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Biomedical subjects

M Ferrazzini

Publications and source records attributed to M Ferrazzini.

8 recordsLinked to original sources
PubMed2001

Evaluation of eardrum laser doppler interferometry as a diagnostic tool.

OBJECTIVES: Laser Doppler interferometry (LDI) of the eardrum allows noncontact optical analysis of its vibrations in response to sound. Although LDI has been widely used in research, it has not yet been introduced into clinical practice as an adjunctive test for otological workup. The aim of this study was to evaluate LDI as a diagnostic tool in the clinical sphere. STUDY DESIGN: Prospective. METHODS: A measurement system was developed based on a commercially available scanning He-Ne laser Doppler interferometer. The study included 129 eardrums of 79 subjects that were divided into 3 groups: 1) normal subjects and 2) patients with sensorineural and 3) conductive hearing loss (HL). All the patients suffering from conductive HL underwent ossiculoplasty, which allowed confirmation of the final diagnosis, and patients were assigned accordingly to the subgroups malleus fixation, incus luxation, and stapes fixation. RESULTS: The modified LDI system allowed bilateral evaluation of a subject within 30 minutes. No significant difference between normal subjects and patients having sensorineural HL were found. However, it was possible to distinguish between normal subjects and patients with conductive HL. Furthermore, the system had the ability to differentiate between various middle ear diseases. These groups differed statistically significantly in terms of manubrium vibration amplitude and resonance frequency. In malleus fixation significant differences in tympanic membrane movement patterns were found. CONCLUSIONS: Our LDI is applicable in clinical otological practice and serves as a valuable addition to the routine audiological investigations for preoperative evaluation of the mobility and integrity of the ossicular chain.

Adult↗
PubMed2001

Intraoperative assessment of stapes movement.

A method is described that allows, for the first time, intraoperative vibration modes assessment of the acoustically stimulated stapes by means of scanning laser Doppler interferometry (LDI). The study was designed to answer the following questions: 1) Is LDI practical for taking measurements during surgery? 2) Are the results comparable to the findings in temporal bone preparations? and 3) Do the vibration characteristics of the stapes change after the posterior incudal ligament is detached from the incus? Seven patients with profound bilateral hearing loss who were undergoing cochlear implantation were included in the study. The measurement system was easily applicable for intraoperative measurements and allowed contact-free analysis with very high accuracy. No major differences in the results from the live human subjects and temporal bone preparations were observed. The stapes movement was predominantly pistonlike at the lower frequencies and became complex at higher frequencies. Sacrificing the posterior incudal ligament had no statistically significant effect on stapes vibration.

Acoustic Stimulation↗
PubMed2000

[Laser doppler interferometry, a new clinical instrument?].

INTRODUCTION: In a prospective trial, the diagnostic value of laser Doppler interferometry (LDI) was analysed in the clinical sphere. METHOD: LDI was compared with standard audiometry for preoperative differential diagnosis of a conductive hearing loss. The intraoperative diagnosis was considered the gold standard. RESULTS: LDI was applicable in the clinical sphere and allowed, in contrast to standard audiological methods, a statistically highly significant differentiation of middle ear pathologies. CONCLUSION: LDI is a valuable addition to standard audiology for preoperative evaluation of the integrity and mobility of the ossicular chain.

Audiometry↗
PubMed1989

Encephalopathy, deafness and blindness in young women: a distinct retinocochleocerebral arteriolopathy?

Three young women (aged 18 years, 19 years and 19 years) who developed progressive neuropsychic and neurologic disturbances with hearing loss and multifocal retinal artery branch occlusions are reported. This retinocochleocerebral syndrome has been reported previously only in 12 young North American women. Its pathogenesis is unknown, but an atypical viral infection of the vessel walls has been suggested. Abnormalities of T lymphocytes subsets in blood in one of the patients suggested an immunological dysfunction, but all other tests, including immunological reactions on brain and skin biopsies, were negative or non-specific. Steroids and immunosuppressive agents have been advocated on an empirical basis, but the second patient showed a substantial recovery without any therapy and the third gradually deteriorated despite azathioprine, cyclophosphamide, prednisone and plasma exchanges. This retinocochleocerebral syndrome probably corresponds to an arteriolopathy of unknown nature.

Adolescent↗
PubMed1988

[Pathogenesis of carotid cerebrovascular accidents in an elderly cohort. Study of 62 patients more than 75 years old].

We have studied the cause of stroke in 62 patients aged over 75 years who suffered transient ischemic attacks (TIA) and minor stroke, compared to a control group of younger (age 45-74 years) patients with stroke of the same severity. Patients aged over 75 years had a higher incidence of events of undetermined origin, cardiac embolism, or multiple etiologies. This contrasted with a low prevalence of ischemic events secondary to stenosing carotid atheromatosis, and (to a lesser extent) hypertensive arteriolopathy, which predominated in the control group. The differences may be explained in part by a different distribution of risk factors in the older and younger patients, the latter being at higher risk for earlier vascular death.

Age Factors↗
PubMed1988

Manic delirium and frontal-like syndrome with paramedian infarction of the right thalamus.

A disinhibition syndrome affecting speech (with logorrhoea, delirium, jokes, laughs, inappropriate comments, extraordinary confabulations), was the main manifestation of a right-sided thalamic infarct involving the dorsomedian nucleus, intralaminar nuclei and medial part of the ventral lateral nucleus. Resolution of conflicting tasks was severely impaired, suggesting frontal lobe dysfunction. These abnormalities correlated with the finding on SPECT of a marked hypoperfusion in the overlying hemisphere predominating in the frontal region. We suggest that this behavioural syndrome was produced by disconnecting the dorsomedian nucleus from the frontal lobe and limbic system.

Afferent Pathways↗
PubMed1988

[Primary lymphoma of the nervous system following radiculoneuritis caused by Borrelia burgdorferi: study of a case].

A 50-year-old man had a primary lymphoma of the central nervous system one year after a tick bite and a radiculoneuritis secondary to Borrelia burgdorferi infection. Determination of antibodies against Borrelia burgdorferi revealed increasing IgM and IgG titers, and the autopsy showed a primary B-cell immunoblastic lymphoma of the brain without evidence of extraneural lymphoproliferative disorder. Lymphoma of the brain is a rare type of central nervous system cancer, and sporadic cases appear without predisposing features such as immunosuppression or viral infection. The controversy surrounding the histogenesis of this neoplasm is reviewed: an unknown agent or a cofactor should provoke cellular proliferation and the formation of a lymphoma.

Animals↗