F. Blair Simmons

Natural History of Sudden Sensorineural Hearing Loss

This is a prospective in-depth study of patients with sudden idiopathic sensorineural hearing loss. We found that 65% recover completely to functional hearing levels spontaneously and independent of any type of medical treatment. The majority do so within 14 days and many within the first few days. Prognosis can be predicted according to the slope of the initial audiogram (low-frequency losses do better than high-frequency losses), hearing at 8 kHz, erythrocyte sedimentation rates, in some select instances spatial disorientation symptoms, and speech discrimination scores. There was a very poor correlation between hearing and vestibular test abnormalities, except hypoactive calorics. There were no correlations with age (excepting the very elderly), with antecedent respiratory infections. hypertension, diabetes, or other chronic diseases. We conclude that there is a fundamental difference in the behavior of apical and basal cochlea losses, that hearing recovery is always better at low than at high frequencies, that because of the high spontaneous recovery rates, tympanotomies seeking perilymph fistulas should be delayed ten days unless there is a progressive hearing loss, and that none of the current recommended treatments, especially histamine, have any effect on the outcome.

Hemodynamics in Sleep-Induced Apnea: Studies during Wakefulness and Sleep

Twelve patients with predominantly obstructive type sleep apnea underwent cardiac catheterization, hemodynamic monitoring, and arterial blood gas analysis during wakefulness and sleep. Abnormalities during wakefulness included systemic hypertension in four of 12, exercise-induced mild pulmonary hypertension in five of 12, and alveolar hypoventilation in one. During sleep nine patients had cyclic elevations of arterial pressure with each apneic episode, exceeding 200 mm Hg systolic in three of 12. Pulmonary artery pressures increased in 10 of 12, exceeding 60 mm Hg systolic in five. Marked degrees of hypoxemia (arterial P02, less than 50 mm Hg in eight of 12) and moderate hypercapnia with respiratory acidosis were associated with these hemodynamic changes. Cyclic upper airway obstruction during sleep may result in hypercapnia, acidosis, and pronounced hypoxemia, which can lead to hemodynamic abnormalities during sleep. Sustained pulmonary hypertension and possibly systemic hypertension may follow. Tracheostomy is an effective therapy and is recommended to symptomatic patients who have predominantly obstructive apnea but no relievable anatomic cause of upper airway obstruction.

Sleep-induced apnea syndrome: Prevalence of cardiac arrhythmias and their reversal after tracheostomy☆

Cardiac arrhythmias during wakefulness and sleep in 15 patients with sleep-induced obstructive apnea, and the effect of atropine and tracheostomy on these arrhythmias were studied by continuous overnight Holter electrocardiographic, respiratory and electroencephalographic recordings. Sleep was characterized by marked sinus arrhythmia in 14, extreme sinus bradycardia ( less than 30 beats/minute) in six, asystole of 2.5 to 6.3 seconds in five, second degree atrioventricular (A-V) block in two, and ventricular arrhythmias--complex premature ventricular beats in 10 and ventricular tachycardia in two. Arrhythmias during wakefulness were limited to premature ventricular beats in six. Atropine administration was partially and tracheostomy highly effective in preventing the majority of these arrhythmias during sleep. Marked sinus arrhythmia during sleep is characteristic of the syndrome of obstructive sleep apnea and is frequently accompanied by potentially life-threatening tachy- and bradyarrhythmias. Possible mechanism of production of these arrhythmias, the mode of action of tracheostomy and atropine, and the probable role of similar arrhythmias in the sudden infant death syndrome are discussed.

Obstructive sleep apnea: Electromyographic and fiberoptic studies

Abstract Seventeen predominantly obstructive sleep apnea patients and four normal controls (all adult males) underwent one or both investigative protocols: (A) A fiberoptic endoscope was introduced intranasally into the pharynx and subjects were monitored continuously and filmed intermittently during wakefulness and sleep. (B) Muscles selected because of their anatomical importance in maintaining the oropharynx during the respiratory cycle were electromyographically implanted intraorally or, in tracheostomy patients, at time of surgery, and subjects were polygraphically monitored during wakefulness and sleep. In both protocols, standard electroencephalogram, chin electromyogram (EMG), electrooculogram (EOG), and respiration were monitored simultaneously. During fiberoptic studies obstructive apnea during sleep first appeared as a partial or total invagination of the posterolateral pharyngeal walls, while the laryngeal inlet remained patent. EMG recordings showed normal firing patterns in patients during unobstructed sleep. During sleep-induced obstructive apnea, however, a significant decrease or complete disappearance of EMG activity was observed in the palatoglossus, palatopharyngeus, genioglossus, superior and middle constrictors of the pharynx, and stylopharyngeus. The obstruction involves absence, during inspiration, of the activity in the pharyngeal dilators needed to counteract the loads abruptly imposed by intrathoracic negative pressure changes.

Estimating Eighth Nerve Survival by Electrical Stimulation

Determining nerve survival is important in selecting patients for cochlear implants, and in predicting outcomes from such implants. In search of a possible method we deliberately destroyed nerve fibers (ganglion cells) in 17 cat cochleas to produce a range of degenerations Months later, we electrically stimulated these ears (and seven controls) and recorded electrical ABR input-output functions. Cats with no surviving ganglion cells showed no ABR activity. Cats with 5%–10% surviving cells had ABRs which typically had normal thresholds but decreased input-output functions. The suprathreshold slopes of these input-output functions reliably predicted ganglion cell survival for all degrees of degeneration. Thus perceptual (or electrical) threshold is a poor indicator of nerve survival. Loudness growth (or growth in the electrically-induced auditory brainstem response) is a good index of surviving ganglion cells.

The Palatopharyngoplasty Operation for Snoring and Sleep Apnea: An Interim Report

We performed palatopharyngoplasty operations on 155 patients as of June 1, 1983, and have 4-month clinical follow-ups on 123 patients. Forty-nine have had repeat polysomnograms (through September 1983) that continue to show the operation is about 50% effective in curing or considerably improving obstructive sleep apnea. Symptomatic (clinical) results in these same patients are much better than 50% and may be the reason why we have had considerable difficulty in obtaining sleep study follow-ups. Snoring was eliminated or much improved in 93% of all patients and 95% of patients without serious obstructive sleep apnea. Daytime symptoms, if any, were improved in 64%. Some form of preoperative sleep study is mandatory in all patients. Two thirds of patients who present with the complaint of snoring and none of the classic symptoms of apnea actually do have total airway obstructions during sleep.

The double‐membrane break syndrome in sudden hearing loss

Some patients with sudden hearing loss actually have two membrane breaks, one at the oval or round window and one further inside the cochlea. One may heal spontaneously and the other not, or both, or neither. It is very likely impossible to detect this early from the threshold audiogram, because the intracochlear breaks allows endolymph and perilymph mixing which spreads over much of the anatomically normal cochlea causing diffuse loss of function. This theory is illustrated by three case histories.

Surgical management of airway obstructions during sleep

Anatomical or physiological airway obstructions during sleep, of which the patient is unaware, cause daytime sleepiness at first, then signs of decreasing mental function, and eventually in some individuals, pulmonary and systemic hypertension. A few of these patients had been recognized before, the Pickwickian syndrome and in children with cardiac problems and large tonsils. The majority, however, present as sleep disorders. This paper describes our surgical experience with improving the airways of 19 children and adults with daytime somnolence.

Auditory Nerve: Electrical Stimulation in Man

Auditory perceptions produced in a person deaf to acoustic stimulation were studied by electrically exciting the auditory nerve through permanently implanted electrodes. Pulsed current as small as 1 microampere peak-to-peak could be perceived. Pitch, as reported by the subject, varied with electrode selection, current amplitude, and pulse repetition rate from about 70 to at least 300 pulses per second. Loudness increased with amplitude and duration of pulse stimuli, and to a lesser extent with repetition rate. The total range in amplitude of the stimulus, from threshold to an uncomfortable loudness, was 15 to 20 decibels. Simultaneous stimulation in separate electrodes produced a number of complex effects.

Sudden idiopathic sensori‐neural hearing loss: Some observations

Sudden idiopathic sensori‐neural hearing loss is more common than generally recognized. Hearing recovers spontaneously within a few hours or days, and the loss is not recognized as cochlear in origin but is blamed on eustachian tube obstruction, because the symptoms can be identical; thus, a large proportion of patients are treated by physicians with decongestants and middle ear inflation, without obtaining audiograms. In an already damaged cochlea, middle ear inflation and other unwarranted procedures, including over enthusiastic audiometry, can lead to further injury. In general, prognosis for recovery from sudden hearing loss correlates best with the interval between symptom onset and the first audiogram, and very poorly with either the type of treatment or the interval between symptoms and the patients first visit to a physician.Sudden idiopathic sensori-neural hearing loss is more common than generally recognized. Hearing recovers spontaneously within a few hours or days, and the loss is not recognized as cochlear in origin but is blamed on eustachian tube obstruction, because the symptoms can be identical; thus, a large proportion of patients are treated by physicians with decongestants and middle ear inflation, without obtaining audiograms. In an already damaged cochlea, middle ear inflation and other unwarranted procedures, including over enthusiastic audiometry, can lead to further injury. In general, prognosis for recovery from sudden hearing loss correlates best with the interval between symptom onset and the first audiogram, and very poorly with either the type of treatment or the interval between symptoms and the patients first visit to a physician.