Neuroplasticity of auditory cortex after stape surgery for otosclerosis: a magnetoencephalographic study.

Aim of the present study was to investigate the tonotopic reorganization of the primary auditory cortex in otosclerotic patients following functional stapedioplasty. Characteristics of auditory cortex activation have been evaluated in a series of 10 otosclerotic patients before and after surgery. In these patients, a magnetoencephalographic recording of evoked magnetic fields has been performed by means of tone-burst monoaural stimulation with frequency octaves between 250 and 2000 Hz. Brain topography of cortex response generators (wave N100m) in patients with otosclerosis has been compared with that observed in a control group of 10 healthy subjects: changes before and after surgery have also been correlated with the functional result as far as concerns improvement in hearing. A significant reduction has been observed in the cortical tonotopic extension in response to the acoustic stimulus in patients "pre-surgery" in comparison with controls: after surgery, tonotopic mapping showed an increase, dimensions becoming comparable to those in control subjects. This increase in size was found to be significantly correlated with duration of the post-operative period. Data emerging from the present study suggest that the cortical auditory areas in man are involved in a "plastic" functional reorganization following changes in the receptor or peripheral deprivation. Reduction in the cortical tonotopic mapping resulting from prolonged lowering of auditory "input" is modified by reorganization of the cortex after the recovery of auditory function: this process occurs over a period of a few weeks.

Tonotopic cortical changes following stapes substitution in otosclerotic patients: a magnetoencephalographic study.

The aim of the study was to investigate and follow up the tonotopic organization of the primary auditory cortex in otosclerotic patients before and after corrective surgery. The characteristics of primary auditory cortex activation were studied in ten otosclerotic patients (i.e., subjects suffering from a conductive hearing loss, prior to and following stapes substitution). Magnetoencephalographic recordings of auditory evoked fields by tone-burst stimulation at octave frequencies between 250 and 2000 Hz were performed during monaural stimulation. The brain topography of the main cortical response (N100m) generators at different tones was studied in patients and compared with ten healthy controls; pre- post-surgical changes were also correlated to their clinical outcome following corrective surgery. A significant decrease of the tonotopic extension in the cortical region responsive to the four explored frequencies was found in patients before surgery with respect to the control population. At the time of postsurgical follow-up, the tonotopic representation had enlarged and was approaching the dimensions seen in normal subjects, although with higher variability. The extent of the enlargement of the postoperative tonotopically organized area was directly correlated with the postsurgery period duration. Our findings indicate that auditory cortical areas of human adults undergo functional reorganization following peripheral alteration of the sensory input entering the CNS. The restriction of the cortical tonotopic region caused by the long-term reduction of acoustic input is followed by a reorganization within the usual boundaries following the recovery of auditory function; this process is taking place in a time scale of a few weeks.

[Laryngeal T4 carcinomas. The possibility of conservative treatment. Long-term oncological and functional results]. / Carciomi T4 della laringe:P possiblitià di trattamento conservativo. Risultati oncologici e funzionali a distanza.

The term laryngeal T4 carcinoma is applied to a heterogeneous group of neoplasias which may be treated following various surgical approaches. The elective therapy in dealing with many of these tumours (minimal cartilage involvement, marginal hypopharyngeal extension, supra-glottic cancer with oro-pharyngeal extension) is that of a conservative approach. Our clinical experience with regard to 276 T4 laryngeal tumours is presented in this paper. Oncological and functional results with partial surgery are reviewed and discussed and long-term results obtained with widened total laryngectomy (plus Radio and/or Chemotherapy) are presented.

Per-oral excision of a pharyngeal branchial cyst after MRI study.

A per-oral approach to pharyngeal branchial cysts is possible, and ideal when they are placed medially to the pharyngeal constrictors and no fistular duct is connected to the mass. At present MRI is found to be the best means of achieving the correct diagnosis of morphology and site.

[Evoked otoacoustic emissions in noise-induced hearing loss]. / Le otoemissioni acustiche evocate nella ipoacusia da trauma acustico cronico.

The Authors evaluated patterns of click-evoked otoacoustic emissions (EOE) in a group of 184 patients exposed to noise in their working environment. The aim of the study was to detect changes in EOE patterns in this group compared to the EOE of healthy subjects. The clinical history of each subject was recorded and otoscopy, pure tone audiogram and impedance tests (tympanometry, stapedial reflex threshold) were carried out in all patients. Noise-induced hearing loss found in 97 patients, unilateral sensorineural hearing loss in 17, other hearing disorders in 24 and normal auditory threshold in 46. EOE recording was carried out in the group of patients with noise-induced hearing loss (97), in the group with normal threshold (46) and in a control group of 15 healthy subjects. EOE recording was obtained using the ILO 88 Otodynamic Analyzer. We introduce a probe into the external ear canal using a non-linear click stimulus (intensity at approximately 85 dB spl) at a 20/sec. rate with a 20 msec. window. Normal EOE were found in the control group. Abnormal EOE were found in 79 cases (81%) of the noise-induced hearing loss group, and in 22 (48%) of the normal threshold group. These data show that noise-exposed subjects have alterations of EOE such as threshold shift missing frequency bands, even in absence of an auditory threshold shift. When EOE were present, the frequency spectrum often showed lack of emissions at high frequencies. This study confirms that cochlear exposure to noise may produce significant alterations of EOE and that this test may be considered highly sensitive in detecting early cochlear damage in chronic acoustic trauma. Therefore, EOE may be used in screening and follow-up of high risk populations such as noise-exposed subjects.

[Pharyngeal cysts of branchial origin, a review of the literature and a clinical case report]. / Cisti faringee di origine branchiale, revisione della letteratura e presentazione di un caso clinico.

Nasal pharyngeal swellings are very often treated without a previous complete clinical examination of the patient and of the disease site. For this reason the recurrence rate of this pathology is quite high. The causes for this phenomenon are likely due to the benign aspect of the tumor and the easy approach to the pharynx. Leaving aside the therapeutical aspect, there are also multiple theories concerning the etiology of pharyngeal cyst based on epidemiological and histopathological observations. Branchiogenic origin very likely seems to be the cause of cystic swelling arising at the lateral side of the pharynx, between the Eustachian tube and the posterior tonsillar pillar. Examination of the case review collected from literature, revealed that diagnostic and therapeutical procedures performed by various authors seem to be very haphazard, ranging from simple physical examination and puncture draining to CT and/or MRI scanning and external trans-mandibular approach to the cyst. The authors describe one case of a subject with a pharyngeal branchial cyst, who had been previously undergone puncture drainage. The correct diagnosis was achieved through MRI and cytologic examination of the fluid aspirated from the cyst. With MRI it was possible to make a correct topo-diagnosis, which localized the position of the cyst in the left pharyngo-tonsillar recesses, medial to the pharyngeal constrictor muscles. MRI also confirmed the absence of fistulous ducts connected to the cyst. These clinical and laboratory data induced us to use an intra-oral approach to the cyst, which was removed by blunt dissection. Physical examination and MRI were repeated six months later and showed the complete removal of the cyst and the presence of a synechia between the upper part of the left posterior pillar and the pharyngeal wall. No further treatment was given because of the absence of symptoms. The authors stress the importance of less invasive surgery in the case of pharyngeal cyst possible after detailed monitoring of the disease site with modern computed tomography CT, MRI.

Head and neck trauma in sporting activities. Review of 208 cases.

Head and neck injuries due to sports and games represent 22.7% of all injuries admitted to the E.N.T. Department of the University of Perugia between 1980 and 1988. Epidemiological and causative factors of these injuries are examined by the authors, together with their treatment: the majority of accidents occurred during soccer games as a consequence of collisions between players. In these cases the most frequently recorded lesion was a nasal fracture. Other sporting activities were responsible for more serious injuries to the maxillo-facial bony, cartilaginous and soft tissue structures. Good results were achieved both on the anatomical and functional planes, except for a few cases of facial disruption and multiple mandibular fractures. The authors stress the importance of preventive measures, consisting of periodical medical check-ups, an adequate level of umpiring and the wearing of protective equipment, such as helmets and masks.

Adenoid-cystic carcinoma (cylindroma) of the pyriform sinus in pediatric age.

Adenoid cystic tumors or cylindromas are malignant tumors typical of salivary tissue which often develop in minor salivary glands and, according to some authors, also in common mucosa glands. In these cases such tumors are particularly malignant owing to the frequency in which they re-occur locally and develop distant metastases. The authors report a case of a cylindroma of the pyriform sinus in a young child. An accurate review of the literature did not reveal any previous reports of analogous cases of cylindroma in the pyriform sinus of such a young subject. This finding created notably difficult problems with regard to therapy planning. After discussion of problems, conservative surgery is indicated as the most suitable treatment in these cases, considering that chemotherapy and radiation therapy alone are not highly effective in treating cylindromas and, furthermore, they are contraindicated because of the young age of the patient.