Chronic Non-Infectious Osteomyelitis of the Petrous Bone: A Case Series

Symptom: Unilateral Facial Paralysis

Introduction: Cholesteatoma of the petrous bone is a rare pathology that grows slowly and is often asymptomatic. Material and Methods: The clinical records of a patient with congenital petrous bone cholesteatome managed surgically in our department were reviewed retrospectively. Results: A 57-year-old man was referred to our department with a 1-month history of sudden left total facial nerve palsy. He has a 30 years history of left-sided hearing disturbance without otorrhea. On physical examination, he showed a normal tympanic membrane, vestibular function was normal, facial examination presented a facial nerve paralysis of grade VI. The audiogram revealed severe sensorineural hearing loss on one side. CT scans revealed a soft tissue density lesion that extended widely from the anterior tympanic cavity to the petrous bone. MRI revealed a lobulated mass with its center at the petrous temporal bone. The lesion had low signal intensity on T1WI images and high signal intensity on T2WI images. We diagnosed a congenital cholesteatoma of the left petrous bone origin and performed surgery. We performed a translabyrinthine approach. The patient's postoperative cochlear function was not preserved. Course was uncomplicated. Conclusion: Congenital cholesteatoma is suggested to arise from epithelial cell rest within the temporal bone. Its slow silent growth may remain asymptomatic for years and cause delay in treatment. It may also involve all the vital anatomical structures within the temporal bone.

Total external ophthalmoplegia and orbital apex syndrome as first presenting feature of Rhabdomyosarcoma involving petrous part of the temporal bone: A case report

Primary Ewing sarcoma affecting the skull base in general and the petrous bone in particular is extremely rare with only 4 reports of Ewing sarcoma arising in the petrous temporal bone in the international medical literature. The authors report for the first time a case of a primary Ewing sarcoma of the petrous temporal bone in a 5-month-old nursling, which became apparent with a complete peripheral facial palsy and ipsilateral surdity. The neoformation was treated by systemic chemotherapy and radiation of the tumor region. The diagnostic steps, therapy, and development of the child are described in detail; the literature concerning Ewing sarcoma originating from the skull in general and from the petrous temporal bone in particular is reviewed. The highlights of this case are an extremely uncommon location, an unusual age of presentation, as well as a unique set of symptoms.

A 45-year-old man presented to the emergency department (ED) after falling down two flights of stairs. He had bilateral raccoon eyes, subconjunctival haemorrhages and CSF otorrhoea suggestive of skull base fracture (SBF). Although he had difficulty speaking and responded inappropriately, giving the impression of mixed dysphasia, written communication was normal, and he complained of deafness and dizziness. Facial motion was barely perceptible and complete eye closure was not possible, consistent with grade 5 facial palsies on the House-Brackmann facial nerve grading system. Bell’s phenomena (Fig. 1) and dysarthrophonia secondary to facial weakness were marked. He was also mildly ataxic. Computed tomography (CT) imaging confirmed extensive SBF and audiometric testing confirmed bilateral deafness. High-resolution axial petrous temporal bone CT (Fig. 2) demonstrated fractures involving the facial canals. The right-sided fracture traversed the fundus of the internal auditory canal, likely transecting the cochlear nerve, and the left-sided fracture involved the otic capsule, likely disrupting auditory and vestibular function. Fig. 1 a A 45-year-old man with facial diplegia. b Patient attempting to close both eyes producing bilateral Bell’s phenomenon. c Magnification of b demonstrating marked bilateral Bell’s phenomenon (more pronounced on the right side) Fig. 2 Right and left axial petrous temporal bone CT. Right axial CT shows a medial subtype of horizontal temporal bone fracture. There is a fracture of the posterior petrous surface (white arrow) extending anteriorly through the fundus of the internal auditory ... Post-traumatic facial nerve palsy complicates 1.5% of SBFs involving the temporal bones [1]. Petrous temporal bone fractures may disrupt the facial nerve, membranous labyrinth and inner ear. While cranial nerves seven and eight may be injured by petrous temporal bone fractures, concomitant bilateral facial weakness and deafness in this setting is extremely rare [2]. Most post-traumatic facial nerve injuries recover with conservative management and time [3, 4]. This case illustrates how bilateral facial weakness and deafness may be mistaken for mixed dysphasia and highlights the need to consider it in patients with apparent speech disturbances in the ED.

Objective To establish standard sites for bur holes that maintain constant anatomical relationships with the skull base and neural structures and can serve as the basal aspect of supratentorial temporooceipital craniotomies such as subtemporal transpetrosalridge approach.Methods To determine cranial-cerebral relationships,the authors delimited 10 adult cadaveric skulls anteriorly and posteriorly the external projection of the petrous bone and the midbrain by CT and Titanium nail.Then bur holes in adult cadaveric skulls were created (kl,the first bur hole,located anterior to the auricle of the ear; k2,the second bur hole,whose base was located 1 cm above the interface of the parietomastoid and squamous sutures; k3,the third bur hole whose base was located 1cm above the asterion).Three bur holes were made on each of the skulls (20 cerebral hemispheres).The author then introduced plastic catheters through the bur holes to evaluate pertinent cranial and neural landmarks.Results The first bur hole appeared to have a particular anatomical relationship with the anterior aspect of the petrous portion of the temporal bone and the most anterior aspect of the midbrain.The second bur hole had a particular relationship with the posterior border of the petrous portion of the temporal bone and with the posterior aspect of the midbrain.The third bur hole was mostly supratentorial and particularly related to the preoccipital notch.Conclusions The middle fossa floor is located anterior to the site of the kl,and the superior surface of the tentorium is posterior to k2.Together with k3,these bur holes can be considered standards for temporooccipital craniotomies such as subtemporal transpetrosalridge approach. Key words: External projection; Skull base; Subtemporal transpetrosalridge approach; Anatomy

The complex anatomy of petrous part of temporal bone makes the craniotomy around this area challenging. To avoid damaging the interior structures of petrous part of temporal bone, the authors used computed tomography to get the projection of the petrous part of temporal bone on skulls, making the external contours of petrous part clear, thus protecting its interior structure as a reference in craniotomy. The objective of this study was to find out the three-dimensional location of 4 points of petrous part of temporal bone. Parameters of 120 patients (240 observations) between 25 and 65 years who were free of abnormalities and pathological changes in temporal bone were measured on high-resolution spiral multiple slice computed tomographic multiple planar reconstruction images that were parallel to the base plane. The data were analyzed by SPSS, statistical software with the comparison between sides and sexes. The authors found the accurate locations that 4 points of petrous part of temporal bone with mastoidale as the origin. Then the authors connect the 3 vertexes of underside and the petrous apex and lengthen it until intersect with skulls to get the external landmarks. In the end, the authors get the safe range that can be applied to the clinical surgery.

Cross-Sectional Imaging Evaluation of Congenital Temporal Bone Anomalies: What Each Radiologist Should Know

The temporal bone consists of four components: the squamous, petromastoid and tympanic portions, and the styloid process. The petrous part houses the auditory apparatus1. This mass of bone is wedged between the sphenoid and occipital bones in the cranial base1. Complete agenesis of the petrous portion of the temporal bone occurs in Michel aplasia2, a congenital malformation associated with congenital hearing loss. Here we describe, for the first time, the sonographic appearance of the petrous part of the temporal bone in normal pregnancies, between 14 and 16 weeks of gestation, using transvaginal sonography (TVS). Approval for the study was given by the Institutional Review Board (Helsinki Committee Protocol). Thirty-four consecutive pregnant women, between 14 and 16 weeks of gestation, were examined after giving written informed consent to take part in the study. All patients were studied during a routine fetal anomaly scan using TVS, with an endocavitary 5–9-MHz transducer (Voluson 730 Expert; GE Medical Systems, Milwaukee, WI, USA). Patients were included in the study if there was a single fetus without evident or suspected fetal malformations and no family history of congenital hearing loss. The fetal head was assessed in transverse sections with the parotid gland first identified as an echoic structure located medial to the external ear; the petrous bone (an annular echogenic structure located medial and superior to the parotid gland) was then identified and measured in its largest anteroposterior diameter (Figure 1, Videoclip S1). The largest of three measurements was documented. The petrous bone was measured on at least one side of the head in each fetus. The examination time was not prolonged in order to permit measurement of the petrous bone (beyond the short time needed for the measurement itself) and no special attempt was made to measure the bone on both sides. However, bilateral measurements were obtained when both sides were visualized easily. Measurement of the petrous bone (calipers) at 15 weeks of gestation. Ant., anterior; Post., posterior; E, eye. In all 34 fetuses the petrous bone was visualized and measured on at least one side, and in eight patients the petrous bones were visualized and measured bilaterally. The median anteroposterior diameter of the petrous bone was 4.5 (range, 3.5–6.1) mm, and the mean ( ± SD) anteroposterior diameter was 4.59 ± 0.53 mm. This is the first report to describe the normal appearance of the fetal petrous bone. The ability to visualize the petrous bone raises the possibility of prenatal diagnosis of congenital malformations of the inner ear, such as Michel aplasia2. Congenital hearing loss owing to malformation of the inner ear is classified into several types3-5. Some of these malformations are associated with malformations of the temporal bone, specifically the petrous portion, which is reported to be malformed in about 20% of cases of congenital deafness4. We measured the petrous bone at 14–16 weeks of gestation because at later gestational ages measurement of the bone is more difficult and time-consuming. However, we now measure the normal petrous bone at up to 40 weeks of gestation. TVS was used because this is the standard technique used in our institution for a routine fetal anomaly scan at the gestational age considered. However, the petrous bone can also be visualized using transabdominal transducers at 14–16 weeks. SUPPORTING INFORMATION ON THE INTERNET The following supporting information may be found in the online version of this article: Videoclip S1 Videoclip showing measurement of the petrous bone in a 15-week fetus. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article. M. Odeh*, E. Ophir*, J. Bornstein*, * Department of Obstetrics and Gynecology, Western Galilee Hospital, Nahariya, Rappaport Faculty of Medicine, Technion, Haifa, Israel

Introduction: Temporal bone has a complex anatomy, divided into five bony divisions, which include squamous part, petrous bone, tympanic part, mastoid process, and styloid process. This contains cranial nerves V, VI, VII, and VIII and vascular structures such as the internal carotid and middle meningeal arteries, the sigmoid sinus, and the jugular bulb. It also harbors the sensorineural and membranous structures of the inner ear. The most common cause of temporal bone fractures is high energy blunt head trauma. For the assessment of temporal fractures, cranial CT is a fundamental and initial diagnostic modality. Complications of temporal bone fractures include facial nerve palsy, cerebrospinal fluid leakage, conductive hearing loss, sensorineural hearing loss, and vertigo. These fractures are divided into longitudinal and transverse based on whether the fracture line is passing parallel to or perpendicular to petrous bone respectively. Materials and Methods: This was a cross-sectional study done at Dr. PSIMS & RF, Gannavaram, Andhra Pradesh. The study period was between January 2015 to December 2018, done on Siemens 16 Slice CT machine with the patients' age ranging from 18 to 70 years who underwent CT brain in view of Road traffic accidents. Results: Among the total number of 30 patients, we have divided into combined fractures of various parts and isolated fractures of various parts. Isolated petrous fracture seen in 3 cases, squamous in 10 and mastoid in 5 patients, among the fractures, isolated squamous (58.8%) is the most common one seen. In thirteen cases (43.3%) combined fractures of at least two parts seen, among the various combinations seen the most common one is squamous – mastoid 7(50%). Among the total number of cases, facial nerve canal is involved in 7(23%) cases, out of which clinically 4(57.1%) cases presented with facial palsy. Carotid canal is involved in 3(10%) cases, pneumocephalus secondary to mastoid fracture in 6(20%) cases. Hemomastoid

Bilateral facial paralysis caused by bilateral temporal bone fracture is a rare clinical entity, with seven cases reported in the literature to date. In this paper, we describe a 40-year-old male patient with bilateral facial paralysis and hearing loss that developed after an occupational accident. On physical examination, House-Brackmann (HB) facial paralysis of grade 6 was observed on the right side and HB grade 5 paralysis on the left. Upon temporal bone computed tomography (CT) examination, a fracture line exhibiting transverse progression was observed in both petrous temporal bones. Our patient underwent transmastoid facial decompression surgery of the right ear. The patient refused a left-side operation. Such patients require extensive monitoring in intensive care units because the presence of multiple injuries means that facial functions are often very difficult to evaluate. Therefore, delays may ensue in both diagnosis and treatment of bilateral facial paralysis.

The term petrous bone cholesteatoma (PBC) refers to lesions extending deep to the bony labyrinth via superior, inferior, and posterior cell tracts. PBC is a rare incidence accounting for only 4-9% of petrous bone lesions. Lesions of petrous bone represent a real surgical challenge due to its complex relationship with critical neurovascular structures. To demonstrate our 40-plus years' experience in the management of PBC, depict the clinical features of PBC according to Sanna's Classification, evaluate the postoperative follow-up of surgically treated PBC patients, and determine the recurrence rate. Retrospective medical record review. Medical records of 298 PBC cases operated from the year 1983 to 2024 were thoroughly evaluated. A total of 298 PBC cases were surgically treated at our center. The average age at presentation in this series was 47 years. Males are more affected than females with a male-to-female ratio of 2.2:1. The most common presenting symptoms were hearing loss (84%), tinnitus (48%), and facial nerve paralysis (45%). Mixed hearing loss (41%) was the commonest audiometric pattern of hearing loss followed by conductive hearing loss (26%) and profound sensorineural hearing loss (4%) and a total of 86 (29%) had anacusis at presentation. On preoperative facial nerve function examination, 133(45%) of patients had various degrees of paresis and complete paralysis whereas 55% had normal HB-I function. The commonest degree of paresis noted was HB-III (18%) followed by HB-VI (5%). A total of 150 (50%) patients had previous otologic surgery and two-thirds of these cases had two or more prior otologic surgeries. According to Sanna's PBC Classification system, we identified that the supralabyrinthine class (44%) is the commonest of all classes followed by massive (33%), infralabyrinthine-apical (9%), infralabyrinthine(8%), and apical (5%) classes in that order. However, only ten patients had congenital type of PBC. Extension to clivus, sphenoid, nasopharynx, intradural space, and occipital condyle was found in 8, 2, 1, and 2 cases respectively. The most commonly used surgical approaches at our center were TO, MTCA with rerouting of the facial nerve, and TLAB with external auditory canal (EAC) closure. Postoperative complications were minimal and the duration of follow-up ranged from one to 458 months with a mean duration of 65 months. Residual lesions were evident in 11 cases (3.7%), with the surgical cavity, middle and posterior fossa dura, and jugular bulb being the commonest sites. Petrous bone cholesteatoma represents diagnostically and surgically challenging lesions of temporal bone which are usually frustrating to the treating surgeon. A high index of clinical suspicion, thorough clinical evaluation examination, and preoperative radiologic evaluation make the diagnosis easier. Preoperative anatomic classification of the lesion enables the physician to choose the appropriate surgical approach. Sanna's classification is widely used to classify PBC in relation to the labyrinthine block. Radical disease removal should always come before hearing preservation. Cavity obliteration is the solution to the problems related to a large cavity. Finally, advancements in lateral skull base approaches create adequate surgical access for the complete removal of the lesion with excellent control of critical neurovascular structures.


 This young adult man presented to ENT clinic with a complaint of left facial weakness and persistent left retro-auricular pain. High resolution CT of the mastoids was performed following clinical assessment.
 In this case, there is extensive sclerotic bony expansion with a ground-glass appearance involving the left zygoma, sphenoid and petrous temporal bone.
 The bony expansion is centred on the medullary bone and has an abrupt zonal transition (Figure 1). The bone involvement encompasses almost complete bony stenosis of the left external auditory meatus down to 1-2mm with consequential fluid in the external auditory canal and middle ears (Figure 2). The bony expansion involves both the tympanic and mastoid segments of the facial canal which are stenosed. The ossicular chain remains intact. The left mastoid air cells are under-pneumatised and completely occupied by fluid.
 DISCUSSION
 Fibrous dysplasia (FD) is a benign congenital process that typical manifests itself as a localized defect in osteoblastic differentiation and maturation. Normal bone is replaced with haphazard fibrous tissue and immature woven bone.1
 Fibrous dysplasia is predominantly a condition of children and young adults (those less than 30 years of age). Disease growth usually halts after the third decade of life. FD may be a monostotic or polyostotic in nature and in some cases is part of a syndrome, such as McCune-Albright.2
 The zygomatic maxillary complex is the most commonly reported location for fibrous dysplasia. The temporal bone is a typical site in polyostotic disease, in up to 70%, but less often observed in monoostotic disease. Disease of the temporal bone most typically results in hearing impairment due to bony stenosis of the external auditory canal. Facial nerve involvement is a less frequent feature, resulting in facial nerve paralysis, due to involvement of the nerve as it exits through the petrous temporal bone.2 The anatomical location of the facial nerve compression is hard to access and treat surgically.3
 CT is the imaging investigation of choice giving the most exquisite bony definition. Typical CT features (as shown in this case) are:
 
 A diffuse ground-glass appearance to the affected bone
 Homogeneously sclerotic bone
 Well-defined borders between the diseased and unaffected bone (abrupt zone of transition)
 Bony expansion, with overlying cortical bone intact
 
 The CT appearances apply equally to the anatomical site involved, however the combination of imaging appearances can be variable presenting a diagnostic dilemma, which may merit a confirmatory bone biopsy.

Objective The purpose of this study was to dissect these structure existed in petrous portions of the temporal bones and the posterior fossa nearby,to measure the distence of those important stuctures around the superior petrosal venous (SPV), to propose the patterns of drainage of the SPV along the petrous ridge in relation to the Meckel cave and internal acoustic meatus (IAM) and to delineate its effect on the surgical exposures obtained in subtemporal transtentorial and retrosigmoid suprameatal approaches. Methods Ten adult cadaveric heads (20 hemispheres) were studied, and data of SPV and the structures around were measured. The patterns of drainage of the SPV along the petrous ridge were characterized according to their relation to the Meckel cave and the IAM based on an examination of 20 hemispheres. Subtemporal trans-tentorial and retrosigmoid suprameatal approaches were performed in two additional cadavers to demonstrate the effect of the drainage pattern on the surgical exposures. Result The SPV originated from the cerebellopontine angle cistern, and were multibranch. According to SPV relationship with the Meckel cave and internal acoustic meatus (IAM), the patterns of drainage of the SPV were classified into three groups. Type Ⅰ emptied into the SPS above or medial to the Meckel cave. The most common type-Type Ⅱ, emptied between the lateral limit of the trigeminal nerve at the Meckel cave and the medial limit of the facial nerve at the IAM. Type Ⅲ emptied into the SPS above and lateral to the boundaries of the IAM Conclusions The site which the SPV emptied into the superior petrosal sinus (SPS) was relationship tightly with the Meckel cave and IAM. According to SPV relationship with the Meckel cave and internal acoustic meatus (IAM). The proposed modified classification system and its effect on the surgical exposure may aid in planning the approach directed along the petrous apex and may reduce the probability of venous complications. Key words: Superior petrosal vein; Superior petrosal sinus; Retrosigmoid approach; Subtemporal approach

Temporal bone fractures are traditionally classified as transverse, longitudinal or mixed. Since these categories have shown little association with clinical symptoms, new classifications have been introduced, including those related to the involvement of the petrous bone and otic capsule. We have formulated a new classification based on the involvement of four parts of the temporal bone (squama, tympanic, mastoid, and petrous) and assessed which of these classification systems is the most rational using a retrospective chart review in hospital settings (KyungHee Medical Center, Seoul, Korea and Samsung Changwon Hospital, Changwon, Korea). The association between each classification and clinical symptoms was examined by analyzing temporal bone computed tomography scans of 129 patients diagnosed as temporal bone fractures over the past 7 years. Using the traditional classification, there was a significant correlation between transverse fractures and the incidence of sensorineural hearing loss. Patients with petrous bone fractures had significantly higher incidence rates of sensorineural hearing loss, vertigo, and eardrum perforation than patients without petrous bone involvement. Involvement of the otic capsule was significantly associated with sensorineural hearing loss and the severity of hearing loss. The associations of the traditional classification and the classification according to the involvement of the otic capsule, four parts of temporal bone with clinical symptoms were not high. Petrous bone fractures were significantly associated with sensorineural hearing loss, vertigo, and eardrum perforation, suggesting that this classification may be optimally associated with clinical symptoms including hearing and the results of otological examination.