Search PubMed⌕ Search

Biomedical subjects

R A Hendrix

Publications and source records attributed to R A Hendrix.

33 records · Page 2Linked to original sources
PubMed1990

Perilymph fistula.

Perilymph fistula, an abnormal communication between the inner ear and the middle ear, is an enigmatic otologic disorder which may present with auditory or vestibular symptoms. It is typically located at the oval or round windows, but several other locations have been suggested. It may be congenital or spontaneous, or due to trauma or surgery. It often poses a diagnostic dilemma because of the lack of a definitive test. Among the differential diagnoses of the perilymph fistula are Ménière's disease, infection, tumor and central nervous system disorders. Clinically, the definitive diagnosis of a perilymph fistula can only be made by exploratory tympanotomy. A current review of the etiology, diagnosis and management of perilymph fistula is presented.

Diagnosis, Differential↗
PubMed1990

Angiotensin-converting enzyme inhibitor induced angioedema of the head and neck.

Angiotensin-converting enzyme (ACE) inhibitors are now in widespread use for the treatment of essential and renovascular hypertension. Consequently, angioedema, an uncommon complication of ACE inhibitor therapy is being encountered with increasing frequency. Since ACE inhibitor angioedema predominantly involves the face, lips, oral cavity, and occasionally the larynx the otolaryngologist is often consulted to evaluate affected patients. Treatment ranges from simple cessation of the drug to emergent airway intervention. The pertinent pharmacologic properties of ACE inhibitors and the pathophysiology of angioedema are discussed. The authors' experience with the evaluation and treatment of ACE inhibitor induced angioedema is presented.

Adrenal Cortex Hormones↗
PubMed1989

The use of magnetic resonance imaging and spectroscopy in the assessment of patients with head and neck and other superficial human malignancies.

The proper demarcation of diseased tissue is important for radiation therapy planning and treatment. The volume to be irradiated is usually identified on radiographs or on x-ray computed tomography (CT) sections. Magnetic resonance (MR)-derived images of the proton T2 relaxation times in small pixel elements, typically 0.5 mm2 or less, provide significantly sharper differentiation between normal and diseased tissue. The T2 values in tissue depend on the tissue composition, histologic condition, and physiologic environment within the tumor. Furthermore, for many tumors the histogram of T2 values has a clear biphasic distribution suggesting that T2 maps may be useful for the identification of necrotic or hypoxic regions within tumors. The distribution of T2 values within the tumor bed shows the general pattern that the T2 values are elevated with a range greater than that seen in normal muscle. Elevated T2 values are not by themselves diagnostic of malignancy; however, they demonstrate the heterogeneity of the microenvironment present within a tumor. The spatial distribution of T2 values is being explored as a method for computer assistance in the delineation of the target volume for treatment planning. In addition, MR P-31 spectroscopic examinations were performed on 30 patients with squamous cell carcinomas of the head and neck. Although hampered by muscle contamination in some P-31 spectra obtained with surface coil profile localization techniques, significant trends can still be appreciated in our data. These trends include the following: (1) the P-31 spectra from malignant tissue have well-resolved spectral lines in the upfield region that correspond to Pi, phosphomonoester (PME), and phosphodiester (PDE) not usually seen in normal muscle; (2) the PDE/B-ATP and PME/B-ATP ratios are greater than unity in all cases; and (3) most of the tumors have higher PME peaks than PDE peaks. The P-31 spectra from patients treated with ionizing radiation changed during and after therapy. Some of the changes could be associated with alteration of the tumor metabolic activity or synthesis and breakdown of lipoproteins. These studies suggest that magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) studies may be useful for both radiotherapy treatment planning and the noninvasive monitoring of patients both before and during treatment.

Carcinoma, Squamous Cell↗
PubMed1989

Integrated magnetic resonance and 31p spectroscopy.

Magnetic resonance imaging (MRI) has proven to be a powerful tool for accurate assessment of the anatomical extent of head and neck neoplasms. The ability to localize precisely defined volumes of interest within tissue with measurement of multinuclear magnetic resonance spectra (1H and 31P) has provided a basis for integrating spectroscopy into the clinical MRI examination. This technique which offers a means for noninvasive monitoring of relative concentrations of mobile metabolites at specific regions within a tumor is discussed. Examples of data obtained from integrated MRI/MRS studies for representative head and neck lesions are presented. The potential role of integrated MRI/MRS to monitor the response of neoplasms to therapy is reviewed.

Carcinoma, Squamous Cell↗
PubMed1989

Otosyphilis: a practical guide to diagnosis and treatment.

The diagnosis and management of patients with suspected treponemal infection of the temporal bone pose some challenges. The following points deserve emphasis: 1) the MHA-TP or FTA-Abs is recommended over the reagin serologic tests (VDRL, RPR); 2) one should regard this process as an attempt to define a subgroup of patients with sensorineural hearing loss who will benefit from a combination of antibiotics and steroid therapy rather than explicitly diagnosing infection of the temporal bone. The response rate to therapy is limited; but, otosyphilis, as one of the few treatable causes of sensorineural hearing loss, must be suspected in the differential diagnosis of a wide range of otologic patients.

Hearing Loss, Sensorineural↗
PubMed1989

Neutron beam therapy in the treatment of advanced head and neck malignancy.

Patients with advanced head and neck cancer continue to present a difficult management problem for the otolaryngologist-head and neck surgeon. This paper discusses the principles of radiation therapy with emphasis on neutron beam therapy as an effective treatment option for advanced malignancy of the head and neck other than squamous cell carcinoma.

Head and Neck Neoplasms↗
PubMed1989

Cervical necrotizing fasciitis: two case reports and review of the literature.

Necrotizing fasciitis is a rapidly progressive mixed-organism infection that, in the neck, involves the superficial and deep cervical fascia. Underestimation of this complication of a "minor head and neck infection" can delay diagnosis and treatment of this often fatal disease process. Thirty-five cases of necrotizing fasciitis involving the neck have been reported previously. Two new cases of cervical necrotizing fasciitis and a review of previously reported cases are presented. Management is discussed. Early diagnosis is critical. Antibiotic therapy and prompt, aggressive surgical intervention are appropriate.

Adult↗
PubMed1989

Esthesioneuroblastoma: problems with diagnosis and management.

Esthesioneuroblastoma is an uncommon tumor arising from the olfactory epithelium of the nasal cavity. Since most cases present clinically with non-specific findings such as unilateral nasal obstruction and intermittent epistaxis, esthesioneuroblastoma is often mistaken for other diseases of the nasal cavity. Histological confirmation of the disease can also be difficult. The aggressive nature of esthesioneuroblastoma is evidenced by frequent local recurrences and occasional distant metastases--further complicating the management of this tumor. The otolaryngologist should possess a high index of suspicion for this rare, but devastating malignancy. Guidelines for the evaluation and treatment are presented.

Humans↗
PubMed1983

Auditory brain stem response and audiologic tests in idiopathic facial nerve paralysis.

Idiopathic facial nerve paralysis is believed by some to represent one aspect of a polyneuropathy. Conventional audiologic tests have not demonstrated involvement of the auditory portion of the eighth cranial nerve in this disorder. A case history is given of a patient with this disorder and an associated abnormal auditory brain stem response (ABR). Our study involved onetime evaluations of 17 patients with idiopathic facial nerve paralysis of varying durations. Each examination included clinical presentation and history, an audiogram, acoustic reflex, and ABR. Another patient had abnormal acoustic reflex test results ("unibox" pattern) suggestive of a brain stem lesion. On reexamination concurrent recovery of the paralysis and acoustic reflex was demonstrated. No auditory system disturbances secondary to the paralysis were detectable by ABR in this survey. The concurrent recovery of the "unibox" acoustic reflex and the facial paralysis suggests the association of a brain stem lesion with idiopathic facial nerve paralysis in this case.

Adolescent↗