Audiograms of 11,577 made Marine officers and enlisted personnel are analyzed by age group and level of hearing for six frequencies: 500, 1,000, 2,000, 3,000, 4,000, and 6,000 Hz. Speech reception thresholds are determined for the average of 500, 1,000, and 2,000 Hz as recommended by the American Academy of Ophthalmology; high-frequency thresholds are determined for the average of 3,000, 4,000, and 6,000 Hz. Hearing impairment (greater than 25 dB ISO) for the speech frequencies is between 0.6% and 5.9%; for the high frequencies the range is 3.4% to 76.5%. For the high frequencies the largest increase in impairment is in the age group 35 to 44 years. No difference in the percentage distribution of hearing impairment is found between a statistically comparable group of civilians and Marines. This is in sharp disagreement with the hypothesis that a greater degree of hearing loss would exist in a military population exposed to more noise than a civilian population. Hearing impairment in the high frequencies caused by noise exposure is a problem of significant magnitude, especially above the age of 35, and may have an effect on speech intelligibility. However, the magnitude of the problem seems to be the same in the military and civilian populations studied.
Chinchillas were made diabetic by streptozotocin intraperitoneal injection, and the cochlear blood vessels were studied using surface preparation techniques after 3, 6, and 12 months of established diabetes. The following findings were reported: (1) a decrease of alkaline phosphatase activity in the walls of cochlear capillaries after six months of established diabetes, (2) a generalized involvement of the cochlear microcirculation as evidenced by the decrease in alkaline phosphatase activity and by narrowing and irregularities of the capillary lumen, and (3) areas of complete capillary closure in the stria vascularis of the basal turn after 6 and 12 months of established diabetes.
An infant with the Beckwith-Wiedemann syndrome is described, with emphasis placed on the occurrence of macroglossia and possible maxillofacial deformities. In addition to placing the syndrome among the clinical entities which result in macroglossia, attention is also brought to concurrent metabolic disorder through hypoglycemia and possible late-occurring visceral malignancy which may produce significant patient compromise.
The effect of carbon monoxide poisoning on the threshold sensitivity of the responses from the auditory cortex, inferior colliculus, and cochlea to acoustic stimuli in guinea pigs was studied. The toxicity of carbon monoxide is believed to be secondary to tissue hypoxia and is partially reversible. Loss of auditory threshold sensitivity in carbon monoxide poisoning is most prominent at the auditory cortex. The loss of sensitivity at the inferior colliculus is the next most severe. There is no loss of sensitivity at the cochlea. The relative vulnerability of the central auditory pathway to carbon monoxide poisoning as compared with the end organ is demonstrated.
Seventy-nine out of 172 patients with abnormal horizontal or vertical optokinetic nystagmus had a specific condition or disease that was diagnosed following a complete ENG. Ocular vertigo, MS, motion sickness, brain stem lesions, cerebellar tumors, cerebellar atrophy, parietal lobe tumors, and Harada syndrome were the diagnoses made. Optokinetic asymmetry--horizontal, vertical, or a combination of these--was the most consistent finding in these conditions (Table). In six patients with cerebellar tumor, abnormal findings on OPK testing suggested the need for further evaluation when physical and neurologic examinations, brain scans, and EEG were normal. Surgery confirmed the diagnosis of cerebellar tumor with these patients. This study suggested the importance of using five progressively faster drum speeds in both the horizontal and vertical planes. All patients who had proven or strongly suspected MS had eye-speed fatigability as the drum speed increased, that is, as the drum speed increased, the eye speed decreased. It is suggested that optokinetic studies be included in the ENG. Vertical asymmetry, although not as common as horizontal, should be included in that 14 patients had only this finding.
There are numerous methods described in the literature for sialocele treatment. Surgical modalities usually involve an operation with possible facial nerve injury, with the risk of a general anesthetic, and with prolonged hospitalization to be considered. Among non-surgical modalities radiation and laissez-faire are of questionable efficacy. Propantheline bromide, which medically interrupts the parasympathetic control of salivary secretion, has proved a safe, effective means of rapid sialocele control.
Audiograms of 11,577 made Marine officers and enlisted personnel are analyzed by age group and level of hearing for six frequencies: 500, 1,000, 2,000, 3,000, 4,000, and 6,000 Hz. Speech reception thresholds are determined for the average of 500, 1,000, and 2,000 Hz as recommended by the American Academy of Ophthalmology; high-frequency thresholds are determined for the average of 3,000, 4,000, and 6,000 Hz. Hearing impairment (greater than 25 dB ISO) for the speech frequencies is between 0.6% and 5.9%; for the high frequencies the range is 3.4% to 76.5%. For the high frequencies the largest increase in impairment is in the age group 35 to 44 years. No difference in the percentage distribution of hearing impairment is found between a statistically comparable group of civilians and Marines. This is in sharp disagreement with the hypothesis that a greater degree of hearing loss would exist in a military population exposed to more noise than a civilian population. Hearing impairment in the high frequencies caused by noise exposure is a problem of significant magnitude, especially above the age of 35, and may have an effect on speech intelligibility. However, the magnitude of the problem seems to be the same in the military and civilian populations studied.
The function of a paralysed axial (laryngeal, facial, extraocular) muscle could conceivably be restored if it were made to contract again like its contralateral partner. A muscle stimulation device was designed and constructed so that the stimulus delivered to a given paralysed muscle was modulated by a signal reflecting the contractile state of its contralateral partner. Studies in dog larygneal muscles indicate that paralysed muscles stimulated by such an open-loop device could mimic their partners. However, their tracking accuracies were limited by the nature of their stimulus-reponse characteristics. On the other hand, significantly greater tracking accuracies were observed if a closed-loop device was employed, that is, if feedback information from the stimulated muscles was also used to control the device stimulus level. Considerations in implanting such a (closed-loop or open-loop) device in paralysed axial muscles for chronic stimulation are discussed.
The perceived pitch mixture of two tones of a dichotically presented chord was studied as a function of the difference between the intensities of the right and left ear tones (ΔI). Previous experiments have shown that, within a wide range of ΔI, the pitch mixture is independent of ΔI. This intensity independence of the pitch mixture of dichotic chords is not seen with monaural chords. Within the range of ΔI over which intensity independence is seen, the pitch mixture of the dichotic chord is determined by another property of the central pitch processor—the ear dominance function. In previous experiments the intensity independent function could only be detected in those subjects with a weak ear dominance function. In the present experiments subjects adjusted the relative intensities of the two tones of a binaural chord to match the pitch mixture of a dichotic chord. Using this method, the intensity independent function was measured directly in all subjects. In addition, the present method provides a direct measure of the magnitude of the suject’s ear dominance function and clarifies the relationship between the effects of the two functions. Subject Classification: [43]65.75, [43]65.54, [43]65.62.
A prospective study of wound infections following major head and neck cancer surgery was undertaken to define a rational approach to trials of antibiotic prophylaxis and initial therapy of these infections. Preoperative aerobic cultures were taken from the planned site of skin incision and from the oropharynx. Both aerobic and anaerobic cultures were obtained from all wound infections. Patients receiving prophylactic antibiotics were excluded from the study. The data indicate that preoperative cultures are not usually predictive of the bacteriology of subsequent wound infection. Mixed aerobic and anaerobic flora were cultured from most wound infections and usually reflected normal anaerobic oropharyngeal flora and/or exogenously acquired Staphylococcus aureus. Bacteroides fragilis was not cultured in this series. Antibiotics selected for trials of prophylaxis or initial treatment of these infections should cover both the resident oral aerobic and anaerobic flora and S aureus. Coverage for B fragilis does not appear necessary. Antibiotic choices might include (1) penicillin G agents plus a penicillinase-resistant penicillin or (2) a parenteral cephalosporin.
A review of the otoneurologic findings in 500 patients with facial paralysis revealed their importance for diagnosis, prognosis, and understanding the pathophysiology of Bell's palsy. Diagnosis. The presence of simultaneous bilateral palsy, facial paralysis associated with lateral rectus palsy, slowly progressive facial weakness with or without hyperkinesis, and facial paralysis that showed no recovery after six months excluded Bell's palsy from the diagnosis. Ipsilateral recurrent palsies were another indication to suspect an underlying cause, since a tumor of the facial nerve caused the paralysis in 30% of the patients with this finding. Signs such as intact forehead movement, alterations in facial sensation, and corneal hypesthesia--although often associated with lesions in the cerebral cortex, cerebellopontine angle, or internal auditory canal--were also found in patients with Bell's palsy. Prognosis. A spontaneous complete recovery following Bell's palsy occurs in about 70% of the patients; but in the presence of a dry eye or dysacousis, the prognosis for a complete recovery drops 10 and 25%, respectively. Pathophysiology. It is proposed that the wide range of neurologic findings associated with Bell's palsy is due to a viral polyneuropathy. This is a disorder that primarily involves sensory nerves, and the facial motor deficit results from involvement of the sensory fibers carried with the facial nerve within the fallopian canal.
: An extended single transverse neck incision was used in an unselected group of 40 patients undergoing a composite resection for carcinoma of the head and neck. While 21 of the 40 patients had a fistula and wound infection develop, carotid artery exposure due to flap necrosis occurred in two patients while carotid artery rupture occurred in only two. The extended single transverse neck incision results in a viable flap because of its excellent blood supply. Despite being subjected to fistula formation and infection, it usually results in excellent carotid artery protection, adequate surgical exposure, minimal cosmetic deformity and does not interfere with primary or secondary reconstruction.
