Hugh D. Curtin

Head and neck imaging

Section I: Sinonasal Cavities Embryology and Congenital Lesions Anatomy and Physiology The Osteomeatal Complex Postoperative Complications of Osteomeatal Surgery Inflammatory Diseases Tumor and Tumor-like Conditions Facial Fractures and Post-Operative Findings SECTION II: Orbit and Visual Pathways Eye: Embryology, Anatomy, and Pathology Orbit: Embryology, Anatomy and Pathology Lacrimal Apparatus: Embryology, Anatomy, and Pathology Visual Pathways: Embryology, Anatomy and Pathology SECTION III: Central Skull Base Skull Base: Embryology, Anatomy and Pathology Imaging of Perineural Tumor Spread in Head and Neck Cancer Section IV: Jaws and Temporomandibular Joints Embryology and Anatomy of the Jaws and Dentition Dental Implants and Related Pathology Dental CT Reformatting Programs and Dental Imaging Cysts, Tumors and Non-Tumorous Lesions of the Jaws Temporomandibular Joints: Anatomy and Pathology VOLUME II. Section V. Temporal Bone Temporal Bone: Embryology and Anatomy Temporal Bone: Imaging Anatomy Temporal Bone: Congenital Anomalies Temporal Bone: Inflammatory Disease Temporal Bone: Trauma Temporal Bone: Otosclerosis and Dysplasias Temporal BoneTumors and Cerebello-Pontine Angle Lesions Temporal Bone: Vascular Tinnitus Section VI. Upper Aerodigestive Tract Oral Cavity: Anatomy and Pathology Pharynx Pediatric Airway Disease Larynx: Anatomy, Pathology, and Post Operative Trachea: Anatomy and Pathology Swallowing Evaluation Section VII. Neck Embryology and Anatomy of the Neck Fascia and Spaces of the Neck Congenital Lesions Lymph Nodes Ultrasound of the Neck Parapharyngeal and Masticator Space Lesions Salivary Glands: Anatomy and Pathology Th

Superior semicircular canal dehiscence presenting as conductive hearing loss without vertigo.

Objective: The objective of this study was to describe superior semicircular canal dehiscence (SSCD) presenting as otherwise unexplained conductive hearing loss without vestibular symptoms. Study Design: Retrospective. Setting: Tertiary referral center. Patients: The study comprised 8 patients (10 ears), 5 males and 5 females aged 27 to 59 years. All 10 ears had SSCD on high-resolution computed tomography scan of the temporal bone. Diagnostic Tests and Results: All 10 ears had significant conductive hearing loss. The air–bone gaps were largest in the lower frequencies at 250, 500, and 1000 Hz; the mean gaps for these 3 frequencies for the 10 ears were 49, 37, and 35 dB, respectively. Bone-conduction thresholds below 2000 Hz were negative (−5 dB to −15 dB) at one or more frequencies in 8 of the 10 ears. There were no middle ear abnormalities to explain the air–bone gaps in these 10 ears. Computed tomography scan and laboratory testing indicated lack of middle ear pathology; acoustic reflexes were present, vestibular evoked myogenic potentials (VEMPs) were present with abnormally low thresholds, and umbo velocity measured by laser Doppler vibrometry was above mean normal. Middle ear exploration was negative in six ears; of these six, stapedectomy had been performed in three ears and ossiculoplasty in two ears, but the air–bone gap was unchanged postoperatively. The data are consistent with the hypothesis that the SSCD introduced a third mobile window into the inner ear, which in turn produced the conductive hearing loss by 1) shunting air-conducted sound away from the cochlea, thus elevating air-conduction thresholds; and 2) increasing the difference in impedance between the oval and round windows, thus improving thresholds for bone-conducted sound. Conclusion: SSCD can present with a conductive hearing loss that mimics otosclerosis and could explain some cases of persistent conductive hearing loss after uneventful stapedectomy. Audiometric testing with attention to absolute bone-conduction thresholds, acoustic reflex testing, VEMP testing, laser vibrometry of the umbo, and computed tomograph scanning can help to identify patients with SSCD presenting with conductive hearing loss without vertigo.

Staging Proposal for External Auditory Meatus Carcinoma Based on Preoperative Clinical Examination and Computed Tomography Findings

An accepted staging system for squamous cell carcinoma of the external auditory meatus is currently lacking and would permit accurate comparison of treatment strategies and results for patients with this unusual neoplasm. In order to develop such a staging system we reviewed the prognostic variables and the accuracy of radiographic diagnoses in 39 patients undergoing temporal bone resection for squamous carcinoma of the external auditory meatus. Predictors of poor survival were extensive tumor involvement, facial nerve paralysis, middle ear involvement, and cervical or periparotid lymphadenopathy. In a comparison of 12 specific anatomic sites, computed tomography was found to be an accurate indicator of histopathologically proven tumor invasion. On the basis of this clinical-radiographic-histopathologic analysis, we propose a TNM staging system for external auditory meatus carcinoma utilizing preoperative computed tomography and physical examination. This system fulfills the requirements of the American Joint Committee on Cancer that a staging system should provide a sound basis for therapeutic planning for cancer patients by describing the survival and resultant treatment of different patient groups in comparable form.

An empirical taxometric alternative to traditional classification of temporomandibular disorders

&NA; A number of investigators have suggested that the generic classification temporomandibular disorders (TMD) may consist of several subsets of patients. Two primary factors are suggested to be significant in discriminating subgroups, namely, presence or absence of TM joint abnormalities and psychological characteristics such as traits, maladaptive behavioral patterns, and gross psychopathology. Few attempts, however, have been made to integrate psychosocial and behavioral parameters in order to identify a taxonomy of TMD patients and, subsequently, to examine the differentiation of subgroups on oral dysfunction/structural abnormalities (OD/SA). The primary purpose of this paper was to develop and cross‐validate an empirically derived classification system of TMD patients. The first study identified three unique subgroups of TMD patients, labeled ‘dysfunctional,’ ‘interpersonally distressed,’ and ‘adaptive copers.’ A second study cross‐validated and confirmed the uniqueness and accuracy of the taxonomy. Subsequent analyses were performed that demonstrated that these groups were not distinguishable on the basis of any measures of OD/SA. The taxonomy identified is compared and contrasted with other reported subgroups of TMD patients and the implications of this classification system for treatment of TMD patients are discussed.

Evaluation of orbital cellulitis and results of treatment.

Optimal management of patients with orbital cellulitis depends on how accurately the disease is classified and on the appropriateness with which antibiotics and surgery are used to treat the disease. Therapy must be adjusted on the basis of the extent of the disease. In order to determine the balance of treatment modalities which is most beneficial for certain disease presentations, we reviewed a series of 303 patients with orbital cellulitis. The anatomical and bacteriological etiology of the disease was determined in each case on the basis of the examination, visual acuity, results of sinus radiography, results of culture, ultrasonography, and computerized tomography. To avoid the 5% complication rate that occurred in this series, an evaluation and treatment protocol is recommended.

Operative exposure and management of the petrous and upper cervical internal carotid artery.

The exposure and operative management of the petrous and upper cervical internal carotid artery (ICA) in 29 patients is detailed. Twenty-seven of these patients had extensive cranial base neoplasms (benign or malignant), 1 had an inflammatory cholesteatoma, and 1 had an aneurysm of the upper cervical ICA immediately proximal to the carotid canal. Preoperative studies useful in the evaluation of these patients included computed tomography, magnetic resonance imaging, cerebral and cervical angiography, and a balloon occlusion test of the ICA with evaluation of neurological status and of cerebral blood flow. The exposure of the upper cervical and petrous ICA was useful to obtain proximal control of the cavernous ICA, aided in the operative approach to extensive petroclival, intracavernous, and parapharyngeal neoplasms, and enabled the total resection of 23 of 27 such tumors. A subtemporal and preauricular infratemporal fossa approach was most commonly used for the exposure of the artery. Intraoperative arterial management consisted of exposure and decompression only, dissection from encasing neoplasm, resection of the invaded arterial segment and vein graft reconstruction, or intentional arterial occlusion. Vascular complications included 1 stroke due to delayed arterial occlusion, 1 stroke and death due to infection spreading from the nasopharynx with bilateral ICA rupture, and 1 pseudoaneurysm formation secondary to wound infection necessitating postoperative balloon occlusion of the ICA. Nonvascular complications included facial nerve paralysis in 10 patients (usually temporary), glossopharyngeal and vagal paralysis in 13 patients requiring Teflon injection of the vocal cord in 9, temporary difficulties with mastication in 9 patients, and wound infection in 3. The surgical exposure and management of the upper cervical and petrous ICA may permit a total operative resection of extensive cranial base neoplasms and is also an alternative for the management of vascular lesions involving these segments of the artery. With malignant neoplasms extending from the nasopharynx, postoperative infection remains a problem and may best be resolved by the use of a vascularized rectus abdominis muscle flap to reconstruct defects of the nasopharynx. Bilateral ICA encasement by neoplasms is also a major problem to be solved. The value of such an aggressive approach to the management of malignant neoplasms remains to be proven.

Lymph node pathology. Benign proliferative, lymphoma, and metastatic disease.

The evaluation of cervical lymph nodes is one of the main indications for performing CT and MR imaging of the neck. Imaging may be done for evaluation of an unknown neck mass, but more commonly the neck is imaged to evaluate potential metastasis from a known mucosal malignancy. CT and MR imaging characteristics of both malignant and nonmalignant nodal diseases are reviewed and the differential diagnosis of nodal pathologies for specific imaging findings are discussed. A recently proposed imaging-based nodal classification for metastatic nodal diseases from head and neck cancer is also described.

Clinical investigation and mechanism of air-bone gaps in large vestibular aqueduct syndrome.

Objectives: Patients with large vestibular aqueduct syndrome (LVAS) often demonstrate an air-bone gap at the low frequencies on audiometric testing. The mechanism causing such a gap has not been well elucidated. We investigated middle ear sound transmission in patients with LVAS, and present a hypothesis to explain the air-bone gap. Methods: Observations were made on 8 ears from 5 individuals with LVAS. The diagnosis of LVAS was made by computed tomography in all cases. Investigations included standard audiometry and measurements of umbo velocity by laser Doppler vibrometry (LDV) in all cases, as well as tympanometry, acoustic reflex testing, vestibular evoked myogenic potential (VEMP) testing, distortion product otoacoustic emission (DPOAE) testing, and middle ear exploration in some ears. Results: One ear with LVAS had anacusis. The other 7 ears demonstrated air-bone gaps at the low frequencies, with mean gaps of 51 dB at 250 Hz, 31 dB at 500 Hz, and 12 dB at 1,000 Hz. In these 7 ears with air-bone gaps, LDV showed the umbo velocity to be normal or high normal in all 7; tympanometry was normal in all 6 ears tested; acoustic reflexes were present in 3 of the 4 ears tested; VEMP responses were present in all 3 ears tested; DPOAEs were present in 1 of the 2 ears tested, and exploratory tympanotomy in 1 case showed a normal middle ear. The above data suggest that an air-bone gap in LVAS is not due to disease in the middle ear. The data are consistent with the hypothesis that a large vestibular aqueduct introduces a third mobile window into the inner ear, which can produce an air-bone gap by 1) shunting air-conducted sound away from the cochlea, thus elevating air conduction thresholds, and 2) increasing the difference in impedance between the scala vestibuli side and the scala tympani side of the cochlear partition during bone conduction testing, thus improving thresholds for bone-conducted sound. Conclusions: We conclude that LVAS can present with an air-bone gap that can mimic middle ear disease. Diagnostic testing using acoustic reflexes, VEMPs, DPOAEs, and LDV can help to identify a non?middle ear source for such a gap, thereby avoiding negative middle ear exploration. A large vestibular aqueduct may act as a third mobile window in the inner ear, resulting in an air-bone gap at low frequencies.

Facial paralysis in children: differential diagnosis.

The differential diagnosis in 170 patients between birth and 18 years of age is reviewed. There are a number of obvious physical findings and historical features that allow one to make a diagnosis rather quickly. Pain, vesicles, a red pinna, vertigo, and sensorineural hearing loss suggest herpes zoster oticus. Slow progression beyond three weeks, recurrent facial paralysis involving the same side, facial twitching, weakness, or no return of function after six months indicate a neoplasm. Bilateral simultaneous facial paralysis indicates a cause other than Bells palsy, such as Guillain-Barré syndrome, pseudobulbar palsy, sarcoidosis, and leukemia. Recurrent facial paralysis associated with a fissured tongue, facial edema, and a positive family history should suggest Melkersson-Rosenthal syndrome.

Ocular Adnexal Lymphoma: Diffusion-weighted MR Imaging for Differential Diagnosis and Therapeutic Monitoring

PURPOSE To describe the magnetic resonance (MR) imaging and diffusion-weighted (DW) imaging features of ocular adnexal lymphomas (OALs), to determine the diagnostic accuracy of apparent diffusion coefficient (ADC) for discriminating OALs from other orbital mass lesions, and to assess whether variations in ADC constitute a reliable biomarker of OAL response to therapy. MATERIALS AND METHODS Institutional ethical committee approval and informed consent were obtained. In this prospective study, 114 white subjects (65 females and 49 males) were enrolled. Thirty-eight patients with histopathologically proved OAL underwent serial MR and DW imaging examination of the orbits. ADCs of OALs were compared with those of normal orbital structures, obtained in 18 healthy volunteers, and other orbital mass lesions, prospectively acquired in 58 patients (20 primary non-OAL neoplasms, 15 vascular benign lesions, 12 inflammatory lesions, 11 metastases). Interval change in ADC of OALs before and after treatment was analyzed in 29 patients. Analysis of covariance and a paired t test were used for statistical analysis. RESULTS Baseline ADCs in OALs were lower than those in normal structures and other orbital diseases (P < .001). An ADC threshold of 775 x 10(-6) mm(2)/sec resulted in 96% sensitivity, 93% specificity, 88% positive predictive value, 98.2% negative predictive value, and 94.4% accuracy in OAL diagnosis. Following appropriate treatment, 10 (34%) of 29 patients showed OAL volumetric reduction, accompanied (n = 7) or preceded (n = 3) by an increase in ADC (P = .005). Conversely, a further reduction of ADC was observed in the seven patients who experienced disease progression (P < .05). CONCLUSION ADC permits accurate diagnosis of OALs. Interval change in ADC after therapy represents a helpful tool for predicting therapeutic response.