Richard L. Goode

Sniffing and smelling: separate subsystems in the human olfactory cortex

The sensation and perception of smell (olfaction) are largely dependent on sniffing, which is an active stage of stimulus transport and therefore an integral component of mammalian olfaction,. Electrophysiological data obtained from study of the hedgehog, rat, rabbit, dog and monkey indicate that sniffing (whether or not an odorant is present) induces an oscillation of activity in the olfactory bulb, driving the piriform cortex in the temporal lobe, in other words, the piriform is driven by the olfactory bulb at the frequency of sniffing. Here we use functional magnetic resonance imaging (fMRI) that is dependent on the level of oxygen in the blood to determine whether sniffing can induce activation in the piriform of humans, and whether this activation can be differentiated from activation induced by an odorant. We find that sniffing, whether odorant is present or absent, induces activation primarily in the piriform cortex of the temporal lobe and in the medial and posterior orbito-frontal gyri of the frontal lobe. The source of the sniff-induced activation is the somatosensory stimulation that is induced by air flow through the nostrils. In contrast, a smell, regardless of sniffing, induces activation mainly in the lateral and anterior orbito-frontal gyri of the frontal lobe. The dissociation between regions activated by olfactory exploration (sniffing) and regions activated by olfactory content (smell) shows a distinction in brain organization in terms of human olfaction.

Bone conducted sound: Physiological and clinical aspects

Objective: The fact that vibration of the skull causes a hearing sensation has been known since the 19th century. This mode of hearing was termed hearing by bone conduction. Although there has been more than a century of research on hearing by bone conduction, its physiology is not completely understood. Lately, new insights into the physiology of hearing by bone conduction have been reported. Knowledge of the physiology, clinical aspects, and limitations of bone conduction sound is important for clinicians dealing with hearing loss and is the purpose of this review. Data Sources: The data were compiled from the published literature in the areas of clinical bone conduction hearing, bone conduction hearing aids, basic research on bone conduction physiology, and recent research on bone conduction hearing from our laboratory. Conclusion: Five factors contributing to bone conduction hearing have been identified: 1) sound radiated into the external ear canal, 2) middle ear ossicle inertia, 3) inertia of the cochlear fluids, 4) compression of the cochlear walls, and 5) pressure transmission from the cerebrospinal fluid. Of these five, inertia of the cochlear fluid seems most important. Bone conduction sound is believed to reflect the true cochlear function; however, certain conditions such as middle ear diseases can affect bone conduction sensitivity, but less than for air conduction. The bone conduction route can also be used for hearing aids; since the bone conduction route is less efficient than the air conduction route, bone conduction hearing aids are primarily used for hearing losses where air conduction hearing aids are contraindicated.

Human middle-ear sound transfer function and cochlear input impedance

The middle-ear pressure gain, defined as the ear canal sound pressure to cochlear vestibule pressure gain, GME, and the ear canal sound pressure to stapes footplate velocity transfer function, SVTF, simultaneously measured in 12 fresh human temporal bones for the 0.05 to 10 kHz frequency range are reported. The mean GME magnitude reached 23.5 dB at 1.2 kHz with a slope of approximately 6 dB/octave from 0.1 to 1.2 kHz and -6 dB/octave above 1.2 kHz. From 0.1 to 0.5 kHz, the mean GME phase angle was 51 degrees, rolling off at -78 degrees /octave above this frequency. The mean SVTF magnitude reached a maximum of 0.33 mm s(-1)/Pa at 1.0 kHz with nearly the same shape in magnitude and phase angle as the mean GME. The ratio of GME and SVTF provide the first direct measurements of Z(c) in human ears. The mean Z(c) was virtually flat with a value of 21.1 acoustic GOmega MKS between 0.1 and 5.0 kHz. Above 5 kHz, the mean Z(c) increased to a maximum value of 49.9 GOmega at 6.7 kHz. The mean Z(c) angle was near 0 degrees from 0.5 to 5.0 kHz, decreasing below 0.5 kHz and above 5 kHz with peaks and valleys.

Three-Dimensional Stapes Footplate Motion in Human Temporal Bones

The literature provides conflicting information on whether the motion of the stapes footplate is piston-like or some other type of motion, such as rotational or rocking. Examination of the three-dimensional (3D) motion of the stapes footplate appears to be an excellent way to understand this complicated motion. Five microsphere reflective targets were placed on the stapes footplate in ten fresh human cadaver temporal bone preparations, and their vibration measured through an extended facial recess approach using a laser Doppler vibrometer. The five target sites on the stapes footplate were center, anterior, posterior, superior and inferior. The stimulus was a sound input of 80–120 dB SPL at the tympanic membrane over a frequency range of 0.1 to 10 kHz. The 3D motion of the stapes footplate was calculated using the velocity amplitude and phase obtained for each target. For frequencies up to 1.0 kHz the vibration of the stapes footplate was primarily piston-like; this motion became complex at higher frequencies, with rotary motion along both the long and short axis of the footplate. When the cochlea was drained, stapes footplate motion became essentially piston-like for all frequencies.

Radiofrequency energy tissue ablation for the treatment of nasal obstruction secondary to turbinate hypertrophy

Objective/Hypothesis: We hypothesized that the success rate of radiofrequency energy (RFe) tissue ablation of the inferior turbinate for nasal obstruction achieved by previous investigators would be improved by using a longer needle electrode and creating two lesions per turbinate. Methods: Ten patients with nasal obstruction secondary to inferior turbinate hypertrophy were prospectively enrolled. A 40‐mm needle delivered RFe to two sites in each inferior turbinate. Patients used a visual analog scale (VAS) to grade nasal obstruction preoperatively and at 1 week and 8 weeks after surgery. Preoperative and postoperative digital images of the nasal cavity were graded for obstruction (0% to 100%) in a blinded manner. Results: All patients (100%) were subjectively improved at 8 weeks. Mean obstruction (VAS) improved from 50% ± 21% to 16% ± 15% (right side) and from 53% ± 29% to 13% ± 13% (left side). Mean improvements were 68% (right side) (P = .004) and 75% (left side) (P = .001). Mean obstruction graded during blinded review of nasal cavity images improved from 73.5% ± 8% to 51% ± 8% (right side) and from 76% ± 6% to 64% ± 7% (left side). Of nine patients using medications for nasal obstruction before treatment, eight (89%) noted no further need for medications at 8 weeks. Conclusion: The use of RFe for submucosal tissue ablation in the hypertrophied inferior turbinate is an effective modality for reducing symptoms of nasal obstruction. Improved results may occur by using a longer needle and creating two lesions per turbinate. Of patients in this study, 100% reported improvement of nasal obstruction.

24-Hour infusion of cis-platinum in head and neck cancers

Eighteen patients with advanced squamous cell cancer of the head and neck were treated with cis‐diamminedichloroplatinum in a 24‐hour infusion. The most frequent dose used was 80 mg/m2 repeated every three weeks. Six were treated preoperatively for Stage III or IV disease, and twelve were treated for recurrent disease. The overall response rate was 72% with one complete remission, >50% regression in six patients, and 25‐50% regression in six patients. Toxicity was minimal: creatinine >2 in 6% of courses, leukopenia in 9%, anemia in 29%, vomiting in 76%, and documented minimal hearing loss in one patient. Plasma and urine platinum levels during infusion are presented. The dosage of 80 mg/m2 administered over 24 hours gives a response rate in head and neck cancers equivalent to that reported with higher doses given by rapid infusion, and toxicity is minimal. Cancer 42:2135–2140, 1978.

Fluid volume displacement at the oval and round windows with air and bone conduction stimulation

The fluids in the cochlea are normally considered incompressible, and the fluid volume displacement of the oval window (OW) and the round window (RW) should be equal and of opposite phase. However, other channels, such as the cochlear and vestibular aqueducts, may affect the fluid flow. To test if the OW and RW fluid flows are equal and of opposite phase, the volume displacement was assessed by multiple point measurement at the windows with a laser Doppler vibrometer. This was done during air conduction (AC) stimulation in seven fresh human temporal bones, and with bone conduction (BC) stimulation in eight temporal bones and one human cadaver head. With AC stimulation, the average volume displacement of the two windows is within 3 dB, and the phase difference is close to 180 degrees for the frequency range 0.1 to 10 kHz. With BC stimulation, the average volume displacement difference between the two windows is greater: below 2 kHz, the volume displacement at the RW is 5 to 15 dB greater than at the OW and above 2 kHz more fluid is displaced at the OW. With BC stimulation, lesions at the OW caused only minor changes of the fluid flow at the RW.

Measurement of the Ossicular Vibration Ratio in Human Temporal Bones by Use of a Video Measuring System

Vibration modes of the ossicles and the lever function were studied in human cadaver temporal bones with an intact cochlea. After placing tiny steel spheres on the ossicles, ossicular vibration to a sound stimulus was measured by observing the displacements of the spheres under a microscope with strobe illumination by means of a video measuring system. The lever ratio varied from 1.9 at 0.6 kHz (minimum) to a peak of 6 near 2 kHz. This relatively high lever ratio at higher frequencies was considered to be caused by a shift of the malleus-incus rotation axis secondary to the loading of the cochlear fluid on the ossicular system. Dependence of the lever ratio on frequency indicated that the rotation axis of the ossicles was not fixed, but variable according to frequency due to a relative increase in the translational movements of the rotation axis of the malleus and incus with frequency.

192Ir pharyngoepiglottic fold interstitial implants. The key to successful treatment of base tongue carcinoma by radiation therapy.

Twenty‐eight patients with squamous carcinomas of the base tongue were seen and evaluated in a conjoint Head and Neck Tumor Board at Stanford between 1976 and 1982. Fourteen patients were treated by combined external beam and interstitial irradiation, 11 of whom had Stage III and IV carcinomas (American Joint Committee). An initial dose of 5000 to 5500 rad was first delivered by external beam irradiation in 5 to 5.5 weeks, followed approximately 3 weeks later by an iridium 192 (192Ir) interstitial implant boost by the trocar and loop technique. The key to successful treatment of these neoplasms was found to be the use of a lateral percutaneous cervical technique, which placed horizontal loops through the oropharyngeal wall above and below the hyoid bone; the superior loop included the pharyngoepiglottic fold and the tonsilloglossal groove. Standard multiple loop implants (submentally inserted) of the base tongue from the vallecula anteriorly to the circumvallate papillae were also used routinely. This approach has been successful, since 10 of the 14 patients (71%) remain without evidence of disease (mean follow‐up, 32 months). There have been only two local recurrences, both on the pharyngoepiglottic fold in patients who did not receive the now standard pharyngoepiglottic fold/lateral pharyngeal wall implants. No patients have relapsed after 18 months. The other 14 patients were treated prospectively during the same period by combining initial resection, radical neck dissection, and postoperative irradiation. In this group, there were more locoregional failures compared to the group treated with radiation therapy alone (5 tongue recurrences and 7 neck relapses); in addition, more severe complications were noted in these 14 patients who received surgery and postoperative irradiation. The authors believe that combined external beam and interstitial irradiation is effective treatment for base tongue carcinomas, especially when the high‐dose distribution includes the adjacent tonsilloglossal groove, pharyngoepiglottic fold, and oropharyngeal wall to and below the level of the hyoid bone, in addition to treating an adequate base tongue volume.

Basilar membrane and osseous spiral lamina motion in human cadavers with air and bone conduction stimuli

The vibration patterns of the round window (RW) membrane in human cadaver temporal bone specimens were assessed by measurements of the velocity of reflective targets placed on the RW membrane with an approximate spacing of 0.2 mm. The velocity was measured in the frequency range 0.1-10 kHz by a laser Doppler vibrometer in four specimens with air conduction (AC) stimulation and in four specimens with bone conduction (BC) stimulation. The response pattern was investigated by analyzing the velocity response of all targets on the RW membrane, by making iso-amplitude and iso-phase contour plots of the membrane surface, and by creating animations of the surface vibration at several frequencies. Similar response pattern was found with AC and BC stimulations. At frequencies below 1.5 kHz, the RW membrane vibrates nearly as a whole in an in-and-out motion and above 1.5 kHz, the membrane moves primarily in two sections that vibrate with approximately 180 degrees difference. Indication of some traveling wave motion of the RW membrane at those frequencies was also found. At higher frequencies, above 3 kHz, the membrane motion is complex with a mixture of modal and traveling wave motion. An increase of the stimulation level did not alter the vibration pattern; it only gave an increase of the RW membrane vibration amplitude corresponding to the increase in stimulation. When the mode of stimulation at the oval window was altered, by the insertion of a 0.6 mm piston, the vibration pattern of the RW membrane changed.