Falx Cerebri Research Articles

Pachymeningitis in Biopsy-Proven Sarcoidosis: Clinical Course, Radiographic Findings, Response to Treatment, and Long-term Outcomes.

Background and ObjectivesMeningeal inflammation is one of the most common manifestations of neurosarcoidosis, occurring in 16%–69% of affected patients. While the clinical and radiographic features of leptomeningitis in neurosarcoidosis are well known, those of pachymeningitis are far less clear. Our primary aim was to study the clinicoradiographic features of pachymeningeal involvement in neurosarcoidosis and its evolution over time in response to treatment.MethodsPatients with a diagnosis of neurosarcoidosis seen at Emory University (January 2011–August 2021) were included if pachymeningeal involvement was evident by MRI and the patient's sarcoidosis was pathologically confirmed (from a CNS or non-CNS site).ResultsTwenty-six of 215 (12.1%) patients with neurosarcoidosis qualified for inclusion. Pathologic confirmation came from CNS tissue in 50%. The median age of onset was 43.5 years; most were male (16/26, 61.5%). Symptoms were primarily related to pachymeningitis in 20/26 (76.9%). Headache (19/26, 73.1%), visual dysfunction (12/26, 46.2%), and seizures (7/26, 26.9%) were the most common symptoms. All patients had cranial pachymeningitis; only a single patient undergoing spinal imaging (1/11, 9.1%) had spinal pachymeningitis. The falx cerebri (16/26, 61.5%) was the most commonly affected dural structure, but the anterior and middle cranial fossae and tentorium cerebelli were frequently involved (12/26 each, 46.2%). The pachymeningeal lesions were unifocal (11/26, 42.3%) or multifocal (15/26, 57.7%) in distribution, nodular morphologically (23/25, 92.0%), and homogeneously enhancing (24/25, 96.0%). Symptomatic improvement occurred with steroids initially in 22/25 (88.0%). Ultimately, 23/26 (88.5%) required initiation of steroid-sparing immunosuppressants, including 8/26 (30.8%) eventually undergoing TNF inhibition. Pachymeningeal relapses occurred in 7/26 (26.9%). The median clinical follow-up was 48 months. The median modified Rankin scale score at last follow-up improved to 1.0 from 2.0 at presentation.DiscussionPachymeningitis due to sarcoidosis often presents with headaches, visual dysfunction, and seizures; it usually affects the dura of the falx cerebri, anterior and middle cranial fossae, and tentorium cerebelli and tends to require steroid-sparing immunosuppressants. It has the potential to relapse, but the prospect for recovery is good.

Stage M Infantile Neuroblastoma With Involvement of Falx Cerebri: Case Report and Literature Review.

Neuroblastoma is the most common extracranial solid tumor in children. When metastasis to the falx cerebri is present, it is classified as stage M; however, its behavior has not been well characterized. Here we present a case of stage M infantile neuroblastoma (NB) with involvement of the falx cerebri, and also summarize the clinical profiles of previously reported cases. Notably, all of the tumors resolved with low-dose chemotherapy alone. Although further study is needed to distinguish NBs presenting at these different intracranial locations, NB with metastasis to the falx cerebri may be categorized as MS when diagnosed at less than 18 months of age.

Physiological Intracranial Calcifications in Children: A computed tomography-based study.

This study aimed to examined the frequency of physiological intracranial calcifications (PICs) in paediatric population using computed tomography (CT). The brain CT scans of consecutive patients (age range: 0-15 years) who had visited Sultan Qaboos University Hospital, Muscat, Oman, from January 2017 to December 2020 were retrospectively assessed for the presence of PICs. The presence of calcifications was identified using 3 mm-thick axial images and coronal and sagittal reformats. A total of 460 patients were examined, with a mean age of 6.54 ± 4.94 years. The frequency of PIC in boys and girls was 35.1% and 35.4%, respectively. PICs were most common in choroid plexus, observed in 35.2% (age range: 0.4-15 years, median: 12 years) of subjects, followed by the pineal gland in 21.1% (age range: 0.5-15 years, median: 12 years) and the habenular nucleus in 13.0% of subjects (age range: 2.9-15 years; median: 12 years). PICs were less common in falx cerebri, observed in 5.9% (age range: 2.8-15 years; median: 13 years) of subjects, and tentorium cerebelli, observed in 3.0% (age range: 7-15 years, median: 14 years) of subjects. PICs increased significantly with increase in age (P <0.001). Choroid plexus is the most frequent site of calcification. Choroid plexus and pineal gland calcifications may be present in infants younger than one year. Recognising PICs is clinically important for radiologists as they can be mistaken for haemorrhage or pathological entities such as neoplasms or metabolic diseases.

P18.02.B Influence of preoperative embolization on intraoperative parameters, hospital stay and neurocognitive outcome compared to surgery alone

Abstract Background Preoperative embolization of meningiomas is used to reduce intraoperative blood loss and facilitate resection. So far, a risk-benefit stratification of this additional intervention on the neurocognitive outcome is missing. This study investigates the influence of preoperative embolization with liquid Embolisate on intraoperative parameters, length of hospital stays and functional outcome. Material and Methods Patients treated for intracranial meningiomas at a single center between January 2019 and June 2021 were reviewed in a retrospective matched-pair analysis. Patients were matched to group A (tumor resected) and group B (preoperatively embolized and tumor resected after 2,27 ± 3,05 days). Matching criteria were tumor diameter and location (convexity, falx cerebri or skull base, frontal, parietal, occipital, temporal). Data collection included MRI (location, tumor- and necrosis volume, edema, complications), DSA (tumor blush, arterial supply), medical history, histological, surgical, clinical course, complications, and haematological parameters, as well as neurocognitive symptoms on admission and discharge from hospital. Results 44 patients with intracranial Meningiomas were included, divides into 2 groups, each encompassing 22 patients (mean age 62,41 years, 40,5% female). The matching criteria tumor diameter (64.21 vs. 63.55 mm, p=0.725) and tumor localisation (p=0.381) showed no significant differences. There were no significant differences in postoperative hospital stay (14.41 ± 9.5 vs. 14.25 ± 16.88 days, p=0.814) and in preoperative perifocal oedema (82% vs. 82%, p=0.397). Preoperative embolization was associated with decreased intraoperative tumor bleeding (67% vs. 14%, p=0.001, PHI= 0.534), longer duration of surgery (4:58 ± 2:44 vs. 06:07 ± 03:00 hours, p=0.037), trend for decrease in perifocal oedema (p=0.052, PHI=0,498), neurocognitive improvement on discharge from hospital (23% vs. 86%, p=0.045, PHI=0.339) and decreased of epileptic seizures (preoperative 18% vs. 18% and postoperative 23% vs. 5%). There was no increase in cumulative complication rate (p=1.0) and no long-term neurocognitive impairments associated with embolization. Conclusion This study suggests that preoperative embolization of intracranial meningiomas significantly decreased intraoperative tumor blood loss but is also associated to an improvement on neurocognitive abilities compared to surgery alone. Importantly, complication rate is not increased. In the future, larger studies and perhaps a randomised control trial might be of value in corroborating these findings. Furthermore, the neurocognitive symptoms should be assessed in a standardised examination form, qualitative parameters such as bleeding tendency should be supplemented by quantifiable parameters, e.g., blood loss in ml.

HMRNet: High and Multi-Resolution Network With Bidirectional Feature Calibration for Brain Structure Segmentation in Radiotherapy.

Accurate segmentation of Anatomical brain Barriers to Cancer spread (ABCs) plays an important role for automatic delineation of Clinical Target Volume (CTV) of brain tumors in radiotherapy. Despite that variants of U-Net are state-of-the-art segmentation models, they have limited performance when dealing with ABCs structures with various shapes and sizes, especially thin structures (e.g., the falx cerebri) that span only few slices. To deal with this problem, we propose a High and Multi-Resolution Network (HMRNet) that consists of a multi-scale feature learning branch and a high-resolution branch, which can maintain the high-resolution contextual information and extract more robust representations of anatomical structures with various scales. We further design a Bidirectional Feature Calibration (BFC) block to enable the two branches to generate spatial attention maps for mutual feature calibration. Considering the different sizes and positions of ABCs structures, our network was applied after a rough localization of each structure to obtain fine segmentation results. Experiments on the MICCAI 2020 ABCs challenge dataset showed that: 1) Our proposed two-stage segmentation strategy largely outperformed methods segmenting all the structures in just one stage; 2) The proposed HMRNet with two branches can maintain high-resolution representations and is effective to improve the performance on thin structures; 3) The proposed BFC block outperformed existing attention methods using monodirectional feature calibration. Our method won the second place of ABCs 2020 challenge and has a potential for more accurate and reasonable delineation of CTV of brain tumors.

Decline of verbal fluency with lateral superior frontal gyrus penetration in subthalamic nucleus deep brain stimulation for Parkinson disease.

Verbal fluency (VF) decline is a well-recognized adverse cognitive outcome following subthalamic nucleus deep brain stimulation (STN DBS) in patients with Parkinson disease (PD). The mechanisms underlying VF decline, whether from stimulation, lesioning, or both, remain unclear. This study aims to investigate the unique effects of DBS lead trajectory on VF beyond previously reported effects of active contact location. The study population included 56 patients with idiopathic PD who underwent bilateral STN DBS. Phonemic and semantic VF scores were compared pre- and postoperatively. Features of the electrode trajectory were measured on postoperative imaging, including distance from the falx cerebri, distance from the superior frontal sulcus, and caudate nucleus penetration. The authors used t-tests, Pearson's correlation, and multiple linear regression analyses to examine the relationship between VF change and demographic, disease, and electrode trajectory variables. The laterality of entry within the left superior frontal gyrus (SFG) predicted greater phonemic VF decline (sr2 = 0.28, p < 0.001) after controlling for active contact location. VF change did not differ by the presence of caudate nucleus penetration in either hemisphere (p > 0.05). Lateral penetration of the SFG in the left hemisphere is associated with worsening phonemic VF and has greater explanatory power than active contact location. This may be explained by lesioning of the lateral SFG-Broca area pathway, which is implicated in language function.

DIAGNOSIS OF GORLIN-GOLTZ SYNDROME IN A PEDIATRIC PATIENT

Gorlin-Goltz syndrome (GGS) is a hereditary autosomal dominant disorder with high penetrance and variable expressivity. It is characterized by several basal cell carcinomas (BCC) of early onset, multiple odontogenic keratocysts (OKs), and skeletal abnormalities. Due to the broad clinical spectrum, treatment must be individualized and requires a multidisciplinary team. We presented a rare case of GGS in an 11-year-old female patient. Extraoral clinical examination showed discrete frontal bossing, hypertelorism, and palmoplantar pits. Imaging exams showed calcification of the falx cerebri and multiple osteolytic lesions in the mandible and maxilla. An incisional biopsy of the lesions was performed. The histopathologic diagnosis was OK. The OKs were treated through marsupialization and enucleation and curettage. The expression of several characteristics of GGS is rare in children and adolescents. Early diagnosis is essential to reduce the morbimortality associated with BCC.

Somatostatin Receptor Targeted PET-Imaging for Diagnosis, Radiotherapy Planning and Theranostics of Meningiomas: A Systematic Review of the Literature.

The aims of the present systematic review are to: (1) assess the diagnostic performance of somatostatin receptor (SSR)targeted positron emission tomography (PET) with different tracers and devices in patients affected by meningiomas; and (2) to evaluate the theranostic applications of peptide receptor radionuclide therapy (PRRT) in meningiomas. A systematic literature search according to PRISMA criteria was made by using two main databases. Only studies published from 2011 up to March 2022 in the English language with ≥10 enrolled patients were selected. Following our research strategy, 17 studies were included for the assessment. Fourteen studies encompassed 534 patients, harboring 733 meningiomas, submitted to SSR-targeted PET/CT (n = 10) or PET/MRI (n = 4) for de novo diagnosis, recurrence detection, or radiation therapy (RT) planning (endpoint 1), while 3 studies included 69 patients with therapy-refractory meningiomas submitted to PRRT (endpoint 2). A relevant variation in methodology was registered among diagnostic studies, since only a minority of them reported histopathology as a reference standard. PET, especially when performed through PET/MRI, resulted particularly useful for the detection of meningiomas located in the skull base (SB) or next to the falx cerebri, significantly influencing RT planning. As far as it concerns PRRT studies, stable disease was obtained in the 66.6% of the treated patients, being grade 1–2 hematological toxicity the most common side effect. Of note, the wide range of the administered activities, the various utilized radiopharmaceuticals (90Y-DOTATOC and/or 177Lu-DOTATATE), the lack of dosimetric studies hamper a clear definition of PRRT potential on meningiomas’ management.

Optic Nerve Sheath Calcification

A 72-year-old man underwent computed tomography to evaluate upper airway congestion. Imaging revealed the incidental findings of calcification in each optic nerve sheath (Fig A, B) and the falx cerebri (Fig B, arrow). The patient had undergone a parathyroidectomy 5 years prior for primary hyperparathyroidism. His serum calcium levels subsequently remained within normal limits. Examination showed no evidence of optic nerve dysfunction, although there was asymmetric optic disc cupping (Fig C, D). Optic nerve sheath calcification may lead to optic atrophy with reduced visual acuity or remain asymptomatic, as in our patient (Magnified version of Fig A-D is available online at www.aaojournal.org).

Alobar holoprosencephaly: a case report

Introduction: Holoprosencephaly (HPE) is a rare congenital malformation of the brain; the incidence rate was 0.49-1.2 cases per 10,000-20,000 term births. HPE occurs due to failure of the prosencephalon division at the stage of brain development during the 4-5 weeks of pregnancy. Alobar HPE is one of the most severe types compared to other types. Most of the fetuses affected by this anomaly will die, and those born alive generally cannot survive for more than a year. This study presented a rare case of a baby with alobar HPE. Case report: A 33-year-old woman referred from Karang asem hospital Bali, G3P0020, 23 weeks gestation, has a poor obstetric history. The ultrasound examination results show no falx cerebri, even cerebellum and hypoechoic picture of the cerebrum. Ultrasound of the face was found a flat nose and hypotelorism. Termination at 28 weeks gestation, a baby boy was born 1000 g with the Apgar score 1-1. Multiple congenital abnormalities were found: flat nose, labiopalatoschizis, polydactyly manus dextra and omphalocele. Conclusion: Alobar HPE is a very rare congenital anomaly. The cause of the disease has not been fully explained. Current therapy is just supportive and has not been able to resolve the source of the problem. Alobar HPE disease has a poor prognosis.

Occipito-transtentorial approach for falcotentorial meningiomas: how I do it

BackgroundFalcotentorial meningiomas are rare tumors that arise at the junction of the dural folds of the tentorium and falx cerebri, at the junction of the vein of Galen with the straight sinus with possible extensions along the course of the straight sinus. Surgery of falcotentorial meningiomas remains challenging due to the intimate neurovascular relationships in the posterior incisural space.MethodsWe describe the key steps of the occipito-transtentorial approach for falcotentorial meningiomas with a video illustration. The surgical anatomy is described along with the advantages and limitations of this approach.ConclusionThe occipito-transtentorial approach offers good surgical exposure and outcomes in carefully selected patients harboring falcotentorial meningiomas. Precise understanding of the relationship between the tumor and the internal cerebral veins, basal veins, and vein of Galen should be thoroughly analyzed as these structures may be infiltrated or displaced.

Physiologic intracranial calcifications incidentally detected on cone beam computed tomography

This study aims to determine the incidence of physiologic intracranial calcifications on cone beam computed tomography (CBCT) and to contribute to the differentiation between physiologic and pathologic intracranial calcifications by sharing their characteristic appearances, with the largest number of patients in the literature and many different types of physiologic calcifications. CBCT images of 996 patients admitted to the clinic between 2018 and 2019 were scanned retrospectively. Petroclinoid (PCL) and interclinoid ligaments (ICL), pineal gland, coronoid plexus, falx cerebri, tentorium cerebelli, and other dural calcifications were evaluated in each radiograph. Physiologic calcification was present in 49.4% of the cases, and pineal gland calcification was the most common (47.6%) type. PCL calcification was detected in 22.1%, and it was mostly bilateral partial. There were complete ICL in 1.2%, coronoid plexus in 11.3%, falx cerebri in 6.3%, tentorium cerebelli in 1.1%, and other dural calcifications in 3.6%. Only PCL calcifications differed between sexes and were more common in males. PCL, pineal gland, and coronoid plexus calcifications were most detected in the third decade of the cases. Intracranial calcifications are detected incidentally in CBCT examinations. Some calcifications may indicate pathologic conditions, and patients may need to be referred for further evaluation.

Neurocranial bones are key to untangling the sea cow evolutionary tree: osteology of the skull of Sobrarbesiren cardieli (Mammalia: Pan-Sirenia)

Abstract The pan-sirenian Bauplan is conservative, probably owing to the constraints of adaptation to an aquatic lifestyle. Gathering morphological data from extinct forms is complex, resulting in poorly resolved phylogenies for stem pan-sirenians. Extant sirenians ossify the falx cerebri and the tentorium cerebelli, membranes of the dura mater of the brain attached to the parietal bone. Nevertheless, these ossifications are not present in some pan-sirenians. The basioccipital bone has received little attention in the literature except for establishing the relative age of individuals. Here, we present new cranial elements and a detailed description of the skull of Sobrarbesiren cardieli, a stem pan-sirenian from the Lutetian of Spain represented by eight individuals; we study its intraspecific variation and palaeoecological implications and explore the evolution of the endocranial structures and the basioccipital bone in pan-sirenians. Six new phylogenetic characters are added to the latest pan-sirenian dataset, resulting in a well-resolved topology where Sobrarbesiren is recovered close to the root, in a clade with Prototherium and Eotheroides aegyptiacum. The basioccipital bone and the ossified endocranial membranes have a phylogenetic signal, and the absence of such endocranial structures represents the plesiomorphic condition for pan-sirenians and is not diagnostic for the family Protosirenidae as previously believed.

Case Report: Unusual Varicella-Zoster Virus Meningoencephalitis With Meningomyelitis Mimicking Central Nervous System Leukemia

BackgroundVaricella-Zoster Virus (VZV) is a human pathogen from the α-subfamily of herpesviruses. In immunocompromised patients, VZV may produce disease of the central nervous system (CNS). Clinical manifestations of CNS infection with VZV are non-specific and can mimic other infectious and non-infectious diseases. Due to similar symptoms, CNS infection with VZV represents a diagnostic challenge. Here, we report a case of a patient who showed laboratory and imaging manifestations mimicking the neoplastic etiology.CaseA 31-year-old man presented with a 3-day history of headache, 5-h of confusion, generalized tonic-clonic seizures, and transient fever. The patient has a history of acute myelogenous leukemia (AML). His cerebrospinal fluid (CSF) studies revealed markedly elevated protein (10.326 g/L) and atypical cells. Meanwhile, the MRI of brain, cervical, and thoracic spine was reported as extensive (frontal, parieto-occipital and temporal pachymeningeal, and falx cerebri) enhancement and irregular thickening. These examinations suggested a suspicion of CNS involvement of AML. However, based on further investigations with metagenomic next-generation sequencing, a final diagnosis of VZV meningoencephalitis with meningomyelitis was made. With acyclovir and foscarnet sodium therapy, repeated CSF studies revealed normal cell count and protein. No atypical cells were found. The repeated brain MRI also revealed obvious resolution of the previous abnormal pachymeningeal enhancement.ConclusionThis case highlights the importance of recognizing the unusual phenomenon of traditional tests in VZV meningoencephalitis with meningomyelitis, and timely using of further precise examinations to detect viral DNA, which is required to prevent missed diagnosis.

Meningioma with holo-sagittal sinus involvement treated successfully with intrinsic sinus surgery: illustrative case.

BACKGROUNDThis report describes an unusual meningioma with a large left frontal component and extensive growth within the sagittal sinus and its successful treatment with a staged approach: left frontal craniotomy followed by a sagittal craniotomy and intrinsic removal of the tumor from the sagittal sinus.OBSERVATIONSA previously healthy 27-year-old presented with 6 months of progressively worsening bilateral headaches, visual changes, and nausea. On examination she had a left cranial nerve VI palsy and severe papilledema. Magnetic resonance imaging revealed a 5.1 × 3.8 × 4.1 cm homogenously enhancing left superior frontal parafalcine extra-axial mass with surrounding vasogenic edema and growth through the sagittal sinus extending just short of the torcula.LESSONSThis case report describes a fast-growing meningioma with a unique pattern of spread, growing through the sagittal sinus as if it were a conduit and resulting in complete occlusion of flow in the sinus. An important recognition in this case was that a robust parasagittal venous plexus had developed on either side of the falx cerebri with drainage to the inferior sagittal sinus. This collateral drainage pattern allowed for an extradural opening of the sagittal sinus from front to back and intrinsic resection of the tumor from the sinus with preservation of the lateral walls of the sinus.

Frequency, shape, and estimated volume of intracranial physiologic calcification in different age groups investigated by brain computed tomography scan: a retrospective study.

Intracranial calcification is referred to calcification of parenchyma and vascular structures in brain which can be physiologic or pathologic. This study was conducted with the purpose of investigating the frequency, location, pattern, dimensions and estimated volume of intracranial physiologic calcification (IPC) by computer tomography in different age groups. In this cross-sectional retrospective study, brain computed tomography scans of 216 patients were analyzed in 9 age groups each containing 24 patients from 2 to 89 years old. Data were analyzed by SPSS software using one way analysis of variance (ANOVA, post hoc Tukey), chi square, and linear regression tests (P≤0.05 was considered significant). Rate of calcification in different areas were as follows: pineal gland (75.0%), habenula (36.4%), pineohabenula (15.0%), right lateral ventricle choroid plexus (RCP) (67.7%), left lateral ventricle choroid plexus (LCP) (62.7%), falx cerebri (26.8%), petroclinoid ligament (13.2%), tentorium cerebelli (6.8%), third ventricle choroid plexus (0.9%), fourth ventricle choroid plexus (2.7%), basal ganglia (0.9%). A significant correlation exists between the presence of calcification in pineal, habenula, RCP, and LCP (P≤0.001). Nodular shape of calcification was dominant (47.9%). Estimated volume of pineal calcification showed increased levels in group 8 (70–79 years old) compared to group 2 (10–19 years old) (P≤0.05). Since the accurate description of radiologic appearance of IPCs (location, shape, and size) accompanied with age and clinical manifestation is of great importance in diagnosis and distinguishing from pathologic calcification—for example in patients with melatonin dysregulation or schizophrenic patients—this study was required.

Maxillofacial Radiology 197

Large field of view cone beam computed tomography (CBCT) images allows the visualisation of anatomical structures outside of the teeth and jaws. These areas include the cranial vault and paranasal sinuses. Occasionally pathology, anatomical variation and various other incidental findings can be seen.1 As the use of CBCT has become more common amongst general dentists and specialists, awareness and understanding of incidental findings are of great importance, for the patient as well as medico-legal reasons. Calcifications that are found as incidental findings on CBCT scans within the brain can be pathological or physiological in origin. areas within the brain where physiological calcifications can be found include the pineal gland, choroid plexus, habenular, tentorium cerebelli, sagittal sinus, and falx cerebri. The most reported form of physiological brain calcifications is in the pineal gland and is thought to be an age-related change.2 Pathological calcifications are less common than the physiological variants and are because of more serious diseases such as infectious diseases, endocrine disorders, metastatic lesions, and primary intracranial tumours, to name a few.

Distribution and possible function of galanin about headache and immune system in the rat dura mater

Galanin (GAL) is a nociceptive transmitter or modulator in the trigeminal sensory system. In this study, GAL expression was investigated in the rat dura mater to demonstrate its possible function in headache using immunohistochemical techniques. The cerebral falx and cerebellar dura mater received abundant blood and nerve supply, and were significantly thicker compared to other portions in the cerebral dura mater. GAL-immunoreactivity was expressed by cell and nerve fiber profiles. Presumed macrophages and dendritic cells contained GAL-immunoreactivity, and co-expressed with CD11b-immunoreactivity. Many isolated and perivascular nerve fibers also showed GAL-immunoreactivity. In addition, GAL-immunoreactive nerve fibers were present in the vicinity of macrophages and dendritic cells with either GAL- or ED1-immunoreactivity. GAL-immunoreactive cells and nerve fibers were common in the cerebral falx and cerebellar dura mater and infrequent in other portions. And, GAL-immunoreactive nerve fibers usually co-expressed calcitonin gene-related peptide (CGRP)-immunoreactivity. In the trigeminal ganglion, a substantial proportion of sensory neurons innervating the dura mater contained GAL-immunoreactivity (mean ± SD, 3.4 ± 2.2%), and co-expressed CGRP-immunoreactivity (2.7 ± 2.1%). The present study may suggest that GAL is associated with nociceptive transduction or modulation in the dura mater. GAL also possibly plays a role in the immune mechanism of the dura mater.

Distance Between the Corpus Callosum and the Falx Cerebri: A Little Explored Measure with Potential Surgical Implication

To perform measurements in normal brain imaging studies from the free edge of the falx cerebri to the genu and the body of the corpus callosum and perform a statistical analysis based on age, type of study, and sex highlighting potential surgical implication of these measurements. In 193 normal brain imaging studies, 3 anatomical points of the corpus callosum were used to measure the distance to the falx cerebri. Horos and RadiAnt DICOM Viewer software were used to perform the measurements. Statistical analysis of data was performed with Minitab18 software. The results obtained in computed tomography (CT) studies were: distance A, mean 2.1065 cm; distance B, mean 2.2677 cm; distance C, mean 1.765 cm. The results obtained in magnetic resonance imaging studies were: distance A, mean 1.7148 cm; distance B, mean 2.1197 cm; distance C, mean 1.5321 cm. Statistically significant differences were obtained in measurements related to the type of study and in measurements made in CT studies related to age. There is a distance from the free edge of the falx cerebri to the genu and body of the corpus callosum of at least 1 cm in both CT and magnetic resonance imaging studies of normal brains. Statistically significant differences were found in the measurements in relation to the type of study and in relation to age in the measurements made in CT studies. These measurements could be important in determining the extent of bone resection in certain types of decompressive craniectomies.

Modal analysis of a human head model with finite element method

Cerebral concussion caused by a contact in American football games is a serious problem today, since its mechanism remains unclear so far. From some prior researches head vibration would induce the cerebral concussion. In this study we had carried out a modal analysis for a human head model consisting of skull, falx cerebri, cerebellar tentorium, cerebrum, cerebral cortex, corpus callosum, cerebellum, brainstem, septum pellucidum, cervical cord, cervical vertebrae, and lateral ventricles (cerebrospinal fluid) with mechanical properties that we referred to some papers. The results show that the 1st, the 2nd and the 3rd modes are sagittal rotation (eigenfrequency: 7.29 Hz), coronal rotation (eigenfrequency: 7.65 Hz), and axial rotation (eigenfrequency: 11.24 Hz), respectively. The maximum of 1st principal stress, 3rd principal stress, equivalent stress and 1st shear stress for these three modes were located in the cervical cord, cervical vertebrae and skull, not inside the brain. On the other hand, the maximum and minimum principal strain were located inside the brain for these three modes. Nucleating higher strain inside the brain might be caused to occur cerebral concussion when the head vibrated due to the contact.