Posterior Cranial Fossa Research Articles

PMON330 The Relationship between Pituitary Volume and Chiari Malformation in Growth Hormone Deficiency and Idiopathic Short Stature

Abstract Patients with a small posterior cranial fossa may present with cerebellar tonsillar herniation through the foramen magnum, known as Chiari malformation (CM). The relationship between CM, pituitary volume (PV), and growth hormone deficiency (GHD) has not yet been explored and is the subject of this abstract. This study seeks to compare the differences in PV in short patients with CM with a diagnosis of either GHD or idiopathic short stature (ISS), to normal controls (NCs). The database of a Peds Endo Center between 2013-21 was queried for patients with CM and who had undergone MRI evaluation. Patients were separated into 4 groups: CM and GHD, CM and ISS, GHD without CM, and ISS without CM. These groups’ PV results were compared with NCs who we previously reported. The ages of short patients with CM (n=29) were compared to the ages of NCs (n=170); no significant difference was found (p = 0.12). The MN and MD PV for patients with GHD alone were 230.8 ± 89.64 and 217.62mm3, respectively. The MN and MD PV for patients with GHD and CM (n=23) were 246.55 ± 128.0 and 200.5mm3, respectively. The MN and MD PV for CM and ISS (n=6) were 671.54 ± 350.25 and 619.55mm3, respectively. The MN and MD PV for NCs were 364.0 ± 145.2 and 346.0mm3, respectively. The PV of patients with GHD alone were compared to the PV of patients with both GHD and CM; there was no significant difference found (p=1.0). Next, the PV of patients with GHD alone were compared to the PV of patients with both ISS and CM which showed that patients with GHD alone had significantly smaller PV compared to patients with both ISS and CM (p<0.05). Lastly, we compared the PV of patients with both GHD and CM versus patients with both ISS and CM, which showed that patients with both GHD and CM had significantly smaller PVs compared to patients with both ISS and CM (p<0.05). The PV of short patients with CM (n=29) were compared to the PV of NCs (n=170) and there was no significant difference found (p = 0.58). Our study demonstrates that PV is smaller in patients with GHD regardless of whether they have CM or not. We speculate that CM appears to be a radiological finding with no significant impact on PV, whereas GHD appears to have a significant impact on PV. Therefore we speculate the small PV exhibited in patients with CM and GHD appear to be related to GHD. A larger sample size will be needed to further elaborate on this concept. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.

Indications and outcomes of endoscopic transorbital surgery for trigeminal schwannoma based on tumor classification: a multicenter study with 50 cases.

Trigeminal schwannoma is a rare CNS tumor and involves the multicompartmental skull base. Recently, the endoscopic transorbital approach (ETOA) has emerged as a technique for minimally invasive surgery. The objective of this study was to evaluate the optimal indications and clinical outcomes of the ETOA for trigeminal schwannomas based on their tumor classification. Between September 2016 and February 2022, the ETOA was performed in 50 patients with trigeminal schwannoma at four tertiary hospitals. There were 15 men and 35 women in the study, with a mean age of 46.9 years. All tumors were classified as type A (predominantly involving the middle cranial fossa), type B (predominantly involving the posterior cranial fossa), type C (dumbbell-shaped tumors involving the middle and posterior fossa), or type D (involvement of the extracranial compartment). Type D tumors were also subclassified by ophthalmic division (D1), maxillary division (D2), and mandibular division (D3). Clinical outcome was analyzed, including extent of resection and surgical morbidities. In this study, overall gross-total resection (GTR) was performed in 35 (70.0%) of 50 patients and near-total resection (NTR) in 9 patients (18.0%). The mean follow-up period was 21.9 (range 1-61.7) months. There was no tumor regrowth or recurrence during the follow-up period. Based on the classification, there were 17 type A tumors, 20 type C, and 13 type D. There were no type B tumors. Of the 13 type D tumors, 7 were D1, 1 D2, and 5 D3. For type A tumors, GTR or NTR was achieved using an ETOA in 16 (94.1%) of 17 patients. Eighteen (90.0%) of 20 patients with type C tumors attained GTR or NTR. Ten (76.9%) of 13 patients with type D tumors underwent GTR. Statistical analysis showed that there was no significant difference in the extent of resection among the tumor subtypes. Surgical complications included transient partial ptosis (n = 4), permanent ptosis (n = 1), transient diplopia (n = 7), permanent diplopia (n = 1), corneal keratopathy (n = 7), difficulties in mastication (n = 5), and neuralgic pain or paresthesia (n = 14). There were no postoperative CSF leaks or enophthalmos during follow-up. This study showed that trigeminal schwannomas can be effectively treated with a minimally invasive ETOA in all tumor types, except those predominantly involving the posterior fossa (type B). For the extracranial compartments, D2 or D3 tumor types often require an ETOA combined with the endoscopic endonasal approach, while D1 tumor types can be treated using an ETOA alone.

Effect of Bone-Borne Trans -Sutural Distraction Osteogenesis Therapy on the Cranial Base of Children With Midfacial Hypoplasia Due to Cleft Lip and Palate.

Bone-borne trans -sutural distraction osteogenesis (TSDO) is widely used to treat midfacial hypoplasia in children with cleft lip and palate; however, its effects on the cranial base are still poorly understood. The authors aimed to study morphological changes in the cranial base after TSDO. Pre and postoperative computed tomography (CT) images of cleft lip and palate children with midfacial skeleton dysplasia who underwent TSDO were collected retrospectively, and their corresponding 3-dimensional models were measured. Results showed no significant change in the length of the anterior or posterior cranial fossa, but the length of the middle cranial fossa increased significantly. The anterior cranial base rotated upward with the sella turcica at the center, whereas the cranial base angle increased. The sphenoid bone exhibited morphological changes. Post-TSDO, the lateral plate of the pterygoid process increased in length. The angle of the 2 lateral plates of the pterygoid process, the greater wings of the sphenoid bone, and the smaller wings of the sphenoid bone decreased. Posterior inclination of the pterygoid process increased. Mean volume of the sphenoidal sinus increased postoperatively compared with the preoperative volume. Apparent changes in the cranial base after TSDO are primarily in the middle cranial fossa, manifesting as an increase in the sphenoid bone body length, expansion of the sphenoidal sinus volume, growth of the pterygoid process forward and downward, a decrease in the angle of both the greater and smaller wings of the sphenoid bone, and an increase in the posterior inclination of the pterygoid process.

Anatomical Aspects and Clinical Application of a Unilateral Uvulotonsillar Approach via a Minimally Invasive Open-Door Suboccipital Craniotomy to Remove Lesions of the Fourth Ventricle and Dorsal Brainstem

Today, a median suboccipital craniotomy with access to the cavity of the fourth ventricle through the foramen of Magendie is widely used to remove neoplasms of the fourth ventricle and brainstem. However, according to modern literature, the median approach to the posterior cranial fossa is associated with a high risk of CSF leakage and pseudomeningocele. We propose a modified unilateral uvulotonsillar approach via a median suboccipital open-door craniotomy, which can potentially reduce the incidence of CSF leakage and preserve the ligamentous apparatus of the craniovertebral junction. Herein, we describe the implementation of this approach on cadaveric material and provide a clinical case. The material used for the study was 3 cadavers and 1 clinical case. Step-by-step dissection imitating the described approach was carried out. During the dissection, surgical landmarks were identified at the macro- and microstages, which should be considered when performing the proposed approach. A detailed description of the technique for performing open-door craniotomy, the features of the incision in the dura mater, unilateral dissection of the uvulotonsillar fissure, and the structures of the cavity of the fourth ventricle that could be visualized through this approach were described. This approach allows preservation of the normal anatomy of the craniovertebral junction and stable fixation of the bone flap. Unilateral dissection of the uvulotonsillar fissure provides adequate visualization of almost all parts of the rhomboid fossa, and the convenience of suturing the minimal arcuate incision in the dura mater potentially reduces the risk of CSF leakage.

Radiological and Morphometric Study of the Emissary Foramens and Canal in the Posterior Cranial Fossa of the Human Skull with Its Neurosurgical Significance.

Objective The posterior condylar canals (PCCs), posterior condylar veins (PCVs), occipital foramen (OF), and occipital emissary vein (OEV) are potential anatomical landmarks for surgical approaches through the lateral foramen magnum. We performed the study to make morphometric and radiological analyses of the various emissary foramens and vein in the posterior cranial fossa. Methods Morphometric study were performed on 95 dry occipital bones and radiological analyses on computed tomography (CT) angiography images of 150 patients. The number of OFs on both sides was recorded and PCC length and mean diameters of the internal and external orifices of PCC were measured for bony specimens. Prevalence of PCV and PCV size was investigated using CT angiography. Results Mean PCC length was higher in the left side (9.85 ± 2.5). Mean diameter of the internal orifice and the external orifice diameter were almost the same. The majority of PCCs (75-79.33%) had 2 to 5 mm diameter; only 4 to 9.2% were small in size (< 2 mm). In CT angiography, PCV was not identified in 23 (15.33%) patients. PCVs were located bilaterally in 105 (70%) and unilaterally in 22 (20.5%) patients. Only 11.3% of PCVs were large in size (> 5 mm), 80% of PCVs were medium sized (2-5 mm), and 8.6% were small sized (< 2 mm). Conclusion Normal values of OF, PCC, PCV, and OEV could serve as a future reference for the understanding of the physiology of craniocervical venous drainage, which is necessary to avoid surgical complications and can also serve as a guide to surgical interventions for pathologies of the posterior cranial fossa, such as tumors and injuries.

Superior eyelid endoscopic transorbital approach to the tentorial area: A qualitative and quantitative anatomic study.

Superior eyelid endoscopic transorbital approach (SETOA) is nowadays gaining progressive application in neurosurgical scenarios. Both anatomic and clinical reports have demonstrated the possibility of taking advantage of the orbital corridor as a minimally invasive route to reach anterior and middle cranial fossae and manage selected surgical lesions developing in these areas. The aim of this paper is to further shed light on other anatomic regions of the skull base as seen from a transorbital perspective, namely, the posterior cranial fossa and tentorial area, describing technical feasibility and steps in reaching this area through an extradural-transtentorial approach and providing quantitative evaluations of the "working area" obtained through this route. Four cadaveric heads (eight sides) were dissected at the Laboratory of Surgical Neuroanatomy (LSNA) of the University of Barcelona, Spain. A stepwise dissection of the transorbital approach to the tentorial area was described. Qualitative anatomical descriptions and quantitative analyses of working were evaluated by using pre- and postdissections CT and MRI scans, and three-dimensional reconstructions were made using Amira software. With the endoscopic transorbital approach, posterior cranial fossa dura was reached by an extradural middle cranial fossa approach and drilling of the petrous apex. After clipping the superior petrosal sinus, the tentorium was divided and cut. An endoscope was then introduced in the posterior cranial fossa at the level of the tentorial incisura. Qualitative analysis provided a description of the tentorial and petrosal surfaces of the cerebellum, middle tentorial incisura, cerebellopontine fissures, and, after arachnoid dissection, by a 30° endoscopic visualization, the posterior aspect of the cerebellomesencephalic fissure. Quantitative analysis of the "working area" obtained after bone removal was also provided. This anatomic qualitative and quantitative study sheds light on the anatomy of the posterior cranial fossa contents, such as the tentorial area and incisura, as seen through a transorbital perspective. The first aim of the article is to enrich the anatomical knowledge as seen through this relatively new corridor and to provide quantitative details and insights into the technical feasibility of reaching these regions in a surgical scenario.

A patient with mosaic USP9X gene variant

The finding of USP9X variants in females has been associated with female-restricted X-linked mental retardation (MRXS99F), a rare syndrome featured by developmental delay and distinct congenital anomalies. Here, we report a female fetus with MRXS99F due to a novel frameshift variant, c.6679_6685delAAATTATinsTCCTG (p.Lys2227SerfsTer2) in USP9X, which was present in a mosaic state in the amniocytes and in the peripheral blood after birth (14% and 30%, respectively). The X methylation status analysis displayed a partially skewed X-inactivation with 80% of inactive paternal X. The first signs of the MRXS99F were prenatally detected at 20 weeks, with an enlarged posterior cranial fossa, an upward rotation of the cerebellar vermis and partial corpus callosum agenesis, together with a cardiac septal defect and a single umbilical artery. After birth and during postnatal follow-up the anal anteriorization and the presence of a bilateral membranous choanal atresia were noted, whereas the MRI revealed the hypo/aplasia of the olfactory bulbs, a widening of the subarachnoid spaces and a delay in the myelinisation. During the 18-months follow-up a severe growth and global developmental delay, together with a bilateral moderate deafness with a threshold at 40 dB, dental enamel erosions and an initial scoliosis were observed. We report the prenatal and postnatal features of a classical MRXS99F phenotype and a mosaic USP9X frameshift variant with a partially skewed X inactivation and discuss genotype/phenotype correlations in view of the published studies so far.

Cough, Cough-Induced, and Primary Cough Headache

Dear Editor, We read the article entitled “Magnetic Resonance Imaging of Leptomeningeal Cyst with Atypical Presentation: Cough-Induced Headache” on the esteemed “Matrix Science Medica” with great interest. Dar et al. presented two adult patients with posttraumatic leptomeningeal cysts presenting as cough-induced headache. The headache worsened on forceful coughing in both individuals. In this context, the presence of growing skull fractures with headache and cough highlights the possible association between this type of headache and cerebrospinal fluid dynamic.[1] Headache associated with coughing is characterized by headaches triggered by a rapid increase in intra-abdominal pressure caused by coughing, sneezing, or straining. It is an uncommon finding with a lifetime prevalence of <1%. Interestingly, the syndrome of cough headache is symptomatic in about 40% of cases, and the majority of these patients have Arnold–Chiari malformation Type I.[2] Herein, we would like to discuss recent studies about this rare condition. Four main mechanisms could explain headaches triggered by cough, which are jugular vein stenosis, cerebrospinal fluid hypervolemia, infection altering vascular tone, and crowdedness of the posterior cranial fossa [Figure 1]. We believe that these mechanisms combined lead to the development of headaches, instead of being separated pathways.Figure 1: Pathophysiological mechanisms related to headache associated with cough. There are four main pathways that are jugular vein stenosis, cerebrospinal fluid hypervolemia, infection alters vascular tone, and crowdedness of posterior cranial fossa. The third version of the diagnostic criteria for primary cough headache of the international classification of headache disordersTakizawa et al. reported a case of an individual presenting with both primary cough headache and headache attributed to temporomandibular disorder. Their report was interesting because headaches associated with referred pain exhibit secondary central nervous system effects that can easily confound clinicians. It is worthy of mentioning that involuntary nonfunctional tooth contact is believed to be an important cause of both types of headaches.[2] Primary cough headaches are mainly observed in adult patients, but cough-induced headaches are potentially symptomatic in the pediatric population. Omata et al. described a 7-year-old boy presenting with powerful cough-induced headaches. Echo examination confirmed right internal jugular vein dilatation during a Valsalva maneuver, and the individual was diagnosed with primary cough headache with internal jugular phlebectasia. Their report brings a new idea about the pathophysiology of this type of headache, which may be associated with the morphology and function of the internal jugular vein.[3] Moreno-Ajona et al. reported a 53-year-old male diagnosed with primary cough headache using indomethacin, which was stopped due to gastroesophageal reflux disease. He was started on noninvasive vagal nerve stimulation (nVNS) using the gammaCore™ device. The individual showed improvement in his symptoms with nVNS, in particular, the parasympathetic reflex arc. This approach has advantages when compared to indomethacin such as good tolerability and safety of neuromodulation.[4] In a recent Chinese respiratory clinic, it was assessed the prevalence, predictive factors, and clinical characteristics of cough headache in 679 patients. The prevalence of cough headache was 18.0% in these coughing patients. The main risk factor for the development of cough headache was age between 31 and 50 years (odds ratio 2.0). Furthermore, cough headache was associated with cough severity. It is noteworthy that headache severity had a positive correlation with cough severity, age, and headache duration.[5] In sum, primary cough headaches are related to a mixture of pathological mechanisms. They are probably more common than we first believed. Moreover, when present in the pediatric population, further evaluation is needed. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initial s will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Morphometric measurements of posterior cranial fossa and craniovertebral junction in Chiari I malformation with and without Syringohydromyelia

Morphometric measurements of posterior cranial fossa and craniovertebral junction in Chiari I malformation with and without Syringohydromyelia

Morphometric Analysis of Posterior Fossa and Foramen Magnum among Pediatric Age Group 6 to 16 Years

Background Configuration and size of the foramen magnum and posterior cranial fossa plays an important role in the pathophysiology of various disorders like Chiari malformations, basilar invagination etc. Thus, a fundamental knowledge of normal anatomy of this region is important to the clinician for diagnosis and treatment. However, we couldn’t find any anatomical study related to the concerned topic among the pediatric population aged 6 to 16 years in Nepal to the best of our knowledge.&#x0D; Objective To attain the baseline results (volume of bony part of posterior cranial fossa and the surface area of foramen magnum) that will help in the better diagnosis, classification, and treatment of diseases related to posterior fossa and craniovertebral junction and serve as a future reference defining an anatomic range in our region.&#x0D; Method This is a retrospective prospective observational study conducted from 1st February 2021 to 31st January 2022 at Dhulikhel Hospital, Kathmandu University Hospital, Kavrepalanchowk, Nepal. We used convenient sampling technique to fulfil our sample size. We considered 68 patients, who got recruited either from our emergency and OPD departments and were fulfilling our criteria of inclusion. Upon the recruitment, 68 consecutive head CT scan of pediatric patients with normal reports (without any bony or soft-tissue abnormality) were studied. Volume of the posterior fossa was calculated with the help of inbuilt “advanced work station - 3D volume calculator” program in 128 slices - SOMATOM PERSPECTIVE CT Scanner from Siemens, Germany. The area of the foramen magnum was calculated using formula πr2, where r is average radius calculated from obtained antero-posterior and transverse diameter.&#x0D; Result The age of the patients ranged between 6 and 16 years with the mean age of 10.56 ± 3.38 years with male to female distribution of 1: 1.125. The mean volume of the posterior fossa was 165.61 ± 8.52 mm3. The mean AP diameter, transverse diameter, and the surface area of foramen magnum were 3.31 ± 0.12 mm, 2.72 ± 0.12 mm, and 28.60 ± 0.09 mm2 respectively.&#x0D; Conclusion Normal ranges of volume of posterior cranial fossa and various dimensions and surface area of foramen magnum of pediatric population were determined using CT scans, which could serve as future reference in Nepal.

Endoscopic Fenestration of Posterior Fossa Arachnoid Cysts

Introduction: Posterior Fossa arachnoid cysts (PFAC) are rare lesions in the childhood. Owing to the wide variety of cystic malformations within the posterior cranial fossa, PFAC have long attracted the attention of pediatric neurosurgeons because they can produce not only neurological symptons but also behaviro and learning deficts, in addition to presenting major surgical challenges. Surgical treatment is warranted in symptomatic patients. Nowadays, neuroendoscopic techniques have established themselves as the treatment of choice of these lesions.&#x0D; Patients and Methods: We present four cases of symptomatic PFAC which were treated using endoscopic neurosurgery. Endoscopic approaches were defined by the presence of hydrocephalus, and discussed in each case.&#x0D; Results : Two cases of quadrigeminal plate cysts, predominantly occupying the infratentorial compartment , one case of supracerebellar cyst and one case of cerebellopontine angle were treated with good results. However, one case of quadrigeminal plate cyst developed a communicating hydrocephalus, requiring placement of cyst-ventricle peritoneal shunt, guided by the neuroendoscope.&#x0D; Discussion and Conclusion : A literature review was performed. The clinical features, the advantages and disadvantages of several surgical treatments are discussed. Symptomatic PFAC should be treated. The relatively good results using endoscopic fenestration buttresses our use as a first-line surgery.

Endolymphatic duct and sac decompression: A new technique for Ménière's disease treatment.

The present article aims to introduce the endolymphatic duct and sac decompression technique (DASD) and to give a spotlight on its benefits in Ménière's disease (MD) treatment. Eighty-two patients with intractable MD which met the inclusion criteria were recruited and underwent DASD. This technique allows a meningeal decompression of the duct and the sac from the posterior cranial fossa to the labyrinthine block. The authors considered as main outcomes, the change of the dizziness handicap inventory (DHI) results, with the evaluations of the three sub-scales (Functional scale, Physical scale, and Emotional scale); ear fullness and tinnitus change on the perceptions of the patient; and hearing stage with four-Pure Tone Average (500 hz-1000 hz-2000 hz-4000 hz). The differences between the preoperative and the postoperative score were evaluated. A comparison with the literature was conducted. After a 14-month follow-up, patients that underwent DASD reported a remarkable improvement of the symptoms in all three functional scales, confirmed by the total DHI. The difference between preoperative and postoperative scores is statistically significant. The data describe an ear fullness and tinnitus improvement. The multi-frequency tonal average before and after the surgery does not suggest a worsening of the value for any of 82 patients. The modification of sac surgery includes the endolymphatic duct in the decompression area allowing inner ear functional improvement, vertigo control, ear fullness improvement with minimal risk of facial nerve paralysis, and hearing loss. DASD is an improved old surgical technique.

Craniofacial morphology in adults with osteogenesis imperfecta-A cross-sectional study.

The aim of this study was to compare the craniofacial and neurocranial morphology of adults with osteogenesis imperfecta (OI) with controls and to elucidate whether osseous origin impacts on morphological deviations in OI. Fifty-four adults (mean age 45.8) with OI type I, 14 adults (mean age 42.6) with OI types III/IV and 49 adult controls (mean age 41.0) were included. All participants had European ethnicity. Cranial morphology was assessed by 2D-cephalometry. Comparison between groups was made by multiple regression analyses. Comparison between OI groups and controls: (1) Dimension of the maxilla and mandible, respectively was reduced (P < .01), and in relation to the posterior cranial base, the maxilla was retro-positioned (P < .001), and the mandible was prognathic (P < .001). (2) The anterior face height was reduced (P < .04), and in OI types III/IV only, the maxilla was posteriorly inclined (P < .001). (3) Anterior cranial base (P < .001) and the dimension sella-frontale (P < .02) were short. (4) The sagittal dimension of the posterior cranial fossa was increased (P < .01), and the vertical dimension was reduced (P < .01). Adults with OI had a hypoplastic, retro-positioned and posteriorly inclined maxilla, a hypoplastic and forward-positioned mandible, and a reduced anterior face height. Deviations were seen in morphology of the posterior cranial fossa. The impact of OI on cranial morphology was generally more evident in OI type III/IV than in OI type I. OI impacts on osseous cranial structures irrespective of bony origin being intramembranous or endochondral.

Surgical Management of Chiari Malformation Type I and Instability of the Craniocervical Junction Based on Its Pathogenesis and Classification.

We investigated the mechanism underlying Chiari malformation type I (CM-I) and classified it according to the morphometric analyses of posterior cranial fossa (PCF) and craniocervical junction (CCJ). Three independent subtypes of CM-I were confirmed (CM-I types A, B, and C) for 484 cases and 150 normal volunteers by multiple analyses. CM-I type A had normal volume of PCF (VPCF) and occipital bone size. Type B had normal VPCF and small volume of the area surrounding the foramen magnum (VAFM) and occipital bone size. Type C had small VPCF, VAFM, and occipital bone size. Morphometric analyses during craniocervical traction test demonstrated instability of CCJ. Foramen magnum decompression (FMD) was performed in 302 cases. Expansive suboccipital cranioplasty (ESCP) was performed in 102 cases. Craniocervical posterolateral fixation (CCF) was performed for CCJ instability in 70 cases. Both ESCP and FMD showed a high improvement rate of neurological symptoms and signs (84.4%) and a high recovery rate of the Japanese Orthopaedic Association (JOA) score (58.5%). CCF also showed a high recovery rate of the JOA score (69.7%), with successful joint stabilization (84.3%). CM-I type A was associated with other mechanisms that caused ptosis of the brainstem and cerebellum (CCJ instability and traction and pressure dissociation between the intracranial cavity and spinal canal cavity), whereas CM-I types B and C demonstrated underdevelopment of the occipital bone. For CM-I types B and C, PCF decompression should be performed, whereas for small VPCF, ESCP should be performed. CCF for CCJ instability (including CM-I type A) was safe and effective.

Adult medulloblastoma: a case report

BackgroundMedulloblastoma is a malignant brain tumor that is common in children but very uncommon in adults, especially those older than 40 years, accounting for less than 1% of all primary brain tumors in adults. Although surgery and radiotherapy play an important role treatment of adult medulloblastoma, the use of chemotherapy is controversial. This is the first instance of adult medulloblastoma at the Ocean Road Cancer Institute in Tanzania.Case descriptionWe report the case of a 51-year-old female of African ethnicity who was diagnosed with high-risk hemispheric posterior cranial fossa medulloblastoma of classic type with World Health Organization central nervous system grade 4 and Chang stage M0. Immunohistochemistry, reticulin stain, and molecular subtyping could not be done because they were not available. She was treated by subtotal posterior cranial fossa tumor resection followed by adjuvant concurrent chemo-craniospinal radiation and adjuvant chemotherapy.ConclusionEven in adults over 50 years old, medulloblastoma should be included in the differential diagnosis of posterior fossa tumor. Adult medulloblastoma is a very rare and very heterogeneous tumor, but it has a good prognosis. Immunohistochemistry and molecular subclustering are difficult to implement in low-income countries such as Tanzania owing to cost. Treatment of adult medulloblastoma is highly heterogeneous among (and even within) facilities. There is no evidence that the extent of resection enhances survival. While craniospinal radiation therapy improves survival, there is controversy about the role of chemotherapy in managing adult MB.

Craniofacial development in patients of Tessier No.0 cleft with a bifid nose using 3D computed tomography.

ObjectiveConsiderable studies have focused mainly on the facial deformity of Tessier No.0 cleft with a bifid nose, but the deformity of the skull is not well understood. Therefore, our study aimed to explore the evolution of cranial dysmorphology and the chronology of Tessier No.0 cleft with a bifid nose, by three-dimensional measurements.MethodsNinety-six non-surgical patients and computed tomographic scans were included (Tessier No.0 cleft with a bifid nose, n = 48; controls, n = 48) and divided into five age subgroups. Craniofacial cephalometric measurements were analyzed by Mimics software.ResultsThe widening of nasal bone was the most remarkable and persistent from 2 years old appropriately. The overall cranial base length in patients compared with controls increased 11.8% (p < 0.01) on average. The middle and posterior cranial fossa increasing accounted for most of this change. The cranial base angles also showed increased obviously. By analyzing the linear of the nasopharynx and respiratory tract, it was found that its development did not affect respiration.ConclusionsThe cranial base deformity of Tessier No.0 cleft with a bifid nose consists of the whole skull base and particularly the middle and posterior cranial base length increase. At the same time, there may be late closure of the spheno-occipital synchondrosis and sella displacement. We believe this study is unique in providing valuable data for elucidating the pathological and morphological abnormalities of skull base development in Tessier No.0 cleft with a bifid nose.

Low apparent diffusion coefficient in an extracranial brain tumor: a case report

BackgroundMedulloblastoma is well known as the most common malignant brain tumor identified in children, frequently found at an intra-axial location in the posterior cranial fossa. Extra-axial medulloblastoma is uncommon and often misdiagnosed. We believe that a thorough understanding of atypical medulloblastoma cases is important in daily practice.Case presentationWe present the unique case of a 39-year-old woman of Asian descent who suffered from headaches and right-sided hearing impairment. A right extra-axial medulloblastoma with an extremely low apparent diffusion coefficient of 0.404 × 10−3 mm2/second was detected on magnetic resonance imaging. The initial diagnosis suggested schwannoma or hemangioblastoma. However, the postoperative histopathologic findings indicated medulloblastoma (World Health Organization grade IV). Pre- and postoperative magnetic resonance imaging revealed no drop metastasis, but adjuvant radiation therapy was still required as a standard treatment therapyConclusionsExtra-axial medulloblastoma is an uncommon tumor that is often mistaken for other cerebellopontine angle neoplasms. We describe a rare example of extra-axial medulloblastoma, characterized by a low apparent diffusion coefficient. When evaluating an atypical cerebellopontine angle neoplasm, the apparent diffusion coefficient should be considered a relevant indicator.

Morphometric Study on Types of Asterion in Dry Human Skull of Nepalese Origin

Introduction: The asterion is important bony landmark of skull important for surgical approach to the posterior cranial fossa. The variation is type of asterion is due to presence or absence of lambdoidal suture, parietomastoid suture and occipitomastoid suture. Asterion is starry or triangular depression located 2.5cm behind the upper part of root of ear. Asterion is meeting point of lambdoidal suture, parietomastoid suture and occipitomastoid suture. Materials and Methods: Altogether 26 dry adult human skulls were collected from Department of Anatomy at School of Basic Sciences in Chitwan Medical College for research. Gender and ethnicity were undefined. All damaged skull and newborns are excluded. Both sides of skull were studied for location and type of asterion. The types of asterion were noted by observing the presence or absence of all three sutures. Photograph were taken and studied. Statistical analysis was done using SPSS 17. Results: Twenty-six human skulls of unknown gender were examined. Two types of asterion were observed. The type I asterion was 88.5 percent and type II asterion was 11.5 percent on both side of skull. Conclusion: we believe that there are different types of asterion present in human skull. Asterion is the important surgical landmark. Thereby, the finding may be helpful in surgical approach and intervention.

ANATOMICAL RISK FACTORS FOR THE COMPLICATED POSTOPERATIVE PERIOD IN THE SURGERY OF EXTRACEREBRAL TUMORS OF THE POSTERIOR CRANIAL FOSSA

Tumors of the base of the posterior cranial fossa are among the most difficult for surgical treatment in neurosurgery. Numerous studies are being conducted on the factors that determine clinical manifestations and treatment outcomes. The aim of the study was to study the linear and angular parameters of the posterior cranial fossa in patients with extracerebral neoplasms and to evaluate their effect on the results of surgical treatment. Craniometric study of linear and angular parameters of the posterior cranial fossa was performed in 115 patients with sub-tentorial extracerebral tumors. A computer program was used to determine the longitudinal, transverse and height diameters of the head, the length, width and height of the posterior cranial fossa, the sagittal diameter of the foramen magnum, the length of the clivus, the length of the posterior part of the skull base, the basilar angle, the Boogard’s angle, the posterior angle of the base of the skull, angle of the cerebellar mantle, angle of inclination of the clivus, angle of inclination of the scales of the occipital bone and angle of convergence of the pyramids of the temporal bones. These parameters were determined on magnetic resonance tomograms in the sagittal projection on the median section and in the axial projection, on the section passing at the level of the internal auditory canals. The main group consisted of 15 patients who developed vascular complications after surgery, the second comparison group included 100 patients with uncomplicated postoperative course. The predominant head shapes according to the transverse-longitudinal index in both groups were brachycephalic (53.3 and 54%, respectively). There was no acrocephaly (high and narrow head forms) among patients with complications, while in the control group this type was registered in 12% of cases. Certain craniometric prerequisites for a complicated course of the postoperative period have been identified, allowing a more selective approach to the tactics of treating these patients. The risk group includes patients with large values ​​of the basilar angle and the angle of inclination of the scales of the occipital bone, having a narrower and elongated shape of the posterior cranial fossa.

A Frontal Route to Middle and Posterior Cranial Fossa: Quantitative Study for the Lateral Transorbital Endoscopic Approach and Comparison with the Subtemporal Approach

Skull base lesions within the middle cranial fossa (MCF) remain challenging. Recent reports suggest that transorbital endoscopic approaches (TOEAs) might be particularly suitable to access the MCF and expose the lateral wall of the cavernous sinus and the Meckel's cave. The present study was developed to compare the nuances of the subtemporal approach (STA) with those of the lateral TOEA (LTOEA) to the MCF and posterior cranial fossa (PCF) in cadaveric specimens. After orbital craniectomy, interdural opening of the cavernous sinus lateral wall (CSlw), exposure of the Gasserian ganglion, and extradural elevation of the temporal lobe was performed. Next, anterior endoscopic petrosectomy was performed and the PCF was accessed. We quantitatively analyzed and compared the angles of attack and distances between LTOEA and STA to different structures at the CSlw, petrous apex (PA), and PCF. Cadaveric dissection through the LTOEA completely exposed the CSlw and PA. LTOA exhibited larger distances than the STA to all targets. Importantly, these differences were greater at the PA and its surrounding key anatomic landmarks. The horizontal and vertical angles of attack allowed by the LTOA were smaller both for the CSlw and PA. However, these differences were not significant for the vertical angle of attack at the CSlw. LTOEA provides a direct ventral route to the medial aspect of MCF, PA, and PCF. Although TOEAs are versatile approaches, the unfamiliar surgical anatomy and limited instrument maneuverability demand extensive cadaveric dissection before moving to the clinical setting.