Optimal Diagnostic Criteria and a Staging System for Otogenic Skull Base Osteomyelitis.

Objective Diagnostic criteria for otogenic skull base osteomyelitis (SBO) have been conflicting among researchers. We aimed to propose clinically useful diagnostic criteria and a staging system for otogenic SBO that is associated with infection control and mortality. Design The present study is designed as a retrospective one. Setting This study was conducted at the University Hospital. Participants Thirteen patients with otogenic SBO who met the novel rigorous diagnostic criteria consisted of symptomatic and radiological signs on high-resolution computed tomography (HRCT) and magnetic resonance imaging (MRI). Simple refractory external otitis was not included. A staging system according to disease extent revealed by HRCT and MRI is proposed: lesions limited to the temporal bone (stage 1), extending to less than half (stage 2), exceeding the midline (stage 3), and extending to the whole of the clivus (stage 4). All patients received long-term antibiotic therapy. Patients were divided into infection-uncontrolled or -controlled groups based on symptoms, otoscopic findings, and C-reactive protein level at the last follow-up. The mean follow-up period was 27.7 months. Main Outcome Measures Possible prognostic factors, such as immunocompromised status and symptoms, including cranial nerve palsy, pretreatment laboratory data, and treatments, were compared between the infection-uncontrolled and -controlled groups. Disease stages were correlated with infection control and mortality. Results The infection-uncontrolled rate and mortality rate were 38.5 and 23.1%, respectively. There were no significant differences in possible prognostic factors between the infection-uncontrolled and -controlled groups. HRCT-based stages significantly correlated with infection control and mortality. Conclusion We proposed here the clinically useful diagnostic criteria and staging systems that can predict infection control and prognosis of otogenic SBO.

Lemierre's Syndrome Due to Malignant Otitis Externa: Imaging Studies Revealed Its Systemic Dissemination.

Lemierre's syndrome is characterized by internal jugular vein thrombosis and systemic septic embolism; it is a fatal complication of upper respiratory tract infections. To date, it has not been demonstrated how the upper respiratory tract inflammation spreads from the primary infection site to internal jugular vein and systemic thrombosis. We report a very rare case of Lemierre's syndrome derived from malignant otitis externa in which the spread of infection and thrombosis process were identified by imaging. A 61-year-old man with severe diabetes mellitus visited our hospital with consciousness disturbance and right posterior neck pain. He complained of right ear pain and otorrhea several days prior to the neck pain. Contrast-enhanced computed tomography demonstrated thrombosis in internal jugular vein and multiple lung abscesses. Temporal bone images revealed continuous lesions from skull base osteomyelitis to suboccipital abscess and sigmoid sinus thrombosis. We diagnosed the patient as having Lemierre's syndrome secondary to skull base osteomyelitis following malignant otitis externa. The patient clinically recovered with a combination of drainage of suboccipital abscess and long-term administration of antibiotics, which is the standard treatment of malignant otitis externa. Considering the details of imaging and bacterial examination is very useful for understanding the pathophysiology and determining appropriate treatment in Lemierre's syndrome pathophysiology and determining appropriate treatment in Lemierre's syndrome.

Traumatic Nonmissile Penetrating Transnasal Anterior Skull Base Fracture and Brain Injury with Cerebrospinal Fluid Leak: Intraoperative Leak Detection and an Effective Reconstruction Procedure for a Localized Skull Base Defect Especially After Coronavirus Disease 2019 Outbreak.

BACKGROUND: Cerebrospinal fluid (CSF) leakage after penetrating skull base injury is relatively rare compared with close head injuries involving skull base fractures. CASE DESCRIPTION: We report the case of a 65-year-old man who had presented with epistaxis and serous rhinorrhea. When he had fallen to the ground near his bee boxes, a garden pole had poked into his right nostril. He had instantly removed the pole from his nostril himself. However, immediately after removal of the pole, he had developed nasal bleeding and serous rhinorrhea. He then drove to our emergency room. Computed tomography showed pneumocephalus with a minor cerebral contusion in the left frontal lobe and a penetrating injury in the left anterior skull base. His CSF leakage had not resolve spontaneously within 1 week after the injury with strict bed rest. We repaired the CSF leakage using a fat (adipose tissue)-on-fascia autograft plug and caulked the defect in the anterior skull base with the fat-on-fascia graft (FFG) plug through the left nostril with endoscopic guidance. The CSF rhinorrhea was successfully controlled. Intranasal local application of fluorescein aided in the detection of the direction of flow of the CSF leakage. CONCLUSIONS: Endonasal endoscopic caulking of a skull base defect using an FFG plug can be useful to treat CSF leakage due to the localized skull base defect, especially in the coronavirus disease 2019 pandemic. It is simple, inexpensive, and timesaving. It requires no special skills nor sophisticated instruments that can cause aerosolization, reducing the risk of infection during the surgery.

Patient-specific 3D-printed Model-assisted Supracochlear Approach to the Petrous Apex.

OBJECTIVE: To present a case of pediatric cholesteatoma that invaded the petrous apex (PA) and discuss the usefulness of preoperative three-dimensional (3D) surgical simulation on a personal computer (PC) and patient-specific 3D printed model-assisted surgery. PATIENT: A 5-year-old boy with congenital cholesteatoma underwent a planned two-stage canal wall up mastoidectomy. The cholesteatoma had invaded the PA from a small space anterior to the superior semicircular canal (SSCC). During the removal of this lesion in the first surgery, the tip of a 1-mm round knife broke off and fell into the PA. The surgeon could not remove it, as it was thought that opening the space might damage the SSCC and the facial nerve (FN). INTERVENTION: Before the second surgery, a preoperative 3D surgical simulation on a PC was performed, and an approach to the PA via the triangle surrounded by the SSCC, FN, and middle cranial fossa, namely, the supracochlear approach, was discovered. A patient-specific 3D-printed model, which had been drilled to make each surface of the triangle including the SSCC, FN, and middle cranial fossa visible in the PC simulation surgery, was then created and a 3D-printed model-assisted surgery was planned. RESULTS: By placing the sterilized patient-specific 3D model close to the surgical field, the cholesteatoma and iatrogenic foreign body could be successfully removed from the PA without damaging the important surrounding structures. CONCLUSIONS: Preoperative 3D surgical simulations and intraoperative patient-specific 3D-printed model-assisted surgeries are new, powerful tools that aid in performing challenging surgeries on temporal bones.

Associative responses to visual shape stimuli in the mouse auditory cortex.

Humans can recall various aspects of a characteristic sound as a whole when they see a visual shape stimulus that has been intimately associated with the sound. In subjects with audio-visual associative memory, auditory responses that code the associated sound may be induced in the auditory cortex in response to presentation of the associated visual shape stimulus. To test this possibility, mice were pre-exposed to a combination of an artificial sound mimicking a cat's "meow" and a visual shape stimulus of concentric circles or stars for more than two weeks, since such passive exposure is known to be sufficient for inducing audio-visual associative memory in mice. After the exposure, we anesthetized the mice, and presented them with the associated visual shape stimulus. We found that associative responses in the auditory cortex were induced in response to the visual stimulus. The associative auditory responses were observed when complex sounds such as "meow" were used for formation of audio-visual associative memory, but not when a pure tone was used. These results suggest that associative auditory responses in the auditory cortex represent the characteristics of the complex sound stimulus as a whole.

Otosclerosis: anatomical distribution of otosclerotic loci analyzed by high-resolution computed tomography.

PURPOSE: To clarify the anatomical distribution of otosclerotic loci in otosclerosis. METHODS: Ninety-five patients with surgically confirmed uni- or bilateral otosclerosis were enrolled into the study. Hypodense areas observed in the otic capsule by high-resolution computed tomography (HRCT) were defined as otosclerotic loci. The location and number of lesions were examined, and the probability of lesion overlap and correlation with age/hearing parameters (air and bone conduction threshold, air-bone gaps) were tested. RESULTS: Otosclerotic loci were confirmed by HRCT in 77 out of 115 operated ears. The three commonly affected sites were the anterior part of the oval window (ant-OW), anterior part of the internal auditory canal (ant-IAC), and pericochlear area (PCochA), with lesions detected in 96.1%, 46.8%, and 26.0% of ears, respectively. Only the ant-OW area was affected in 48.1% of the ears; the ant-IAC in 3.9%; and PCochA in none with significant differences (p < 0.01). The ant-OW lesions preferentially overlapped with ant-IAC (44.6%) than PCochA lesions (27.0%) (p < 0.05). Among double sites diseases, triple sites diseases occurred more commonly in the ant-OW + PCochA group (80%) than ant-OW + ant-IAC group (48.5%) (p < 0.05). There was no correlation between a number of lesions and age/hearing parameters. CONCLUSIONS: Based on the probability of lesion overlap, otosclerotic lesions may initiate at ant-OW followed by ant-IAC and later PCochA. Although the number of lesions showed no immediate correlation with hearing level or age, anatomical stage of the disease estimated by the location and the number of otosclerotic loci could be useful in predicting the future hearing status.

A case of lateral sinus insufficiency with acute otitis media: Early surgical intervention for prevention of lateral sinus thrombosis.

OBJECTIVE: To describe a case of lateral sinus insufficiency, presumably occurring just prior to lateral sinus thrombosis (LST), and to discuss the importance of early surgical intervention and the pathophysiology of full-blown LST. CASE REPORT: A 4-year-old boy developed headaches and vomiting after exhibiting typical symptoms of acute otitis media. Contrast-enhanced CT revealed narrowing of the sigmoid sinus medially by gas and low-density material. We diagnosed the patient with suspected LST and consequently performed mastoidectomy. A large amount of bloody pus was found in the mastoid cavity and below the bony sinus plate. Sigmoid sinus blood flow was completely restored after drainage of the hemorrhagic and purulent material, and the patient recovered fully. CONCLUSION: Because of the anatomical features of the dural venous sinus, hemorrhage per diapedesis may be strongly associated with the development of LST. In the patient with suspected LST, early diagnosis and surgery prior to the development of intravenous thrombus are key for full recovery from this condition.