Petrous Bone Research Articles

A Rare Case of Intracerebral Pneumocephalus Caused by Preexisting Multiple Bone Defects and Encephalocele after Resection of Meningioma

Pneumocephalus is generally secondary to direct damage to the skull base. Spontaneous intracerebral pneumatocele without head injury was extremely rare, but previously reported as a serious complication of shunt procedures. We describe a 40-year-old man with intracerebral pneumocephalus who previously underwent craniotomy for large frontal convexity meningioma and lumbo-peritoneal shunting. He presented with gait disturbance 14 months after tumor resection. Computed tomography and magnetic resonance imaging showed intracerebral pneumocephalus in the right temporal lobe, which continued into the mastoid air cells through a bone defect of the right petrous bone. We performed urgent right temporal craniotomy to reduce the mass effect and to repair the fistula. Intraoperatively, bone defects were identified at the roof petrous bone, into which the encephalocele had penetrated. The herniated cerebral parenchyma was removed, and the pneumocephalus opened. The dura was closed with sutures and covered with fascia. To elucidate the underlying mechanism for the development of intracranial pneumocephalus, the previous images obtained before or immediately after resection of meningioma were reviewed. We founded that multiple preexisting bone defects and encephaloceles, one of which was considered to be the cause of the intracerebral pneumocephalus. This case demonstrates that intracerebral pneumocephalus can be caused by preexisting bone defect and encephalocele, and this finding may be useful for prediction of pneumocephalus after shunt procedures.

Role of mitochondrial dna analyses in provenancing unknown human skeletal remains: Probabilities and limitations

Ancient degraded remains of human origin can be identified using ancient DNA analyses. The mitochondrial DNA is a useful tool to solve unsolved cases in relation to identification of an individual where nuclear DNA is too degraded or insufficient to be used for the purpose. Comparative analysis of mtDNA content in petrous bone and the tooth-root cementum have revealed that later is best substrate for studying genomic analyses of ancient human populations The dental DNA is less prone to contamination, and the preservation of ancient DNA from dental samples is easier than bones. The selection of correct decontamination method, appropriate extraction protocol provides best results and thus increases value of bones and teeth as a forensic evidence in cases where identity establishment is problematic. In this review article, the current status of the methods used in ancient DNA research, the advantages and the limitations of this archaeogenetical method have been presented.

Meningiomas of the posterior petrous bone: surgical anatomy and postoperative results of 130 consecutive patients

Meningiomas of the posterior petrous bone: surgical anatomy and postoperative results of 130 consecutive patients

The inner morphology of the petrosal bone of the endemic elephant of Tilos Island, Greece

The inner morphology of the petrosal bone of the endemic elephant of Tilos Island, Greece

Analysis of temporal bone thickness outside of the petrous temporal bone between superior semicircular canal dehiscence and normal patients

BackgroundSSCD is a rare inner ear disorder. This study aims to compare the thickness of the temporal bone beyond the petrous portion between healthy subjects and those with SSCD to determine whether the etiopathology of SSCD is localized to the petrous temporal bone or generalized to other parts of the temporal bone. MethodsA retrospective chart review of electronic medical records from September 2011 to February 2018 was conducted at a single-institution study at the University of California, Los Angeles. Participants were divided into two groups: Group 1 had a confirmed diagnosis of SSCD, while Group 2 had no known ear or temporal bone pathology. Participants’ high-resolution coronal and axial temporal bone computed tomography scans were analyzed. Regions within the temporal bone were measured and compared between the two groups. ResultsA total of 262 scans were included. Group 1 consisted of 103 scans, while Group 2 consisted of 159 scans. There was no statistically significant difference in the thickness of temporal bones between patients diagnosed with SSCD and patients without otologic disease. ConclusionThe results suggest that the etiology of SSCD is limited to the petrous portion of the temporal bone. SSCD may be unrelated to a larger process of global temporal bone degeneration. Additional clinical screening for regions outside the petrous temporal bone is not warranted unless SSCD patients present with symptoms characteristic of other temporal bone pathologies.

Morphometric analysis of the petrous bone - A preliminary study of intra- and inter-observer variation of basic measurements.

Studies of cremated skeletal remains show that the petrous part of the temporal bone often survives the burning process due to its dense and robust structure. Because of its frequent occurrence and well preservation in skeletal material from archaeological and forensic context, it has repeatedly been investigated for patterns of sexual dimorphism and potential to estimate sex from skeletal remains. Although being a relatively small skeletal element, the posterior part of the petrous bone has several anatomical features that serve as characteristic landmarks for the application of metric studies. Furthermore, sex-specific differences have also been recognised for the dimensions of the medial and lateral angle of the Internal acoustic canal (IAC). However, the accuracy of estimating an individual's sex based on measurements of the petrous bone has met with varying degrees of success. The purpose of this study was to see how well certain variables were identified and measured, but also to recognise the reproducibility of the results. In an initial approach five variables were selected and measured on ten petrous bones from an archaeological context. In addition, a total of forty casts were prepared in order to measure the angular dimensions. It was found that the basic measurements of all variables show high variations, but in only one variable, measurements were very inconsistent as evidenced by the large intra- and inter-observer errors. In terms of the angle dimension the results show that the range of variation was higher for the lateral angle and that the intra-observer error was found to be much lower for the medial angle than for the lateral one. The results show potential in the use of these methods in terms of repeatability, but also indicate that the metric assessment is prone to false application caused by the morphological variations of the individual landmarks.

Classification criteria for primary diagnosis of chronic suppurative otitis media

The work aimed to analyze the available literature in the international and Russian databases to identify the classification criteria for determining the timing of the primary diagnosis of chronic suppurative otitis media. Materials and methods . A review of the literature on the diagnostic criteria of chronic suppurative otitis media, pathomorphological mechanisms of osteolysis, and factors predicting the chronicity were emphasized, as well as aggressiveness and recurrence of the inflammatory process of the mucous membrane of the middle ear cavity and bone tissue of the petrous pyramid. Based on the literature analyzed, the transition time from acute state to chronic mucous membrane inflammation of the middle ear cavity and persistent perforation formation of the tympanic membrane has not yet been documented, and therefore, the timing of the operation, as a favorable outcome for recovery, is delayed. Results . An analysis of the literature showed that to date, enough classifications, or rather, groups of chronic diseases of the middle ear and its consequences have been published, which indicates the imperfection of the classification criteria for diagnosing chronic suppurative otitis media. Severe pathological changes in the mucous membrane of the middle ear cavities, with purulent fusion, replacement with granulation tissue, and transition of inflammation to the underlying bone tissue with the development of irreversible morphological processes of the temporal bone structures by the type of osteonecrosis, osteoproliferation, and osteosclerosis, which determines the course of chronic purulent otitis media, its outcome, and the risk of complications. Conclusion . Through a combination of the results of literature reviews on the study of clinical experience data from international and Russian specialists, we present the definition of chronic suppurative otitis media as a chronic disease of the middle ear cavity with the formation of a persistent perforation or retraction pockets of the tympanic membrane for a period of 1 month after an episode of acute otitis media with radiographic-tomographic confirmation of latent otoantritis/mastoiditis. Consequently, the diagnosis established enables us to regulate the approach of managing a patient with chronic suppurative otitis media.

Surgical treatment of cholesteatomatous labyrinthine fistula by hydrodissection

Middle ear cholesteatoma is a destructive lesion that can potentially erode the bone. Cholesteatoma is a clinical diagnosis in the vast majority of cases. Patients must be systematically investigated for the presence of signs suggestive of complications, the most common of which is labyrinthine fistula. However, the clinical features of labyrinthine fistula are inconstant and the fistula sign may sometimes be negative. CT scan of the petrous temporal bone is performed systematically to specify the site and extension of the cholesteatoma, and to assess the extent of osteolysis that can result in exposure of the membranous labyrinth. Surgical treatment has three main objectives: complete resection of the cholesteatoma, which is the only way to avoid residual cholesteatoma, prevention of recurrence by an adapted, preferably one-step, technique, and restoration of good quality hearing. Hydrodissection of the cholesteatoma matrix in the presence of labyrinthine fistula is a simple technique that can achieve the three main general objectives of cholesteatoma surgery.

Association between superior semicircular canal dehiscence and other dehiscences in temporal bone.

The study of the association between superior semicircular canal and other dehiscences in the temporal bone. We have studied computed tomography of radiologically diagnosed people with superior or posterior semicircular canal dehiscences, in four health centres. In addition, we have studied one isolated human temporal bone, one skull and one cadaver head belonging to the collection of the Department of Human Anatomy and Histology of the University of Zaragoza that had dehiscence in the superior semicircular canal. The most frequent association that we observed was between superior semicircular canal dehiscence and tegmen tympani dehiscence (37.33%). Three cases (two clinical cases and one isolated temporal bone) showed multiple associated dehiscences (tegmen tympani, mastoid antrum, posterior semicircular canal, internal auditory canal, glenoid cavity, tympanum bone and geniculate ganglion) associated with superior semicircular canal dehiscence. When the superior semicircular canal dehiscence is associated to other in the petrous bone (tegmen tympani, mastoid antrum, posterior semicircular canal, internal auditory canal) could be grouped into the same syndrome called "otic capsule syndrome", since they have the same origin and common aetiology (otic capsule).

CS-09 Extra-parenchymal (Peripheral) Atypical Teratoid / Rhabdoid Tumors

AT/RT is a malignant embryonal tumor reported by Rorke in 1996. Authors reported first AT/RT in Japan in 1998. This tumor entity was included as new malignant embryonal tumor in WHO 2000, and tumors of Japanese patients has been reported more than 80 cases in the past. This AT/RT is a tumor in the brain parenchyma that a medulloblastoma and PNET and the possibility that it has been misdiagnosed have had pointed out. On the other hand, it is reported that there is the type that we should call peripheral AT/RT which rarely occurs in extra-parenchyma. We want to propose that there is such special tumor group. In the results, age: 17 infants were main (2nd - 14 years old after birth). tumor location: 22 sellar or parasellar regions, 8 CP angles, 7 oculomoter nerves, and 3 petrous bone, treatment: duration of survival significantly improved all macroscopic tumor resection by the operation, but, in small pontine part AT/RT, an outcome tended to be poor. On the other hand, in AT/RT which occurred in the sellar region, all cases adult woman tended to have good prognosis. It is necessary for AT/RT (central AT/RT) in the brain to recognize that there is extra-parenchymal AT/RT (peripheral AT/RT) tumor which we reported this time which came to be recognized widely.

Jugular Foramen's Paraganglioma in a Patient with Von Hippel-Lindau Disease: Case Report

AbstractGlomus jugular tumors, also known as paragangliomas (PGLs), are rare and related to several clinical syndromes described. These are located in the carotid body, the jugular glomus, the tympanic glomus and the vagal glomus. The symptoms are directly related to the site of involvement and infiltration. These lesions have slow growth, are generally benign and hypervascularized, have a peak incidence between the age of 30 to 50 years old; however, when associated with hereditary syndromes, they tend to occur a decade earlier. Several familial hereditary syndromes are associated with PGLs, including Von Hippel-Lindau disease (VHL) in < 10% of the cases. The diagnosis and staging of PGLs are based on imaging and functional exams (bone window computed tomography [CT] with a “ground moth” pattern and magnetic resonance imaging (MRI) with a “salt and pepper” pattern). The cerebral angiography is a prerequisite in patients with extremely vascularized lesions, whose preoperative embolization is necessary. The histopathological finding of cell clusters called “Zellballen” is a characteristic of PGLs. Regarding the jugular foramen, the combination of two or three surgical approaches may be necessary: (1) lateral group, approaches through the mastoid; (2) posterior group, through the retrosigmoid access and its variants; and (3) anterior group, centered on the tympanic and petrous bone. In the present paper, we report a case of PGL of the jugular foramen operated on a young female patient who underwent a surgery with a diagnosis of Von Hippel-Lindau Disease (VHL) at the Neurosurgery Service of the Hospital Heliópolis, São Paulo, state of São Paulo, Brazil in 2018, by the lateral and posterior combined route.

Fatal trauma in a mummified shrew: Micro-CT examination of a little ancient Egyptian bundle

Micro-computed tomography examination was used to identify the content of a little ancient Egyptian mummy bundle and to analyze pathologies and the cause of death. The bundle contained a complete shrew with preservation of the skeleton and soft tissues. The species of the adolescent shrew was classified as Crocidura religiosa. The skull revealed bilateral impression fractures of the skullcap indicating probably one hit on each side. The skull base was fractured and the left petrous bone broke out. The alignment of the spine was interrupted between the first and second thoracic vertebra resulting in a complete obstruction of the spinal canal and disconnection of the preserved spinal cord. The adjacent dorsal soft tissues of the shrew were markedly thickened and contained an irregularly bordered area that was filled with air. This finding was suggested to represent the residual cavity after haemorrhage that was replaced by air during the desiccation within the mummification process. This fatal spinal trauma was most probably caused by a mousetrap. After death, the shrew’s body must have been effectively desiccated before wrapping with multiple textile layers. The procedure of capturing and killing of a shrew prior to the production of a votive mummy as described in this study represents a tessera in the knowledge of ritual practices within the ancient Egyptian animal cult.

A Rare Case of Endolymphatic Sac Tumour: Clinical, Radiological, Pathological and Immunohistochemical Findings with Review of Literature.

Endolymphatic sac tumour (ELST) is a rare low grade malignant epithelial tumour of the petrous temporal bone, thought to arise from papillary epithelium of the endolymphatic sac. They may occur sporadically or in association with Von-Hippel Lindau disease. ELST is extremely rare neoplasm with benign histopathological appearance and clinically destructive behaviour. Because of the rarity of this tumour, it can easily be confused with other tumours such as paraganglioma, middle ear adenoma, metastatic carcinomas or choroid plexus papilloma. We report here a rare case of ELST with review of literature and discuss the differentiating features of ELST from its mimickers, showing a papillary configuration.

Modified classification of infralabyrinthie cholesteatoma and scale of cholesteatoma extention

Introduction. Petrous temporal bone (PTB) cholesteatoma is an epidermal cyst, which is the result of uncontrolled growth of keratinizing squamous epithelium in the petrous part of the temporal bone. Cholesteatoma is classified into congenital, acquired, and iatrogenic.Objective. To discuss the classification of infralabyrinthine petrous bone cholesteatoma (PBC), add modified classificationand to propose adequate differential surgical management.Methods. The setting was a National Medical Scientific Center of Otorhinolaryngology FMBA (Russia). The data of 14 patients who underwent surgery for different variations of infralabyrinthine PBC from 2017 till 2020 were analyzed and included into the study (with respect to localization type of the approach used, complications, recurrences and outcome). The follow-up period ranged from 6 to 34 months with a median of 18 months.Results. Based on preoperative CT scans and intraoperative findings a Scale of Cholesteatoma extension CLIF(APO) and Modified classification of infralabyrinthine cholesteatoma (in relation to mastoid segment of the facial nerve) are proposed. The scale includes the main anatomical structures of the temporal bone and the adjacent parts of the occipital and sphenoid bones, which may be involved in the cholesteatoma process: cochlea, vestibule and semicircular canals, internal auditory canal, jugular foramen, bony chanal of the internal carotid artery, petrous apex, occipital condyle. Based on the modified classification and scale we present an algorithm for decision making and surgical approach choosing.Conclusion. The implementation of the Scale of Cholesteatoma Extension in Otology and Radiology practice will allow to preoperatively diagnose the extension of PBC, unify the data of the localization of cholesteatoma; allows standardization in reporting and continuity at all stages of treatment. The modified classification proposed by us in this article facilitate the algorithm for selecting the type of surgical approach and determine whether to perform less aggressive combined microscopic approaches with endoscopic control.

Infralabyrinthine petrous bone cholesteatoma (literature review)

A literature review on the infralabyrinthine petrous bone cholesteatoma (PBC) was presented in this article. Attention is paid to etiology and clinical symptoms of the disease, classifications. All modern classifications divide cholesteatoma with localization under the labyrinth into two big groups: infralabyrinthine and infralabyrinthine apical. This is not enough to determine the algorithm of surgical tactic of these patients. The most used approaches to the infrlabyrinyhine area and lateral skull base were analyzed (infralabyrinthine and infracochlear, subtotal petrosectomy, transotic approach, group of transcochlear approaches, infratemporal and translabyrinthine approaches). Possible variants of the surgery ending are described (tympanoplasty or “cul-de-sac” closure). Comparison of the results of different authors, starting from 1990, in which the infralabyrinthine cholesteatoma was distinguished as a separate class was carried out. 16 publications were analyzed based on the type of used classification, the total number of cases with infralabyrinthine cholesteatoma, the type of surgical approach, the complications and recurrence rate. The total number of patients was 141, 84 with infralabyrinthine (59,6%), 57 (40,4%) with infralabyrinthine apical PBC. The most common type of surgery were subtotal petrosectomy, transcochlear approach in different variations and transotic approach. The recurrence rate ranged from 0 to 29%. This paper identifies unresolved issues, the necessity of new classification and algorithm of surgical management based on it.

A systematic investigation of human DNA preservation in medieval skeletons

Ancient DNA (aDNA) analyses necessitate the destructive sampling of archaeological material. Currently, the cochlea, part of the osseous inner ear located inside the petrous pyramid, is the most sought after skeletal element for molecular analyses of ancient humans as it has been shown to yield high amounts of endogenous DNA. However, destructive sampling of the petrous pyramid may not always be possible, particularly in cases where preservation of skeletal morphology is of top priority. To investigate alternatives, we present a survey of human aDNA preservation for each of ten skeletal elements in a skeletal collection from Medieval Germany. Through comparison of human DNA content and quality we confirm best performance of the petrous pyramid and identify seven additional sampling locations across four skeletal elements that yield adequate aDNA for most applications in human palaeogenetics. Our study provides a better perspective on DNA preservation across the human skeleton and takes a further step toward the more responsible use of ancient materials in human aDNA studies.

Human DNA extraction from highly degraded skeletal remains: How to find a suitable method?

Retrieving DNA from highly degraded human skeletal remains is still a challenge due to low concentration and fragmentation, which makes it difficult to extract and purify. Recent works showed that silica-based methods allow better DNA recovery and this fact may be attributed to the type of bones and the quality of the preserved tissue. However, more systematic studies are needed to evaluate the efficiency of the different silica-based extraction methods considering the type of bones. The main goal of the present study is to establish the best extraction method and the type of bone that can maximize the recovery of PCR-amplifiable DNA and the subsequent retrieval of mitochondrial and nuclear genetic information. Five individuals were selected from an archaeological site located in Catalonia-Spain dating from 5th to 11th centuries AD. For each individual, five samples from different skeletal regions were collected: petrous bone, pulp cavity and cementum of tooth, and rib and limb bones. Four extraction methods were tested, three silica-based (silica in-suspension, HE column and XS plasma column) and the classical method based on phenol-chloroform. Silica in-suspension method from petrous bone and pulp cavity showed the best results. However, the remains preservation will ultimately be the key to the molecular result success.

Value of the Petromeatal Angle in Predicting Outcome of Translabyrinthine Resection of Vestibular Schwannomas.

Factors associated with extent of tumor resection (EOR) and facial nerve outcomes include tumor size, anterior extension of the tumor, patient age, and surgical approach. To check whether preoperative measurement of the petromeatal (PMA), petroclival (PCA), and petrous-petrous (PPA) angles can help in predicting EOR, facial nerve outcome, and cerebrospinal fluid (CSF) leak occurrence in patients undergoing vestibular schwannoma (VS) surgery via the translabyrinthine approach (TLA). A total of 75 patients were included in this retrospective study. Preoperative magnetic resonance imaging constructive interface in steady state and postcontrast T1-weighted sequences through the internal acoustic meatus were used to measure the PMA, PCA, and PPA. There was a statistically significant association between tumor size and EOR; every additional cm in tumor size decreases the odds of gross-total (GTR)/near-total (NTR) resection by 524% (P=.0000355).After controlling for tumor size, the logistic models revealed a significant effect of the angles on EOR. For example, in a patient with a 2-cm VS, every additional degree in PMA, PCA, and PPA increases the odds of GTR/NTR by 2.3% (P=.0000571), 4.05% (P=.0000397), and 0.37% (P=.0000438), respectively.After adjusting for tumor size, sex, and age, the effect of PMA on the occurrence of an immediate postoperative facial nerve deficit and CSF leak indicated a trend towards significance (P=.0581 and P=.0568, respectively). More obtuse petrous bone angles, namely PMA, PCA, and PPA, are good predictors of GTR or NTR in patients undergoing VS surgery via TLA and may be associated with better facial nerve outcomes and lower CSF leak occurrences.

How I do it: retrosigmoid intradural inframeatal petrosectomy

BackgroundLesions infiltrating the petrous temporal bone are some of the most complex to treat surgically. Many approaches have been developed in order to address these lesions, including endoscopic endonasal, anterior petrosectomy, posterior petrosectomy, and retrosigmoid.MethodWe describe in a stepwise fashion the surgical steps of the retrosigmoid intradural inframeatal petrosectomy.ConclusionThe retrosigmoid intradural inframeatal petrosectomy may afford satisfactory exposure with limited drilling and minimal disruption of perilesional anatomical structures. It can provide excellent surgical results, especially for soft tumors, while minimizing surgical morbidity.

Imaging of facial neuritis using T2-weighted gradient-echo fast imaging employing steady-state acquisition after gadolinium injection.

MRI is the modality of choice for the imaging of facial neuritis. Previously, gadolinium-enhanced T1-weighted imaging of the petrous bone, then FLAIR sequences were thought to be most informative for acute facial neuritis imaging. The aim of this study is to evaluate the value of contrast-enhanced T2-weighted sequence for the diagnosis of acute facial neuritis and compare it to contrast-enhanced T1-weighted and FLAIR sequences. We included 50 patients with an acute unilateral idiopathic peripheral facial neuritis. An MRI (3T) with three sequences was performed (T1-weighted, T2-weighted and FLAIR), all acquired after intravenous contrast-media injection. The contrast-enhanced T2-weighted sequence appeared to be the most accurate one for the diagnosis of acute facial neuritis (Se 94%, Sp 100%, accuracy 98.2%, p < 0.001), with a pathological facial nerve strongly (grade 2-3) enhancing and a homogenous enhancement along the course of the entire facial nerve. Contrast-enhanced T1-weighted (Se 80%, Sp 100%, accuracy 94.1%) and FLAIR sequences (92%, Sp 88%, accuracy 90%, p < 0.001) showed lower accuracy. On T1-weighted sequence, a strong enhancement (blurred margins) of the canalicular segment was observed in 80% of the cases when it was never observed in normal nerves. A strong (= iso to hyperintense to the petrous fat signal) and diffuse (all segments) enhancement of the facial nerve on T2-weighted steady-state free precession sequence is a sensitive and specific sign for the diagnosis of acute idiopathic facial neuritis, and appears superior to T1WI and FLAIR sequences.