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Biomedical subjects

N J Johnsen

Publications and source records attributed to N J Johnsen.

At least 19 recordsLinked to original sources
PubMed1992

On the evidence of auditory evoked magnetic fields as an objective measure of tinnitus.

The purpose of the present study was to determine the utility of auditory evoked magnetic fields as an objective measure of tinnitus. The auditory evoked magnetic fields of 14 patients with tinnitus and of 14 sex- and age-matched controls were measured by means of a 7-channel BTI neuromagnetometer. Stimuli were 1 kHz tone-bursts presented randomly. Tinnitus patients and controls were similar with respect to latencies and amplitudes of the N100m and P200m, and with respect to the locations and moments of the equivalent current dipoles. The present study could not support the notion that specific abnormalities of the auditory evoked magnetic fields are characteristic of patients with tinnitus.

Acoustic Stimulation↗
PubMed1991

Bilateral sudden deafness and acute acquired toxoplasmosis.

An 18-year-old woman, while suffering from acute acquired toxoplasmosis, experienced sudden deafness and a total loss of vestibular function first in the right ear and three months later also in the left. Following treatment with sulphadiazine and pyrimethamine, hearing was retrieved to such a degree that the patient was enabled to communicate by means of a body-worn hearing aid and lip-reading. Taking the differential diagnostic possibilities into account, we believe that toxoplasmosis was the cause of the severe hearing loss. Since effective treatment seems to be available, we recommend that patients with acute bilateral sensorineural hearing loss of unknown origin are examined for acute toxoplasmosis with a view to instituting chemotherapy.

Acute Disease↗
PubMed1991

Otologic sequelae after pneumococcal meningitis: a survey of 164 consecutive cases with a follow-up of 94 survivors.

As part of a comprehensive study on sequelae after pneumococcal meningitis, 94 of 111 consecutive survivors were re-examined 4 to 16 years after discharge. Twenty-three patients had otological sequelae after pneumococcal meningitis. In these patients, 17 had hearing losses, 7 had tinnitus, 9 had vertigo, 13 had vestibular areflexia, 4 had loss of smell, and 3 had loss of taste. Among the patients with hearing loss, 4 were bilaterally deaf, 6 were unilaterally deaf, and 2 had mild and 5 had slight hearing losses. From correlations with extensive data from the medical records, preadmission antibiotic treatment appeared to protect from acousticovestibular damage. Purulent otitis media and otosurgical intervention did not correlate to the fatality rate or the development of sequelae. Acute purulent otitis media appeared as a concomitant manifestation, rather than the focus of pneumococcal meningitis.

Adolescent↗
PubMed1989

Evoked acoustic emissions from the human ear. V. Developmental changes.

Twenty young children, in whom evoked acoustic emissions were recorded at birth, were re-examined at the age of 4 years. None of the children showed evidence of sensorineural hearing impairment and it was possible to record a reproducible emission in all ears, which displayed normal otoscopy and tympanometry (n = 9). The new recordings were compared with those obtained at birth and the latency and the amplitude of the response both appeared unchanged. However, in some ears the frequency content of the dominant part of the emission was considerably lower at the age of four. The implication of this finding is briefly discussed in view of recent data on cochlear development, obtained from animal research.

Child, Preschool↗
PubMed1989

Otospongiosis and sodium fluoride. A clinical double-blind, placebo-controlled study on sodium fluoride treatment in otospongiosis.

The effect of sodium fluoride treatment in patients with otospongiosis has been evaluated in a prospective clinical double-blind, placebo-controlled study of 95 patients. The results showed a statistically significant greater deterioration of hearing loss in the placebo group than in the group actively treated with 40 mg of sodium fluoride daily. These results support the view that sodium fluoride can change otospongiotic, active lesions to more dense, inactive otosclerotic lesions.

Adult↗
PubMed1988

Evoked acoustic emissions from the human ear. IV. Final results in 100 neonates.

Evoked acoustic emissions were recorded from both ears in a series of 100 consecutive normal newborns. We used the same stimulus, a 2-kHz click, and recording technique as previously described. Analysis of the data showed that evoked emissions could be identified in all ears, except one at 70 dBaud (i.e. approximately 30 dB nHL). No significant differences could be demonstrated between males and females or between left and right ears with regard to the latency of the emissions, the peak-to-peak amplitude, the main frequency component, or the waveform correlation between the two 70 dBaud recordings in each ear. However, a significant correlation between left and right ears was found for the amplitude and frequency of the emissions. Practical and methodological problems related to the recording were elucidated. The tail of the stimulus artifact sometimes interfered with the first part of the emissions even though the recordings were made in a time window delayed 5 ms relative to the stimulus onset. We tried to solve this artifact problem by different off-line techniques, but found no useful solution. We therefore continued to use only a cosine tapering of the first 2 ms of the time window. Three different ways of determining latencies were evaluated and we found that the 'envelope' technique was the most simple and reliable. Recording of evoked acoustic emissions is a quick and non-invasive method and provided that the presence of the emissions is related to normal cochlear function, it can be used as a screening test in newborns.(ABSTRACT TRUNCATED AT 250 WORDS)

Audiometry, Evoked Response↗
PubMed1979

The frequency of patulous Eustachian tubes in pregnancy.

Two-hundred and seventy pregnant women (540 ears) were examined for patulous Eustachian tubes. The diagnosis was established by means of a Madsen Zo 70 electroacoustic impedance bridge. Nineteen of the patients were found to have patulous Eustachian tubes in 1 or both ears as evidenced by impedance variations synchronous with the respiration. Only 5 of these women had any subjective symptoms. Nine other women had symptoms, but their Eustachian tubes were closed at the time of examination. The results were related to the duration of the gestation, to oestrogen production and weight gain during pregnancy. A significant correlation was found was found between patulous Eustachian tube and elevated serum oestriol values.

Adolescent↗
PubMed1979

Inherited congenital bilateral atresia of the external auditory canal, congenital bilateral vertical talus and increased interocular distance.

Six out of twenty descendants of a reportedly affected grandfather have congenital bilateral symmetrical and isolated subtotal atresia of the external auditory canal. Four of the six affected descendants have bilateral foot anomalies--two affected cousins having congenital vertical talus. All of the three affected boys in the third generation have increased interocular distance. Short fifth fingers, bilateral single transverse palmar creases, pyloric stenosis and congenital exotropia were found infrequently and are considered coincidental features. Apart from the atresia, oto-rhinolaryngologic examination, mental function, dermatoglyphics, IgA, kidney function and heart function of the affected descendants were all normal. The karyotype of four affected descendants examined was normal. An autosomal dominant inheritance with variable expressivity is suggested.

Abnormalities, Multiple↗
PubMed1979

Carcinoma of the parotid gland following sialography with thorotrast. Report of two cases.

Two cases are presented of malignant tumour of the parotid gland following sialography with Thorotrast, 28 and 45 years previously. Both cases were histologically established as squamous cell carcinoma and the presence of Thorotrast in the tumours was confirmed by autohistoradiography. It is suggested that the tumours may have developed from metaplastic ductal epithelium after many years of exposure to the alpha radiation from Thorotrast deposits in the gland.

Autoradiography↗
PubMed1978

Perennial rhinitis: an analysis of skin testing, serum IgE, and blood and smear eosinophilia in 201 patients.

Allergen skin testing, eosinophil counting in blood and nasal smear and serum IgE determination were performed in patients with simple perennial rhinitis, and in patients with rhinitis and asthma. The results were compared with those obtained in normal controls. As a positive skin test was demonstrated in 40% of patients with simple rhinitis and in 88% of patients with rhinitis and asthma, skin testing is considered relevant in all patients with perennial rhinitis. While blood eosinophil count and serum IgE level were elevated in a fair proportion of asthmatic patients, only a few subjects with simple perennial rhinitis had an elevated level, and the diagnostic values of these tests is questionable. On the other hand, examination of a nasal smear for eosinophils could usually separate the patients from the controls. The study emphasizes the importance of making a distinction between simple perennial rhinitis and perennial rhinitis associated with other symptoms and diseases.

Adolescent↗
PubMed1978

Positional nystagmus of the persistent type.

In a 6-year period (1970-1975), a total number of 10,730 patients were examined oto-neurologically by the same physician, all of the patients being referred from the neuromedical and neurosurgical departments. Persistent positional nystagmus is in this material the same as central positional nystagmus, because the lesion in all cases was of central origin. Central positional nystagmus was found to be a rare symptom, since it was only demonstrated in 124 patients (1%). Central positional nystagmus was defined as being with no latency, low and irregular frequency, nonfatiguable with no accompanying dizziness, and the patients examined in the following positions: right and left side, supine and with hanging head. In 52 cases (42%) the nystagmus was only demonstrated with hanging head. The diagnoses were dominated by intracranial tumors (34 infra-tentorial, 19 supratentorial). Among other diagnoses encountered were intracranial vascular disease, encephalopathia, epilepsy and multiple sclerosis. 21 patients were children under 15 years of age, and in this group the intracranial tumors, especially the infratentorial, were even more dominant.

Adolescent↗
PubMed1977

Intranasal allergen challenge during corticosteroid treatment.

The effect of a corticosteroid drug on type I reactions in the nose was studied in eighteen hay fever patients. They were treated with a daily dosage of 800 microng beclomethasone dipropionate intranasally for I week, in a double-blind, placebo-controlled cross-over trial. Allergen challenge on the last day of each treatment period showed that steroid treatment diminished sneezing and rhinorrhoea, but the effect was not statistically significant (P = 0-10). Immediate nasal blockage was unaffected. There is a marked discrepancy between the minor protection offered by beclomethasone dipropionate in type I allergy, as suggested in this study and the marked efficacy of the drug in the treatment of hay fever. It is suggested that two factors may account for this discrepancy. First, the significance of "delayed" reactions for hay fever symptoms. Second, the difference between a single allergen provocation and continuous exposure. It is suggested that a slight steroid inhibition of immediate reactions following allergen provocation is potentiated during natural exposure due to inhibition of the priming of the end-organ.

Administration, Intranasal↗
PubMed1976

Multiple sclerosis. The value of clinical vestibular examination.

A clinical vestibular examination was carried out on 82 patients with multiple sclerosis (MS) selected on McAlpine's criteria. Spontaneous nystagmus, positional nystagmus or pathological caloric test were found in 49 (60%) patients. Pathological horizontal optokinetic nystagmus occurred in 47 (57%) patients. In 36 cases horizontal optokinetic nystagmus was pathological to both sides, in 28 cases combined with a pathological vertical optokinetic nystagmus, indicative of diffuse intracerebral lesions. Lesions in the central vestibular system and in the optokinetic pathways were frequently discovered in early or atypical cases of MS.

Adult↗