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Background: The present study examined the computed tomography (CT) findings after surgery and overnight drainage for chronic subdural hematoma (CSDH) to clear the significance of inner superficial subarachnoid CSF space and outer subdural hematoma cavity between the brain surface and the inner skull., Methods: A total of 73 sides in 60 patients were evaluated. Head CT was performed on the day after surgery and overnight drainage (1st CT), within 3 weeks of surgery (2nd CT), and more than 3 weeks after surgery (3rd CT). Subdural and subarachnoid spaces were identified to focus on density of fluid, shape of air collection, and location of silicone drainage tube, etc. Cases with subdural space larger than the subarachnoid CSF space were classified as Group SD between the brain and the skull. Cases with subarachnoid CSF space larger than the subdural space were classified as Group SA. Cases with extremely thin (<3 mm) spaces between the brain and the skull were classified as Group NS., Results: Group SA, SD, and NS accounted for 31.9, 55.6 and 12.5% of cases on the 1st CT. No statistical differences were found between Groups SA, SD, and NS in any clinical factors, including recurrence. Group SA were found significantly more on 1st CT than on 2nd and 3rd CT., Conclusions: Subarachnoid CSF space sometimes expands between the brain and skull on CT after surgical overnight drainage. Expansion of the arachnoid space may be a passive phenomenon induced by overnight drainage and delayed re-expansion of the brain parenchyma.

Background and Objective: To assess the ability of urgent head computed tomography (CT) scan screening to detect patients who can evolve to brain death (BD)., Patients and Method: Patients who underwent urgent head CT scan and meet the following criteria: midline shift greater than 5mm and/or decrease or absence of basal cisterns. A follow-up for 28 days of each patient was made. Epidemiological data (sex, age, cause of brain injury), clinical data (level of consciousness, severity index in the CT) and patient outcomes (death, BD, discharge or transfer) were recorded. This was a prospective observational study., Results: One hundred and sixty-six patients were selected for study, with mean age 60.08 (SD 21.8) years. A percentage of 49.4 were men and the rest women. In the follow-up, 20,5% (n=34) had BD. In univariate analysis, intracerebral hemorrhage, Glasgow Coma Scale score less than 8 and alteration of basal cisterns were statistically significant in predicting BD (P<.05). Multivariate analysis showed that patients with compression of basal cisterns were 20 (95% confidence interval [95% CI] 2.61 to 153.78; P=.004] times more likely to progress to brain death, while the absence there of 62.6 (95% CI 13.1 to 738.8; P<.001] times more., Conclusions: Our work shows that data as easy to interpret as compression/absence of basal cisterns can be a powerful tool for screening patients at risk for progression to BD., (Copyright © 2014 Elsevier España, S.L.U. All rights reserved.)

The purpose of this series was to describe sonographic features of an isolated widened fetal subarachnoid space with a thin cerebral mantle and possible associations. Between January 2004 and December 2013, fetuses with a prenatal diagnosis of a widened subarachnoid space were prospectively recruited and followed. Histories of medical and familial diseases, as well as other demographic data such as drug exposure and lifestyles, were assessed and prospectively recorded. The women were investigated for possible associated factors. Ten pregnant women were recruited. Their fetuses showed various degrees of a widened subarachnoid space, ranging from 5 to 20 mm. Nearly all were diagnosed in the second half of pregnancy. Four cases had normal brain structures documented at midpregnancy anomaly screening. Only 1 case had a prenatal diagnosis of a widened subarachnoid space at 20 weeks' gestation. Two fetuses had exposure to alcohol in utero; 2 were proven to have cytomegalovirus infection; 1 had subarachnoid hemorrhage secondary to maternal use of warfarin; and 1 had a diagnosis of lissencephaly. Only 1 case in this series had normal postnatal development. A prenatal series of fetal widened subarachnoid spaces with possible associated factors is described. Although such relationships were not fully proven, they should be index cases for future studies., (© 2015 by the American Institute of Ultrasound in Medicine.)

The presence of sulcal hyperdensity in patients after endovascular procedures is not necessarily attributable to hemorrhage. It may frequently indicate the absolute or concomitant extravasation of contrast material into the subarachnoid spaces.This case report describes the clinical case of an 84-year-old patient with 90% stenosis of the right internal carotid who presented with a diffuse gyral and sulcal hyperdensity in the right temporal-occipital and frontal lobes at routine post-carotid stenting (CAS) brain CT scan. The patient was asymptomatic and CT findings were interpreted as contrast enhancement hyperattenuation and no therapeutic decisions were made. A 24-hour follow-up brain CT demonstrated the complete resolution of the hyperdensity, confirming the diagnosis.In this patient we considered the concomitant presence of gyral and sulcal hyperdensity as the consequence of reversible damage to the blood-brain barrier (BBB) determining a transitory extravasation of contrast material. Asymptomatic gyral and subarachnoid contrast enhancement following CAS is generally indicative of benign and transitory damage to the BBB and is not to be misinterpreted as hemorrhage., (© The Author(s) 2015 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.)

Despite a variety of diagnostic methods, differentiation of symptoms of normal pressure hydrocephalus from those of atrophic processes of the brain is still a difficult task. In the present study an attempt of non-invasive differential diagnosis of normal pressure hydrocephalus (NPH) and brain atrophy (BA) was presented using volumetric analysis of CT images of the head by means of VisNow proprietary software. The analysis was based on the number of voxels converted to the amount of cerebrospinal fluid (CSF) in the subarachnoid space, skull base casters, and the ventricular system. The results demonstrate that the mean volumes of CSF in these compartments in patients with NPH differed significantly from those in BA. Similarly, the mean volumes of CSF in the subarachnoid space and skull base casters in patients with BA differed significantly from those in NPH. Volumetric assessment presented in the paper by application of VisNow software seems useful in the evaluation of NPH and brain BA.

The recently introduced rabbit blood shunt subarachnoid haemorrhage model is based on the two standard procedures of subclavian artery cannulation and transcutaneous cisterna magna puncture. An extracorporeal shunt placed in between the arterial system and the subarachnoid space allows examiner-independent SAH in a closed cranium. Despite its straightforwardness, it is worth examining some specific features and characteristics of the model. We outline technical considerations to successfully perform the model with minimal mortality and morbidity. In addition, we discuss outcome measures, advantages and limitations, and the applicability of the model for the study of early brain injury and delayed cerebral vasospasm after SAH.

Intradural dermoid cysts may rupture and subsequent subarachnoid dissemination of lipid droplets has been described before. However, the rupture of a spinal dermoid cyst into the central spinal canal is a rare entity. In this context, dissemination of fat into the intracranial subarachnoid space with local progression is a peculiar finding that, to the best of our knowledge, has not been published so far. We describe the case of a 28-year-old man with a dermoid cyst at the upper lumbar level as part of a complex congenital craniospinal malformation, presenting with new unspecific neurologic symptoms. CT and MRI revealed disseminated intraventricular and subarachnoid lipid droplets intracranially and in the spine not present on previous CT and MRI scans obtained eight years earlier. Thus, repeated rupture of a spinal dermoid cyst with subarachnoid spread and/or secondary proliferation should be suspected.

CSF outflow through the cribriform plate near the olfactory nerves and the outflow along brain and spinal nerves are together known as peripheral CSF outflow pathway (PCOP). It is still not clear whether the PCOP has pathogenetic relevance. Our previous clinical observations have indicated that CSF may interact with nerves along the PCOP and in this article we present our finding of CSF outflow demonstrated by myelography in a single patient. We also discuss unexplained experimental pain pathomechanisms against the background of the PCOP hypothesis. We observed that CSF flowed along lumbar nerves in distal direction at a speed of about 10 cm per hour on its way through the tissues, mainly muscles. Total CSF outflow volume at the lumbar site was remarkable. CSF outflow at lumbar nerves was also documented by neuroradiology. It is plausible that CSF signaling serves for interaction with nerves along the PCOP, which could explain previously unknown pathomechanisms in pain generation. Experimental findings of tactile pain hypersensitivity within lumbosacral pain pathways could be explained by releasing of molecules, microparticles, or exosomes into the CSF by mast cells, which then move with CSF outflow along the PCOP and interact with nerves, initiating even retrograde synaptic stripping.

Although the diagnosis of nonsyndromic single suture craniosynostosis (NSSC) can usually be made by clinical examination, computed tomography (CT) is still commonly used in preoperative evaluation. This practice has been questioned in light of recent studies that document a small, but measurable, increased risk of malignancy from CT-associated radiation. The purpose of this study was to examine whether preoperative CT for patients with NSSC provided clinically important information beyond confirmation of craniosynostosis. We performed a retrospective analysis of all patients with NSSC undergoing cranial vault remodeling at our center from March 1999 to March 2011. Only patients with complete preoperative CT scans available for review were included. Staff pediatric neurosurgeons were blinded to patient diagnosis and official radiology report, analyzed the CT images, and documented the site of synostosis and any other findings. Of the 231 patients, 80 met the inclusion criteria. Sites of synostosis included sagittal (51 patients), coronal (17 patients), metopic (11 patients), and frontosphenoidal (1 patient). Clinical diagnosis correlated with radiographic site of fusion in all patients except the patient with frontosphenoidal synostosis. Incidental findings were documented in more than 50% of the patients including prominent extra-axial cerebrospinal fluid (n = 36, 45%), ventriculomegaly (n = 5, 6.25%), choroid fissure cyst (n = 2), cavum septum pellucidum (n = 2), Chiari malformation (n = 1), and prominent perivascular space (clinically nonsignificant finding, n = 1). Incidental findings required additional follow-up or management in 5 patients (6.25%). Our findings support the use of preoperative imaging in this population to identify intracranial anomalies that cannot be discerned by clinical examination. Whereas many findings were not clinically important, some required additional attention.

Cerebrospinal fluid (CSF) dynamics in the spinal subarachnoid space (SSS) have been thought to play an important pathophysiological role in syringomyelia, Chiari I malformation (CM), and a role in intrathecal drug delivery. Yet, the impact that fine anatomical structures, including nerve roots and denticulate ligaments (NRDL), have on SSS CSF dynamics is not clear. In the present study we assessed the impact of NRDL on CSF dynamics in the cervical SSS. The 3D geometry of the cervical SSS was reconstructed based on manual segmentation of MRI images of a healthy volunteer and a patient with CM. Idealized NRDL were designed and added to each of the geometries based on in vivo measurments in the literature and confirmation by a neuroanatomist. CFD simulations were performed for the healthy and patient case with and without NRDL included. Our results showed that the NRDL had an important impact on CSF dynamics in terms of velocity field and flow patterns. However, pressure distribution was not altered greatly although the NRDL cases required a larger pressure gradient to maintain the same flow. Also, the NRDL did not alter CSF dynamics to a great degree in the SSS from the foramen magnum to the C1 level for the healthy subject and CM patient with mild tonsillar herniation (∼ 6 mm). Overall, the NRDL increased fluid mixing phenomena and resulted in a more complex flow field. Comparison of the streamlines of CSF flow revealed that the presence of NRDL lead to the formation of vortical structures and remarkably increased the local mixing of the CSF throughout the SSS.

External hydrocephalus (EH) is a benign clinical entity in which macrocephaly is associated with an increase in volume of the subarachnoid space, especially overlying both frontal lobes, and a normal or only slight increase in volume of the lateral ventricles. Several pathogenic hypotheses have been proposed but the most accredited theory seems to be delayed maturation of the arachnoid villi. There is a consensus that this is a benign entity, correlated to a familial predisposition and, in some cases, inheritance. CT and MRI are very important to make a diagnosis but also to establish the prognosis in patients who encounter the rare complications such as subdural haematomas. In conclusion, CT and MRI can provide a highly accurate diagnosis in these patients, allowing a preliminary assessment of the prognosis, particularly regarding the enlarged subarachnoid space limits and the "cortical vein" sign which can predict a further complication. These results are obtained with the same examination performed in a standard CT or MRI study of the brain and no injection of contrast medium is needed.

Objective: To investigate the reason for and the course of the double-layer appearance in the postoperative computed tomographies (CTs) of chronic subdural hematoma (CSDHs)., Methods: We reviewed CSDH cases that were operated on during the last 3 years, between January 2008 and December 2010. We checked the preoperative, early postoperative, and late postoperative CTs of these patients. We investigated the relationship between the formation of a double-layer appearance and the prognoses and demographic characteristics of the patients., Results: Our database included 119 cases. A double-layer appearance was found in the postoperative CTs of 34 cases. The mean age of double-layer cases was older (72.5 ± 12.1) than that of the remaining 85 cases (63.1 ± 17.8). We did not find any relationship between the double-layer appearance and the reoperation/recurrence/death rates., Conclusions: The double-layer appearance after evacuation of a CSDH might be caused by enlargement of the subarachnoid space and is not related to the presence of any residual hematoma. This appearance is not considered as a reason for reoperation.

Background and Purpose: The relationship between enlarged subarachnoid spaces and subdural collections is poorly understood and creates challenges for clinicians investigating the etiology of subdural collections. The purpose of this study was to determine the prevalence of subdural collections on cross sectional imaging in children with macrocephaly correlating with subarachnoid space enlargement., Materials and Methods: The radiology information system of a large pediatric medical center was reviewed for "macrocrania" and "macrocephaly" on reports of cranial MRI/CT examinations in children <24 months of age, over a 24-month period. Head circumference was obtained from the clinical record. Studies were reviewed blindly for subdural collection presence and subarachnoid space size. Children with prior cranial surgery, parenchymal abnormalities, hydrocephalus, or conditions predisposing to parenchymal volume loss were excluded. Chart review was performed on those with subdural collections., Results: Imaging from 177 children with enlarged head circumference was reviewed. Nine were excluded, for a final cohort of 168 subjects (108 with enlarged subarachnoid space). Subdural collections were identified in 6 (3.6%), all with enlarged subarachnoid space (6/108, 5.6%). In 4, subdural collections were small, homogeneous, and nonhemorrhagic. In 2, the collections were complex (septations or hemorrhage). Two children were reported as victims of child abuse (both with complex collections). No definitive etiology was established in the other cases., Conclusions: The prevalence of subdural collections in imaged children with macrocrania was 3.6%, all occurring in children with enlarged subarachnoid space. Our results suggest that enlarged subarachnoid space can be associated with some subdural collections in this cohort. Despite this, we believe that unexpected subdural collections in children should receive close clinical evaluation for underlying causes, including abusive head trauma.

Objectives: Failed lumbar puncture (LP) is a common indication for referral for radiologically guided LP. This study aims to evaluate what percentage of the hospital population would fail an LP using a standard 9-cm needle because of obesity and a skin to subarachnoid space distance greater than 9 cm., Methods: Images of 402 consecutive patients undergoing computed tomography of the abdomen and pelvis were reviewed. Skin to subarachnoid space distance was calculated using sagittal images. A survey was conducted among junior hospital doctors to assess their experience of performing lumbar puncture in obese patients., Results: Four hundred patients were included. Fifty-five patients (13.8 %) had a skin to subarachnoid space distance greater than 9 cm. Intra-abdominal fat, subcutaneous fat and abdominal girth correlated with distance between the skin and subarachnoid space. Among junior doctors, 68.3 % (n = 41) reported LP failure on an obese patient; 78.4 % (n = 47) were unaware of the existence of a longer needle and 13.3 % (n = 8) had experience using a longer needle., Conclusions: A significant proportion of the hospital population will fail LP with a standard length spinal needle. Selecting a longer needle may be sufficient to successfully complete LP in obese patients., Key Points: • Lumbar puncture failure commonly leads to referral for an image-guided procedure • Standard lumbar puncture may fail in 13.8 % of patients due to obesity • 78.4 % of trainee doctors are unaware of the existence of longer spinal-needles • Using longer spinal needles may allow successful LP in obese patients.

Cerebral air embolism is a rare complication of central venous catheterization. A 61-year-old man developed a left-sided hemiparesis immediately after his right jugular venous catheter removal. A diffusion-weighted magnetic resonance imaging (MRI) obtained 2 h after the symptom onset was normal. However, postgadolinium cerebral spinal fluid enhancement was seen on fluid-attenuated inversion-recovery MRI. A repeat diffusion-weighted MRI, 18 h later, showed restricted diffusion in the bilateral hemispheres. Disruption of the blood-brain barrier caused by the air bubbles might lead to accumulation of gadolinium in the subarachnoid space. Postgadolinium cerebral spinal fluid enhancement may be an early, sensitive predictor of blood-brain barrier disruption and impending cerebral infarct after air embolism.

Background: For unilateral spinal block, local anesthetics should affect the spinal nerves of 1 side. With full flexion of the spine, the sunken cauda equina becomes tightened and is suspended in the middle of the subarachnoid space. We performed this study to assess whether spinal flexion facilitates unilateral spinal anesthesia., Methods: Hyperbaric bupivacaine (8 mg) was administered at the L3-4 interspace through a 25-gauge Quincke needle at a rate of 0.02 mL/s. Patients were randomly allocated to group F (with full spinal flexion) or group N (the hips and back straightened). After maintaining the lateral position for 15 minutes with or without spinal flexion, patients were gently returned to the supine position. Spinal blockade was assessed by loss of pinprick sensation and the modified Bromage motor scale., Results: While the lateral position was maintained, sensory block was noted on the nondependent side in 14 of 16 patients in group N (87.5%) but only in 1 of 16 patients in group F (6.3%) (P < 0.001). The median level of sensory block in group N was L5 on the nondependent side just before turning to the supine position. When patients were returned to the supine position, sensory blockade on the nondependent side was noted in all group N patients (100%) and 15 group F patients (93.7%). The sensory level on the nondependent side between group N and group F were similar after turning supine., Conclusions: Strict unilateral sensory block was not achieved even after lateral decubitus positioning with spinal flexion, when 8 mg hyperbaric bupivacaine was administered manually at a conventionally slow rate through a beveled spinal needle. However, maintaining flexion of the spinal column during lateral decubitus positioning altered the initial onset of sensory block with respect to laterality.

Objectives: Aim of this study was to compare the utility of susceptibility weighted imaging (SWI) with the established diagnostic techniques CT and fluid attenuated inversion recovery (FLAIR) in their detecting capacity of subarachnoid hemorrhage (SAH), and further to compare the combined SWI/FLAIR MRI data with CT to evaluate whether MRI is more accurate than CT., Methods: Twenty-five patients with acute SAH underwent CT and MRI within 6 days after symptom onset. Underlying pathology for SAH was head trauma (n=9), ruptured aneurysm (n=6), ruptured arteriovenous malformation (n=2), and spontaneous bleeding (n=8). SWI, FLAIR, and CT data were analyzed. The anatomical distribution of SAH was subdivided into 8 subarachnoid regions with three peripheral cisterns (frontal-parietal, temporal-occipital, sylvian), two central cisterns and spaces (interhemispheric, intraventricular), and the perimesencephalic, posterior fossa, superior cerebellar cisterns., Results: SAH was detected in a total of 146 subarachnoid regions. CT identified 110 (75.3%), FLAIR 127 (87%), and SWI 129 (88.4%) involved regions. Combined FLAIR and SWI identified all 146 detectable regions (100%). FLAIR was sensitive for frontal-parietal, temporal-occipital and Sylvian cistern SAH, while SWI was particularly sensitive for interhemispheric and intraventricular hemorrhage., Conclusions: By combining SWI and FLAIR, MRI yields a distinctly higher detection rate for SAH than CT alone, particularly due to their complementary detection characteristics in different anatomical regions. Detection strength of SWI is high in central areas, whereas FLAIR shows a better detection rate in peripheral areas., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

Objective: To evaluate nocturnal polysomnogram findings in children with suspected symptomatic Chiari type I malformation, correlate them with clinical and magnetic resonance imaging data and to determine if this information has value in clinical decision making process., Methods: A retrospective review identified 24 children with type I Chiari malformation, presumed symptomatic who had undergone neurological assessment, cranial magnetic resonance imaging and nocturnal polysomnography. Perimedullary subarachnoid space effacement on the magnetic resonance studies and the magnitude of cerebellar tonsillar descent in relation to the McRae line were correlated with frequency of obstructive or central sleep apnea, number of cortical arousals and evidence of impaired vocal mobility on laryngoscopy. The Wilcoxon rank sum test was applied for continuous variables and the Fisher exact test for categorical variables., Results: The median age of the subjects was 6 years. The findings from 16/24 subjects with perimedullary subarachnoid space effacement (effaced group) were compared with those of 8/24 in the non-effaced group. The central apnea index [1.5 (IQR 1-3.5) versus 0.5 (IQR 0-1.5)] and cortical arousal index [12 (IQR 10-19) versus 8 (IQR 6.5-9)] were significantly higher in the effaced group than in the non-effaced group (p=0.0376 and 0.0036 respectively). Greater descent of tonsils as measured by distance from the McRae line to the tonsil tip was associated with significantly higher central apnea index, total arousal index and respiratory event related arousals. Measurements of clivus-canal angle, Klauss index and pB-C2 line did not correlate with abnormalities on polysomnography., Conclusion: The central apnea and arousal indices derived from the nocturnal polysomnogram correlate well with magnetic resonance imaging findings of subarachnoid space effacement and degree of tonsillar herniation. In children with Chiari type I malformation, the nocturnal polysomnogram findings provides important information that aids in the decision making process about proceeding with surgical decompression., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Background: Babies born before 28 weeks' gestation have lower plasma thyroid hormone concentrations than more mature infants. This may contribute to their risk of poor developmental outcome. Previous studies have suggested that thyroxine supplementation for extremely preterm neonates may be beneficial. The aim of this study was to investigate the effect of administration of supplemental thyroxine to very premature babies on brain size and somatic growth at 36 weeks' corrected gestational age (CGA)., Methods: In this explanatory multicentre double blind randomised placebo controlled trial, 153 infants born below 28 weeks' gestation were randomised to levothyroxine (LT4) supplementation or placebo until 32 weeks' CGA. The primary outcome was brain size assessed by the width of the subarachnoid space measured by cranial ultrasound at 36 weeks' CGA. Lower leg length was measured by knemometry., Results: Babies in the LT4-supplemented and placebo groups had similar baseline characteristics. There were no significant differences between infants given LT4 (n=78) or placebo (n=75) for width of the subarachnoid space, head circumference at 36 weeks' CGA, body weight at 36 weeks' CGA or mortality. Infants who received LT4 had significantly shorter leg lengths at 36 weeks' CGA although adjusted analysis for baseline length did not find a statistical difference. There was a significant correlation between low FT4 and wider subarachnoid space. No unexpected serious adverse events were noted and incidence of adverse events did not differ between the two groups., Conclusion: This is the only randomised controlled trial of thyroxine supplementation targeting extremely premature infants. Supplementing all babies below 28 weeks' gestation with LT4 had no apparent effect on brain size. These results do not support routine supplementation with LT4 for all babies born below 28 weeks' gestation., Trial Registration: Current Controlled Trials ISRCTN89493983EUDRACT number: 2005-003-09939.

Gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA) is a contrast agent commonly used for enhancing MRI. In this paper, the authors report on 2 cases of postoperative inadvertent administration of Gd-DTPA directly into a ventriculostomy tubing side port that was mistaken for intravenous tubing. Both cases demonstrated a low signal on MRI throughout the ventricular system and dependent portions of the subarachnoid spaces, which was originally believed to be CSF with areas of T1 shortening in the nondependent portions of the subarachnoid spaces, and misinterpreted as basal leptomeningeal enhancement and meningitis. The authors propose that the appearance of profound T1 hypointensity within the ventricles and diffuse susceptibility artifact along the ependyma is pathognomonic of intraventricular Gd-DTPA and should be recognized.

Background: The subarachnoid space (SAS) and ventricular width (VW) in normal infants and children were studied with ultrasonography to provide the objective measurement and define a normal range for these measurements. The additional aim was to determine the stable ratio as a SAS/VW., Materials and Methods: A total of 100 healthy subjects, including 48 males and 52 females, were studied. The cases were divided into 3 age groups: 0-6 months(n = 65), 7-12 months (n = 24) and > 13 months (n = 11). Transfontanel ultrasonography was performed in all the cases. SAS, VW and the SAS/VW ratios were calculated. The study was approved by the ethical committee. All parents were informed about the sonographic examination and their approvals were taken., Results: SAS was calculated as 3.1 (0.5-6) mm and VW was calculated as 3.6(1.3-5) mm. SAS/VW ratio was 0.9 ± 0.3. There was no statistically significant difference among SAS, VW and SAS/VW ratios in 3-97 percentile group (p > 0.05)., Conclusions: Ultrasonography can be used as a practicable and reproducible modality in the measurement of SAS and VW in healthy children. It is a non-invasive method and allows for serial follow-up. SAS/VW ratio can be used as an index in healthy children.

Objective: The objective of this study was to determine whether subarachnoid space width at the site of lumbar puncture in infants changed between 3 positions: flat lateral decubitus, 45-degree tilt, and sitting., Methods: Healthy infants younger than 4 months presenting electively to a pediatric radiology department were enrolled. Exclusion criteria included signs of dehydration, illness, or previous spine/brain surgery. Subarachnoid space width at L3-L4 was measured by ultrasound with the subject placed in 3 randomly ordered positions: flat lateral decubitus, 45-degree tilt lateral decubitus, and sitting. The 3 positions were collectively compared using both repeated-measures analysis of variance and linear mixed models (LMMs) adjusted for potential confounders. Pairs of positions were compared using LMM adjusted for potential confounders., Results: Fifty subjects were enrolled (15 male and 35 female patients). Patient weight was significantly correlated with subarachnoid space width (P = 0.02). There was no statistically significant difference in subarachnoid space width between the 3 positions (repeated-measures analysis of variance P = 0.32, LMM P = 0.40). Comparisons of pairs of positions were not significantly different: flat and 45 degrees P = 0.24, 45 degrees and sitting P = 0.98, and flat and sitting P = 0.23., Conclusions: The subarachnoid space width did not significantly change between the 3 positions. An increase in lumbar puncture success rate with sitting or tilt position could be due to other factors such as increased cerebrospinal fluid pressure, increased interspinous space widening, or improved identification of landmarks.

The authors report a case in which intravitreous silicone oil migrated into the ventricles. They note that intraventricular silicone oil can be misdiagnosed as intraventricular hemorrhage and neurosurgeons should be aware of this possibility. This 58-year-old woman with a history of Type II diabetic mellitus and retinal detachment (resulting from diabetic retinopathy), which had been treated with intravitreous silicone tamponade, presented with dizziness and headache approximately 10 years after the intravitreous silicone treatment. Over the next 6 years she underwent 2 non-contrast-enhanced brain CT studies and 1 MRI study for evaluation of her symptoms. On CT scan, extension of the intraocular silicone along the optic nerve was evident. Two hyperdense nodules were observed freely floating in the right lateral and fourth ventricles, remaining in the nondependent portion of ventricles in both supine and prone positions. On T2-weighted MRI, the left orbital content and the intraventricular nodules all demonstrated chemical shift artifacts typically associated with silicone. The imaging findings were characteristic for intraventricular silicone after silicone oil tamponade. The patient's dizziness and headache were treated symptomatically and she was followed up at the outpatient department. Migration of intravitreous silicone oil into the cerebral ventricles is a rare complication. Intraventricular silicone oil can mimic intraventricular hemorrhage. Radiographically, intraventricular silicone oil can be distinguished from hemorrhage as silicone oil tends to stay in the nondependent portion of the ventricle. Chemical shift artifacts on MRI may help establishing the diagnosis of intraventricular silicone oil. Currently, there is no consensus on surgical removal of intraventricular silicone oil, and in the majority of cases reported in the literature, the patients were asymptomatic.

Myelo-computed tomography of a paraparetic 14-year-old dog revealed subarachnoid distension with an intradural filling defect above the T13-L1 disc space. T12-L1 hemilaminectomy followed by durotomy allowed removal of a large piece of degenerated disc material that compressed the spinal parenchyma. Full return to function was achieved 10 days post-surgery. The distension was likely secondary to the intradural herniation, and is a rare and distinct finding.

Rebleeding leads to lots of patients' disability and mortality after spontaneous subarachnoid hemorrhage (SAH), but the risk factors of rebleeding have not been fully understood. More evidence showed apolipoprotein E (apoE protein, APOE gene) influenced the outcome of spontaneous SAH. In this study, we aimed to investigate the relationship of APOE polymorphisms with rebleeding after spontaneous SAH. A total of 185 patients with spontaneous SAH were involved in the current study. Genomic DNA was extracted from venous blood samples to identify the APOE genotype by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Rebleeding was defined as acute clinical deterioration that was accompanied by computed tomography (CT) evidence of rebleeding in the subarachnoid space. A total of 21 patients occurred rebleeding in 185 patients with spontaneous SAH in the hospital. Data were analyzed by χ(2)-test and logistic regression analyses. The statistical analysis indicated no significant association between APOE genotype and rebleeding in a Chinese population.

Objectives: The symptom and neuroimaging as indications for treating arachnoid cysts (ACs) are not adequate. Understanding the communication between cyst and subarachnoid space is helpful for decision-making. We took a dynamic study of ACs using CT cisternography (CTC) and proposed a classification of arachnoid cysts., Materials and Methods: Total 52 symptomatic patients with ACs were enrolled in this prospective study. CTC images were ordered, in all enrolled patients, at the 1, 3, 6, 12, 24 and 48 h after the intrathecal Omnipaque administration. Enhancement in cysts was measured quantitatively and was compared with neighboring subarachnoid spaces. All enrolled patients were allocated randomly in 2 groups. The CTC result was considered before treatment in one group (CTC group), while another group was surgically treated without considering CTC results (surgical group)., Results: ACs in our study were classified into 3 types: complete (cyst filling time at 1 h), incomplete (filling time began at 3 h) and noncommunicating cysts (no or slight filling after 24 h). Twenty-two patients in CTC group with incomplete communicating, or noncommunicating cysts underwent surgeries. And other 6 patients with complete communicating cysts were closely observed. In CTC group, the symptom of all surgical patients was relieved, and 5 out of 6 observational patients showed clinical improvement or no deterioration during the follow-up. In surgical group, only 18 out of 24 patients showed clinical improvement after surgeries, and there were 6 patients showing no difference before and after surgeries in symptom and in imaging., Conclusions: This classification based on dynamic CT cisternography is useful for the decision of surgical indication. Some symptomatic patients with complete communicating ACs may not need surgical intervention., (Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.)

Study Design: Quantitative in vivo ultrasound imaging study of spinal cord and dura morphology after acute experimental spinal cord injury (SCI) and decompression in a pig model., Objective: To study the morphological changes of the spinal cord and dura immediately after surgical decompression for acute SCI., Summary of Background Data: Surgical decompression for traumatic SCI is currently a topic of debate. After decompression, relief of bony impingement on the thecal sac and spinal cord can be confirmed intraoperatively. However, postoperative imaging often reveals that the cord has swollen to fill the subarachnoid space. Little is known about the extent and timing of this morphological response., Methods: Yucatan miniature pigs received sham surgery (N = 1) or a moderate (N = 6, 20 g, 2.3 m/s) or high (N = 6, 20 g, 4.7 m/s) severity weight-drop SCI followed by 8 hours of sustained compression (100 g) and 6 hours of postdecompression monitoring. Sagittal-plane ultrasound images were used to quantify spinal cord, dura, and subarachnoid space dimensions preinjury and once per hour after decompression., Results: Animals with a moderate SCI exhibited a residual cord deformation of up to 0.64 mm within 10 minutes of decompression, which tended to resolve during 6 hours because of tissue relaxation and swelling. For animals with high-severity SCIs, cord swelling was immediate and resulted in occlusion of the subarachnoid space within 10 minutes to 5 hours, whereas this occurred for only half of the moderate injury group., Conclusion: Decompression of an acute SCI may result in residual cord deformation followed by gradual swelling or immediate swelling leading to subarachnoid occlusion. The response is dependent on initial injury severity. These observations may partly explain the lack of benefit of decompression in some patients and suggest a need to reduce cord swelling to optimize the clinical outcome after acute SCI.

Background and Objectives: To assess the accuracy of the ultrasound (US) to predict the depth to reach lumbar intrathecal and epidural spaces in order to decrease the number of puncture attempts., Methods: Thirty-one patients (25 males and 6 females), ASA I or II participated in this study. The transversal ultrasound image of the lumbar spine was obtained at the level of the L3-L4 space. An anesthesiologist without prior information performed the spinal anesthesia through the predicted target area. The distance between the skin and the anterior portion of the flavum ligamentum which is supposedly the bottom limit of the intrathecal depth or an approximation of the depth of the epidural space (ED-US) was measured by ultrasound and it was compared with the distance between the skin and the anterior portion of the flavum ligamentum on the needle (ED-N)., Results: ED-US and ED-N were respectively 5.15±0.95cm and 5.14±0.97cm; these distances were not significantly different (p>0.0001). A significant correlation r=0.982 [95% CI 0.963-0.992, p>0.0001] was observed between the ED-US and ED-N measurements. Bland-Altman analysis showed an accuracy of 0.18cm; tolerated variations ranged from -0.14cm to -0.58cm., Conclusions: This study supports the idea that the US transversal plane allows the identification of axial anatomical structures and provides physicians with efficient information to perform spinal anesthesia., (Copyright © 2012 Elsevier Editora Ltda. All rights reserved.)

Aim: To report on the cerebrospinal fluid (CSF) exchange between the intracranial spaces (ie, basal cisterns) and the subarachnoid space (SAS) of the optic nerve (ON) in subjects with normal-tension glaucoma (NTG) compared with control subjects without NTG or other forms of glaucoma., Methods: CT cisternography of the brain and orbits was performed in 18 patients with NTG (7 women, 11 men; mean age 64.9 ± 8.9 years) and in four patients without glaucoma or intracranial disease (4 women; mean age 62.8 ± 18.4 years). The density of contrast-loaded cerebrospinal fluid (CLCSF) in the intracranial spaces and in the SAS surrounding the ONs was measured in Hounsfield units., Study Design: Unmasked, prospective series. Statistical analysis was performed using an independent two-tailed t test and the non-parametric Spearman correlation test., Results: The density of CLCSF in the SAS surrounding the ONs in the NTG group was significantly reduced compared with its density in the intracranial CSF spaces and in the SAS of ONs measured in the control group (p=0.006). There were no significant differences between men and women within the NTG group (p>0.35)., Conclusions: The finding of a difference in the concentration gradients between the CLCSF within the intracranial spaces and the SAS of the ONs in this group of NTG patients compared with control subjects supports the hypothesis of a disturbed CSF exchange between the CSF in the intracranial spaces and the CSF in the SAS surrounding the ONs. The disturbance of CSF dynamics in this specific CSF pathway can be explained by ON compartmentation. The clinical importance of this finding warrants further investigation.

Background: In the past, sporadic demonstrations of the existence of a subarachnoid subdiaphragmatic cistern have been published. The aim of this study was to evaluate the anatomical characteristics of the subdiaphragmatic cistern of the pituitary gland., Methods: After a complete review of the literature published on the topic, we report anatomical observations of the subdiaphragmatic cistern and its relationship to the pituitary gland and to the chiasmatic cistern. Ten cadaveric heads were studied using different techniques and surgical methods (plastination, plastic casts of the subarachnoid spaces, microscopic and transsphenoidal endoscopic approaches). Moreover, 3-T magnetic resonance images of ten healthy volunteers were analyzed to investigate the presence and anatomical variability of the subdiaphragmatic cistern., Results: By means of our qualitative radioanatomic study, we found that the roof of the subdiaphragmatic cistern is formed by the diaphragma sellae, the floor by the superior face of the pituitary gland, the lateral walls by the arachnoidea extending laterally through the medial walls of the cavernous sinus, and the medial walls by the infundibular stem. The subdiaphragmatic cistern communicates by means of the ostium of the diaphragm with the chiasmatic cistern., Conclusion: We confirmed the existence of the subdiaphragmatic cistern. The overused term "suprasellar cistern" refers more to a complex of cisterns, formed by the subdiaphragmatic cistern, below the diaphragma sella, and by the chiasmatic cistern, above it, in direct communication with the lamina terminalis and carotid cisterns.

Horses with intracranial lesions and severe ataxia are not good anesthesia candidates; however, only one method to obtain cerebrospinal fluid (CSF) from the cervical region in a standing horse has been reported. This method is not performed routinely due to the difficulty for sample acquisition. Our hypothesis is that standing cervical centesis can be performed in horses without complication. Ultrasound-guided centesis of the CSF between C1 and C2 in 11 clinically normal horses and two horses with neurologic signs were performed. Horses were sedated and ultrasound was used to identify the subarachnoid space and spinal cord between C1 and C2. With ultrasound guidance, a needle was introduced into the dorsal aspect of the subarachnoid space using a lateral approach. Ten milliliters of CSF was obtained and analyzed. Two normal horses in this study had moderate red blood cell contamination in the CSF (940 and 612 RBC/microl). One horse had 11 RBC/microl and the remaining horses had < 4 RBC/microl. The total procedure time was approximately 2 min. No reaction was observed and no complications were detected up to 48 h after the procedure. Ultrasound-guided centesis between C1 and C2 is a rapid procedure that causes minimal to no reaction in standing, sedated horses used in this study. The use of ultrasound to guide a standing C1-2 centesis of the subarachnoid space provides an additional route to obtain CSF for analysis in the equine patient.

This paper analyses the case reports for three children in which a papilledema occurred before the age of one year. Furthermore, an analysis is also given of three further case reports for children aged less than one year in which, in spite of open fontanelle, no papilledema was found, however, a dilatation of the sub-arachnoidal space was demonstrated echographically. Even in children less than one year of age in which an open fontanelle still exists and in whom a neuro-paediatric clarification of internal hydrocepalus is made, in spite of opththalmoscopically inconspicuous findings for the papilla an echography is indispensable for the evaluation of the sub-arachnoidal space. Here, the early recognition of a dilatation of the retro-bulbar sub-arachnoidal space can possibly prevent the occurrence of a consecutive optic atrophy. At the present time, the data available do not allow the recommendation of an upper age limit for an echographic examination., (© Georg Thieme Verlag KG Stuttgart · New York.)

Pseudo-subarachnoid hemorrhage (PSAH) is a false-positive finding on cranial computed tomography (CT) in patients with cerebral edema. Its appearance on CT resembles subarachnoid hemorrhage despite the absence of subarachnoid blood. We report the finding of PSAH in a case of massive valproic acid overdose.

Reasons for Performing Study: Despite modern medical diagnostic imaging, it is not possible to identify reliably the exact location of spinal cord compression in horses with cervical vertebral stenotic myelopathy (CVSM). Vertebral canal endoscopy has been successfully used in man and a technique for cervical vertebral canal endoscopy (CVCE) has been described in equine cadavers., Objective: To determine the feasibility and safety of CVCE in healthy mature horses., Methods: Six healthy mature horses were anaesthetised. A flexible videoendoscope was subsequently introduced via the atlanto-occipital space into the epidural space (epiduroscopy, Horses 1-3) or the subarachnoid space (myeloscopy, Horses 4-6) and advanced to the 8th cervical nerve. Neurological examinations were performed after surgery and lumbosacral cerebrospinal fluid (CSF) analysed in horses that had undergone myeloscopy., Results: All procedures were completed successfully and all horses recovered from anaesthesia. Anatomical structures in the epidural space (including the dura mater, nerve roots, fat and blood vessels) and subarachnoid space (including the spinal cord, blood vessels, arachnoid trabeculations, nerve roots and the external branch of the accessory nerve) were identified. During epiduroscopy, a significant increase in mean arterial pressure was recognised, when repeated injections of electrolyte solution into the epidural space were performed. In one horse of the myeloscopy group, subarachnoid haemorrhage and air occurred, resulting in transient post operative ataxia and muscle fasciculations. No complications during or after myeloscopy were observed in the other horses. CSF analysis indicated mild inflammation on Day 7 with values approaching normal 21 days after surgery., Conclusions: Endoscopic examination of the epidural and subarachnoid space from the atlanto-occipital space to the 8th cervical nerve is possible and can be safely performed in healthy horses., Potential Relevance: Cervical vertebral canal endoscopy might allow accurate identification of the compression site in horses with CVSM and aid diagnosis of other lesions within the cervical vertebral canal., (© 2011 EVJ Ltd.)

Background: Intraspinal navigation with catheters and fiberscopes has shown feasible results for diagnosis and treatment of intraspinal and intracranial lesions. The most common approach, lumbar puncture, has allowed access to the spinal cord, however, coming with the difficulties of fiberscope damage and decreased torque for guidance. Our objective in this study is to allow an alternate access, the sacral hiatus, with guide wire assistance into the subarachnoid and intracranial structures, while easing the angle of entry and increasing torque., Methods: We advanced catheters with guide wire and fluoroscopy assistance into the sacral hiatus of three cadavers. After entry, the thecal sac was punctured and the catheter with guide wire was advanced rostrally until positioned in the basal cisterns of the brain. We confirmed catheter placement with contrast injection, autopsy, and dissection., Results: In our study, the sacral hiatus was easily accessed, but resistance was found when attempting to puncture the thecal sac. The advancement of the catheter with guide wire assistance glided easily rostrally until some mild resistance was discovered at entry into the foramen magnum. With redirection, all catheters passed with ease into the basal cisterns. Positioning was confirmed with contrast injection with fluoroscopy evidence, autopsy, and dissection. There was no macroscopic or microscopic evidence of damage to the spinal roots, spinal cord, or cranial nerves., Conclusion: The sacral hiatus with guide wire assistance is an accessible conduit for uncomplicated entry into the subarachnoid and basal cistern space without damaging surrounding structures.

Background: Acute and unexpected neuropsychiatric disturbances can herald subarachnoid haemorrhage (SAH). We investigated the risk factors for neuropsychiatric disturbances in acute SAH and analysed the relation between neuropsychiatric disturbances and location and amount of haematic densities and hydrocephalus., Methods: We assessed a sample of 108 consecutive patients with an acute (≤ 4 days) SAH (61 aneurysmal, 47 non-aneurysmal SAH), before aneurysmal treatment, using DSM-IV-TR criteria and the Montgomery Åsberg Depression Rating Scale and Mania Rating Scale, the Denial of Illness Scale, the Catastrophic Reaction Scale and the Apathy Evaluation Scale, excluding patients with severe consciousness or language disturbance. Performance on each scale was related to (i) the total amount of haematic densities in 10 basal cisterns/fissures and in the four ventricles, using the Hijdra et al. rating scale, (ii) the haematic densities in the prepontine cistern and the convexity of the brain and (iii) hydrocephalus., Results: Depression (45%), apathy (42%), denial (21%) and catastrophic reaction (17%) were frequent in acute SAH patients. Mania was present in two patients. Denial was associated with higher haematic densities in the left and right basal sylvian fissure and in the 4th ventricle (P < 0.01) and with hydrocephalus (P = 0.05). Catastrophic reaction and depression were associated with previous mood disorder (P < 0.007). Apathy was associated with blood in the left or right lateral ventricles (P < 0.03)., Conclusions: In the first 4 days of SAH, depression, apathy, catastrophic reaction and denial were rather frequent. SAH haematic densities were associated with denial and apathy, but not with depression, mania or catastrophic reaction., (© 2010 The Author(s). European Journal of Neurology © 2010 EFNS.)

Aims: To determine cerebrospinal fluid (CSF) dynamics between intracranial CSF spaces and CSF in the subarachnoid space (SAS) of optic nerves (ONs) in 10 patients with papilloedema., Methods: Prospective assessment of 10 patients with papilloedema and two control subjects using CT cisternography and analysis of CSF for the presence of lipocalin-like prostaglandin D synthase (betatrace protein)., Results: CT cisternography showed a progressively reduced influx of contrast-loaded CSF from intracranial CSF spaces into the SAS. The lowest concentration of contrast-loaded CSF was found in the region of the ON immediately behind the globe, where the ON sheath was widened (possibly by unfolding) in all patients compared with normal subjects. The concentration of lipocalin-like prostaglandin D synthase differed between the spinal CSF and the CSF in the SAS, with a markedly higher concentration in the SAS., Conclusion: The results of this study suggest that CSF turnover in the SAS of the ON is reduced in patients with papilloedema from various causes and that the composition of CSF differs between spinal CSF and that surrounding the ON.

Background Context: Traumatic pneumorrhachis (PR) is a rare entity, consisting of air within the spinal canal. It can be classified as epidural or subarachnoid, identifying the anatomical space where the air is located, and is associated with different etiologies, pathology, and treatments., Purpose: To conduct a systematic review of the scientific literature focused on the etiology, pathomechanism, diagnosis, and treatment of PR, and to report a case of an asymptomatic epidural type., Study Design: International medical literature has been reviewed systematically for the term "traumatic pneumorrhachis" and appropriate related subject headings, such as traumatic intraspinal air, traumatic intraspinal pneumocele, traumatic spinal pneumatosis, traumatic spinal emphysema, traumatic aerorachia, traumatic pneumosaccus, and traumatic air myelogram. All cases that were identified were evaluated concerning their etiology, pathomechanism, and possible complications., Samples: Studies that included one of the aforementioned terms in their titles., Methods: A systematic review was performed to identify, evaluate, and summarize the literature related to the term "traumatic pneumorrhachis" and related headings. Furthermore, we report a rare case of an asymptomatic epidural PR extending to the cervical and thoracic spinal canal. We present the current data regarding the etiology, pathomechanism, diagnosis, and treatment modalities of patients with PR., Results: The literature review included 37 related articles that reported 44 cases of traumatic PR. Only isolated case reports and series of no more than three cases were found. In 21 cases, the air was located in the epidural space, and in 23 cases, it was in the subarachnoid space. Most of the cases were localized to a specific spinal region. However, eight cases extending to more than one spinal region have been reported., Conclusions: Traumatic PR is an asymptomatic rare clinical entity and often is underdiagnosed. It usually resolves by itself without specific treatment. We stress the significance of this information to trauma specialists, so that they may better differentiate between epidural and subarachnoid PR. This is of great significance because subarachnoid PR is a marker of severe injury. The management of traumatic PR has to be individualized and frequently requires multidisciplinary treatment, involving head, chest, and/or abdomen intervention., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Objective: It has been shown that the components of the vertebral canal (dura mater, pia mater, subarachnoid space, spinal cord parenchyma and central canal) can be visualized intraoperatively with the help of ultrasonography. This study was conducted to document the intraoperative sonographical findings of disc extrusion and to determine imaging criteria for the localisation of the extrusion and the consecutive changes of the spinal cord parenchyma., Material and Methods: 43 dogs of different breeds with a diagnosed disc extrusion were sonographically examined immediately after establishing the surgical decompression (hemilaminectomy, laminectomy, ventral slot) (examination 1) and again after removal of disc material (examination 2)., Results: In all 34 patients the extruded disc material could be imaged sonographically appearing as inhomogenous, hyperechoic areas of moderate echogenicity. There was a distal shadowing dependent on the grade of calcification in 53% of the patients in examination 1 and in 79% at examination 2. Furthermore, a tendency towards a central localisation of the disc prolapse (67.6% in examination 1 and 57.1% examination 2) was observed. Intraoperative identification of disc extrusion could be accomplished in 79% of the cases. Intraoperative haemorrhage highly significantly impaired the assessment of the spinal cord (p<0.0001)., Conclusion: Intraoperative spinal ultrasonography using a linear probe with a frequency from 5 to 10 MHz is a valuable tool for the visualization of spinal structures. It provides information for intraspinal navigation and evaluation of the extent of spinal lesions as well as the state of decompression. Bleeding has a negative influence on the visualization of the spinal canal.

A 61-year-old woman presented with aneurysmal subarachnoid hemorrhage (SAH) associated with multiple remote intracerebral hemorrhages (ICHs). She had undergone microsurgical neck clipping for ruptured right middle cerebral artery aneurysm and ventriculo-peritoneal shunting 16 years previously. Computed tomography revealed SAH predominantly in the basal cistern and ambient cistern, in association with multiple ICHs in the bilateral tegmentum of the brain stem and right caudate nucleus. Digital subtraction angiography revealed an aneurysm at the P(1) segment of the left posterior cerebral artery. The ruptured aneurysm was microsurgically clipped via a left subtemporal approach without complications. Simultaneous occurrence of aneurysmal SAH and multiple remote ICHs is rare. The spatial pattern of the ICHs in the present case is apparently unique.

Neurocysticercosis is an endemic disease in Latin America, Asia and Africa with growing occurrence in industrialized countries due to the increase in migration from low- and middle-income to high-income countries. The most severe clinical presentation is when the parasite is located in the subarachnoid space at the base of the brain (NCSAB). Aside from its clinical presentation, the severity of this form of the disease is due to the difficulties in diagnosis and treatment. Although NCSAB frequency is lower than that reported for the parenchymal location of the parasite, its clinical relevance must be emphasized. We provide a critical review of the central epidemiological, clinical, diagnostic and therapeutic features of this particular form of the disease, which is still associated with unacceptably high rates of morbidity and mortality.

Intracranial dermoid cysts are rare tumors derived from ectopic epithelial cells. They are slow-growing benign entities, but can cause significant morbidity through compression of neurovascular structures and, rarely, rupture into the subarachnoid space. We present a rare case of a spontaneously ruptured intracranial dermoid cyst presenting as new onset seizures due to chemical meningitis caused by dissemination of fat droplets.

Unlabelled: Pneumocephalus and pneumorrhachis are rare findings, and may result from a variety of causes, including severe asthma or trauma. We describe a case, where intracranial and intraspinal air was found after trauma to the chest wall., Case Report: A 24-yr-old patient suffered multiple trauma in a traffic accident, including a closed head injury and bursting fractures of theTh 7, 8 and 9 vertebral bodies with laceration of the spinal cord. Reposition of the spinal column was complicated by wound infection and septic shock. Intraoperatively, accidental extubation led to migration of gastric contents and was complicated by possible rupture of the oesophagus. Postoperative CT scan revealed the presence of air within the mediastinum, cranium and the entire spinal canal. The osteosynthetic material was removed, and the air quickly reabsorbed. The paraplegic patient was discharged from ITU in a satisfactory condition., Discussion: The most probable cause of the complication was traumatic rupture of the oesophagus and penetration of air via lacerated dura mater, to the spinal canal and the cranium. Conservative treatment was successful and led to complete (beside paraplegia) recovery.

Aim: We aimed to show the significance of the anterior pontine membrane as a determining structure between the subdural and subarachnoid space in the clival region., Material and Methods: Five adult cadaver heads and five cerebral hemispheres were used. The skull vault and hemipheres were removed by sectioning through the pontomesencephalic junction. Five other heads hemispheres were removed but the arachnoid membrane was protected and the cerebral side of the clival dura mater was dissected. In another specimen, the dural porus of the abducens nerve was sectioned for histological evaluation. Three cases of hematoma at the clivus were presented to support our findings., Results: The anterior pontine membrane is the arachnoid membrane forming the anterior wall of the prepontine cistern with its lateral extension at the skull base. This membrane forms the subdural and subarachnoid spaces by forming a barrier between the clival dura mater and neurovascular structures of the brainstem. There were rigid fibrous trabeculations between both cerebral and periosteal dural layers forming the basilar plexus as the interdural space in the clivus., Conclusion: The anterior pontine membrane separates the subdural and subarachnoid spaces at the clival region. The hematomas of the clival region require to be evaluated with consideration given to the existance of the subdural space.