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Biomedical subjects

S Di Girolamo

Publications and source records attributed to S Di Girolamo.

At least 19 recordsLinked to original sources
PubMed2001

Surgery of otosclerosis in the elderly.

Auditory results following stapes surgery in 26 patients with otosclerosis >60 years of age at the time of surgery were compared with those obtained in 140 patients <60 years undergoing stapes surgery during the same time period. Stapedotomy was performed in all cases. The mean follow-up period was 29 months. Hearing results as judged by postoperative air-bone gaps were as good in the older age group as in the younger patients. Moreover, complications of surgery, such as postoperative formation of perilymphatic fistula, did not occur more frequently in elderly vs younger patients. On the basis of the results obtained, it is concluded that stapes surgery should be offered to elderly patients with the same indications as younger patients with otosclerosis.

Adult↗
PubMed2001

Auditory brainstem and cochlear implants: functional results obtained after one year of rehabilitation.

Very little information has been published on the clinical outcome of auditory brainstem implants (ABI). The present paper evaluates results obtained in a patient affected by a bilateral acoustic neuroma in type II neurofibromatosis who received an implant during removal of the residual tumor. One year later surgical revision of the ABI was necessary because no auditory sensation was obtained after ABI activation. Twelve months after the surgical revision, 12 electrodes out of 15 evoked auditory sensation. The results of rehabilitation were compared with those obtained in a group of eight postlingually deaf patients with cochlear implants (CI). Twelve months postoperatively the CI patients identified 97.7 +/- 5.1% of bisyllabic words in a closed set while the ABI patient identified 86%. CI patients recognized 87.1 +/- 11.3% of sentences and 81.3 +/- 14.8% of words with contextual cues while the ABI patient recognized 75% and 65% respectively. Speech recognition improved more slowly in the ABI patient than in the CI patients and his scores for open-set words and sentences without lip reading and contextual cues were poorer. Although the results obtained in the ABI patient were not as good as those obtained in the CI patients, the ABI patient said his quality of life was improved.

Adult↗
PubMed2001

SPET monitoring of auditory cortex activation by electric stimulation in a patient with auditory brainstem implant.

Auditory cortex activation following multifrequency acoustic stimulation has been evaluated by means of single photon emission tomography (SPET) in one patient before and after an auditory brainstem implant (ABI). No activation could be observed after acoustic stimulation before ABI. After ABI stimulation in the coronal and axial slices, the activation within the temporal cortex contralateral to the stimulated ear was twice (43.76%) that of normal controls (23.94 +/- 2.74%). This marked difference was not present in other selected cortical auditory areas (homolateral temporal, homolateral and contralateral parietal cortices). The temporal cortex was also examined with six consecutive sagittal slices from 18.75 mm up to 56.25 mm lateral to the midline. A very strong activation (51.20%) compared with that of normal controls (9.94 +/- 7.45%) was detected in the 25.26-mm sagittal slice of the temporal cortex contralateral to the stimulated side. The remaining sagittal slices showed an almost normal post-stimulatory activation. As the 25.26-mm sagittal slice corresponds to the medial part of the auditory temporal cortex, its activation suggests that electrode stimulation is concentrated on the region of the cochlear nucleus in which the neurons that transduce high frequencies are located. SPET can be considered useful, in combination with electric auditory-evoked potentials, to obtain information on ABI placement and function, effectiveness of acoustic stimulation, degree of cortical stimulation and tonotopic spatial distribution of auditory cortex activation.

Adult↗
PubMed2001

Effects of contralateral white noise stimulation on distortion product otoacoustic emissions in myasthenic patients.

Myasthenia gravis (MG) induces a reduction of transient evoked otoacoustic emissions (TEOAEs) and distortion product otoacoustic emissions (DPOAEs) that reverses partially after administration of an acetylcholinesterase (AChE) inhibitor. In normal subjects a contralateral acoustic stimulation (CAS) produces an amplitude reduction of TEOAEs and DPOAEs. This effect, called contralateral suppression (CS), is mediated by the efferent auditory system. Twenty subjects affected by MG underwent DPOAE recording with and without contralateral white noise in a drug-free baseline period ('basal') and 1 h ('post') after administration of a reversible AChE inhibitor. In 'basal' condition CAS did not induce significant DPOAE amplitude changes but a paradoxical slight increase was observed. After drug administration, CAS produced a significant decrease of DPOAE amplitudes for middle frequencies (f(2) between 1306 and 2600 Hz). In normal controls CAS caused a significant decrease (P<0.001) for all frequencies. The amount of CS in controls and in the MG 'post' condition was not significantly different. The increased acetylcholine (ACh) availability following drug consumption seems to partially restore outer hair cell function and enhances their electromotility; a further influx of ACh due to CAS yields to restoration of the CS. These findings also suggest that DPOAEs may be useful in the diagnosis of MG and for monitoring the effectiveness of treatment.

Acoustic Stimulation↗
PubMed2001

The role of cholinergic transmission in outer hair cell functioning evaluated by distortion product otoacoustic emissions in myasthenic patients.

Outer hair cells (OHCs) are the source of otoacoustic emissions, following a tropomyosin-miosin-dependent contraction, which are regulated by the olivocochlear bundle via the release of acetylcholine (ACh). ACh acts on ACh receptors (AChR) located on the OHC post-synaptic membrane. In myasthenia gravis (M.G.) neuromuscular transmission is reduced due to the action of AChR autoantibodies. It has previously been shown that M.G. induces a reduction in transient evoked otoacoustic emissions (TEOAEs), which is reversed after administration of a cholinesterase (AChE) inhibitor. Distortion product otoacoustic emissions (DPOAEs) were recorded before and 60 min after oral administration of 60 mg pyridostigmine bromide in 25 patients with normal hearing affected by M.G. The results were compared with those from 25 age-matched normal controls. Mean values of DPOAE amplitude in myasthenic patients were significantly (p < 0.05) lower at all frequencies before drug administration. All patients showed an overall significant (p < 0.05) increase in DPOAE amplitude after drug administration, although without reaching the control values. Such a recovery was more evident and highly significant (p < 0.01) for middle and high frequencies and could be explained by a higher concentration of ACh receptors in the basal and middle cochlear turns. These data seem to confirm the role of ACh in the neurotransmission of the auditory efferent system and may represent a new in vivo model for the investigation of the physiology of this system.

Acetylcholine↗
PubMed2001

Vestibulo-ocular reflex modification after virtual environment exposure.

Immersion in an illusory world is possible by means of virtual reality (VR), where environmental perception is modified by artificial sensorial stimulation. The application of VR for the assessment and rehabilitation of pathologies affecting the vestibular system, in terms of both diagnosis and care, could represent an interesting new line of research. Our perception of reality is in fact based on static and dynamic spatial information perceived by our senses. During head movements in a virtual environment the images on the display and the labyrinthine information relative to the head angular accelerations differ and therefore a visuo-vestibular conflict is present. It is known that mismatches between visual and labyrinthine information may modify the vestibulo-oculomotor reflex (VOR) gain. We studied the post-immersion modifications in 20 healthy subjects (mean age 25 years) exposed to a virtual environment for 20 min by wearing a head-mounted display. VOR gain and phase were measured by means of harmonic sinusoidal stimulation in the dark before, at the end of and 30 min after VR exposure. A VOR gain reduction was observed in all subjects at the end of VR exposure which disappeared after 30 min. Our data show that exposure to a virtual environment can induce a temporary modification of the VOR gain. This finding can be employed to enable an artificial, instrumental modification of the VOR gain and therefore opens up new perspectives in the assessment and rehabilitation of vestibular diseases.

Adult↗
PubMed2001

Postural control and glycerol test in Ménière's disease.

Ménière's disease is a clinical disorder, characterized by fluctuating hearing loss, recurrent spontaneous episodic vertigo, tinnitus and aural fullness, which may be defined as the idiopathic syndrome of endolymphatic hydrops. The most important test for diagnosis of Ménière's disease is the glycerol test. This is a simple and rapid method and several authors have confirmed its efficiency for identifying endolymphatic hydrops. This test provides information on the cochlear response to the osmotic changes produced by glycerol in the inner ear, whereas modifications in the vestibular labyrinth are usually not evaluated. The aim of this study was to evaluate the effects of glycerol on postural control during attacks of Ménière's disease, and to correlate this data with data on cochlear function. After the glycerol test, an improvement in postural control was recorded in 70% of patients, with all patients reporting a recovery of vertigo. The impairment of postural control during endolymphatic hydrops could be related to a pressure increase in the labyrinth, which interferes with the normal dynamics of the endolymph, and a rapid functional recovery could occur during an osmotic depletion. Dynamic posturography improves the sensitivity of the glycerol test and may therefore be useful in the diagnosis and staging of Ménière's disease.

Adult↗
PubMed2000

A novel venombin B from agkistrodon contortrix contortrix: evidence for recognition properties in the surface around the primary specificity pocket different from thrombin.

A novel thrombin-like enzyme (named contortrixobin) has been purified to homogeneity from the venom of Agkistrodon contortrix contortrix by affinity chromatography on arginine-Sepharose, anionic exchange chromatography, and HPLC. The complete amino acid sequence has been determined by Edman degradation and by mass spectral analysis of peptides generated by enzymatic cleavage. A microheterogeneity at the level of residue 234 has been detected, as demonstrated by peptides differing for the occurrence of Pro234 ( approximately 85%) or Asp234 ( approximately 15%). Contortrixobin (i) has six disulfide bonds whose sequence positions have been determined by mass spectrometry and (ii) does not contain carbohydrates in its structure. As expected, the 234 residue sequence of contortrixobin exhibits strong homology with snake venom serine proteases acting on either fibrinogen or other blood coagulation components. The interaction of contortrixobin with chromogenic substrates indicates a higher specificity for arginine over lysine in the primary subsite and a faster attack to ester than amides. The hydrolytic activity of contortrixobin is strongly inhibited by diisopropyl fluorophosphate and to a less extent by phenylmethylsulfonyl fluoride, benzamidine, and 4', 6-diamidino-2-phenylindole; hirudin (a specific alpha-thrombin inhibitor) as well as basic pancreatic trypsin inhibitor has a small effect on contortrixobin's catalytic properties. Contortrixobin (i) preferentially releases fibrinopeptide B from human fibrinogen, (ii) activates blood coagulation Factors V and XIII with a rate 250-500-fold lower than human alpha-thrombin, and (iii) does not induce thrombocyte aggregation, intracytoplasmatic calcium ion increase in platelets, and activation of Factor VIII. Evidence for biorecognition properties different from thrombin is also reported.

Agkistrodon↗
PubMed2000

Preliminary experiences with contact endoscopy of the larynx.

Nine patients with laryngeal polyps, four with Reinke's edema, three with leukoplakia, one with papilloma and one with malignant tumor were studied by means of laryngeal contact endoscopy during microlaryngoscopy. This technique allowed in vivo and in situ visualization of the superficial layer of the laryngeal epithelium after staining with methylene blue. Cell structures evaluated were the size and color of the nuclei, the nucleus/cytoplasm ratio, nuclear and cytoplasmic contours, the presence of nucleoli, mitoses and keratoses, as well as the microvascular network of the mucosa and superficial cellular changes from normal to pathological. The normal squamous epithelium of the vocal cord showed a homogeneous cellular population with regular nuclear and cytoplasmic morphological characteristics and a uniform nucleus-to-cytoplasm ratio. Specific cellular epithelial patterns and several alterations of the vascular distribution were found in different pathological conditions. Cytological pictures obtained at contact endoscopy were consistent with histological findings in all the patients studied.

Adult↗
PubMed2000

Postural control in horizontal benign paroxysmal positional vertigo.

Sixteen patients affected by benign paroxysmal positional vertigo of the horizontal semicircular canal (BPPV-HSC) were investigated by means of dynamic posturography (DP) and during bithermal caloric stimulation. Data were compared to data from 40 patients with benign paroxysmal positional vertigo of the posterior semicircular canal (BPPV-PSC) and 20 healthy controls. No postural deficit was observed before or after a liberative Lempert's manoeuvre when patients were compared to control subjects. BPPV-PSC postural scores were significantly impaired compared to scores from the BPPV-HSC group. A residual significant postural impairment was also observed after a successful liberative manoeuvre in the BPPV-PSC group. Electronystagmographic recordings before recovery revealed significant hypoexcitability of the affected ear in 8/16 patients of the BPPV-HSC group. After the liberative manoeuvre, a symmetric bilateral response to caloric stimulation was recorded in all patients. Three main conclusions can be drawn from the present data. First, disorders of the horizontal semicircular canal do not change postural control. Second, dynamic posturography can detect the postural imbalance due to posterior semicircular canal dysfunction even after resolution of paroxysmal vertigo attacks. Third, utricular dysfunction can be ruled out as a cause of the residual postural deficit observed in BPPV-PSC patients. Therefore the recovery delay observed even 1 month after the liberative manoeuvre in the BPPV-PSC-group might be due to the persistence of small amounts of residual debris in the canal, to paralysis of ampullar receptors, or to the time needed for central vestibular re-adaptation.

Caloric Tests↗
PubMed2000

[Paranasal sinus mycoses].

In recent years there has been a marked increase in mycosis infections of the paranasal sinuses, attributed both to an increase in the survival of subjects at risk and improved diagnostic techniques (endoscopy, CT, MR) able to identify cases which had previously gone unrecognized and treated as aspecific chronic sinusitis. The present study involves 45 cases (4.3%) out of a total of 1050 patients who had undergone endoscopic surgery for sinusopathy between April 1994 and December 1998. Following the Katzenstein classification, the cases were broken down into non-invasive chronic mycoses or fungus ball (34 cases), allergic mycoses (7), chronic indolent invasive mycoses (3) and fulminating invasive mycosis (1 case). The mycetes most often involved was Aspergillus Fumigatus (76.9%). The recurrent symptom was facial algia, followed by nasal obstruction. Paranasal sinuses endoscopy did not modify the specific picture. CT presented such indicative signs as focal areas with non-homogeneous intensity, images of metal-like foreign bodies and endosinus calcifications in 84.4% of the cases. MR--performed in only 6 cases--always presented T2 images showing the typical signal void area corresponding to pathological lesions. All patients underwent endoscopic surgery of the paranasal sinus. The effectiveness of this treatment differed according to the clinical form. In the fungus balls surgery always resolved the pathology without requiring subsequent pharmacological treatment. In allergic mycosis, surgery improved the symptom of nasal respiratory obstruction but local drug treatment was required. With the aid of drug treatment, surgery resolved chronic indolent invasive mycoses and prevented the endocranial progression of complications. In the cases of fulminating invasive mycosis, timely surgery prevented the onset of endocranial complications and made it possible to perform antimycotic polychemotherapy to control the disease. This experience shows how important a protocol involving several different tests is in diagnosing the many clinical forms of paranasal sinus mycoses and distinguishing them from sinusopathies. Endoscopic surgery is indicated for all forms of paranasal sinus mycoses although the realistic objectives differ according to type.

Adolescent↗
PubMed2000

[Revascularized jejunum loop in hypopharyngeal reconstruction: oncological and functional results].

The aggressiveness of hypopharyngeal cancer makes broad resectioning of the circular pharyngolaryngoesophageal segments necessary, followed by reconstruction to restore the anatomical gap created as fully as possibly creating a neoesophagus with thin walls that can easily be released. Over the years several procedures have been fine tuned for reconstruction of the upper digestive tract employing transposed viscera, miocutaneous pedunculated flaps, revascularized fascio-cutaneous or visceral free flaps. Currently the revascularized jejunum loop is one of the most commonly used methods in the reconstruction of the hypopharynx. Its popularity is due to some anatomical and physiological advantages: it requires transposition of a brief intestinal tract anatomically well adapted to the reconstruction site, ensuring rapid functional recovery. The authors report the oncological and functional results obtained in 25 patients who underwent circular pharyngolaryngectomy followed by reconstruction with a revascularized jejunum loop. The percentage of transplant survival was 90% and local and general complications were reduced to a minimum. The functional results--both in terms of deglutition and phonation--were satisfactory while patient survival (6-37 months follow-up) was in line with that reported by other authors for the same tumor (47%). Although prognosis for hypopharyngeal-esophageal neoplasms is still quite poor, this experience shows that circular pharyngolaryngectomy followed by reconstruction with autotransplant of the jejunum is an excellent choice since it offers the patient a prompt, acceptable functional recovery and a fair quality for his remaining life.

Aged↗
PubMed2000

[Difficulties in the clinical, radiological and therapeutic evaluation of the initial stage of mucormycosis of the rhinosinus].

The initial diagnosis and subsequent treatment of rhino-orbital mucormycoses is quite difficult, particularly because the patient may find it difficult to accept aggressive therapeutic protocols, even when free of any endocranial involvement. The authors draw inspiration from a clinical case of rhino-orbital mucormycosis in a patient suffering from decompensated type I diabetes mellitus to discuss the main clinical-diagnostic and therapeutic aspects of this disorder. Timely medical-surgical treatment proves extremely important for prognosis, preventing the intracranial extension of the lesion which is the cause of death in 80% of such cases. As regards the diagnostic protocol, careful clinical, radiological monitoring with CT and NMR--in strict interdisciplinary cooperation between otorhinolaryngologist, radiologist, ophthalmologist, microbiologist and histopathologist--is especially important. Radical surgery, at times demolition, associated with correction of the metabolic decompensation, systemic therapy with Amphotericin B and localbi-weekly medication for three months constitutes the best therapeutic protocol for treatment of this disorder.

Adult↗
PubMed2000

[Post-parotidectomy Frey's syndrome. Treatment with botulinum toxin type A].

The Frey's syndrome, manifest after parotid trauma, is characterized by head and neck hyperemia and abundant sweating of the hyperemic skin in response to gustatory stimuli. The use of the botulin toxin to treat the symptoms in patients with Frey's syndrome has been described in numerous studies. For some time up until now our Center has achieved excellent results using the group A botulin toxin to overcome the hypertonus of the cricopharyngeal muscle in patients who had undergone laryngectomy and were rehabilitated with voice button. We have sought to extend the use of this toxin to Frey's syndrome, a relatively frequent complication of parotidectomy. A total of 86 patients participated in the study: 41 males (47.6%) and 45 females (52.4%) ranging in age from 25 to 77 years (average age 51 years). Of these patients 7 (8.1%) had undergone post-operative radiotherapy. Of the 86 patients studied, 18 referred significant symptoms in terms of abundance and frequency. The syndrome was considered severe if the symptoms were present at each meal and if the patient indicated a significant worsening of his quality of life. Intermittent episodes were indicated by 22 patients. The remaining 46 (43.5%) did not complain of any symptoms. The exact extension of the cervicofacial gustatory sweating was evaluated using the Minor test and the involved region was divided into 1 square centimeters sections. The amount of skin surface involved ranged from 10 to 80 square centimeters. The type A neurotoxin was frozen and was reconstituted with a sterile saline solution at a final concentration of 2.5 UI/0.1 ml. The intracutaneous infiltration was performed without anesthesia, infiltrating 0.1 ml of solution, containing 2.5 UI of toxin into the center of each 1 square centimeters section. Statistical analysis was performed to evaluate the potential relationship between how long the treatment was effective, incidence of recurrence, seriousness of the crises and the following variables: age, sex, histology, cutaneous surface involved, injected dose of botulin toxin and post-operative radiotherapy. In the group of 18 patients with severe symptoms (20.9%) the benefit was immediate in all cases although the recurrence rate was 50%. The Frey's syndrome symptoms disappeared within 7 days of infiltration. In the group of 22 patients with less severe involvement (25.5%), the treatment gave positive, definitive results in 16 patients (72.7%). Those patients whose symptoms persisted were treated a second time with an infiltration of 2.5 UI per square centimeters. We feel that the use of the type A botulin toxin is the most appropriate treatment for the Frey's syndrome. In fact, such treatment offers the following advantages: it is effective within 7 days, has limited side effects, can be applied on an outpatient basis, is inexpensive and is positively considered by the patients.

Adult↗
PubMed2000

The role of ocular oscillations upon visually dependent postural stabilization in patients affected by congenital nystagmus.

Visually dependent postural stabilization decreases as a consequence of a long-standing reduction of visual cues in patients affected by congenital nystagmus. The aim of the present study was to verify whether the changes in postural control in this group of patients are due to ocular oscillations or to reduced visual acuity. Therefore, postural control was evaluated when the nystagmus was blocked by the blocking position or by prisms and compared with the postural score observed in a group of normal controls whose visual acuity had been artificially reduced to the same level as that of the patients using Bangerter's filters. The results show a statistically significant improvement of visually dependent postural stabilization when ocular oscillations are inhibited either by the gaze blocking position or by prisms. They also show that postural control in normal subjects with Bangerter's filters is reduced, but is still significantly better than that observed when ocular oscillations are inhibited in patients affected by congenital nystagmus. Our data strongly support the role of ocular oscillations in visually dependent postural control, since postural impairment recovered under any condition in which ocular oscillations were abolished, despite differences in visual acuity. Our data also show that reduced visual acuity decreases visually dependent postural control to a lesser degree than ocular oscillations. This could be due to the fact that ocular oscillations are a disturbing input, usually inhibited centrally, in order to avoid oscillopsia. This mechanism is probably responsible for the reduced role of visual cues in the postural control in this group of patients. The reduction of visual acuity, by comparison, merely causes a decrease in visual cues, depending on the degree of visual loss. It can be concluded that the impaired postural control in patients affected by congenital nystagmus is mainly due to ocular oscillations, with reduced visual acuity creating a secondary effect.

Adult↗
PubMed1999

CO2 laser subtotal arytenoidectomy and posterior true and false cordotomy in the treatment of post-thyroidectomy bilateral laryngeal fixation in adduction.

A total of 39 patients with bilateral post-thyroidectomy vocal cord paralysis in adduction underwent CO2 laser subtotal arytenoidectomies with removal of the posterior third of the false and true vocal cords. Total airway resistance (Rtot) evaluated before and 4-10 months after surgery showed marked preoperative impairment before and significant improvement after surgery (P < 0.05). In five patients revision surgery was performed due to a progressive impairment of respiratory function. A variable degree of voice breathiness was observed after surgery; the maximum phonation time mean values were lower than normal and peak sound pressure levels 63 +/- 5 dB. In three cases aspiration was present in the first postoperative days, but swallowing dysfunctions disappeared within 1 week. Subtotal arytenoidectomy with removal of the posterior third of the true and false vocal folds was found to be a satisfactory surgical treatment for bilateral vocal cord paralysis in adduction. However, further research is still needed to define the surgical procedure able to balance respiratory, phonatory and sphincteric functions optimally.

Adult↗