PubMed HealthSearch

Biomedical subjects

M Rosignoli

Publications and source records attributed to M Rosignoli.

At least 19 recordsLinked to original sources

Plexiform neurofibroma of the cervical portion of the vagus nerve.

The authors describe a rare case of plexiform neurofibroma of the cervical portion of the vagus nerve, and discuss its aetiopathogenesis, clinical, histological and therapeutic features, emphasizing the difference from other benign tumours of the vagus nerve. The clinical characteristics of the mass, ultrasound tomography, CT scanning and digital subtraction angiography were useful in defining its extension and relationships with the surrounding structures. Surgery is the treatment of choice. After mentioning the most commonly employed surgical approaches, they emphasize the advantages of the lateral-cervical approach which allows a wide exposure of the possible sites of origin of the tumour and its complete removal. Finally they stress the need of an accurate histological and immunohistochemical examination in order to differentiate neurofibromas from neurilemmomas.

Adult

Cochlear and neural dysfunction in acoustic neuroma: can they be separately revealed by auditory brain-stem wave V latency?

Cochlear and retrocochlear lesions may be differentiated by a diagnostic index (D5), which is derived from the patient's auditory brain-stem wave V latency and pure-tone hearing threshold at 2 to 4 kHz. The D5 values obtained from 49 cases of acoustic neuroma (AN) have been shown to share some properties with D5 values of patients with cochlear hearing loss (280 cases), indicating a lesser prolongation of wave V latency in cases with pronounced hearing loss. Assuming this finding is indicative of some degree of cochlear impairment concomitant to the neural dysfunction, AN data were corrected in an attempt to remove the effects of cochlear impairment. The resulting D5 values could reflect the delay in wave V solely due to the neural dysfunction. A significant relationship between these D5 values and tumour size seems to support this hypothesis.

Adult

Observations on the ABR I-V interval in a clinical sample of elderly patients.

ABR I-V interval in elderly patients, analysed by multiple regression analysis, was found to be dependent on hearing threshold slope and sex, while the contribution of age and hearing loss was not significant. Since these results partly disagree with other reports which demonstrate that I-V interval is significantly related to age and hearing threshold, caution is suggested in inferring general conclusions on age effects, if data are drawn from clinical samples.

Aged

[Midline granuloma and Wegener's granulomatosis].

Necrotizing lesions of upper respiratory tract have always been among the most enigmatic diseases of the head and neck region. Nowadays a great deal of nosographic confusion still remains along with numerous doubts concerning diagnostic and therapeutic strategies to be followed in dealing with many diseases often erroneously defined "midline granuloma". In fact, a large variety of diseases appear or may appear as midline destructive lesions in the upper respiratory tract. Each of these, including infections, immune and neoplastic disorders, obviously requires a different therapy. The clinician must have a very good knowledge of the problem in order to make a rational approach to diagnosis and therapy. Wegener's granulomatosis is quite different from "midline granuloma" and must be diagnosed promptly so that an appropriate therapy may be determined as soon as possible. Unlike in the case of "midline granuloma", a prompt therapy is often very effective and gives long periods of remission. In this disease, nevertheless, the etiopathogenesis of both diseases is unknown, precise protocols for diagnosis or treatment do not exist (every case must be considered separately) and prognosis is very poor. On the basis of their personal experience and of an accurate review of Literature, the Authors present a systemic and up-to-date monographic study focusing particular attention on the most recent diagnostic techniques, such as immunohistochemical techniques which utilize monoclonal antibodies, indispensable in the cases of "midline granuloma", and immunofluorescent techniques searching antibodies to cytoplasmic antigens of neutrophil granulocytes, of great value in dealing with Wegener's granulomatosis not only in establishing an initial diagnosis, but also in making prognosis and in controlling the evolution of the disease. The paper also discusses differential diagnosis of midline destructive disorders, highly important for a correct and rational initial approach in diagnosis. Every disease described in the section concerning differential diagnosis must be excluded in order to make an accurate diagnosis of "midline granuloma" in that no typical histopathologic or clinical signs of this particular, destructive disorder. Finally, the authors focus their attention on new etiopathogenetic hypotheses and their therapeutic implications. The most interesting of them are surely those that consider "midline granuloma" the manifestation of a malignant lymphoma as well as those that explain the recent success obtained in treatment of Wegener's granulomatosis using trimethoprim and sulfamethoxazole asserting a possible essential role of infections in the etiology of the disease.

Adult

[Relations and variability of the stapedial reflex threshold and psychoacoustic discomfort threshold].

Ten normal hearing subjects were subjected to repeated measurement of the stapedial reflex threshold (RT) and loudness discomfort threshold (DT) during five separate sessions. On the average DT was 4.8 dB higher than the RT. The sessions did not affect the intra-individual variance of either threshold. A regression analysis demonstrated that a significant linear relationship exists between RT and DT. However, DT may be lower than RT when the latter is shifted towards its upper variance boundary. Hence, RT and DT are not equivalent as indicators of the upper limit of loudness tolerance; since DT revealed a low intra-subject variance, such a psychoacoustic measurement may be reliably used for clinical purposes.

Acoustic Impedance Tests

40-Hz steady-state responses in newborns and in children.

The authors investigated the 40-Hz steady-state responses (SSR) in 32 full-term newborns and in 10 normal children (5-8 years old), using 500-Hz tone bursts. The 40-Hz SSR threshold is located at about 50 and 30 dB nHL in newborns and older children, respectively. The latencies of both P1 and N1 waves decreased significantly with age, while the amplitudes increased. No significant latency and amplitude intersex differences have been observed. Moreover, with age, the 40-Hz SSR became more stable, their test-retest replicability improved, and P1-N1 wave occurrence increased. The authors finally discuss the possible underlying mechanisms of these findings and conclude that the 40-Hz SSR are difficult to obtain and are scarcely reliable in defining the low-frequency threshold in newborns. The stability and reliability of the responses increase with age, and the electrophysiological and behavioral thresholds to low-frequency stimuli tend to overlap.

Audiometry, Evoked Response

Microbial flora of surface versus core tonsillar cultures in recurrent tonsillitis in children.

Surface and 'core' tonsillar specimens were collected from 60 children, between 2 and 14 years of age, suffering from recurrent tonsillitis, in order to establish the reliability of surface tonsillar swabbing technique and to define the most frequently involved aerobic and anaerobic microorganisms. From the qualitative point of view, the same mixed aerobic and anaerobic flora were obtained in both samples thus demonstrating the reliability of the surface swabbing technique. From the quantitative point of view, 187 microorganisms, 129 (69.2%) aerobes and 58 (30.8%) anaerobes were isolated from surface cultures while 184, 109 (59.2%) aerobes and 75 (40.8%) anaerobes from the core cultures, thus demonstrating a greater number of anaerobes in the core of the tonsil. The most common isolated aerobic microorganisms were the alpha- and beta-hemolytic Streptococci, the Neisseriae and the Staphylococcus aureus; the predominant anaerobic ones were the Fusobacterium nucleatum, the Bacteroides sp. and the Veillonella parvula. The isolated staphylococcus aureus and the bacteroides sp. were all beta-lactamase producers.

Adolescent

Auditory brainstem responses in noise-induced permanent hearing loss.

Fifty-four patients (108 ears) with presumed noise-induced hearing loss, were subjected to tonal and speech audiometry, impedance tests and measurements of auditory brainstem responses (ABR), in order to check for possible retrocochlear involvement. ABR data indicated that latency values of waves I, III and V, as well as III-I, V-III and V-I intervals fell within the normal range in all cases (M +/- 2 SD), even for fast repetition rates (51 stim/s). Poor waveform resolution of early components, particularly of wave I, was found in 12 ears (11.1%) and a total absence of evoked potentials not always related to the hearing loss, occurred in 5 ears (4.6%).

Acoustic Impedance Tests

40-Hz auditory event-related potential in normal adults.

40-Hz event-related potentials (AERP) in response to 0.5-, 1-, 2- and 4-kHz tone pips were studied in 45 subjects (18 males and 27 females) in order to assess their reliability and threshold in normal adults and to study the effects of stimulus frequency and intensity on their latency and amplitude. In all subjects well-formed and reproducible 40-Hz AERP were detected, thus showing a good reliability of 40-Hz AERP to tone pips. The response was always detectable within 15 dB nHL intensity level and showed a sequence of positive (P1, P2 and P3) and negative (N1, N2 and N3) waves. It has also been observed that the latency of the first component following the acoustic stimulus decreased at increasing stimulus frequency and intensity, while the amplitude of the whole response increased upon increasing stimulus intensity. It can be suggested that the 40-Hz AERP to tone pips may represent a useful tool in assessing auditory threshold in the low-frequency range.

Adolescent

Effects of sex on auditory brainstem responses in infancy and early childhood.

The effects of sex on I-III, III-V and I-V interwave intervals and I, III, V ABR waves latency values have been studied in 171 normal children born at term, 94 males and 77 females, aged between 2 and 720 days. The obtained data confirm that latency values decrease progressively with age, and show that there is a statistically significant difference in wave III and V latency values and in III-V and I-V intervals between males and females. Moreover, these differences seem to increase with age. The authors also discuss the possible underlying mechanisms and claim that even in infancy, sex-related variability should be taken into account.

Brain Stem

Radioisotopic method for nasal mucociliary function evaluation.

In 13 healthy young adults, nasal mucociliary transport velocity was measured by means of albumine microsphere labeled with Tc99m as a tracer. M + ISD of clearance velocity values and of the half time radioactivity (T1/2) resulted to be respectively 1.02 + 0.22 cm/min and 1.07 + 0.24 min. A significant correlation (P less than 0.05) between half time clearance (T1/2) values of the radioactive particles and the mucociliary velocity ones could be detected, making T1/2 a reliable and rapidly obtainable parameter for determining nasal mucociliary function. Advantages and disadvantages of the different techniques are discussed.

Adult

Auditory brainstem responses to middle- and low-frequency tone pips.

Auditory brainstem responses (ABR) evoked by clicks allow a threshold evaluation for the high-frequency range (2-4 kHz) but not for middle and low frequencies (0.5-1 kHz). In 19 normally hearing subjects aged between 24 and 40 years. ABRs have been recorded using clicks and 0.5- and 1-kHz tone pips, with durations of 6 and 3 ms, respectively, and rise-decay times of 3 and 1.5 ms. The input signal was filtered by a passband filter of 20-5 000 Hz. Parameters of tracings elicited by the different kinds of stimuli are compared. Tone-pip ABR morphology does not show the conventional seven peaks but a single large vertex-positive wave. On the ascending branch high-frequency potentials, probably corresponding to the I, II, III and IV-V click-evoked peaks, were visible in some cases, but they rapidly disappeared as the stimulus intensity was decreased. Their 2.3-3 ms greater mean latency values are presumably related to the rise times of the stimuli employed. In terms of bioelectric generators, this large vertex-positive peak probably corresponds to the Jewett V wave. It probably represents a generalized asynchronous dendritic activity. Thus it is possible to obtain ABRs to middle- and low-frequency stimuli. Mean amplitude values of the slow wave are considerably higher than those of the Jewett V wave, but standard deviations are also larger. The positive wave has been identified in response to 1-kHz tone pips in 100% of cases at 30 dB nHL and in 52% of cases at 20 dB, while for 0.5-kHz tone pips in 73.7% of cases at 30 dB and in 57% at 20 dB. On the whole the threshold is located between 15 and 30 dB nHL.

Acoustic Stimulation

Middle-latency auditory components in response to clicks and low- and middle-frequency tone pips (0.5-1 kHz).

Middle-latency auditory components (MLC) in response to clicks and tone pips have been recorded in 20 normal subjects, aged between 26 and 32 years, in order to verify their reliability in response to frequency-specific stimuli (0.5 and 1kHz). The results indicate a good reliability of MLC obtained when using tone pips. The responses show the conventionally labeled Po, Na, Nb, Pb waves. The latencies of these waves tend to be greater than those of the corresponding waves elicited by clicks and their amplitudes are smaller. This is probably due to an asynchrony of the responses. The Po and Pa waves are the most resistant to decreasing stimulus intensity, as both are clearly detectable down to 20 dB nHL, but Po is the best threshold index because at 20 dB it has a more clear-cut shape than Pa. According to the latency values obtained for MLC elicited by both clicks and tone pips, the Po wave is probably generated at the inferior colliculus level. The latency shift towards the click-elicited Jewett wave V is mainly due to the different filter settings employed. The morphology of MLC elicited by tone pips is less affected by changes in stimulus frequency than that of corresponding auditory brainstem responses. Thus, MLC are a reliable indicator for defining low- and middle-frequency auditory thresholds.

Acoustic Stimulation

The behaviour of wave V latency in cochlear hearing loss.

The audiological approach to the early diagnosis of cerebellopontine angle tumours (APC) is based mainly on ABR. In present work, wave V latency has been studied in two groups of patients: 308 cochlear cases and 74 retrocochlear cases (APC surgically confirmed tumours), in order to increase the sensitivity and specificity of the diagnostic indexes I-V, IT5 and Delta V. Wave V latencies have been evaluated in relation to hearing loss at 2-4 kHz and audiometric profile. Both these factors show a highly significant positive correlation with the latency, which consequently increases proportionally to hearing loss and high-frequency audiometric loss. A multiple regression analysis was therefore used to analyse the effects from the two variables, and a correction factor was calculated to compensate the latency values for hearing loss and threshold configuration. The effects of such a correction on the clinical results consist mainly of a reduction in the rate of cochlear false-negative results, which corresponds to improving the ABR specificity.

Audiometry, Evoked Response

[Invasive nasosinusal aspergillosis in an immunocompetent patient].

The authors describe a case of invasive nasosinusal aspergillosis in an immunocompetent patient. After a careful bibliographic review, they emphasize that in the present case the diagnosis was made by means of fungal culture as the clinical picture, imaging techniques and histopathological findings were aspecific. The pathogenetic agent resulted Aspergillus tamarii which belongs to the Aspergillus flavus group and is one of the most unusual agents in literature. The treatment of choice, in the invasive form, is surgery that should be as radical as possible followed by a medical therapy. In the present case, after two-phase radical surgery on all the paranasal sinuses, medical treatment with traconazole was employed with excellent local results at a follow-up of one year.

Adult

[Considerations on analysis time duration in a posturographic study in normal subjects].

In order to evaluate the importance of analysis time on posturographic parameters (average X, Y and R, Sway Path, Sway Area, Ellipse Area) both with eyes open and closed, 24 normal subjects were examined for an overall period of 60 seconds. Mean +/- 1 SD values of each parameter were obtained for each time interval (0-20, 20-40, 40-60 sec.) into which the overall period was divided. With the eyes open, the parameters for each time interval did not differ significantly and they were always lower than those obtained with the eyes closed. On the other hand, with the eyes closed, there was a significant reduction in the various parameters as analysis time progressed. In 4 out of 24 subjects an inverse behaviour was detected. The authors conclude that the open-eye analysis time could be limited to 20 sec while, due to changes observed in the various posturographic parameters, closed-eye analysis time should be extended to 60 seconds. The analysis time may prove important in identifying peripheral or central vestibular pathologies since it may be that some of them induce earlier alterations of posturographic parameters while in other pathologies such changes are observed later on.

Adult