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Biomedical subjects

F B Simmons

Publications and source records attributed to F B Simmons.

At least 19 recordsLinked to original sources
PubMed1990

Severity of obstructive sleep apnea.

A four-level severity scale for obstructive sleep apnea is offered using four criteria: maximum oxygen desaturation, apnea/hyponea index, symptoms of excessive day-time sleepiness, and symptoms of related cardiac disease. Oxygen desaturation and the apnea/hyponea index for 175 patients, all having had uvulopalatopharyngoplasty surgery, showed 19% mild, 33% moderate, 17% moderately severe, and 31% severe obstructive sleep apnea. There was a very poor correlation between oxygen desaturations and number of obstructive events, which demands that both be used in any estimation of disease severity.

Humans↗
PubMed1988

Comparison of electrophonic and auditory-nerve electroneural responses.

Electrophonic and auditory-nerve electroneural responses were recorded from the inferior colliculus of the cat. The electrophonic response appeared at a latency 1.0-1.5 ms later than the electroneural response, due to the time requirements for cochlear transduction. The electrophonic response also demonstrated very slow growth of response amplitude with increasing stimulus current as compared to the electroneural response. Aminoglycoside perfusion of the cochlea eliminated the electrophonic component from the evoked response record and left the electroneural component relatively unchanged, indicating that the electrophonic is an acoustic stimulus that requires an intact auditory end organ for transduction.

Animals↗
PubMed1987

Speech perception by four single-channel cochlear implant users.

Four profoundly deaf adults, each a recent recipient of a scala tympani implant, underwent auditory and auditory-visual speech comprehension evaluations. Two subjects had multiple-electrode auditory prostheses, and 2 had single-electrode implants. All subjects were tested preoperatively with a high-power hearing aid, and postoperatively with a single-channel wearable sound processor. Reported here are the results of the first formal speech recognition tests which were conducted during the 8 months after the sound processor fitting. Three subjects had used the single-channel processor on a daily basis for up to 8 months at the time of postoperative testing. The 4th subject was a nonuser. On listening tests, a comparison between pre- and post-implant scores revealed little difference for any subject. On postoperative speechreading tasks, all subjects identified medial consonant phonemes and 2-digit numerals better with stimulation than without. The 3 frequent users of the device experienced significant improvement on connected-discourse tracking, and their speechreading of videotaped and live voice CID Everyday Sentences (Davis & Silverman, 1978) was enhanced with the addition of stimulation. The nonuser was a very proficient speechreader at the outset and exhibited no significant difference on connected-discourse tracking with and without stimulation. Moreover her ability to speechread Everyday Sentences was hampered slightly by the addition of stimulation. This single-channel sound processor functioned as a sensory supplement for the 3 frequent users, but no subject was able to use the processor as a sensory substitute.

Adult↗
PubMed1987

Infant hearing screening: program implementation and validation.

Congenital and early-onset hearing losses were discovered in 6.1% of 975 Intensive Care Nursery (ICN) graduates. The methods used were neonatal screening by Crib-O-Gram (COG) and high risk register, in combination with repeated behavioral hearing tests at 1 to 3 years. This 7-year longitudinal study had follow-up hearing evaluations for a remarkably high 84% of all subjects. Significant losses that interfered with speech and language development (1000 to 8000 Hz average loss greater than 45 dB HL bilaterally) were found in 4.3% of infants. COG in combination with subsequent behavioral hearing screening was a sensitive strategy for detecting significant hearing loss: only one child was missed with this combination. Alone, COG sensitivity to significant hearing losses was 79.3%, but would have been higher had a stricter passing criterion been adopted. Behavioral hearing screenings detected bilateral hearing losses of even mild (greater than 20 dB HL) degree. Sensitivity to significant hearing losses was 82.6% and would have been improved if test frequencies greater than 3000 Hz were included in the screen. Even if screening failure occurred at 1 year of age, the age of actual confirmation of hearing loss depended on severity of the loss and ear involvement. Significant hearing losses were confirmed earlier than less severe or unilateral losses. Although behavioral screenings could be done during the first year of life, continued follow-up was required to detect progressive hearing losses.

Acoustic Stimulation↗
PubMed1986

Delayed onset hearing loss in a two-year old.

This paper describes a delayed onset sensorineural hearing loss in a baby known to have normal hearing until at least 13 months. A mild high-frequency loss was discovered quite by accident at 25 months. The bilaterally symmetrical loss progressed over the next 6 months to no measurable high-frequency hearing and a 70 dB threshold at 500 Hz. To our knowledge this is the youngest completely documented case of what has been called hereditary delayed onset hearing loss. However, in this instance, and perhaps unsuspected in others, this child had bilateral oval and round window fistulas whose repair may have not only arrested the progression of her loss, but even improved her residual hearing sensitivity.

Audiometry↗
PubMed1986

Two emerging perilymph fistula "syndromes" in children.

This paper proposes two relatively common "syndromes" seen in children with perilymph fistulas using illustrative case reports. One, a 2 1/2-year-old child with bilaterally symmetric progressive sensorineural hearing loss, was found to have bilateral oval and round window fistulas. The other was a child who presented originally with an unexplained unilateral sensorineural loss. It was only when hearing deteriorated in the opposite ear several years later that a perilymph fistula was suspected and confirmed by tympanotomy. The clinical presentations and other details of these cases diverge widely, but may represent two emerging syndromes of perilymph fistulas in children: 1. a congenital or hereditary predisposition, and the other, 2. sudden hearing loss in the "good" ear of children with an unexplained sensorineural hearing loss in the opposite ear.

Audiometry↗
PubMed1985

Palatopharyngoplasty failure, cephalometric roentgenograms, and obstructive sleep apnea.

Nine patients with obstructive sleep apnea who underwent unsuccessful palatopharyngoplasty (PPP) as documented by polygraphic monitoring had abnormal cephalometric roentgenogram measurements. Findings indicated a small posterior airway space and inferiorly placed hyoid bone. Cephalometry performed with appropriate techniques to investigate soft tissue location should be obtained systematically in obstructive sleep apneic patients before any surgery is performed. The roentgenogram finding is a helpful guide in deciding whether PPP alone or PPP in combination with other surgical procedures would be more efficacious.

Adult↗
PubMed1979

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 clchlea causing diffuse loss of function. This theory is illustrated by three case histories.

Adult↗
PubMed1978

Identification of hearing loss in infants and young children.

An infant's hearing loss is detectable at any age. In spite of the importance of identifying deafness early, we do a poor job largely because the medical community is neither aware nor convinced that finding hearing loss is worth the trouble. There are two public health strategies for early detection, the high risk register (family history, hyperbilirubinemia, prematurity, rubella, and maxillofacial anomalies) and behavioral screening. The advantages and disadvantages are discussed. The incidence of handicapping hearing loss in newborns is 1 per 380 births and 1 per 61 in babies admitted to an intensive care nursery. This is higher than generally believed and may be one favorable result of using a new automated hearing screening system--the Crib-o-gram. In most deaf babies there is more than one risk factor present. Evaluating a hearing suspect baby demands a high index of suspicion, and taking the parent's suspicions seriously. The chances that a hearing loss exists at one year of age is about 1 in 4 on parental suspicion alone, regardless of what the physician's opinion might be. Immediate referral upon suspicion needs to occur more often than it does.

Attitude of Health Personnel↗
PubMed1978

Fluid dynamics in sudden sensorineural hearing loss.

A change in fluid pressure in one intracochlear compartment also causes a pressure gradient in the other. Thus, one membrane break is likely to cause a secondary break. We have presented indirect evidence for such double membrane breaks in sudden hearing loss, and argue that one of the two breaks can heal spontaneously while the other remains active.

Adult↗
PubMed1978

Respiration during sleep in children.

In 22 children (11 boys and 11 girls), aged 9 to 13 years, respiration was monitored during one night of sleep. No child had a significant history of breathing problems during sleep. Sleep was recorded using standard techniques (electroencephalography, electrooculography, electromyography), and respiration was measured with nasal thermistors and abdominal or thoracic strain gauges. Respiratory pauses (five seconds or longer) were determined for all sleep stages. Respiratory rate was scored only in the first and last sleep cycles and during ten waking minutes before sleep onset. Respiratory rate was significantly affected by wakefulness or stage of sleep: highest in wakefulness and stage 1, lowest in stage 2 of the last sleep cycle. Regularity of respiratory rate showed a similar effect. Variance of respiratory rate was significantly lower in girls than boys. Respiratory pauses during sleep were seen in every child, ranging from 3 to 40 pauses per night (average, 17.2 for boys and 18.0 for girls). Significantly greater numbers of pauses per minute were seen in stage 1 and rapid eye movement (REM) sleep than in stages 2, 3 and 4. The longest respiratory pause was 25 seconds. The conclusion is made that a small number of respiratory pauses during sleep are normal in children of this age.

Adolescent↗
PubMed1977

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.

Apnea↗