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1.
The small-signal linear characteristics of afferent responses from the isolated semicircular canal were described by the use of white-noise rotational acceleration inputs. The results, based on cross-correlation analysis, showed a striking and systematic variation in linear system impulse response characteristics from afferents which innervated different regions of the receptor. Afferents from centrally located nerve bundles innervating the crest region of the crista exhibited an initial maximum response amplitude followed by a rapid decay. In contrast, afferents from extreme rostral and caudal nerve bundles innervating the crista slopes exhibited an initial rise up to a low-amplitude maximum followed by a slower decay. These results imply that the afferents innervating a single canal do not merely carry redundant information concerning current head acceleration, but could be considered an ensemble of specific classes of filters that are tuned individually to specific classes of head movements. On the basis of these considerations, a new hypothesis of matched filter detection was proposed as relevant to information processing and dynamic control in central vestibular pathways.  相似文献   

2.
The collaboration of surgeons, radiation oncologists, chemotherapists, dentists, oral surgeons, prosthodontists, and speech therapists has led to major advances in the management of the difficult cancers of the head and neck area. The advent of myocutaneous flaps and the facilitation of microsurgical free flaps have ushered in an era of one-stage reconstructions to shorten the hospital stay and improve the overall therapeutic, functional, and cosmetic results.  相似文献   

3.
Melanomas of the skin and mucous membranes of the head and neck region are an uncommon problem for most clinicians. The article emphasizes the differences in terms of biological aggressiveness and treatment between lentigo maligna (LM) and lentigo maligna melanoma (LMM), superficial spreading melanoma (SSM), and nodular melanoma de novo. The results of radiotherapy in the treatment of melanoma of the head and neck are reviewed, and indications are suggested for the use of irradiation in the management of patients with this tumor. A brief discussion of the results of treatment of mucosal melanomas is given.  相似文献   

4.
Plasmacytomas are rare tumors that often appear in the head and neck region and are characterized by a monoclonal proliferation of plasma cells. On both clinical presentation and pathologic examination these tumors may be confused with more common tumors of the head and neck. The purpose of this article is to review our experience with these rare neoplasms, with emphasis on clinical, pathologic, and therapeutic features. On retrospective chart review, we identified 20 patients with the diagnosis of plasmacytoma of the head and neck region at the Cleveland Clinic Foundation between 1976 and 1993. Records were reviewed with regard to initial symptoms, location of the neoplasm, diagnostic evaluation, treatment modalities, and survival. Of the 20 cases we identified, the tumor arose in the sinonasal/nasopharyngeal region in 11 (55%). Two cases (10%) represented medullary plasmacytomas, arising in the clavicle and presenting as supraclavicular masses. The mean follow-up was 60.2 months (range 6 to 131 months). In 15 of the 20 cases, immunohistochemistry staining for immunoglobulin light chain production was conducted. One of the two cases (50%) classified as medullary plasmacytoma demonstrated conversion to multiple myeloma, whereas only 2 of 18 cases of extramedullary plasmacytoma (11%) converted to multiple myeloma. The primary modality of treatment was radiation therapy with typical doses of 4500 to 6000 cGy. Kaplan-Meier survival estimates demonstrated 95% survival at 1 year, 82% survival at 5 years, and 10-year estimated survival of 72%. Plasmacytomas of the head and neck region are rare and on initial evaluation must be distinguished from multiple myeloma. The diagnostic evaluation includes appropriate radiologic and pathologic studies including immunohistochemistry. Despite the typical presentation as a locally destructive tumor, plasmacytomas are highly radiosensitive, and 70% to 80% survival may be obtained with the use of radiotherapy. Patients with plasmacytomas require long-term follow-up to detect conversion to multiple myeloma.  相似文献   

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AIM: Investigation of the relationship between the pO2-status of primary tumors, their cervical neck node metastases and normal tissues in squamous cell carcinomas of the head and neck. PATIENTS AND METHODS: Pretreatment oxygenation of primary tumors, their neck node metastases and of the contralateral sternocleidomastoid muscle was assessed in 16 patients with histologically proven advanced squamous cell carcinomas of head and neck. Oxygenation was measured with a polarographic microelectrode system (Eppendorf-pO-Histograph). Using CT/MRT additionally the volume of the tumors was estimated. RESULTS: A highly significant correlation existed between the median pO2 of primary tumors and their neck node metastases and between the relative proportion of hypoxic values (< 5 mm Hg) of both anatomic sites (both p = 0.0001) (Figure 1). Primary tumors were not different from their neck node metastases, neither regarding the pO2 median values nor in view of the relative frequency of hypoxic values (Table 1). No correlation was found between the volume of primary tumors and the one of their neck node metastases. For volume of tumors and the oxygenation status no relationship was found as well. Significantly different was the median pO2 in the muscles from the one of the malignant tissues (p = 0.0004). CONCLUSION: The results suggest that for to estimate the oxygenation status of squanious cell carcinomas of the head and neck pO2 measurements of primary tumors and neck node metastases are equally sufficient.  相似文献   

7.
Perineural spread of head and neck tumors is a form of metastatic disease in which tumor disseminates to noncontiguous regions along the endoneurium or perineurium. Both computed tomography (CT) and magnetic resonance (MR) imaging can help detect perineural spread, although MR imaging is the modality of choice because of its multiplanar capability, its superior soft-tissue contrast, and the decreased amount of artifact from dental hardware. Perineural spread most commonly occurs in adenoid cystic carcinoma and squamous cell carcinoma. Nerve enlargement may lead to foraminal enlargement and, ultimately, to foraminal destruction, findings that are best seen at CT. Extension through the foramen ovale and involvement of the Meckel cave is best seen on coronal T1-weighted MR images, and nerve enhancement is best seen on fat-suppressed T1-weighted MR images. Other radiologic findings include obliteration of fat planes at foraminal openings, neuropathic atrophy, cavernous sinus enlargement, and replacement of the trigeminal subarachnoid cistern with soft tissue. The pathway of perineural tumor spread is predictable with knowledge of the pertinent cranial nerve anatomy; however, patients with radiologically or pathologically proved perineural spread may have normal nerve function at clinical examination. Therefore, it is imperative that the radiologist be familiar with both normal cranial nerve anatomy and the radiologic appearance and assessment of perineural tumor extension.  相似文献   

8.
We have identified a distinctive malignant soft tissue neoplasm that occurred in the head and neck region of six children. Histologically, these neoplasms presented an array of features ranging from low-grade spindle cell to high-grade fibrohistiocytic histologies and often had myoid characteristics. Ultrastructural and immunohistochemical studies indicated that they contained neoplastic myofibroblasts that were variably positive for vimentin (4 positive/4 tested), alpha-smooth muscle actin (4/5), muscle-specific actin (5/5), desmin (2/5), and v-src protein substrate p80/85 (4/5). Three patients died of rapidly progressive unresectable local disease, one died of metastatic and local disease, and two are alive 13 months and 8 years after wide resection. We conclude that these neoplasms form a distinctive subset of pediatric soft tissue sarcomas that display an aggressive clinical behavior, typically with local recurrence, and exhibit features of myofibroblastic differentiation.  相似文献   

9.
PURPOSE: To determine the effect of epidural analgesia on biochemical markers of stress, plasma oxytocin concentrations and frequency of uterine contractions during the first stage of labour. METHODS: Nine nulliparous women, in spontaneous labour, with a singleton fetus and cervical dilatation < or = 5 cm were enrolled. Epidural bupivacaine 0.25% (range 10-14 ml) was administered and bilateral sensory blockade to ice (T8-L4) achieved. Blood samples were collected before the epidermal block and every 10 min for one hour after the block was achieved for the measurement of plasma beta-endorphin, cortical, glucose, lactate and oxytocin concentrations. No exogenous oxytocin was given. Intensity of pain was assessed at the time of the blood sampling using a 10 cm visual analogue scale (VAS). The frequency of uterine contractions was recorded for 60 min before and after the epidural block. RESULTS: There was a decrease in plasma beta-endorphin and cortisol concentrations after epidural block (P < 0.01). There were no changes in plasma glucose and lactate concentrations. The mean VAS for pain decreased 10 min after epidural block was achieved and remained < 2 throughout the study period (P < 0.001). Mean plasma oxytocin concentrations did not change. The frequency of uterine contractions before and after the epidural block was similar. CONCLUSIONS: The metabolic stress response to the pain of labour was attenuated by epidural analgesia. In contrast, plasma oxytocin concentration and frequency of uterine contractions were unaffected by the attenuation of metabolic stress response.  相似文献   

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BACKGROUND: Lymphoepithelioma (squamous cell carcinoma with associated lymphoid stroma) commonly occurs in the nasopharynx, rarely at other sites. As a result, the clinical course and optimal treatment of nonnasopharyngeal lymphoepithelioma of the head and neck have not been well described. This retrospective study was undertaken to analyze the clinical course of the disease in patients treated at a single institution and to formulate recommendations for treatment based on that experience as well as results reported in the literature. METHODS: Between 1950 and 1994, 34 patients with nonnasopharyngeal lymphoepithelioma of the head and neck were treated at the University of Texas M. D. Anderson Cancer Center. The patients' medical records were reviewed and their pathologic specimens evaluated. The primary tumor sites were: oropharynx (24 patients), salivary gland (4), laryngohypopharynx (4), and the maxillary sinus/nasal cavity (2). Assessed in accordance with the 1992 American Joint Committee Against Cancer TNM staging system, T classifications were TX-2, T1-7, T2-8, T3-10, and T4-7, and N classifications were N0-8, N1-5, N2-15, and N3-6. Treatment consisted of radiotherapy for 24 patients, excisional biopsy of the primary tumor followed by radiotherapy for 7 patients, and surgery for 3 patients. Of the patients treated with radiotherapy, neck dissections were performed on only two, both of whom had persistent lymph node masses after completing radiotherapy. The median dose delivered to the primary tumor was 65 gray (Gy) (range, 46-78 Gy). The median fraction size was 2.1 Gy (range, 1.6-3.2 Gy). RESULTS: The 5-year actuarial disease specific survival and overall survival rates were 59% and 39%, respectively. The 5-year actuarial local control rate for all patients was 94%. For the irradiated patients, the 5-year regional control rates were 77% overall and 83% within the radiation field. The 5-year actuarial rate of distant metastasis for all patients was 30%. For patients who presented with and without regional adenopathy, the 5-year rates of distant metastasis were 36% and 12%, respectively (P = 0.27). CONCLUSIONS: Nonnasopharygeal lymphoepithelioma is a radiosensitive disease. High rates of locoregional tumor control were achieved with radiotherapy at all head and neck sites. The main cause of treatment failure was distant metastasis, which occurred more frequently in patients with lymph node involvement. Radiotherapy is appropriate initial locoregional therapy for patients with this disease. Surgery should be reserved for patients who have persistent disease after completing radiotherapy. Systemic therapy is a reasonable approach for patients who present with regional adenopathy because they have a relatively high rate of distant metastasis.  相似文献   

12.
The incidence of skin cancers is increasing at a rate greater than any other cancer occurring in humans. In this era of managed care, patients with a suspicious skin lesion may first present to their primary care physician for evaluation. Therefore, it is important for the primary care physician to be able to distinguish between benign and malignant pigmented lesions, to know how to evaluate such a patient, and to appreciate the importance of appropriate interdisciplinary management of these patients.  相似文献   

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A review of the basic physics and techniques for acquiring and evaluating magnetic resonance angiograms is provided, including time-of-flight and phase contrast techniques. Magnetic resonance (MR) angiography is becoming a routine method of evaluating carotid bifurcation atherosclerotic disease in both a screening and diagnostic capacity. The expanding clinical utility of MR angiography in the detection of intracranial aneurysms, characterization of arteriovenous malformations, and evaluation of intracranial atherosclerotic disease are also reviewed. Furthermore, MR angiography allows for the noninvasive diagnosis of arterial dissection. Magnetic resonance venography also allows the confirmation of the previously elusive and likely underdiagnosed entity of cerebral venous thrombosis.  相似文献   

15.
An interesting case of a traumatic neuroma of the greater auricular nerve provides the impetus for a discussion of head and neck neuromas. Traumatic neuromas of the head and neck are relatively rare. Division of the greater auricular nerve during parotidectomy occasionally results in a traumatic neuroma. We report a case of a 73-year-old woman who presented with a traumatic neuroma nine years after undergoing superficial parotidectomy with dissection of the facial nerve for a mixed tumor. The patient had a 1.5 cm x 1.0 cm mass located below the old surgical site over the anteromedial border of the sternocleidomastoid muscle. The patient's past history was significant for Frey's syndrome, which is the result of abnormal neurologic growth. On first impression, the tumor was thought to be a recurrence of neoplastic disease; however, because of the evaluation, traumatic neuroma was suspected. An attempt at fine-needle aspiration of the mass was too painful to be carried out. At surgery, a whitish tumor was excised which, on final pathologic examination, revealed traumatic neuroma. The surgical literature is reviewed and the subject of head and neck neuromas, including their evaluation and management, is thoroughly discussed. Knowledge of this possible diagnosis may spare the patient and the surgeon needless worry, as well as unnecessary procedures, once tumor recurrence has been ruled out.  相似文献   

16.
PURPOSE: Survival for pediatric rhabdomyosarcoma has improved with the use of multidrug chemotherapy and external beam radiotherapy. This study was performed to determine survival in a cohort of patients treated on one of three multidrug treatment protocols for head and neck rhabdomyosarcoma and to identify factors that place patients at risk for treatment failure. METHODS: Pertinent prognostic variables including age, sex, subsite of origin, resectability, and TNM stage were analyzed by the Kaplan-Meier methods with comparisons between variables performed using the Prentice-Wilcoxon test statistic. RESULTS: Overall 5-year survival was 74% (95% confidence interval 64% to 84%). Local failure accounted for the cause of death in 10 patients, and 8 died of disseminated disease. On univariate analysis, each variable contributing to the TNM staging system was significant in determining survival; invasiveness (P = 0.01), size (P = 0.02), nodal metastases (P <0.01), and distant disease (P <0.01). CONCLUSION: Survival has improved for head and neck rhabdomyosarcoma treated with multimodality therapy. Patients with advanced-stage disease are at greatest risk for treatment failure and require the most aggressive therapy.  相似文献   

17.
In Germany about 8500 dog-bite injuries in the face occur every year; more than 50% of the victims are infants and schoolchildren. Besides dogs, other animals such as cats or horses may be responsible for these accidents. Even human bites are reported. The predominant areas are the nose and the auricles. The tissue defects may be superficial, but they can even cause amputations, including severe vascular and nerve or bony destruction. Systemic antibiotic therapy is needed when the wound is infected. The surgical approach to bite injuries includes local wound cleansing, careful excision of necrotic tissue and primary closure of the wound whenever possible. Regarding the importance of surgery in the head and neck area plastic-reconstructive techniques including autologous transplantations and various local or regional flaps should be used at the time the wound is first repaired.  相似文献   

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The prognosis of patients with advanced gallbladder carcinoma remains dismal. In the English language literature, we found only one 5-year survivor with peripancreatic lymph node metastases. We herein report a patient with marked peripancreatic nodal metastases, who has exhibited the longest survival (6 years) without recurrence after a pancreaticoduodenectomy combined with extended cholecystectomy. This outcome suggests that pancreaticoduodenectomy may be effective for clearance of peripancreatic nodal metastases from gallbladder cancer.  相似文献   

20.
The authors study the practical aspects of head and neck expansion: choice of material, choice of flaps obtained by skin expansion. They then examine the specific features of expansion in this anatomical region, where it is frequently used, with emphasis on preservation of aesthetic units and the specificities of skin hair and natural orifices. Scalp expansion in the context of baldness is discussed in a separate article.  相似文献   

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