Ludwig Podoshin

Auditory brain stem evoked potentials: clinical promise of increasing stimulus rate.

Auditory brain stem evoked potentials (ABEPs) were recorded from 10 adults and 10 children who where neurologically and audiometrically normal. ABEPs were recorded in response to 75 dB HL clicks presented at rates of 10/sec and 50/sec. Normative values were calculated for amplitude and latency, as well as for inter-peak amplitude ratio and a variety of inter-peak latency differences and interaural differences at the two stimulus presentation rates. Normative values of the effect of increasing stimulus rate were calculated as well. Measures of changes in ABEPs between stimulus rates of 50/sec and 10/sec were the only derived measures that were significantly different between our adult and child normal populations. In addition, 50 patients with various conditions affecting the brain stem were examined. Increasing stimulus presentation rate had a significant effect on detection of abnormality in ABEPs from the patients examined. Measures of changes in ABEPs between stimulus rates of 50/sec and 10/sec seemed to be sensitive to a subset of abnormalities in our patient population. The case histories of the patients indicate that the subset may be impaired synaptic function. Measures of the effect of rate on ABEPs may complement the traditional measures that are primarily sensitive to white matter lesions.

Drug-induced tinnitus and other hearing disorders.

SummaryTinnitus and hearing loss, both reversible and irreversible, are associated both with acute intoxication and long term administration of a large range of drugs. The mechanism causing drug-induced ototoxicity is unclear, but may involve biochemical and consequent electrophysiological changes in the inner ear and eighth cranial nerve impulse transmission. Over 130 drugs and chemicals have been reported to be potentially ototoxic. The major classes are the aminoglycosides and other antimicrobials, anti-inflammatory agents, diuretics, antimalarial drugs, antineoplastic agents and some topically administered agents.Prevention of drug-induced ototoxicity is generally based upon consideration and avoidance of appropriate risk factors, as well as on monitoring of renal function, serum drug concentrations, and cochlear and auditory functions before and during drug therapy. Ototoxicity, although not life-threatening, may cause considerable discomfort to patients taking ototoxic drugs, and in some cases drug discontinuation may be necessary to prevent permanent damage.Much research has been performed to investigate the causes and mechanisms of ototoxicity, to try to prevent this complication. Despite these efforts, ototoxicity still occurs, and there is much work to be done in order to understand the mechanism of ototoxicity of different drugs and to prevent hearing loss and tinnitus in the future.

Cisplatin ototoxicity in guinea pigs with special reference to toxic effects in the stria vascularis

The toxic effects of cisplatin (cis‐diamminedichloroplatinum [II]) on the organ of Corti are well established. Few and conflicting data on this drugs effects on the stria vascularis exist. The present study presents animal experiments on the toxic effects of cisplatin in the stria vascularis and in the organ of Corti. Cisplatin‐induced toxicity in albino and pigmented guinea pigs was evaluated morphologically and functionally, using light and transmission electron microscopy as well as auditory brainstem‐evoked potentials on the organ of Corti and the stria vascularis. The results showed variability in hearing thresholds, ranging from no change to hearing loss of 30 dB, and prominent damage in the organ of Corti and in the stria vascularis. The toxic effects to both the organ of Corti and the stria vascularis should be considered when cisplatin is used in chemotherapy.

Effects of peritonsillar infiltration on post-tonsillectomy pain. A double-blind study.

The concept that local infiltration of the operative area with a local anesthetic when using general anesthesia could alleviate postoperative pain is well known. We tested this concept on 129 patients scheduled for elective tonsillectomy. The patients were investigated in a double-blind, randomized study, and the operation was carried out via the standard technique of infiltrating the peritonsillar area preoperatively. The results indicated that preincisional infiltration of the tonsils with bupivacaine hydrochloride markedly decreased the intensity of pain following tonsillectomy, well beyond the immediate postoperative period.

A simple method of measuring the nasal airway in clinical work

The problem of measuring the nasal airway is discussed, and the previous literature has been reviewed. A simple method of measuring the airway and the degree of nasal obstruction has been proposed.

Ototoxicity of ear drops in patients suffering from chronic otitis media

The sensorineural hearing loss in 150 patients with chronic otitis media who were treated in the Haifa Medical Center (Rothschild) during a ten year period was studied. There were 124 patients treated with a mixture containing neomycin, polymyxin B and dexamethasone and a control group of 26 patients with dexamethasone only. All patients were followed up for a period of 1-2 years. Patients with hearing loss due to factors such as previous ear surgery, family history, exposure to noise etc., have been excluded. The conclusions reached were that there is a relationship between the period of disease and the sensorineural hearing loss and that the local treatment with a mixture containing neomycin + polymyxin B appears to contribute to the worsening of the sensorineural hearing loss in patients with chronic otitis media. Our numbers are small and further studies must be done, but the fact that currently used ear drops may produce a sensorineural hearing loss should not be ignored.

ENDOTHELIAL INJURY OF CAPILLARIES IN THE STRIA VASCULARIS OF GUINEA PIGS TREATED WITH CISPLATIN AND GENTAMICIN

The drugs cisplatin and gentamicin are used for treatment of various cancer patients suffering from infection. The authors report a detailed electron microscopic study of blood vessels in stria vascularis of guinea pigs after treatment with cisplatin alone and in combination with gentamicin. The most distinctive features expressing endothelial cellular injury were mitochondrial, including occasional paracrystalline inclusions; electron-lucent foci with depleted organelles; intracytoplasmic vacuole formations; lipid bodies; cytoplasmic extrusions located on the luminal surface; and severe luminal constriction of part of the vessels from animals treated with the combined drugs. The study suggests that the damage to strial capillaries due to treatment with cisplatin alone and in combination with gentamicin may contribute to the injurious effects of these drugs on the strial tissue. Furthermore, the results of this study may enlarge the awareness of the potential vascular damage and vascular complications in additional body systems after medical use of cisplatin alone or in combination with gentamicin.

Toxic effects of cisplatin alone and in combination with gentamicin in stria vascularis of guinea pigs.

The toxic effects on the stria vascularis of treatment with cisplatin alone and combined with the aminoglycoside antibiotic, gentamicin, were studied in guinea pigs. The toxicity induced in albino and pigmented guinea pigs was investigated morphologically with light and transmission electron microscopy, and functionally by brainstem‐evoked response audiometry. The results of hearing thresholds were variable, ranging from no change in one ear in some of the animals to a hearing loss of 20 dB in one or both ears when treated with low‐dose cisplatin alone or in combination with gentamicin. Bilateral deafness resulted from high‐dose cisplatin combined with gentamicin. The combined treatment produced prominent structural damage in the stria vascularis. The results should be considered when aminoglycoside therapy is required in conjunction with cisplatin.

Unusual complication of an ingested foreign body

Migration of a foreign body from the mouth and throat to the subcutaneous tissue of the neck is very rare. We present a case of a migrating foreign body (a piece of straw) from the floor of the mouth to the neck. To our knowledge, this is the second case reported in the English literature.

Is the Vestibular System Affected by Middle Ear Effusion

The association between middle ear effusion (MEE) and vestibular pathology is controversial. To investigate this point, 50 children with MEE scheduled for myringotomy and grommet, and 20 normal hearing children without MEE scheduled for adenotonsillectomy, underwent vestibular investigations by craniocorpography and rotatory chair, preoperatively and postoperatively. Most of the correlations, preoperative vs. postoperative, and study vs. control groups, were nonsignificant. Assuming that serous labyrinthitis is responsible for vestibular involvement in MEE, the lack of significant vestibular pathology in our study could probably be explained by the fact that no children with acute otitis media episodes or otalgia were included. (OTOLARYNGOL HEAD NECK SURG 1993;109:421-6.)