Cochlear hearing loss and viral infection

A group of about 100 consecutive patients admitted to an otorhinolaryngological outpatient department for treatment of cranial nerve affections underwent detailed neurological, audiological and laboratory examinations. Of 34 patients with hearing loss, objective signs of viral infection were found in 12. The hearing loss was sensorineural of the cochlear type, in 7 cases of the high-frequency type, in 5 cases of the low-frequency (Menière) type. Within one year after the onset of the disease the hearing loss had disappeared in all but 2 cases. Reversible dysfunction of two or more cranial nerves was found in 7 of 8 cases examined. In the cerebrospinal fluid the cell count and the total protein and gamma-globulin values were increased in most patients. Our findings indicate a reversible sensorineural hearing loss to be part of a viral-induced meningoencephalitis and cranial polyneuropathy. The mechanism of the reversible low- and high-frequency hearing loss is discussed.

Hypercoagulability as a cause of sudden neurosensory hearing loss

Fourteen patients with a documented sudden neurosensory hearing loss and four patients with other diseases causing neurosensory hearing loss were studied. The standardized coagulation workup included hematocrit, activated partial thromboplastin generation time, thrombin generation, prothrombin time, phase platelet count, platelet adhesivity, protamine sulfate, serum antithrombin III activity, fibrinogen, and Factor VIII values. Ony those patients having documented evidence of a neurosensory hearing loss occurring within hours or days were included in this study. Eight of the 14 paitents with a documented sudden neurosensory hearing loss satisfied our laboratory criteria for a diagnosis of in vitro hypercoagulability. Three of these patients had abnormal thrombin generation values, 4 had abnormal serum antithrombin III values, and 1 had an elevated platelet count. Four other patients with other diseases causing neurosensory hearing loss did not show evidence of in vitro hypercoagulability. It would appear from this data that coagulation abnormalities play a role in the pathogenesis of sudden neurosensory hearing loss.

Arnold-Chiari malformation--some otoneurological features

Arnold-Chiari malformation was diagnosed in five patients with vertigo. Four were of anatomical type I. A case report is given of one patient who presented features of a unilateral cerebellopontine angle lesion. Downward beating vertical nystagmus was an important finding in three of the five patients. Other clinical and radiological features of the condition are discussed.

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.

[Hypacusis in acquired hypothyroidism (author's transl)]

We examined 56 patients with latent or clinical hypothyroidism and a control group of 18 patients with acute hypothyroidism. We were especially interested in the localization and extent of hearing abnormalities. 45% of the patients with chronic hypothyroidism showed a hearing loss. 2 of these patients had a pure conductive loss, 7 a combined hearing loss and 16 a sensorineural hearing loss. We demonstrated hair cell damage in 13 of the patients with chronic hypothyroidism. This loss was mild to moderate in over 90% of the cases. Although several patients had basilar-cochlear hearing losses, no characteristic audiograms could be found. 50% of the patients showed a small improvement in hearing after thyroid substitution therapy. The results of our examinations are discussed in detail.

Meningitis and hearing loss in children

The hospital records for 100 cases of meningitis in which acute audiometric data has been obtained were reviewed. The incidence of sensorineural hearing loss was found to be 6%. The severity of hearing impairment varied from mild to profound and was frequently bilateral and irreversible. Two-cases showed asymmetrical involvement, and in one case, there was subsequent improvement in threshold sensitivity. Factors that influenced the incidence of neurologic sequela included severity of the initial disease process, age of the patient, and duration of symptoms before diagnosis and treatment. We discuss the pathophysiologic mechanisms that may account for such hearing loss, and we emphasize the importance of early diagnosis and intensive antimicrobial therapy. Careful neurologic evaluation is required after recovery and must include periodic sequential audiometric testing.

Cochlear otosclerosis. A continuing fantasy

Sensorineural hearing loss without an associated conductive loss cannot be attributed to otosclerosis.

Bullous myringitis with sensorineural hearing loss

Bullous myringitis is manifested by moderately severe otalgia associated with vesicles on the tympanic membrane and medial external auditory canal wall. This disease occurs mainly in young adults, most commonly in winter, and is usually preceded or accompanied by an upper respiratory infection. A reversible sensorineural loss developed in three of 22 patients. Complement fixation antibody studies performed on ten patients failed to implicate Mycoplasma pneumoniae, influenza virus types A or B, or adenovirus as the causal agent.

Auditory involvement in thalassemia major

The auditory function of 75 children affected by homozygous beta0-thalassemia, managed with a low transfusion scheme and treated irregularly with low doses of desferrioxamine, and of 75 controls were examined. In 12 patients a mild bilateral conductive hearing impairment due to bony hypertrophy and/or adenoid hypertrophy was found. In 43 cases a moderate monolateral or bilateral sensory-neural hearing loss at high frequencies with recruitment phenomenon was observed. Ferritin levels were determined in a randomly chosen group of these patients with (14) and without heaing loss (11). In the subjects with sensory-neural hearing loss the mean ferritin levels were significantly higher than in those with no hearing defect. There was no obvious relation between sensory-neural damage on the one hand and Hb levels and unit of blood transfused on the other. The results of this study suggest that iron overload could be a cause of damage in the high frequency elements of the auditory mechanism. Intermittent hypoxia and slow 8th nerve compression due to bony hypertrophy as causes of auditory involvement are also discussed.

Abrupt (sharp cut) type sensorineural hearing loss--a human temporal bone study--

Histopathology of a case of bilateral sensorineural hearing loss of abrupt (sharp cut) type is reported. While there was a 45 dB gap in threshold between 1,000 Hz and 2,000 Hz bilaterally, the patient had a good hearing at 1,000 Hz and lower frequencies. The patient was suffering from Takayasu's arteritis. Major histopathological findings were as follows: Almost complete loss of the outer hair cells from the basal end to 12 mm area in the left cochlea (length: 30.5 mm) and 13 mm in the right (length: 31.5 mm). The inner hair cell of the same region was also missing in the left cochlea, and to a lesser degree in the right. There was a clear separation between the normal and the pathological organ of Corti. Marked loss of the cochlear neuron was noted in the same region. Blood vessels within the cochlea and the internal auditory meatus were normal. Bilateral abrupt (sharp cut) type sensorineural hearing loss with unknown etiology is a group of inner ear disease due to abiotrophy of the organ of Corti and cochlear neuron. Disposition or hereditary factor possibly plays an important role in the development of hearing loss.

[Unilateral deafness (author's transl)]

Unilateral conductive deafness has a readily determined aetiology in most cases. In contrast, unilateral sensorineural hearing loss requires more refined and extensive investigation. The most frequent causes of unilateral sensorineural hearing loss in our patients were sudden deafness, Menière's disease, cranio-vertebral dysplasia and cerebellopontine angle tumors. Early diagnosis of acoustic neuroma or other lesions of the internal auditory meatus or cerebellopontine angle requires special attention. The definitive diagnosis of these tumors often demands intensive clinical investigation but a high degree of suspicion may be entertained following modern routine audiometry, vestibular function testing and radiological examination. The importance of early diagnosis of these lesions is stressed with regard to the mortality rate for larger tumors and to the preservation of facial nerve function. The reliability of different diagnostic investigations is documented.

[Hearing loss and hyperthyroidism (author's transl)]

The audiometric findings on 23 patients with diquited hypothyroidism for a minimum of 4 months to a maximum of 20 years are presented. Audiometric tests, including acustic impedance measurements (tympanometry, stapedius reflex) were performed on all patients before and after an adequate substitution therapy. In 12 patients there was a definite impairment of hearing before the substitution therapy. Eight of them have shown a mild to moderate sensory-neural deafness. Four showed a mixed deafness, in three of which a negative pressure of 300 mm H2O was measured in the middle ear, the fourth one had a seromucotympanon. In three patients with pure sensory-neural deafness the stapedius reflex was elicitated only 30 dB over the pure tone threshold in speech frequencies. The audiometric measurements after an adequate substitution therapy of minimum 4 months has shown a definite improvement of hearing loss.

Otosclerosis: vestibular symptoms and sensorineural hearing loss

Of 546 patients with otosclerosis, 500 who had not had ear surgery were divided into four groups according to the relative and absolute amounts of sensorineural hearing loss in the hearing-impaired ears. The first three groups of patients had progressively less of a conductive component and progressively more of a sensorineural component to their hearing losses. The fourth group of patients had pure sensorineural hearing impairments. The remaining 46 patients were placed in group V. They had bilateral hearing losses and had had a prior unilateral stapedectomy for otosclerosis and they had received medical therapy for otosclerosis. The following conclusions were reached: 1 Further clinical evidence was obtained supporting the existence of the entity “pure labyrinthine otosclerosis.” However, there can be difficulties in the diagnosis of this condition. 2 The incidence of vestibular symptoms in patients with otosclerosis increased as the relative and absolute amounts of sensorineural hearing loss increased and was much higher than one would expect in the normal population. In addition, with increasing sensorineural hearing loss, the severity of vestibular symptoms increased along with the incidence of depression in vestibular function determined by the bithermal caloric test in patients with vestibular Symptoms. 3 A preliminary study on the administration of a combination of calcium gluconate, sodium fluoride, and vitamin D to patients with otosclerosis who had vestibular symptoms indicated that the therapy controlled vestibular symptoms in a high percentage of these patients. 4 A preliminary study on the administration of calcium gluconate, sodium fluoride, and vitamin D to patients with otosclerosis indicated that in a high percentage of patients the deterioration in hearing was stopped. A small but significant number of patients had reversal of their hearing loss. 5 Side effects of treatment with a combination of calcium gluconate, sodium fluoride, and vitamin D were not serious and were reversible, and there appears to be no contraindication to this therapy for healthy adults.

Some observations in a case of acoustic neuroma

The subject was a 47-year-old male with a moderate asymmetrical sensorineural hearing loss that initially presented cochlear signs except for positive stapedius reflex results. Over the course of only five weeks, he developed the audiological constellation of retrocochlear involvement. The retrocochlear results were confirmed by the removal of an acoustic tumour. The results highlight the importance of audiological monitoring and reflex measures in the identification of acoustic neuromas. Several observations provide insight into the apparent relationship between loudness and the stapedius reflex. The findings are discussed with reference to a proposed extension of Borg's recent theory that elevated reflex thresholds and reflex decay reflect differing degrees of the eighth nerve destruction.

Acoustic neurinoma in a child: a case study

This case study reports the audiological and surgical findings for a nine-year-old boy with an acoustic neurinoma. He was suspected of having a right ear retrocochlear lesion following three audiological evaluations in four years. The initial evaluation indicated normal hearing ability. The second and third evaluations indicated a progressive right ear hearing loss, characterized by reduced word discrimination ability and absent acoustic reflexes. The patient had a 5 cm acoustic neurinoma compressing and adherent to the brain stem. The tumor was successfully removed following three operations employing an otoneurological and neurosurgical team approach through a retromastoid exposure. Postoperative recovery was uneventful. Facial nerve function was not disturbed, however attempts to preserve hearing on the involved side were not successful.

Paget's disease and hearing loss

Hearing loss, tinnitus, and vertigo have long been associated with Paget's disease of the bone. We reviewed the records of 463 patients with Paget's disease who were seen in the otolaryngology department. Hearing loss was common. It was our observation that mixed hearing losses were part of the disease process. Sensorineural hearing loss was the most frequent loss, but it usually was not part of the disease process. Tinnitus, vertigo, or both were seen in about 20% of these patients.

Possible effects of kanamycin and incubation in newborn children with low birth weight

In an acoustico-vestibular follow-up investigation of 91 four- to six-year-old children with birth weight below 2000 g, the same incidence of sensorineural hearing loss (19%) was found in 54 children treated with kanamycin in the neonatal period as in a group of 37 infants not treated with kanamycin. When comparing a group of children treated with both kanamycin and incubator (54 children) with a group treated with incubator only (16 children), no definite signs of synergism between incubator noise and kanamycin were found. However, the 5 cases of moderate or severe hearing loss all belonged to the group treated with both incubator and kanamycin. These 5 children had more severe neonatal complications, especially apnea, cyanotic spells and hyperbilirubinemia, which may increase the severity of the hearing loss. Among 56 incubator treated children with normal hearing (ISO standards) 52% had an audiogram pattern suggesting minor noise-provoked cochlear lesions. Among 18 non-incubator treated children with normal hearing only one child (6%) had a similar pattern. It should be stressed, however, that these children had no clinical symptoms of hearing loss.

Sudden or fluctuating hearing loss and vertigo in children due to perilymph fistula

Five cases are presented of children with rapid onset of sensorineural hearing loss, disequilibrium, or both, who were found at exploratory tympanotomy to have a perilymph fistula. Four of the children had histories suggesting that antecedent barotrauma or physical exertion contributed to the development of the fistula. One child with congenital unilateral craniosynostosis had a residual temporal bone abnormality on the same side as the perilymph fistula. Two children had identifiable anatomic abnormalities in the middle ear. A classification of perilymph fistula is proposed that describes a congenital, an acquired, and a combined type of fistula. Inner ear fluid dynamics and patency of the cochlear aqueduct appear to be important factors in pathogenesis. Children with unexplained fluctuating or sudden onset of sensorineural hearing loss, and children with unexplained disequilibrium or vertigo should be suspected of having a perilymph fistula. The history can be singularly important in raising the suspicion that a perilymph fistula may be present. Although audiometric, vestibular, and radiographic studies can be helpful, there is no way to prove the presence or absence of a fistula without directly viewing the middle ear. Tympanotomy with repair of the fistula does not assure improvement in hearing.

Management of the labyrinthine fistula

Preoperative, operative and postoperative findings in 97 cases of labyrinthine fistula are presented. The majority of patients had had symptoms of chronic otitis media for 20 years or more and manifested some degree of sensorineural hearing impairment. Two-thirds had experienced dizziness. The fistula was limited to the lateral semicircular canal in 83 cases and involved the labyrinth more extensively in 14 instances. The intact canal wall technique was used in less than 60% and an open cavity technique in a quarter of the cases. Severe or total sensorineural hearing impairment developed postoperatively in 8% of the lateral canal cases and in over half of the extensive fistula cases. Five per cent had incapacitating dizziness for up to 6 months postoperatively. When a labyrinthine fistula is encountered in an only hearing ear, a classified modified radical mastoidectomy is usually recommended. In other instances, the procedure performed will vary with the status of the opposite ear, the extent of the fistula, the sensorineural function of the involved ear and the size of the mastoid.

The etiology of neurosensory hearing defects in preterm infants

We retrospectively investigated the influence of gestational age, perinatal risk, and the duration of incubator care periods in 193 surviving preterm infants with a gestational age between 28 and 36 weeks raised in our intensive care nursery incubators from 1965--1967. 24 (12.4%) of the children showed definite neurosensory hearing defects, which were particularly encountered in the high frequencies. No correlation could be substantiated between hearing difficulties and hyperbilirubinemia, streptomycin application and gestational age. This study does not support the assumption that the duration of noise exposure in currently used incubators is a major determinant for the development of deafness in otherwise healthy preterm infants. Our study did show, however, a strong correlation between the sum of all perinatal risk factors and neurosensory hearing loss.

The longitudinal course of congenital rubella encephalitis in nonretarded children

The neurologic course of congenital rubella syndrome was traced in 29 nonretarded children to 9 to 12 years. During the first two years, manifestations involved abnormal tone and reflexes (69%), motor delays (66%), feeding difficulties (48%), and abnormal clinical behavior (45%). Hearing loss was documented in 76%. From three to seven years, poor balance, motor incoordination (69%), and behavioral disturbances (66%) predominated. Hearing losses increased to 86%. Currently, at 9 to 12 years, 25 have residua which include learning deficits (52%), behavioral disturbances (48%), poor balance (61%), muscle weakness (54%), and deficits in tactile perception (41%). Two additional children now have hearing loss. The encephalitic manifestations of congenital rubella syndrome are diverse. Overriding problems differ at each phase of childhood. Current deficits influence progress in educational and home environments. For these children, adequate intelligence alone does not guarantee academic success.

Hearing impairment in children of low birthweight

Audiometer evaluations were carried out on a population of 204 low birth weight (LBW) children and 123 controls. In the LBW group, 6 children (3.3%) had a bilateral loss and 5 (2.5%) had a unilateral sensorineural high-frequency hearing loss. No case of sensorineural hearing loss was found among the controls. There were 13 (6.4%) cases of conductive loss among the LBW sample, compared with 3 (2.4%) among the controls. Correlation coefficients showed a relationship between sensorineural impairment and: bilirubin level, incubator time, antibiotic history, and neurological status. Subsequent multiple classification analyses showed that, while incubator time and bilirubin level are each significant predictors of sensorineural loss, this is not the case with antibiotics or neurological status. Neurological status was closely associated with the syndrome of LBW, high bilirubin level, extended incubator time and sensorineural loss. However, no significant relationship could be found between neurological impairment and these predictors nor can it be regarded as useful in predicting hearing loss in this population.