented guinea pigs were exposed to 105 dB broad band noise for 6 h per day for five consecutive days with each group receiving the various gaseous mixtures either during noise exposure or for 1 h immediately after noise exposure. A control group received the same noise exposure but respired air. Auditory threshold shifts, as measured by the auditory evoked brainstem response, were measured at 2,4,8,12,16, 20 and 24 kHz. Recordings were taken pre-exposure and at Day 1, 3, 5, and Weeks 2 and 3 after noise exposure. Carbogen, given during noise exposure, resulted in a trend toward less post noise exposure threshold shift (as compared to controls) which reached statistical significance by Week 3 at all frequencies except 2 and 20 kHz. Subjects given Carbogen after exposure also showed a general trend toward decreased noise induced threshold shifts, as compared to controls, but this was not statistically significant. The mixture of 5% CO2/air given during noise exposure yielded no difference in threshold shifts as compared to controls. When 100% oxygen was administered during noise exposure, a marked decrease in noise induced threshold shifts could be seen as compared to controls, with differences reaching statistical significance by day 5 at most frequencies. These results indicate that oxygen (i.e. cochlear-oxygenation) is a more important factor than CO2 (i.e., as a vasodilator) in protection of the cochlea from noise induced damage.

Jugular foramen schwannomas: diagnosis and suggestions for surgical management.

Schwannomas arising in the parapharyngeal space are rare lesions; however, those originating in the jugular foramen are even less common. Two cases, each with marked intra- and extracranial extensions, are discussed. Clinical presentation and preoperative evaluation emphasizing computerized tomographic and magnetic resonance imaging will be presented. An aggressive two-stage surgical approach consisting of a retrosigmoid craniectomy combined with infratemporal removal is advocated for those lesions arising within the jugular foramen.

Intraoperative cranial nerve monitoring during posterior skull base surgery.

Intraoperative monitoring of neurophysiologic function is rapidly evolving as an important adjunct during skull base surgery to reduce the incidence of neurologic deficit. Facial nerve monitoring is an excellent model, since electrical and mechanical evoked potentials can be directly presented to the surgeon in real-time through an acoustic loudspeaker display. The lower cranial nerves may also be monitored using similar electromyographic techniques. Auditory system monitoring is more difficult due to the low amplitude response that requires averaging and filtering to extract the evoked potential. In conjunction with auditory monitoring, improved hearing preservation may be further enhanced by concomitant facial nerve monitoring, since the surgeon is alerted to traumatic manipulations that may affect both facial and cochlear nerves. Techniques and interpretative issues are presented to maximize the efficacy and safety of cranial nerve monitoring.

Three-dimensional x-ray computed tomography of the temporal bone as an aid to surgical planning.

Three-dimensional x-ray computed tomography (3DCT) has been useful in planning surgical procedures involving craniofacial reconstruction, the pelvis, hip, spine, knee and shoulder. The clinical use of 3DCT in temporal bone surgery has not been evaluated. We used 3DCT to assess temporal bone anatomy in 9 patients. These cases evaluated two encephaloceles, two postinflammatory dehiscences, two temporal bone fractures, one glomus jugulare tumor, one acoustic neuroma, and one meningioma. We found 3DCT useful in these temporal bone applications as a supplement to standard two-dimensional CT scanning (2DCT). While 3DCT provided a better preoperative understanding of the underlying anatomy, no treatment was modified solely on the basis of the information derived from the 3-D presentation of data. We conclude that, although 3DCT images have some qualitative advantages over 2DCT techniques, their value in further defining temporal bone morphology must be evaluated against the cost entailed by their use.

Malleus head fixation: association with pseudohypoparathyroidism.

Pseudohypoparathyroidism (PHP) is a heterogenous syndrome resulting from bone and renal resistance to parathyroid hormone (PTH). Hypocalcemia and hyperphosphatemia occur despite elevated PTH levels. Head and neck manifestations of PHP include tetany, laryngeal spasm, and ectopic calcification in the eye, dentition, subcutaneous tissue and brain. The first case of malleus head fixation caused by ectopic calcification in a PHP patient is reported. Normalization of serum calcium and phosphate levels does not appear to retard or correct this abnormality. Ossiculoplasty or amplification is currently the recommended treatment in PHP patients with malleus head fixation.

Massive ossifying fibroma of the temporal bone.

Ossifying fibromata are rare lesions of the temporal bone. Because the tumors tend to progress and can become clinically massive, early complete resection is advised whenever feasible to prevent clinically evident recurrences and potentially life-threatening complications.