Sudden hearing loss and cerebellopontine angle tumors

Lesions of the cerebellopontine angle may cause a sudden hearing loss. To illustrate and reaffirm the importance of a thorough neurotologic evaluation we performed a retrospective review of the audiologic and clinical data available on 506 patients with proven lesions of the cerebellopontine angle. Seventy-seven patients (15.2%) were found to have a history commensurate with sudden hearing loss. We reviewed the relevant audiologic data as well as the clinical circumstances of this select patient population.     

H1 and H2 histamine receptors in the in vitro nasal mucosa

The effect of histamine was studied on canine nasal blood vessels with an in vitro muscle tension measuring technique. Observations suggest that histamine has at least four different effects: 1) inhibits the contraction induced by nerve terminal stimulation, 2) relaxes the smooth muscle under sustained contraction, 3) contracts the smooth muscle, 4) enhances (nor)epinephrine-induced contraction. Both H1 and H2 histamine receptors were identified in the mucosal blood vessels of the canine nasal septum. H1 receptors were present at the surface of vascular smooth muscle and mediated the contractile response (3) due to opening calcium influx channels. H2 receptors existed at both sympathetic nerve terminals and the muscle cell membrane. Stimulation of either H2 receptor caused muscle relaxation. The presynaptic H2 receptors mediated vasodilation through the inhibition of norepinephrine release from the nerve endings. Postsynaptic H2 receptors caused direct muscle relaxation possibly through an increase in cyclic AMP. Both H1 and H2 antagonists worked well, whereas agonists did not properly produce theoretically expected results in these specimens.     

Bronchopulmonary dysplasia and pulmonary insufficiency of prematurity. Lack of correlation of outcome with gas exchange abnormalities at 1 month of age

A review of all infants admitted to the two intensive care nurseries in Seattle from July 1, 1980, through Dec 31, 1981, was performed to evaluate the outcome of infants still requiring supplemental oxygen and/or mechanical ventilation at 1 month of age. Sixty-three infants were identified. Fifty-six infants survived to at least 2 years of age, including 11 of 13 in the subgroup of infants requiring 40% or more oxygen at 1 month of age. Eight (14%) of the 56 survivors have required prolonged rehospitalization for pneumonia or other respiratory illnesses in the first two years following birth. We conclude that the degree of gas exchange impairment assessed at 1 month of age does not predict ultimate outcome from neonatal chronic lung disease.     

Trisomy 18 with Ectopia Cordis, Omphalocele, and Ventricular Septal Defect: Case Report

A case of thoracoabdominal ectopia cordis was diagnosed by ultrasonography at 21 week's gestation. Chromosomal analysis showed full trisomy 18. This case supports the associationl of thoracoabdominal ectopia cordis (Cantrell's pentad) with chromosomal errors, specifically trisomy 18.     

Suspected genetic disease

To formulate an accurate diagnosis and provide adequate management of genetic problems associated with ear malformations or hearing loss, the otolaryngologist must have an awareness of possible genetic causes of these disorders. Careful evaluation of the family history as well as examination or testing of family members might be required to arrive at a correct diagnosis. The clinical geneticist can provide assistance to the clinician with contemporary information about additional useful diagnostic studies, the possibility of prenatal diagnosis of the disorder, or in the process of genetic counseling so as to enhance the family's overall adjustment to the problem.     

Acute bacterial conjunctivitis. Bacteriology and clinical implications

We report the results of eye culture specimens, obtained from patients under 20 years of age, submitted to the Bacteriology Department of our institution from January 1 through April 30, 1983. A total of 72 specimens were positive for one or more strains of bacteria. The most commonly isolated bacteria was Hemophilus influenzae (34 strains, 42%), followed by Staphylococcus epidermidis (11 strains, 13.75%) and Streptococcus pneumoniae (9 strains, 11.25%). Mean age of patients with H. influenzae (excluding a 20-year-old patient) was 15 months with standard deviation of 13 months. Chloramphenicol and tetracycline showed excellent in vitro activity against bacteria of all age groups. Tetracycline may prove to be the drug of choice for the treatment of acute conjunctivitis if comparative clinical data support its in vitro superiority.     

Minoxidil for control of acute blood pressure elevation in chronically hypertensive children

Twenty-three episodes of acute elevation of BP related to renal disease in 13 chronically hypertensive children 2 to 18 years of age were treated with a single oral dose of minoxidil. All except one patient were receiving a diuretic and all but one a beta-blocking agent at the time of minoxidil treatment. The goal of lowering BP to or below the 95th percentile for age within four hours of minoxidil administration was achieved in 14 of 23 treatment episodes. The goal was achieved in nine of 11 (82%) when the dose of minoxidil was greater than or equal to 0.2 mg/kg and in five of 12 (42%) when the dose was less than 0.2 mg/kg (P less than .05). In patients treated with greater than or equal to 0.2 mg/kg of minoxidil, mean systolic and diastolic BP decreased significantly from pretreatment values within one hour. In patients receiving less than 0.2 mg/kg, mean systolic BP was never significantly reduced and mean diastolic BP did not change significantly for two hours. Adverse effects were minimal. The results indicate that minoxidil in a dose of 0.2 mg/kg in combination with a diuretic and beta-blocking agent will lower BP to safe levels in most patients with severe hypertension related to renal disease within four hours with minimal side effects.     

Psychophysical evidence for rod vulnerability in age-related macular degeneration

PURPOSE: To determine whether there is rod system dysfunction in the central retina of patients with age-related macular degeneration (AMD). METHODS: Dark-adapted sensitivity (500-nm stimulus) and light-adapted sensitivity (600 nm) were measured psychophysically at 52 loci in the central 38 degrees (diameter) of retina in 80 patients with AMD, and results were compared with those from older adult normal controls. All dark-adapted data were corrected for preretinal absorption. RESULTS: Mean field dark-adapted sensitivity was significantly lower in AMD patients as a group than in normal subjects. Within the AMD group were subsets of patients with normal mean dark- and light-adapted sensitivities; reduced dark-adapted sensitivities without detectable light-adapted losses; both types of losses; and, least commonly, only light-adapted losses. Regional retinal analyses of the dark-adapted deficit indicated the greatest severity was 2 degrees to 4 degrees or approximately 1 mm from the fovea, and the deficit decreased with increasing eccentricity. CONCLUSIONS: These psychophysical results are consistent with histopathologic findings of a selective vulnerability for parafoveal rod photoreceptors in AMD. The different patterns of rod and cone system losses among patients at similar clinical stages reinforces the notion that AMD is a group of disorders with underlying heterogeneity of mechanism of visual loss. Dark-adapted macula-wide testing may be a useful complement to the more traditional outcome measures of fundus pathology and foveal cone-based psychophysics in future AMD trials.     

Traumatic flap displacement after LASIK

CASE REPORT: We present a case of traumatic displacement of corneal flap in the superior temporal quadrant 13 days after LASIK. The flap was repositioned after gentle irrigation of BSS, cleaned the interface and then drying the flap to verify its stability. In the next day the flap was adhered, clear cornea,smooth and visual acuity without correction was 1.00. DISCUSSION: We should try immediately to reposition the flap after traumatic displacement, as in this case.     

Do cholinergic neurons directly innervate nasal blood vessels?

The main aim of this work was to provide additional evidence that cholinergic neurons can induce nasal vasodilation by inhibiting norepinephrine release, not by a direct action on nasal blood vessels. We induced a degeneration of the nasal sympathetic neurons in order to observe the effects of electrical stimulation of the cholinergic neurons on nasal blood vessels. Electrical stimulation had no measurable effect. One interpretation of this result is that cholinergic fibers control vasomotor tone by inhibiting the output of the sympathetic neurons, i.e., they have a presynaptic influence. However, it should be stressed that the data were obtained from in vitro experiments, which may not reflect the true in vivo processes. Additional evidence was obtained to demonstrate that electrical stimulation of the in vitro nasal tissue causes contraction by the release of norepinephrine from remnants of sympathetic nerve fibers remaining in the tissue. Also, there is no evidence of transganglionic degeneration in the cervical sympathetic nerve.