Intracranial Regions Research Articles

Comparison of Magnetic Resonance Imaging and Computed Tomography in the Evaluation of the Olfactory Cleft and Ethmoidal Cells.

No study has examined whether magnetic resonance imaging (MRI) alone can be used for evaluating olfactory cleft and ethmoidal sinus in patients with olfactory disorders. Therefore, we analyzed the discrepancies between computed tomography (CT) and MRI in the imaging of the olfactory cleft and ethmoidal sinus. Patients who underwent CT and MRI within 30 days were evaluated. Age, sex, diagnosis, presence of bronchial asthma (BA), peripheral blood eosinophil percentage, and CT and MRI findings were retrospectively reviewed, and the sinuses were assessed on a scale of 0 to 3. Overall, 146 patients with 292 sinuses were enrolled. The ethmoid sinus score and the olfactory cleft score had 77.1% and 72.6% image similarity in CT and MRI. Sex and BA status were not associated with olfactory cleft score discrepancies (sex: P = 0.52, BA: P = 0.41). Magnetic resonance imaging scores tended to be rated higher than the CT scores as age increased, although this difference was not statistically significant (P = 0.09). The higher the peripheral blood eosinophil percentage, the more the magnitude by which the CT score tended to exceed the MRI score; however, this finding was also not statistically significant (P = 0.11). Magnetic resonance imaging scans should be limited to the evaluation of intracranial regions. Scans of olfactory cleft and ethmoid cells are not accurate for the assessment of olfactory dysfunction.

Spike-associated networks and intracranial electrographic findings.

Functional connectivity is providing new insights into the network nature of epilepsy with growing clinical applications. Our objective was to validate a novel magnetoencephalography-based method to non-invasively measure the epileptic network. We retrospectively identified pediatric and adult patients with refractory focal epilepsy who underwent pre-surgical magnetoencephalography with subsequent intracranial electrographic monitoring. Magnetoencephalography tracings were visually reviewed, and interictal epileptiform discharges ("spikes") were individually marked. We then evaluated differences in whole-brain connectivity during brief epochs preceding the spikes and during the spikes using the Network-Based Statistic to test differences at the network level. In six patients with statistically-significant network differences, we observed substantial overlap between the spike-associated networks and electrographically active areas identified during intracranial monitoring (the spike-associated network was 78% and 83% sensitive for intracranial electroencephalography-defined regions in the irritative and seizure onset zones, respectively). These findings support the neurobiological validity of the spike-associated network method. Assessment of spike-associated networks has the potential to improve surgical planning in epilepsy surgery patients by identifying components of the epileptic network prior to implantation.

4216 A TL1 team approach to investigate attention and learning at the intracranial network level and assess the effect different cognitive rehabilitation strategies have on measures of attention and learning

OBJECTIVES/GOALS: 1) Investigate the network level interactions of attention and learning during an attention network task (ANT) and an implicit learning contextual cueing (CC) task. 2) Assess the effect attention rehabilitation strategies have on behavioral and neural responses pre/post-attentional intervention. METHODS/STUDY POPULATION: This study involves refractory epilepsy patients with implanted intracranial electrodes and moderate-to-severe traumatic brain injury (m/sTBI) survivors. In epileptic patients, we will identify connectivity of cortical regions via the ANT, which probes components of attention (alerting, orienting, and executive control) and a CC task that probes implicit learning. We hypothesize that modulation of attention and learning can be seen at the network level. In TBI we will assess improvement following two attention rehabilitation paradigms behaviorally; and use our results from epileptic patients to guide measurement of treatment-related neuroplastic change via scalp electroencephalography. RESULTS/ANTICIPATED RESULTS: When the proposed objectives are complete, we expect to determine how the implicit learning rate in m/sTBI changes as a result of both direct attention and metacognitive-strategy training, and discern the neuroanatomical networks associated with attention and implicit learning based on connectivity results. We expect to identify intracranial regions and networks that exhibit modulatory effects associated with attention and implicit learning. Additionally, we anticipate that deficits in attention will be mitigated following training and hypothesize that implicit learning rate will improve in TBI patients as a result of both attentional rehabilitation paradigms. DISCUSSION/SIGNIFICANCE OF IMPACT: Characterizing intracranial activity in epilepsy patients will give electrophysiology data unattainable in TBI patients. This intracranial perspective will enable us to propose mechanisms of action that may result from our interventions and enable critique of current rehabilitation treatments.

Extracranial versus intracranial hydro-hemodynamics during aging: a PC-MRI pilot cross-sectional study

BackgroundBoth aging and changes in blood flow velocity between the extracranial (intraspinal) and intracranial regions of cerebral vessels have an impact on brain hydro-hemodynamics. Arterial and venous cerebral blood flows interact with cerebrospinal fluid (CSF) in the both the cranial and spinal systems. Studies suggest that increased blood and CSF flow pulsatility plays an important role in certain neurological diseases. Here, we investigated the changes in blood-CSF flow pulsatility in the cranial and spinal systems with age as well as the impact of the intracranial compartment on flow patterns.MethodPhase-contrast magnetic resonance imaging (PC-MRI) was performed in 16 young and 19 elderly healthy volunteers to measure the flows of CSF and blood. CSF stroke volume (SV), blood SV, and arterial and venous pulsatility indexes (PIs) were assessed at intra- and extracranial levels in both samples. Correlations between ventricular and spinal CSF flow, and between blood and CSF flow during aging were also assessed.ResultsThere was a significant decrease in arterial cerebral blood flow and intracranial venous cerebral blood flow with aging. We also found a significant increase of intracranial blood SV, spinal CSF SV and arterial/venous pulsatility indexes with aging. In regard to intracranial compartment impact, arterial and venous PIs decreased significantly at intracranial level in elderly volunteers, while young adults exhibited decrease in venous PI only. Intracranial venous PI was paradoxically lower than extracranial venous PI, regardless of age. In both sample groups, spinal CSF SV and aqueductal CSF SV were positively correlated, and so were extracranial blood and spinal CSF SVs.ConclusionThe study demonstrates that aging changes blood flow but preserves blood and CSF interactions. We also showed that many parameters related to blood and CSF flows differ between young and elderly adults.

PULMONARY AND INTRACRANIAL RADIOGRAPHIC PRESENTATIONS OF LANGERHANS CELL HISTIOCYTOSIS

Background. Langerhans Cell Histiocytosis is a rare disease that affects 1 to 2 adults per million worldwide and often consists of systemic manifestations including pulmonary, intracranial and osteolytic lesions and endocrinologic abnormalities such as Diabetes Insipidus.
 Objective. The objective of this case report was to expand the medical literature of this rare disease.
 Methods. A case report of a 51-year-old female patient presenting with systemic symptoms as a result of Langerhans Cell Histiocytosis is presented.
 Results. A 51-year-old female presented with epistaxis, fatigue, polydipsia, polyuria, headaches and dyspnea. After initial x-rays showed multiple lung and liver nodules and the patient suffered subsequently from a unilateral pneumothorax, an open lung biopsy was recommended. On a pathological basis, the patient was diagnosed with Langerhans Cell Histiocytosis. This report focuses on the radiological presentations of the manifestations of Langerhans Cell Histiocytosis, particularly the presentations in the lung and intracranial regions.
 Conclusions. Langerhans Cell Histiocytosis is an incredibly rare disease that presents systemically. Recognizing and differentiating radiographic presentation of these patients is important to determine the need for confirmation by biopsy and early chemotherapeutic intervention.

Quantification of changes in brain morphology following posterior fossa decompression surgery in women treated for Chiari malformation type 1.

While 84% of patients surgically treated for Chiari malformation type 1 (CM1) demonstrate improved quality of life after posterior fossa decompression surgery, there are many risks associated with this surgery. Surgical planning to identify candidates likely to improve postoperatively may benefit from an improved understanding of morphological changes after decompression surgery. To evaluate these changes, we quantified 59 morphological parameters on 42 CM1 adult female patients before and after CM1 decompression surgery. Fifty-nine morphological parameters in the posterior cranial fossa, cranio-cervical, and intracranial regions in the midsagittal plane were evaluated using 42 T1-weighted magnetic resonance images of female CM1 patients before and after surgery, and 42 healthy female controls. Morphological differences before and after surgery were compared through the development of a technique to establish the opisthion location, a key reference point not present after surgery. In addition to the expected reduction of the cranio-caudal dimension of the cerebellum, objective analyses showed a significant increase in the area of the cerebrospinal fluid spaces, posterior (6×) and inferior (2.6×) to the cerebellum (+ 112 ± 102 and + 140 ± 127mm2, respectively). This increased area was primarily impacted by an average reduction in the occipital bone length of 24.5 ± 7.3mm following surgery. Based on multiple angles, results demonstrated a 2°-4° anterior rotation of the cerebellum after surgery. Our results show that decompression surgery results in significant changes in the cerebellum and cerebrospinal fluid spaces. Further investigation should determine how these morphological changes impact clinical outcomes.

Quantitative assessment of the intracranial vasculature in an older adult population using iCafe

Comprehensive quantification of intracranial artery features may help us assess and understand variations of blood supply during brain development and aging. We analyzed vasculature features of 163 participants (age 56–85 years, mean of 71) from a community study to investigate if any of the features varied with age. Three-dimensional time-of-flight magnetic resonance angiography images of these participants were processed in IntraCranial artery feature extraction technique (a recently developed technique to obtain quantitative features of arteries) to divide intracranial vasculatures into anatomical segments and generate 8 morphometry and intensity features for each segment. Overall, increase in age was found negatively associated with number of branches and average order of intracranial arteries while positively associated with tortuosity, which remained after adjusting for cardiovascular risk factors. The associations with number of branches and average order were consistently found between 3 main intracranial artery regions, whereas the association with tortuosity appeared to be present only in middle cerebral artery/distal arteries. The combination of time-of-flight magnetic resonance angiography and IntraCranial artery feature extraction technique may provide an effective way to study vascular conditions and changes in the aging brain.

Application of Quantile Graphs to the Automated Analysis of EEG Signals

Epilepsy is classified as a chronic neurological disorder of the brain and affects approximately 2% of the world population. This disorder leads to a reduction in people’s productivity and imposes restrictions on their daily lives. Studies of epilepsy often rely on electroencephalogram (EEG) signals to provide information on the behavior of the brain during seizures. Recently, a map from a time series to a network has been proposed and that is based on the concept of transition probabilities; the series results in a so-called “quantile graph” (QG). Here, this map, which is also called the QG method, is applied for the automatic detection of normal, pre-ictal (preceding a seizure), and ictal (occurring during a seizure) conditions from recorded EEG signals. Our main goal is to illustrate how the differences in dynamics in the EEG signals are reflected in the topology of the corresponding QGs. Based on various network metrics, namely, the clustering coefficient, the shortest path length, the mean jump length, the modularity and the betweenness centrality, our results show that the QG method is able to detect differences in dynamical properties of brain electrical activity from different extracranial and intracranial recording regions and from different physiological and pathological brain states.

NIR-II fluorescence imaging using indocyanine green nanoparticles

Fluorescence imaging in the second near-infrared window (NIR-II) holds promise for real-time deep tissue imaging. In this work, we investigated the NIR-II fluorescence properties of a liposomal formulation of indocyanine green (ICG), a FDA-approved dye that was recently shown to exhibit NIR-II fluorescence. Fluorescence spectra of liposomal-ICG were collected in phosphate-buffered saline (PBS) and plasma. Imaging studies in an Intralipid® phantom were performed to determine penetration depth. In vivo imaging studies were performed to test real-time visualization of vascular structures in the hind limb and intracranial regions. Free ICG, NIR-I imaging, and cross-sectional imaging modalities (MRI and CT) were used as comparators. Fluorescence spectra demonstrated the strong NIR-II fluorescence of liposomal-ICG, similar to free ICG in plasma. In vitro studies demonstrated superior performance of liposomal-ICG over free ICG for NIR-II imaging of deep (≥4 mm) vascular mimicking structures. In vivo, NIR-II fluorescence imaging using liposomal-ICG resulted in significantly (p < 0.05) higher contrast-to-noise ratio compared to free ICG for extended periods of time, allowing visualization of hind limb and intracranial vasculature for up to 4 hours post-injection. In vivo comparisons demonstrated higher vessel conspicuity with liposomal-ICG-enhanced NIR-II imaging compared to NIR-I imaging.

Hypertelorism Secondary to Mucocele in the Paranasal Sinuses.

Ocular hypertelorism was introduced by Greig as an increased interpupillary distance. The paranasal sinus mucoceles are acquired lesions for various reasons; however, their behavior is progressive, capable of eroding the bone and extending to the orbital and intracranial regions. The objective is to present a clinical case of orbital hypertelorism secondary to mucocele in the paranasal sinuses. This is a 72-year-old male patient who came presenting an increase in volume in the right nasoorbitoethmoidal region. The isodense lesion occupying the maxillary and right ethmoidal sinuses was confirmed by an intimate relationship with the ipsilateral frontal and sphenoidal sinus, with osteolytic involvement of the orbit and nasal region. After incisional biopsy with mucocele results, a wide resection plus facial reconstruction was performed with autologous grafts and osteosynthesis material. Currently, the patient has 1 year of evolution, without significant functional commitment. It is important to consider giant mucoceles as part of the differential diagnoses in patients with deformities in the middle and upper third of the face.

Remote intracranial recurrence of IDH mutant gliomas is associated with TP53 mutations and an 8q gain.

Most IDH mutant gliomas harbor either 1p/19q co-deletions or TP53 mutation; 1p/19q co-deleted tumors have significantly better prognoses than tumors harboring TP53 mutations. To investigate the clinical factors that contribute to differences in tumor progression of IDH mutant gliomas, we classified recurrent tumor patterns based on MRI and correlated these patterns with their genomic characterization. Accordingly, in IDH mutant gliomas (N = 66), 1p/19 co-deleted gliomas only recurred locally, whereas TP53 mutant gliomas recurred both locally and in remote intracranial regions. In addition, diffuse tensor imaging suggested that remote intracranial recurrence in the astrocytomas, IDH-mutant with TP53 mutations may occur along major fiber bundles. Remotely recurrent tumors resulted in a higher mortality and significantly harbored an 8q gain; astrocytomas with an 8q gain resulted in significantly shorter overall survival than those without an 8q gain. OncoScan® arrays and next-generation sequencing revealed specific 8q regions (i.e., between 8q22 and 8q24) show a high copy number. In conclusion, only tumors with TP53 mutations showed patterns of remote recurrence in IDH mutant gliomas. Furthermore, an 8q gain was significantly associated with remote intracranial recurrence and can be considered a poor prognostic factor in astrocytomas, IDH-mutant.

Ultrasound Elastography of the Neonatal Brain: Preliminary Study.

To determine the ultrasound elasticity of the brain in neonates METHODS: Strain elastography was performed in 21 healthy neonates (mean gestational age [GA], 34 weeks; range, 28-40 weeks). Elastographic scores were assigned to the following structures on a 5-point color scale (1-5): ventricle, periventricular white matter, caudate, subcortical, cortical gray matter, and subdural space. Three elastographic images were evaluated in each patient, and median elastographic scores were calculated. The scores were compared between regions and were correlated with the corrected GA. Interobserver agreements for assignment of elastographic scores were analyzed. The ventricle and subdural space showed an elasticity score of 1 in all patients. The cortical gray matter (median, 3.0; first-third quartiles, 2.33-3.33) showed higher elasticity compared to the periventricular white mater (4.0; 3.00-4.00; P < .001), caudate (4.3; 3.67-4.67; P < .001), and subcortical white matter (4.0; 4.00-4.00; P < .001). The caudate showed lower elasticity compared to periventricular white matter (P = .004). The periventricular white matter showed higher elasticity compared to subcortical white matter (P = .009). There was a positive trend between the corrected GA and cortical gray matter elastographic score (γ = 0.376; P = .093). Interobserver agreement was moderate to almost perfect (κ = 0.53-0.89). Neonatal intracranial regions showed different elasticity, which could be accessed by strain elastography. These normal findings should prompt future studies investigating the use of ultrasound elastography in the neonatal brain.

FEATURES OF CEREBRAL HEMODYNAMICS AND MANIFESTATIONS OF HEPATIC ENCEPHALOPATHY IN CIRRHOSIS OF VIRAL ETIOLOGY AT DIFFERENT COMPENSATION STAGES WITH PRESERVED LEFT VENTRICULAR EJECTION FRACTION

Aim . To study the features of the parameters of cerebral hemodynamics in extra and intracranial regions in viral hepatic cirrhosis A, B, C classes according to Child-Pugh with different serum levels of interleukin-2, interleukin-6 and tumor necrosis factor alpha and preserved left ventricular ejection fraction for improvement of diagnostics of stages of chronic hepatic encephalopathy. Material and methods . 107 patients with viral cirrhosis A, B, C classes according to Child-Pugh with different serum levels of interleukin-2, interleukin-6 and tumor necrosis factor alpha were included into the study. The parameters of hemodynamics in common carotid and middle cerebral arteries of the first order of both hemispheres as well as the parameters of echocardiography were studied in all patients. Evaluation of hepatic encephalopathy stages was carried out by the West-Haven symptoms scale and the Reitan test (Number Connection Test) according to the recommendations of the Working group of the XI-th World Gastroenterology Congress. Results . Reduction in the compensation of hepatic cirrhosis A and C classes was accompanied by a thickening of the intima-media complex in the common carotid arteries from 0.69±0.21 mm to 0.79±0.35 mm, respectively. The hemispheric asymmetry of the mean linear blood flow velocity tended to increase from 25.1±2.42% in cirrhosis A class to 39.5±7.94% in cirrhosis C class. The greatest disorders of the hemodynamics in the middle cerebral arteries were observed in hepatic cirrhosis C class due to changes in the linear blood flow velocity parameters, increase in the hemispheric asymmetry of the average linear flow rate up to 33.9±10.5%, reduction in resistance and pulsatility indices to 0.49±0.22 and 1.02±0.21, respectively. Conclusion . Chronic hepatic encephalopathy of all stages can occur in the presence of discirculatory disorders with the development of chronic cerebrovascular insufficiency in viral hepatic cirrhosis A, B, C classes with different serum levels of interleukin-2, interleukin-6 and tumor necrosis factor alpha and preserved systolic function of the left ventricle. The duration of the Number Connection Test more than 200 s, blood flow hemispheric asymmetry more than 40%, decrease in blood flow velocity parameters and vascular resistance indices in the middle cerebral artery below the reference values are associated with a poor prognosis of hepatic encephalopathy. The degrees of cognitive and discirculatory disorders are related with the stages of hepatic cirrhosis compensation. An increase in the degree of cognitive impairments (from ability to logical thinking and attention to disorientation in time and space) is observed in discirculatory disorders and decrease in the stage of cirrhosis compensation.

CT Perfusion in Acute Lacunar Stroke: Detection Capabilities Based on Infarct Location.

Recent studies demonstrated superiority of CTP to NCCT/CTA at detecting lacunar infarcts. This study aimed to assess CTP's capability to identify lacunae in different intracranial regions. Over 5.5 years, 1085 CTP examinations were retrospectively reviewed in patients with acute stroke symptoms with CTP within 12 hours and MRI within 7 days of symptom onset. Patients had infarcts ≤2 cm or no acute infarct on DWI; patients with concomitant infarcts >2 cm on DWI were excluded. CTP postprocessing was automated by a delay-corrected algorithm. Three blinded reviewers were given patient NIHSS scores and symptoms; infarcts were recorded based on NCCT/CTA, CTP (CBF, CBV, MTT, and TTP), and DWI. One hundred thirteen patients met inclusion criteria (53.1% female). On DWI, lacunar infarcts were present in 37 of 113 (32.7%), and absent in 76 of 113 (67.3%). On CTP, lacunar infarcts typically appeared as abnormalities larger than infarct size on DWI. Interobserver κ for CTP ranged from 0.38 (CBF) (P < .0001) to 0.66 (TTP) (P < .0001); interobserver κ for DWI was 0.88 (P < 0.0001). In all intracranial regions, sensitivity of CTP ranged from 18.9% (CBV) to 48.7% (TTP); specificity ranged from 97.4% (CBF and TTP) to 98.7% (CBV and MTT). CTP's sensitivity was highest in the subcortical white matter with or without cortical involvement (21.7%-65.2%) followed by periventricular white matter (12.5%-37.5%); sensitivity in the thalami or basal ganglia was 0%. CTP has low sensitivity and high specificity in identifying lacunar infarcts. Sensitivity is highest in the subcortical white matter with or without cortical involvement, but limited in the basal ganglia and thalami.

Density measurements with computed tomography in patients with extra-axial hematoma can quantitatively estimate a degree of brain compression.

BackgroundExtra-axial hematoma can cause significant brain compression. Guidelines for surgical evacuation include imaging findings (midline shift and hematoma thickness/volume) in conjunction with Glasgow Coma Scale (GCS) scores and/or intracranial pressure (ICP) monitoring. Physiologically, overall brain density should also change with compression. In our observational study, we explored whether overall brain density, defined using computed tomography Hounsfield Units (CT HU), changes after surgical evacuation of extra-axial hematoma.Methods and materialsOnly patients with a surgical acute epidural hematoma or subacute/chronic subdural hematoma were considered. Other exclusion criteria were concurrent intraparenchymal pathology, bilateral pathology, or incomplete follow-up imaging. Between fall 2012 and spring 2015, 22 patients were included in the study. CT head imaging (preoperative, postoperative, and at ∼1- to 2-month clinic visit) were loaded into OsiriX (Pixmeo, Switzerland). All the intracranial regions were selected and all extra-axial features were removed; subsequently, software was used to calculate a global CT HU value.ResultsA repeated-measures ANOVA found significant time effect, p < 0.01, with significance between preoperative versus postoperative CT (p = 0.03) and preoperative versus clinic visit CT (p < 0.01).ConclusionThe results from this study suggest that extra-axial hematomas, which deform the brain, can cause an elevation in global CT HU value; moreover, surgical decompression is associated with lower global CT HU values. The use of global CT HU values in selected populations may serve as an adjunct for the evaluation of surgical lesions.

Central Nervous System and Head and Neck Histiocytoses: A Comprehensive Review on the Spectrum of Imaging Findings.

To understand the general pathophysiology, clinical presentation, and typical imaging characteristics of the most common histiocytoses; comprehend the morphologic and immunohistochemical characteristics of these histiocytoses and the hallmark findings on pathology; and be able to differentiate between these disorders based on their most common presentations.

Nucleolin overexpression is associated with an unfavorable outcome for ependymoma: a multifactorial analysis of 176 patients.

Ependymoma typically has a better overall survival rate than most gliomas. Only a few comprehensive clinical studies have been published, but these are mostly from Western countries and use small sample sizes. Histopathological classification is not sufficient to show variable outcomes, and fails to show prognostic markers of the diverse outcomes; hence, it is essential to understand biological mechanisms. In this study, 176 ependymoma samples (World Health Organization grade II and III) were reviewed at Huashan Hospital. Both children and adults were included. We performed multifactorial analyses of clinical prognostic factors and the biomolecular marker expressions of nucleolin, epidermal growth factor receptor (EGFR) and caveolae-associated protein caveolin-1 by immunohistochemistry. We identified the probabilities of progression-free survival and overall survival using univariate and multivariate statistical methods. The participants were diagnosed with ependymomas between 2002 and 2010, including distributions of tumor locations in intracranial and extracranial regions. Nucleolin was overexpressed in 67% of our samples, demonstrating a subgroup with poor outcome; particularly infratentorial and anaplastic ependymomas. There was no significant correlation between the expression of EGFR and caveolin-1 and clinical outcomes. Clinically, inferior prognosis was observed with regard to age (<18years), intracranial location, high grade ependymomas, and incomplete resection. We found that nucleolin was an unfavorable prognostic predictor for ependymomas. Moreover, our findings show a subset of aggravating outcomes in high-grade and posterior fossa tumors.

Maxillary Artery: Functional and Imaging Anatomy for Safe and Effective Transcatheter Treatment

The maxillary artery is a terminal branch of the external carotid artery. Although the main maxillary artery trunk and most of its branches course within the extracranial space and supply the organs and muscles of the head and neck, other surrounding soft tissues, and the oral and rhinosinusal cavities, other branches supply the dura mater and cranial nerve and can anastomose to the internal carotid artery (ICA). Various pathologic conditions of the intracranial, head, and neck regions can involve the branches of the maxillary artery. Many of these diseases can be treated with endovascular approaches; however, there is a potential risk of complications in the brain parenchyma and cranial nerves related to the meningoneuronal arterial supply and anastomoses to the ICA. Therefore, familiarity with the functional and imaging anatomy of the maxillary artery is essential. In the past, conventional angiography has been the standard imaging technique for depicting the maxillary artery anatomy and related pathologic findings. However, recent advances in computed tomographic, magnetic resonance, and rotational angiography have further elucidated the maxillary artery anatomy by means of three-dimensional representations. Understanding the functional and imaging anatomy of the maxillary artery allows safe and successful transcatheter treatment of pathologic conditions in the maxillary artery territories.

The Intracranial Facial Nerve as Seen Through Different Surgical Windows

The facial nerve has a short intracranial course but crosses critical and frequently accessed surgical structures during cranial base surgery. When performing approaches to complex intracranial regions, it is essential to understand the nerve's conventional and topographic anatomy from different surgical perspectives as well as its relationship with surrounding structures. To describe the entire intracranial course of the facial nerve as observed via different neurosurgical approaches and to provide an analytical evaluation of the degree of nerve exposure achieved with each approach. Anterior petrosectomies (middle fossa, extended middle fossa), posterior petrosectomies (translabyrinthine, retrolabyrinthine, transcochlear), a retrosigmoid, a far lateral, and anterior transfacial (extended maxillectomy, mandibular swing) approaches were performed on 10 adult cadaveric heads (20 sides). The degree of facial nerve exposure achieved per segment for each approach was assessed and graded independently by 3 surgeons. The anterior petrosal approaches offered good visualization of the nerve in the cerebellopontine angle and intracanalicular portion superiorly, whereas the posterior petrosectomies provided more direct visualization without the need for cerebellar retraction. The far lateral approach exposed part of the posterior and the entire inferior quadrants, whereas the retrosigmoid approach exposed parts of the superior and inferior quadrants and the entire posterior quadrant. Anterior and anteroinferior exposure of the facial nerve was achieved via the transfacial approaches. The surgical route used must rely on the size, nature, and general location of the lesion, as well as on the capability of the particular approach to better expose the appropriate segment of the facial nerve.

Neurofibromatosis type 1 (NF1) associated with tumor of the corpus callosum

Neurofibromatosis type 1 (NF1), one of the most common neurocutaneous disorders, is a multisystemic disease associated with tumors in any organ of the body, especially in the central nervous system and also the peripheral nervous system. Pilocytic astrocytomas have been described in almost all intracranial regions in patients with NF1. However, only a few patients with NF1 and tumor of the corpus callosum have been reported to date. An 11-year-old white Spanish boy was evaluated due to a family history of NF1 and low performance test scores in school. He was studied from the neurological and intellectual level points of view. Magnetic resonance (MR) study revealed a tumor in the anterior-middle portion of the corpus callosum and a Wechsler Intelligence Scale for Children-Revised showed verbal IQ of 92, a performance IQ of 108, and a total IQ of 100. In addition, he showed attention deficit and hyperactivity disorder. Tumors of corpus callosum in patients with NF1 are very uncommon. The patient presented in this paper consulted due to family history of NF1, progressive hyperactivity, and below average school performance. The MR study showed tumor in the corpus callosum. Tumor histology was not investigated.