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Biomedical subjects

P J Jastreboff

Publications and source records attributed to P J Jastreboff.

At least 19 recordsLinked to original sources
PubMed2006

Clinical trial to compare tinnitus masking and tinnitus retraining therapy.

CONCLUSION: Both tinnitus masking (TM) and tinnitus retraining therapy (TRT) can be effective therapies for amelioration of tinnitus. TM may be more effective for patients in the short term, but with continued treatment TRT may produce the greatest effects. OBJECTIVES: Although TM and TRT have been used for many years, research has not documented definitively the efficacy of these methods. The present study was a controlled clinical trial to prospectively evaluate the clinical efficacy of these two methods for US military veterans with severe tinnitus. SUBJECTS AND METHODS: Over 800 veterans were screened to ensure that enrolled patients had tinnitus of sufficient severity to justify 18 months of individualized treatment. Qualifying patients (n=123) were placed quasi-randomly (alternating placement) into treatment with either TM or TRT. Treatment was administered at 0, 3, 6, 12, and 18 months. Outcomes of treatment were evaluated primarily using three self-administered tinnitus questionnaires (Tinnitus Handicap Inventory, Tinnitus Handicap Questionnaire, Tinnitus Severity Index). RESULTS: Findings are presented from the three written questionnaires with respect to three categories of patients: describing tinnitus as a 'moderate,' 'big,' and 'very big' problem at baseline. Based on effect sizes, both groups showed considerable improvement overall. In general, TM effects remained fairly constant over time while TRT effects improved incrementally. For the patients with a 'moderate' and 'big' problem, TM provided the greatest benefit at 3 and 6 months; benefit to these TRT patients was slightly greater at 12 months, and much greater at 18 months. For patients with a 'very big' problem, TM provided the greatest benefit at 3 months. For these latter patients, results were about the same between groups at 6 months, and improvement for TRT was much greater at 12 months, with further gains at 18 months.

Acoustic Stimulation↗
PubMed2000

Tinnitus Retraining Therapy (TRT) as a method for treatment of tinnitus and hyperacusis patients.

The aim of this paper is to provide information about the neurophysiologic model of tinnitus and Tinnitus Retraining Therapy (TRT). With this overview of the model and therapy, professionals may discern with this basic foundation of knowledge whether they wish to pursue learning and subsequently implement TRT in their practice. This paper provides an overview only and is insufficient for the implementation of TRT.

Hair Cells, Auditory↗
PubMed1999

Carbamazepine in the treatment of Lyme disease-induced hyperacusis.

Lyme disease-induced hyperacusis can be an intensely disabling, chronic condition that is accompanied by posttraumatic stress disorder-like psychobehavioral sequelae. The authors describe effective treatment of 2 patients with carbamazepine. Speculations regarding a mode of action are offered.

Adult↗
PubMed1996

Salicylate-induced changes in auditory thresholds of adolescent and adult rats.

Shifts in auditory intensity thresholds after salicylate administration were examined in postweanling and adult pigmented rats at frequencies ranging from 1 to 35 kHz. A total of 132 subjects from both age levels were tested under two-way active avoidance or one-way active avoidance paradigms. Estimated thresholds were inferred from behavioral responses to presentations of descending and ascending series of intensities for each test frequency value. Reliable threshold estimates were found under both avoidance conditioning methods, and compared to controls, subjects at both age levels showed threshold shifts at selective higher frequency values after salicylate injection, and the extent of shifts was related to salicylate dose level.

Acoustic Stimulation↗
PubMed1996

Neurophysiological approach to tinnitus patients.

The principal postulate of the neurophysiological model of tinnitus is that all levels of the auditory pathways and several nonauditory systems play essential roles in each case of tinnitus, stressing the dominance of nonauditory systems in determining the level of tinnitus annoyance. Thus it has been proposed to treat tinnitus by inducing and facilitating habituation to the tinnitus signal. The goal is to reach the stage at which, although patients may perceive tinnitus as unchanged when they focus on it, they are otherwise not aware of tinnitus. Furthermore, even when perceived, tinnitus does not evoke annoyance. Habituation is achieved by directive counseling combined with low-level, broad-band noise generated by wearable generators, and environmental sounds, according to a specific protocol. For habituation to occur, it is imperative to avoid masking tinnitus by these sounds. Since 1991, > 500 tinnitus patients have been seen in our center. About 40% exhibited hyperacusis to varying degrees. A survey of > 100 patients revealed > 80% of significant improvement in groups of patients treated with the full protocol involving counseling and the use of noise generators. Notably, in patients who received counseling only, the success rate was < 20%. The improvement in hyperacusis was observed in approximately 90% of treated patients.

Counseling↗
PubMed1995

Salicylate-induced abnormal activity in the inferior colliculus of rats.

The evaluation of the spontaneous activity of 471 units from the external nucleus of the IC revealed that salicylate induces an increase of the spontaneous activity and the emergence of a bursting type of activity longer than 4 spikes. For sharply tuned units, the affected cells were from the frequency range of 10-16 kHz, which corresponds to the behaviorally measured pitch of salicylate-induced tinnitus in rats. An exogenous calcium supplement, provided under the conditions shown to attenuate the behavioral manifestation of salicylate-induced tinnitus, abolished the modification of the spontaneous activity induced by salicylate. Finally, profound changes of activity were observed for cells not responding to contralateral sound. We propose that the observed long bursts of discharges represent tinnitus-related neuronal activity. The results are consistent with the hypothesis that GABA-mediated disinhibition is involved in the processing of tinnitus-related neuronal activity.

Acoustic Stimulation↗
PubMed1994

Alleviation of mortality induced by salicylate and stress.

Protection from the deleterious effects of the interaction of environmental stress and salicylate by calcium supplement was investigated in 96 pigmented rats. Within a 2 x 2 x 4 factorial design, rats were assigned to groups defined by: A) ad lib access to 1) plain tap water, or 2) 50 mM calcium chloride solution; B) exposure to stressors consisting of daily 10 h periods of 1) 98 dB SPL noise, or 2) confinement precluding movements; C) daily injections of 233, 350, or 410 mg/kg of sodium salicylate or the saline vehicle. For subjects maintained on tap water, weight loss and mortality increased with salicylate levels, with all subjects dying in the group drinking water and injected with 410 mg/kg. Calcium protected all of the subjects in the noise stress group but not in the confined group.

Administration, Oral↗
PubMed1994

Neurophysiological model of tinnitus: dependence of the minimal masking level on treatment outcome.

Validity of the neurophysiological model of tinnitus (Jastreboff, 1990), outlined in this paper, was tested on data from multicenter trial of tinnitus masking (Hazell et al., 1985). Minimal masking level, intensity match of tinnitus, and the threshold of hearing have been evaluated on a total of 382 patients before and after 6 months of treatment with maskers, hearing aids, or combination devices. The data has been divided into categories depending on treatment outcome and type of approach used. Results of analysis revealed that: i) the psychoacoustical description of tinnitus does not possess a predictive value for the outcome of the treatment; ii) minimal masking level changed significantly depending on the treatment outcome, decreasing on average by 5.3 dB in patients reporting improvement, and increasing by 4.9 dB in those whose tinnitus remained the same or worsened; iii) 73.9% of patients reporting improvement had their minimal masking level decreased as compared with 50.5% for patients not showing improvement, which is at the level of random change; iv) the type of device used has no significant impact on the treatment outcome and minimal masking level change; v) intensity match and threshold of hearing did not exhibit any significant changes which can be related to treatment outcome. These results are fully consistent with the neurophysiological interpretation of mechanisms involved in the phenomenon of tinnitus and its alleviation.

Acoustic Stimulation↗
PubMed1994

Covariation of binaural, concurrently-measured spontaneous otoacoustic emissions.

Simultaneous recordings of binaural spontaneous otoacoustic emissions (SOAEs) were made for 2 female subjects. For SOAEs below about 3.6 kHz measured within a testing session, the frequencies of nearby monaural and binaural SOAEs tended to move in tandem, whereas widely separated SOAEs did not. Across many testing sessions spanning a menstrual cycle, all monaural and binaural SOAE frequencies shifted in tandem. Possible mechanisms consistent with these results are discussed.

Acoustic Stimulation↗
PubMed1994

An animal model of tinnitus: a decade of development.

Although tinnitus affects approximately 9 million people in the United States, a cure remains elusive and the mechanisms of its origin are speculative. The crucial obstacle in tinnitus research has been the lack of an animal model. Over the last decade we have been creating such a model by combining a variety of methodologies, including a behavioral component, to allow for the detection of tinnitus perception. Initially, 2-deoxyglucose had been used to map changes in the metabolic activity after unilateral destruction of the cochlea. It has been found that the initial decrease of the metabolic rate in the auditory nuclei recovered to preoperative values, which could be attributable to the development of tinnitus. The spontaneous activity of single units recorded from the inferior colliculus before and after salicylate administration revealed an increase of discharges, which might reflect the presence of salicylate-induced tinnitus. Recent data have confirmed, and further elaborated this observation, including the discovery of abnormal, epileptic-like, neuronal activity. Finally, the authors have developed a behavioral model of tinnitus, tested it extensively, and used it to measure tinnitus pitch and loudness. The model is presently used for investigating the hypotheses for the mechanisms of tinnitus.

Animals↗
PubMed1993

Electrical tinnitus suppression: frequency dependence of effects.

Electrical stimulation through a round window electrode has been evaluated in 9 patients with unilateral deafness and severe tinnitus. Three subjects were permanently implanted with positive long lasting results. Analysis of the threshold of sound perception, tinnitus suppression and auditory discomfort levels as a function of current frequency revealed the advantage of low frequency stimulation. In 2 patients the loudness of electrically evoked sound perception was balanced against tones in the hearing ear. Our results can be interpreted as indicating that processes other than auditory masking are responsible for electrical tinnitus suppression.

Acoustic Stimulation↗
PubMed1993

A neurophysiological approach to tinnitus: clinical implications.

This paper presents a neurophysiological approach to tinnitus and discusses its clinical implications. A hypothesis of discordant damage of inner and outer hair cells systems in tinnitus generation is outlined. A recent animal model has facilitated the investigation of the mechanisms of tinnitus and has been further refined to allow for the measurement of tinnitus pitch and loudness. The analysis of the processes involved in tinnitus detection postulates the involvement of an abnormal increase of gain within the auditory system. Moreover, it provides a basis for treating patients with hyperacusis, which we are considering to be a pre-tinnitus state. Analysis of the process of tinnitus perception allows for the possibility of facilitating the process of tinnitus habituation for the purpose of its alleviation. The combining of theoretical analysis with clinical findings has resulted in the creation of a multidisciplinary Tinnitus Centre. The foundation of the Centre focuses on two goals: the clinical goal is to remove tinnitus perception from the patient's consciousness, while directing research toward finding a mechanism-based method for the suppression of tinnitus generators and processes responsible for enhancement of tinnitus-related neuronal activity.

Auditory Perception↗
PubMed1991

Quinine-induced tinnitus in rats.

Quinine ingestion reportedly induces tinnitus in humans. To expand our salicylate-based animal model of tinnitus, a series of conditioned suppression experiments was performed on 54 male-pigmented rats using quinine injections to induce tinnitus. Quinine induced changes in both the extent of suppression and recovery of licking, which followed a pattern that paralleled those produced after salicylate injections, and which may be interpreted as the result of tinnitus perception in animals. These changes depended on the dose and time schedule of quinine administration. Additionally, the calcium channel blocker, nimodipine, abolished the quinine-induced effect in a dose-dependent manner.

Animals↗
PubMed1991

Generalization of conditioned suppression during salicylate-induced phantom auditory perception in rats.

Tonal frequency generalization was examined in a total of 114 pigmented male rats, 60 of which were tested under the influence of salicylate-induced phantom auditory perception, introduced before or after lick suppression training. Thirty control subjects received saline injections, and the remaining 24 subjects served as noninjected controls of tonal background effects on generalization. Rats were continuously exposed to background noise alone or with a superimposed tone. Offset of background noise alone (Experiment I), or combined with onset or continuation of the tone (Experiments II and III) served as the conditioned stimulus (CS). In Experiment I, tone presentations were introduced only after suppression training. Depending on the time of salicylate introduction, a strong and differential influence on generalization gradients was observed, which is consistent with subjects' detection of salicylate-induced, high-pitched sound. Moreover, when either 12- or 3 kHz tones were introduced before or after Pavlovian training to mimic salicylate effects in 24 rats, the distortions in generalization gradients resembled trends obtained from respective salicylate injected groups. Experiments II and III were aimed at evaluating the masking effect of salicylate-induced phantom auditory perception on external sounds, with a 5- or a 10-kHz tone imposed continuously on the noise or presented only during the CS. Tests of tonal generalization to frequencies ranging from 4- to 11- kHz showed that in this experimental context salicylate-induced perception did not interfere with the dominant influence of external tones, a result that further strengthens the conclusion of Experiment I.

Animals↗
PubMed1990

Phantom auditory perception (tinnitus): mechanisms of generation and perception.

Phantom auditory perception--tinnitus--is a symptom of many pathologies. Although there are a number of theories postulating certain mechanisms of its generation, none have been proven yet. This paper analyses the phenomenon of tinnitus from the point of view of general neurophysiology. Existing theories and their extrapolation are presented, together with some new potential mechanisms of tinnitus generation, encompassing the involvement of calcium and calcium channels in cochlear function, with implications for malfunction and aging of the auditory and vestibular systems. It is hypothesized that most tinnitus results from the perception of abnormal activity, defined as activity which cannot be induced by any combination of external sounds. Moreover, it is hypothesized that signal recognition and classification circuits, working on holographic or neuronal network-like representation, are involved in the perception of tinnitus and are subject to plastic modification. Furthermore, it is proposed that all levels of the nervous system, to varying degrees, are involved in tinnitus manifestation. These concepts are used to unravel the inexplicable, unique features of tinnitus and its masking. Some clinical implications of these theories are suggested.

Humans↗
PubMed1990

Nimodipine, an L-channel Ca2+ antagonist, reverses the negative summating potential recorded from the guinea pig cochlea.

Nimodipine, an L-type Ca2+ channel antagonist, was tested using sound-evoked cochlear potentials in guinea pigs to investigate whether these channels are involved in cochlear function. Perilymph spaces of guinea pig cochleae were perfused with artificial perilymph solutions containing 0.1-10 microM nimodipine at a rate of 2.5 microliters/min for 10 min. The cochlear potentials evoked by 10 kHz tone bursts of varying intensities were recorded from the basal turn of the scala vestibuli. Cochlear perfusion of nimodipine resulted in reversible, dose-related suppression of the compound action potential of the auditory nerve (CAP; N1-P1), a prolongation of N1 latency at suprathreshold levels, an elevated CAP threshold, a decrease in N1 latency at a constant amplitude measured at CAP threshold, a reduction in cochlear microphonics (CM), and a reduction of the negative summating potential (SP) to a point where it became positive (i.e., a reversal of SP). The endocochlear potential (EP) was not affected. These results support the hypothesis that L-type Ca2+ channels are directly involved in the operation of the organ of Corti. We speculate that L-type Ca2+ channels are integrally involved in generation of a negative summating potential and the dc motion of the cochlear partition described by others.

Animals↗
PubMed1990

Tinnitus. I: Auditory mechanisms: a model for tinnitus and hearing impairment.

A model is proposed for tinnitus and sensorineural hearing loss involving cochlear pathology. As tinnitus is defined as a cortical perception of sound in the absence of an appropriate external stimulus it must result from a generator in the auditory system which undergoes extensive auditory processing before it is perceived. The concept of spatial nonlinearity in the cochlea is presented as a cause of tinnitus generation controlled by the efferents. Various clinical presentations of tinnitus and the way in which they respond to changes in the environment are discussed with respect to this control mechanism. The concept of auditory retraining as part of the habituation process, and interaction with the prefrontal cortex and limbic system is presented as a central model which emphasizes the importance of the emotional significance and meaning of tinnitus.

Auditory Pathways↗