L G Johnsson

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Old World monkeys were exposed to octaveband noise from 0.5 to 8 kHz at 120 dB SPL, 8 hours daily for 20 days. Restricted permanent threshold shifts and localized loss of outer hair cells were produced, which were reasonably well correlated with the exposure frequencies. There was also a loss of both inner and outer hair cells at the extreme basal end of(More)
Fiber diameters were analyzed in the meatal segment of the cochlear nerve from 7 temporal bones obtained from 7 patients. Two patients had normal hearing for their age. Two had sustained noise exposure and one had presbyacusis of predominantly neural type. The cochleae displayed characteristic degeneration patterns. The other two manifested hearing loss of(More)
A multicentre study of the inner ears of an 88-year-old patient with vertiginous spells and severe hearing loss in the left ear was performed, employing regular and block surface preparations, light and electron microscopy with qualitative and quantitative evaluation of the cochlear and vestibular nerves. There was severe hydrops of the left cochlea and(More)
Temporal bones from five patients with hearing loss as a result of aminoglycoside treatment were examined by the method of microdissection and surface preparations, followed by celloidin embedding and serial sectioning of the modiolus. Three patients had received the newer antibiotics, gentamicin, tobramycin, and amikacin; the other two neomycin. In the(More)
Various forms of sensorineural degeneration patterns related to noise exposure are illustrated in six pairs of temporal bones selected from a group of 33 male patients with histories of noise exposure. For the entire group the commonest form of lesion, associated with a 4-kHz dip in the audiogram, was a relatively diffuse degeneration in the second quadrant(More)
Although the cochlear toxicity of dihydrostreptomycin (DHSM) is well-recognized in man, it has always proved difficult to demonstrate in animals. Hearing thresholds in M. nemestrina monkeys remained essentially unchanged after DHSM 100 mg/kg im daily for 8 months, but E. patas monkeys were severely deafened by DHSM 20 mg/kg for 90 days, a regimen formerly(More)
A small intracochlear neurinoma was found in the temporal bone of a 54-year-old man who had no history of hearing loss or dizziness. The tumor was small, confined to the scala tympani, and did not visibly alter the tissues around it. The neurinoma was derived from the distal processes of the cochlear neuron. Intralabyrinthine tumors can cause auditory and(More)
The myelinated radial fibres in the osseous spiral lamina and the myelinated fibres in the cochlear nerve in the internal auditory canal as well as the sensory cells were counted in cochleae from 15 dissected temporal bones from 8 patients. Light microscopy was carried out on semithin sections of epoxy resin embedded tissue. Audiometry had been performed(More)
Cochlear hair cell counts from individuals who had clinically normal hearing prior to their death have been plotted for various age bands as a function of the number of hair cells per millimetre against their position in the cochlea. Position has been expressed as the distance of that observation of hair cell density from the base of the cochlea, divided by(More)
The inner ears obtained from an infant who died of severe congenital cytomegalovirus infection were examined using virological and morphological methods. The techniques of microdissection and surface preparations, immunofluorescent microscopy, and transmission and scanning electron microscopy were employed. Cytomegalovirus was isolated from the perilymph.(More)