Simple procedure for assessing diffuse subarachnoid hemorrhage successfully created using filament perforation method in mice

The murine model of subarachnoid hemorrhage (SAH) is a valuable experimental tool for investigating molecular and cellular mechanisms, and the endovascular filament perforation technique can be used to simulate prominent pathophysiological features observed after human SAH; however, current validation methods for assessing an appropriate SAH model are limited. Here, we introduce a simple procedure for selecting a mouse model of diffuse SAH. SAH was induced in 24 mice using a standard filament perforation method. After confirming survival at 24 h, SAH was scored 0-1 based on T2*-weighted images on whole-brain magnetic resonance imaging (MRI) and visual surveillance of the cisterna magna (CM) through the dura mater. The CM-based SAH grading correlated well with a reference parameter defined by extracted brain (r2 = 0.53, p < 0.0001). The receiver operating characteristic curve revealed a sensitivity of 85% and a specificity of 91% for detecting diffuse SAH, with a similar area under the curve (0.89 ± 0.06 [standard error of the mean]) as the MRI-based grading (0.72 ± 0.10, p = 0.12). Our data suggest that confirming an SAH clot in the CM is a valuable way to select a clinically relevant diffuse SAH model that can be used in future experimental studies.

FLAIR hyperintensity in the subarachnoid space: Main differentials

The fluid-attenuated inversion recovery (FLAIR) sequence forms part of the vast majority of current diagnostic protocols for brain MRI. This sequence enables the suppression of the signal from cerebrospinal fluid, facilitating the detection of disease involving the subarachnoid space. The causes of hyperintensity in the arachnoid space in this sequence can be divided into two main categories: hyperintensity due to disease and hyperintensity due to artifacts. Hyperintensity due to tumors, inflammation, vascular disease, or hypercellularity of the cerebrospinal fluid or hematic contents is well known. However, numerous other non-pathological conditions, mainly due to artifacts, that are also associated with this finding are a potential source of diagnostic errors.

Magnetic Resonance Imaging Diagnosis in Normal Pressure Hydrocephalus

BACKGROUND

Idiopatic normal pressure hydrocephalus (iNPH) is a progressive neurologic syndrome featured by the triad of gait disturbance, mental deterioration and urinary incontinence, associated with ventriculomegaly and normal cerebrospinal fluid (CSF) pressure. The clinical presentation may be atypical or incomplete, or mimicked by other diseases, so conventional neuroradiologic imaging plays an important role in defining this pathology. iNPH pathophysiologic mechanisms have not yet been fully elucidated, although several studies have demonstrated the involvement of the glymphatic system, a highly organized fluid transport system, the malfunction of which is involved in the pathogenesis of several disorders including normotensive hydrocephalus.

METHODS

Recent studies have shown how crucial in the diagnosis of this pathology is the definition of morphologic biomarkers, such as ventricular enlargement disproportionate to cerebral atrophy and associated ballooning of frontal horns; periventricular hyperintensities; and corpus callosum thinning and elevation, with callosal angle <90 degrees.

RESULTS

Another interesting feature that is becoming a well-recognized factor to look for and useful for the diagnosis of iNPH is disproportionately enlarged subarachnoid space hydrocephalus, which includes enlarged ventricles, tight high-convexity and medial surface subarachnoid spaces, and expanded Sylvian fissures. A correct choice of MRI sequences is important for a proper characterization identification of others diseases that may underlie this pathology. Magnetic resonance imaging allows us to evaluate CSF flow, enabling us to define qualitative and quantitative parameters necessary for the purpose of accurate iNPH diagnosis.

CONCLUSIONS

iNPH can represent a real diagnostic challenge; a proper correlation among clinical features, traditional MRI, and CSF dynamics analysis can lead to a correct diagnosis.

Extensive widening of Virchow-Robin spaces in the frontal lobe: two case reports and systematic review of the literature

AIM

To report our experience on giant tumefactive Virchow-Robin spaces (GTVRS) in the frontal lobe and perform a systematic review of previous reports on GTVRS.

MATERIALS AND METHODS

This is a retrospective single-center study reporting the clinical manifestations, magnetic resonance (MR) imaging appearance, differential diagnosis, and management of two patients diagnosed with frontal lobe GTVRS at Bahcesehir University School of Medicine Goztepe Hospital in the past 5 years. A systematic literature search was performed in the PubMed and Google Scholar databases, with case selection criteria including Virchow-Robin spaces (VRS) size greater than 1.5 cm, frontal lobe localization, and the presence of MR imaging. The search strategy included only English language keywords. The systematic review was searched between database inception and May 6, 2022.

RESULTS

A total of 18 cases were included in the study. Of the 15 cases with known sex, nine were female and six male. The median age was 29.8 with an age range of 4-57. Eleven of the 18 lesions were in the right frontal lobe. The lesions were multilocular in 15 cases and unilocular in three cases. All lesions had signal intensity as cerebrospinal fluid, showed no perifocal edema, and did not enhance. A hyperintensity was noted around the 14 lesions on the FLAIR sequence. Ten lesions showed cortical thinning adjacent to the lesion. No abnormality was detected on DWI, SWI, and MRS. Follow-up imaging was available in ten patients without any interval change. Unnecessary surgical interventions were noted in three cases.

CONCLUSIONS

The results of reported cases and the literature review emphasize the role of MR imaging in the diagnosis of frontal lobe GTVRS. Beyond diagnostic consideration, GTVRS may have prognostic value and often indicate a "don't touch lesion" albeit requiring further consideration on a case-to-case basis. Familiarity with this entity improves diagnostic accuracy and, prevents accidental diagnosis of any neoplasm or other diseases.

Ecchordosis physaliphora presenting as hypnic headache

Ecchordosis physaliphora (EP) is a rare benign congenital hamartomatous lesion originating from remnants of the notochord. EP has never been associated with hypnic headache before. We report for the first time two cases of EP associated with an hypnic headache. The latter is a form of sleep-related nocturnal headache whose pathogenesis has not been fully elucidated. A 61-year-old woman and a 41-year-old man had been complaining of a dull headache that woke them up every night for many months. In both cases, an enlarged cystic lesion in the prepontine cistern, compatible with ecchordosis physaliphora, was found on brain MRI. A diagnosis of hypnic headache secondary to EP was made. Ecchordosis physaliphora presenting as hypnic headache had never been described before. The low prevalence of both conditions (EP and HH) and their presence in two cases might suggest a possible causal association between the two conditions.

Correlation of Prepontine Cisternal Space Thickness with the Severity of Neurovascular Conflict and its Role in Predicting Outcome of Medical Management in Cases of Trigeminal Neuralgia

Background

Trigeminal neuralgia (TN) is a debilitating disorder that presents with sudden onset of severe, unilateral, paroxysmal, and lancinating pain usually lasting for few seconds to few minutes.

Aims and Objectives

The main aim of our study was to correlate the prepontine cisternal space thickness, with a severity of neurovascular compression (NVC) and percentage reduction of pain (patient outcome).

Materials and Methods

Ours is an observational prospective study of 40 patients presenting with TN for magnetic resonance imaging in our department. Patients were followed up on medical treatment and their pain severity evaluated on their follow-up visit. Patients were divided into two groups based on prepontine cisternal space (Group A: ≤4 mm, Group B: >4 mm) and into three groups based on the percentage reduction of pain, Group 1 (0-35%), Group 2 (36-70%), and Group 3 consisted of patients with pain reduction of more than 70%. Ipsilateral prepontine cisternal space thickness was correlated with grade of NVC and percentage reduction of pain.

Results

Mean percentage of pain reduction in group A and group B was 34.12 and 60.68%, respectively. Approximately 23.80% of grade1 NVC were seen in group A and 76.20% in group B, while 80% of grade 3 NVC were seen in group A and only 20% were seen in group B.

Conclusion

There was poor response to medical treatment, in patients with narrowed prepontine cisternal space thickness with an inverse relationship between the grade of NVC and cisternal space thickness.

Tightened Sulci in the High Convexities as a Noteworthy Feature of Idiopathic Normal Pressure Hydrocephalus

OBJECTIVE

The presence of tightened sulci in the high-convexities (THC) is a key morphological feature for the diagnosis of idiopathic normal pressure hydrocephalus (iNPH), but the exact localization of THC has yet to be defined. The purpose of this study was to define THC and compare its volume, percentage, and index between iNPH patients and healthy controls.

METHODS

According to the THC definition, the high-convexity part of the subarachnoid space was segmented and measured the volume and percentage from the 3D T1-weighted and T2-weighted magnetic resonance images in 43 patients with iNPH and 138 healthy controls.

RESULTS

THC was defined as a decrease in the high-convexity part of the subarachnoid space located above the body of the lateral ventricles, with anterior end on the coronal plane perpendicular to the anterior commissure-posterior commissure (AC-PC) line passing through the front edge of the genu of corpus callosum, the posterior end in the bilateral posterior parts of the callosomarginal sulci, and the lateral end at 3 cm from the midline on the coronal plane perpendicular to the AC-PC line passing through the midpoint between AC and PC. Compared to the volume and volume percentage, the high-convexity part of the subarachnoid space volume per ventricular volume ratio < 0.6 was the most detectable index of THC on both 3D T1-weighted and T2-weighted magnetic resonance images.

CONCLUSIONS

To improve the diagnostic accuracy of iNPH, the definition of THC was clarified, and high-convexity part of the subarachnoid space volume per ventricular volume ratio <0.6 proposed as the best index for THC detection in this study.

The ESAS-score: A histological severity grading system of subarachnoid hemorrhage using the modified double hemorrhage model in rats

Objective

The amount of extravasated blood is an established surrogate marker for subarachnoid hemorrhage (SAH) severity, which varies in different experimental SAH (eSAH) models. A comprehensive eSAH grading system would allow a more reliable correlation of outcome parameters with SAH severity. The aim of this study was to define a severity score for eSAH related to the Fisher-Score in humans.

Material and methods

SAH was induced in 135 male rats using the modified double hemorrhage model. A sham group included 8 rats, in which saline solution instead of blood was injected. Histological analysis with HE(hematoxylin-eosin)-staining for the visualization of blood was performed in all rats on day 5. The amount and distribution of blood within the subarachnoid space and ventricles (IVH) was analyzed.

Results

The mortality rate was 49.6% (71/143). In all except five SAH rats, blood was visible within the subarachnoid space. As expected, no blood was detected in the sham group. The following eSAH severity score was established (ESAS-score): grade I: no SAH visible; grade II: local or diffuse thin SAH, no IVH; grade III: diffuse / thick layers of blood, no IVH; grade IV: additional IVH. Grade I was seen in five rats (7.9%), grade II in 28.6% (18/63), grade III in 41.3% (26/63) and grade IV in 22.2% (14/63) of the rats with eSAH.

Conclusion

The double hemorrhage model allows the induction of a high grade SAH in more than 60% of the rats, making it suitable for the evaluation of outcome parameters in severe SAH.

Pituitary Adenoma: A review of existing classification systems based on anatomic extension and invasion

Pituitary adenomas are common, benign tumours, that can be classified in many ways including their functionality, size and anatomical extension. Historically, larger more invasive adenomas with extension into parasellar regions were deemd untreatable. However, with increasing operative sophistication, and more precise and effective radiation options; it is no longer the case, and therefore it becomes even more important for a comprehensive classification system for these tumours. Herein, the authors present an updated review on the available classification systems for large pituitary adenomas, based on their anatomic extension and invasion of adjacent anatomic structures.

Mdivi-1 ameliorates early brain injury after subarachnoid hemorrhage via the suppression of inflammation-related blood-brain barrier disruption and endoplasmic reticulum stress-based apoptosis

Aberrant modulation of mitochondrial dynamic network, which shifts the balance of fusion and fission towards fission, is involved in brain damage of various neurodegenerative diseases including Parkinson's disease, Huntington's disease and Alzheimer's disease. A recent research has shown that the inhibition of mitochondrial fission alleviates early brain injury after experimental subarachnoid hemorrhage, however, the underlying molecular mechanisms have remained to be elucidated. This study was undertaken to characterize the effects of the inhibition of dynamin-related protein-1 (Drp1, a dominator of mitochondrial fission) on blood-brain barrier (BBB) disruption and neuronal apoptosis following SAH and the potential mechanisms. The endovascular perforation model of SAH was performed in adult male Sprague Dawley rats. The results indicated Mdivi-1(a selective Drp1 inhibitor) reversed the morphologic changes of mitochondria and Drp1 translocation, reduced ROS levels, ameliorated the BBB disruption and brain edema remarkably, decreased the expression of MMP-9 and prevented degradation of tight junction proteins-occludin, claudin-5 and ZO-1. Mdivi-1 administration also inhibited the nuclear translocation of nuclear factor-kappa B (NF-κB), leading to decreased expressions of TNF-ɑ, IL-6 and IL-1ß. Moreover, Mdivi-1 treatment attenuated neuronal cell death and improved neurological outcome. To investigate the underlying mechanisms further, we determined that Mdivi-1 reduced p-PERK, p-eIF2α, CHOP, cleaved caspase-3 and Bax expression as well as increased Bcl-2 expression. Rotenone (a selective inhibitor of mitochondrial complexes I) abolished both the anti-BBB disruption and anti-apoptosis effects of Mdivi-1. In conclusion, these data implied that excessive mitochondrial fission might inhibit mitochondrial complex I to become a cause of oxidative stress in SAH, and the inhibition of Drp1 by Mdivi-1 attenuated early brain injury after SAH probably via the suppression of inflammation-related blood-brain barrier disruption and endoplasmic reticulum stress-based apoptosis.

Intracranial subarachnoid fat and hemorrhage secondary to sacral fracture with spondylopelvic dissociation

We describe a case of fat droplets and blood in the cerebral subarachnoid space secondary in a patient with a complex sacral fracture without associated cranial trauma, a few days after admission. To our knowledge, there is only one published case with similar findings and without any other underlying lesion as cause. We explain the differences in the mechanism of production between this direct fat embolism and brain fat embolism syndrome, which is an intravascular embolism with different radiological appearance. The most important features of sacral fracture with spondylopelvic dissociation are described. Finally, this entity should be taken into account in the differential diagnosis of the few causes of fat in the subarachnoid space. In the context of high-energy trauma fractures of the sacrum or spine must be ruled out as a potential cause of this uncommon intracranial finding.

Acute hypoxia diminishes the relationship between blood pressure and subarachnoid space width oscillations at the human cardiac frequency

Background

Acute hypoxia exerts strong effects on the cardiovascular system. Heart-generated pulsatile cerebrospinal fluid motion is recognised as a key factor ensuring brain homeostasis. We aimed to assess changes in heart-generated coupling between blood pressure (BP) and subarachnoid space width (SAS) oscillations during hypoxic exposure.

Methods

Twenty participants were subjected to a controlled decrease in oxygen saturation (SaO₂ = 80%) for five minutes. BP and heart rate (HR) were measured using continuous finger-pulse photoplethysmography, oxyhaemoglobin saturation with an ear-clip sensor, end-tidal CO₂ with a gas analyser, and cerebral blood flow velocity (CBFV), pulsatility and resistive indices with Doppler ultrasound. Changes in SAS were recorded with a recently-developed method called near-infrared transillumination/backscattering sounding. Wavelet transform analysis was used to assess the relationship between BP and SAS oscillations.

Results

Gradual increases in systolic, diastolic BP and HR were observed immediately after the initiation of hypoxic challenge (at fifth minute +20.1%, +10.2%, +16.5% vs. baseline, respectively; all P<0.01), whereas SAS remained intact (P = NS). Concurrently, the CBFV was stable throughout the procedure, with the only increase observed in the last two minutes of deoxygenation (at the fifth minute +6.8% vs. baseline, P<0.05). The cardiac contribution to the relationship between BP and SAS oscillations diminished immediately after exposure to hypoxia (at the fifth minute, right hemisphere -27.7% and left hemisphere -26.3% vs. baseline; both P<0.05). Wavelet phase coherence did not change throughout the experiment (P = NS).

Conclusions

Cerebral haemodynamics seem to be relatively stable during short exposure to normobaric hypoxia. Hypoxia attenuates heart-generated BP SAS coupling.

Taenia crassiceps injection into the subarachnoid space of rats simulates radiological and morphological features of racemose neurocysticercosis

PURPOSE

Neurocysticercosis is a major public health concern. Although its eradication appears feasible, the disease remains endemic in developing countries and has emerged again in Europe and in the USA. Basic studies on neurocysticercosis are needed to better understand the pathophysiologic mechanisms and, consequently, to improve treatment perspectives. Much has been published on experimental parenchymal neurocysticercosis, but there are no experimental models of racemose neurocysticercosis.

METHODS

Cysts of Taenia crassiceps were injected into the subarachnoid space of 11 rats. After 4 months, magnetic resonance imaging (MRI) was performed to verify the occurrence of ventricular dilatation and the distribution of cysts in the cerebrospinal fluid compartments. The histologic assessment was done focusing on changes in the ependyma, choroid plexus, and brain parenchyma.

RESULTS

MRI and histologic assessment confirmed the findings similar to those seen in human racemose neurocysticercosis including enlargement of the basal cisterns, hydrocephalus, and inflammatory infiltration through the ependyma and choroid plexus into cerebrospinal fluid spaces.

CONCLUSIONS

We developed a simple model of racemose neurocysticercosis by injecting cysts of T. crassiceps into the subarachnoid space of rats. This model can help understand the pathophysiologic mechanisms of the disease.

Cerebrospinal fluid diversion in patients with enlarged Virchow-Robin spaces without ventriculomegaly

OBJECTIVE

Enlarged Virchow-Robin spaces (eVRS) are an MRI biomarker in several neurological diseases of inflammatory, neurodegenerative, vascular, metabolic, or genetic origin. We report on a further condition in which eVRS were observed in patients with an ongoing chronic hydrocephalus-like clinical picture without ventriculomegaly who improved after CSF diversion, and we discuss the possible mechanisms underlying this finding.

MATERIALS AND METHODS

A retrospective study of seven patients presenting progressive gait, cognitive, and urinary disturbances in association with eVRS was undertaken.

RESULTS

All patients presented an Evans ratio <0.30 and >20 eVRS at the level of basal ganglia and periventricular parenchyma as assessed by T2-weighted MRI. All patients underwent prolonged external lumbar drainage (PELD) with good response. Six patients received ventriculoperitoneal shunt with improvement of their clinical status compared to that before PELD (follow-up: 8-58 months, mean 24.6). The seventh patient did not undergo ventriculoperitoneal shunt and received a second PELD with persistent improvement (follow-up: 14 months).

CONCLUSIONS

Our results indicate that a mechanism involving CSF accumulation and stasis in the subarachnoid space was at least a concurrent factor of this clinical picture. This study should stimulate new perspectives on the role of CSF disturbances in the pathogenesis of diseases associated with VRS enlargement.

Cdk5 inhibitor roscovitine alleviates neuropathic pain in the dorsal root ganglia by downregulating N-methyl-D-aspartate receptor subunit 2A

Cyclin-dependent kinase 5 (Cdk5) is a member of the small proline-directed serine/threonine kinase family. Cdk5 is not involved in cell cycle regulation, but is implicated in neurodegenerative disorders. However, the role of Cdk5 in neuropathic pain remains unclear. This study aimed to evaluate the possibility that Cdk5 is involved in neuropathic pain in the dorsal root ganglia (DRG). We injected intrathecally Cdk5 inhibitor roscovitine in rat model of chronic compression of dorsal root ganglion and examined pain behaviors and the expression of N-methyl-d-aspartate receptor subunit 2A (NR2A) but not NR2B or NR1 in DRG. We found that roscovitine alleviated neuropathic pain, causing decline in paw withdrawal mechanical threshold and paw withdrawal thermal latency. Furthermore, roscovitine inhibited NR2A expression in DRG. These data suggest that Cdk5-NR2A pathway regulates neuropathic pain in DRG, and intrathecal injection of roscovitine could alleviate neuropathic pain. Our findings provide new insight into the analgesic effects of Roscovitine and identify Cdk5-NR2A pathway as a potential target for effective treatment of neuropathic pain.

Hydrocephalus due to extreme dilation of Virchow-Robin spaces

Virchow-Robin spaces (VRS) are extensions of the subarachnoid space surrounding perforating blood vessels entering the brain parenchyma. VRS are fluid filled, but almost virtual and only visible on MRI of the brain when dilated. Such dilations are commonly asymptomatic. In rare cases, extreme dilations can be observed; the clinical repercussions of which remain unclear. We report the case of a patient presenting symptoms of normal pressure hydrocephalus due to extreme VRS mesencephalon dilations.

[The usefulness of the evaluation of volumetric and posturographic parameters in the differential diagnosis of hydrocephalus]

INTRODUCTION

A variety of diagnostic methods in normal pressure hydrocephalus and brain atrophy, it testifies to the difficulties in contrast to both teams. Develop a safe diagnostic tool having comparable statistical accuracy of the infusion test results would be of great clinical significance. The chances of implementing such a procedure in clinical practice, it may be a combination of these syndromes in the functional assessment (Posturography) the assessment of morphological CNS (volumetric).

THE AIM

To evaluate and summary of the results of two non-invasive diagnostic methods morphological (posturography) and functional (volumetric) with results that were obtained from tests infusion.

MATERIAL AND METHODS

The evaluation of volumetric and posturographic research was conducted in 39 patients including 27 patients with brain atrophy (BA) and in 12 patients with hydrocephalus (NPH). Volumetric measurements were made using proprietary software VisNow. Posturographic measurements performed using manual posturograph Pro-Med.

RESULTS

Both the volume of CSF obtained by volumetric assessment, as well as the values of the analyzed parameters posturographic, highly correlate with the results of resistance resorption (R). The BA radius values sway with eyes open and closed R_OZ R_OO were consistent with test results infusion of 100% in the NPH radius values showed 75% compliance with the test results infusion. Volumetric parameters: the volume of CSF contained in the subarachnoid space and basal cisterns (SV) and the volume of CSF system intracranial ventricular (VV) were found in both patients NPH and BA 100% compatible resorption resistance (R).

CONCLUSIONS

Simultaneous use of two non-standard methods of non-invasive (posturographic and volumetric) in the diagnostic process is a proposal to recognize normal pressure hydrocephalus and brain atrophy non-invasive methods, while maintaining very high statistical significance.

Validation and evaluation of the volumetric measurement of cerebellopontine angle cistern as a prognostic factor of microvascular decompression for primary trigeminal neuralgia

BACKGROUND

The aim of this study was to analyze the prognostic factors of trigeminal neuralgia (TN) after microvascular decompression (MVD), and to evaluate the volumetric parameters of the cerebellopontine angle (CPA) cistern as a pathogenic factor and imaging predictor.

METHODS

This retrospective study included 70 patients with primary TN treated with pure MVD, followed up for at least 1 year and evaluated by high-resolution MR imaging. The volume of the CPA cistern was calculated bilaterally, and the "Cistern Deviation Index" was defined to represent degree of deviation of the CPA cistern. Clinical data and volumetric parameters were compared between patients with TN and age- and sex-matched controls without TN, and between the recurrent and non-recurrent patients.

RESULTS

The transposition procedure had a better outcome than the interposition procedure (P < 0.001). There was a significant difference in the volume of CPA cistern between the affected and unaffected side (152.1 ± 50.1 vs. 179.9 ± 63.7 mm(3), P < 0.001) in patients with TN, while no significant difference between the right and left side (158.7 ± 44.6 vs. 163.1 ± 49.8 mm(3), P = 0.162) in controls. The Cistern Deviation Index was significantly larger in controls than in patients with TN (P = 0.048), and in the non-recurrent patients than in recurrent patients (P = 0.040).

CONCLUSION

We demonstrated that the volumetric parameters of the CPA cistern are a marker for understanding the pathogenesis of TN and useful for predicting the recurrence after MVD. The Cistern Deviation Index might contribute to deciding the surgical approach.

Prevalence of subdural collections in children with macrocrania

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.

3D mapping of cerebrospinal fluid local volume changes in patients with hydrocephalus treated by surgery: preliminary study

OBJECTIVE

To develop automated deformation modelling for the assessment of cerebrospinal fluid (CSF) local volume changes in patients with hydrocephalus treated by surgery.

METHODS

Ventricular and subarachnoid CSF volume changes were mapped by calculating the Jacobian determinant of the deformation fields obtained after non-linear registration of pre- and postoperative images. A total of 31 consecutive patients, 15 with communicating hydrocephalus (CH) and 16 with non-communicating hydrocephalus (NCH), were investigated before and after surgery using a 3D SPACE (sampling perfection with application optimised contrast using different flip-angle evolution) sequence. Two readers assessed CSF volume changes using 3D colour-encoded maps. The Evans index and postoperative volume changes of the lateral ventricles and sylvian fissures were quantified and statistically compared.

RESULTS

Before surgery, sylvian fissure and brain ventricle volume differed significantly between CH and NCH (P = 0.001 and P = 0.025, respectively). After surgery, 3D colour-encoded maps allowed for the visual recognition of the CSF volume changes in all patients. The amounts of ventricle volume loss of CH and NCH patients were not significantly different (P = 0.30), whereas readjustment of the sylvian fissure volume was conflicting in CH and NCH patients (P < 0.001). The Evans index correlated with ventricle volume in NCH patients.

CONCLUSION

3D mapping of CSF volume changes is feasible providing a quantitative follow-up of patients with hydrocephalus.

KEY POINTS

• MRI can provide helpful information about cerebrospinal fluid volumes. • 3D CSF mapping allows quantitative follow-up in communicating and non-communicating hydrocephalus. • Following intervention, fissures and cisterns readjust in both forms of hydrocephalus. • These findings support the hypothesis of suprasylvian block in communicating hydrocephalus. • 3D mapping may improve shunt dysfunction detection and guide valve pressure settings.

Post-traumatic syringomyelia: CSF hydrodynamic changes following spinal cord injury are the driving force in the development of PTSM

Post-traumatic syringomyelia (PTSM) is a disorder that occurs infrequently following spinal cord injury (SCI), characterized by progressive neurological deterioration resulting from syrinx expansion originating in proximity to the traumatic epicenter. Several pathogenetic factors are associated with this disorder, however, the precise mechanism of the development of PTSM is controversial. Combined anatomical alterations and molecular changes following trauma to the spinal cord and arachnoid participate in the development of this condition. These factors include narrowing or obstruction of the subarachnoid space (SAS), central canal occlusion, myelomalacia, and alterations in intramedullary water permeability. If a patient sustains a SCI with delayed progressive deterioration in neurological function, in association with the MRI appearance of syringomyelia (SM), the diagnosis of PTSM is straightforward. The treatment of PTSM has not undergone any significant changes recently. The surgical treatment of PTSM consists of reconstructing the SAS or shunting fluid away from the syrinx to other locations. The advantages and disadvantages of each procedure will be discussed. With greater understanding of the mechanisms contributing to the development of SM, including advanced diagnostic methods and further advances in the development of artificial dural and shunting tubing, future therapies of PTSM will be more effective and long-lasting. Incorporation of alterations of AQP4 expression provides an intriguing possibility for future treatment of PTSM.

Near-infrared transillumination back scattering sounding--new method to assess brain microcirculation in patients with chronic carotid artery stenosis

Purpose

The purpose of the study was to assess the responses of pial artery pulsation (cc-TQ) and subarachnoid width (sas-TQ) to acetazolamide challenge in patients with chronic carotid artery stenosis and relate these responses to changes in peak systolic velocity (PSV), cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT) and time to peak response (TTP).

Methods

Fifteen patients with carotid artery stenosis ≥90% on the ipsilateral side and <50% on the contralateral side were enrolled into the study. PSV was assessed using colour-coded duplex sonography, CBF, CBV, MTT and TTP with perfusion computed tomography, cc-TQ and sas-TQ with near-infrared transillumination/backscattering sounding (NIR-T/BSS).

Results

Based on the ipsilateral/contralateral cc-TQ ratio after acetazolamide challenge two groups of patients were distinguished: the first group with a ratio ≥1 and the second with a ratio <1. In the second group increases in CBF and CBV after the acetazolamide test were significantly higher in both hemispheres (ipsilateral: +33.0%±8.1% vs. +15.3%±4.4% and +26.3%±6.6% vs. +14.3%±5.1%; contralateral: +26.8%±7.0% vs. +17.6%±5.6% and +20.0%±7.3% vs. +10.0%±3.7%, respectively), cc-TQ was significantly higher only on the ipsilateral side (+37.3%±9.3% vs. +26.6%±8.6%) and the decrease in sas-TQ was less pronounced on the ipsilateral side (−0.7%±1.5% vs. −10.2%±1.5%), in comparison with the first group. The changes in sas-TQ following the acetazolamide test were consistent with the changes in TTP.

Conclusions

The ipsilateral/contralateral cc-TQ ratio following acetazolamide challenge may be used to distinguish patient groups characterized by different haemodynamic parameters. Further research on a larger group of patients is warranted.

[Ocular coloboma and results of brain MRI: preliminary results]

INTRODUCTION

Congenital ocular colobomas are the result of a failure in closure of the embryonal fissure. We present a prospective study (2007-2011) in which we report brain MRI findings in children with ocular coloboma.

PATIENTS AND METHODS

Thirty-five children (54 eyes) were included; 15 boys, 20 girls with a median age of 24.0 months (1.0-96.0) at first presentation. Within 2 to 3 months following complete ophthalmologic examination, brain MRI was performed.

RESULTS

Colobomas were bilateral in 19 cases and unilateral in 16 cases. Eleven different types of coloboma were identified. Of 54 eyes, 74% demonstrated optic nerve coloboma, of which 28 were severe. Of 35 MRI's performed, abnormalities were present in 86%: gyration abnormalities (n=21), lateral ventricular dilatation (n=17), dilatation of the Virchow-Robin and subarachnoid spaces (n=14), signal abnormalities and brain stem malformations (n=14), white matter signal abnormalities (n=11), corpus callosum abnormalities (n=10). Most of these abnormalities were related. Gyration abnormalities were the most frequent. There was no significant association between the severity of the coloboma and the abnormalities found (P=1.0). Likewise, there was no significant association of gyration abnormalities with the severity of coloboma in children (P=1.0).

DISCUSSION AND CONCLUSION

This study shows, for the first time, the existence of frequent cerebral abnormalities on MRI in children with ocular coloboma. The most common abnormality being gyration abnormalities, in 60% of cases.

Large epidermoids of the quadrigeminal cistern: an experience of 15 consecutive cases and review of literature

BACKGROUND

Large epidermoids of the quadrigeminal cistern (LEQCs) of more than 4 cm in size are benign intracranial tumours and present with diverse clinical manifestations. Fifteen cases of LEQC have been treated in our institute over last 10 years.

METHODS

This is a retrospective study of the 15 LEQCs treated in our institute from January 2001 to May 2011. We classified these epidermoids into three types, based on the location of the major bulk of the epidermoid, to tailor surgical approaches to these tumours.

RESULTS

Fifteen patients (age range 14-45 years, mean age 27.2 years) were operated upon after clinicoradiological evaluation. Eight were females and seven were males. The mean duration of symptoms was 9.2 months. Symptoms of raised intracranial pressure were present in ten patients. Surgical approaches included infratentorial-supracerebellar approach in nine cases, the occipital transtentorial approach in five cases and subtemporal approach one case. Complete excision was possible in ten (66.6 %) cases, near total in four (26.6 %) and subtotal excision in one case. Six patients underwent cerebrospinal fluid (CSF) diversion by ventriculoperitoneal (VP) shunt. Twelve patients improved with surgery and are functionally active. One patient developed hemiparesis. There were two deaths in our series.

CONCLUSION

LEQC may present with hydrocephalus, unlike epidermoids at other intracranial locations. Complete surgical excision is possible in most of the patients and it helps in re-establishing the CSF pathway. Early surgery in these patients prevents postoperative shunt dependence. Most of the patients improve after surgery.

CT cisternography in intracranial symptomatic arachnoid cysts: classification and treatment

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.

[Contrast-enhanced MR imaging in bacterial meningitis in children--temporal profile and correlation with the prognosis]

Treatment periods for bacterial meningitis are often very long, and often this prolonged treatment is based on the judgment of its effectiveness by the degree of enhancement on brain magnetic resonance imaging (MRI). In this study, we analyzed the contrast MRI in the acute and recovery phases of bacterial meningitis in twelve patients, and graded the contrast level of the subdural space and subarachnoid space separately. While the contrast level of the subarachnoid space increased with time in 4 cases, that of the subdural space increased in 10 cases, and 9 of them revealed a good prognosis without continuation of the treatment. These findings indicate that increased contrast level of the subdural space is common in the recovery phase of bacterial meningitis, and that repetitive MRI investigation is not valuable to determine the duration of treatment.

[Schistosoma haematobium, a rare aetiology of spinal cord compression]

Human schistosomiasis is the second endemic disease after malaria. About 200 millions people are concerned, particularly in Africa, South America and Asia. Schistosomal spinal cord compression is under reported in Africa and not well known. Authors present the case of a 10-year-old boy with no suggestive past-medical story, admitted for spinal cord compression. MRI shows tumor like intra dural lesion. Schistosomal granuloma was found after lesion removal by posterior approach. Treatment was completed by praziquantel. Controversies of the treatment are presented.

Incomplete oculomotor nerve palsy in the subarachnoid space caused by traumatic brain injury

A patient with traumatic brain injury showed incomplete oculomotor nerve palsy in the subarachnoid space. A 12-year-old girl was hospitalized after a head injury. Neuro-ophthalmic examination showed that the left eye had a ptosis and pupillary involvement. An MRI indicated an intracranial hematoma at the basilar portion of the left temple. The ptosis and pupillary involvement improved after elimination of the hematoma. The presentation patterns are best explained by topographic organization of the third nerve fiber within the subarachnoid space. This case suggests that the topographic organization of the third nerve should be considered in diagnosis of oculomotor nerve palsy.

Significance of Virchow-Robin spaces in patients newly diagnosed with multiple sclerosis: a case-control study in an Arab population

OBJECTIVE

To assess the frequency and extent of dilatation of Virchow-Robin (VR) spaces at three levels of the brain in patients of Arab ethnicity in Kuwait recently diagnosed with multiple sclerosis (MS) and compare the results with age- and gender-matched controls.

METHODS

The magnetic resonance imaging (MRI) scans performed within 3 months of the clinical diagnosis of 80 patients recently diagnosed with active MS were compared to those of 80 age- and gender-matched controls with headache but without any neurological deficits for the frequency and size of VR spaces. MRI was done with noncontrast axial and coronal T(1)W FSE, axial T(2)W FSE, axial T(2)W FLAIR and sagittal FLAIR sequences followed by postcontrast axial and coronal T(1)W sequences. The frequency of VR spaces in MS patients and controls at midbrain, lenticulostriate vessels and supraventricular levels was analyzed using a two-tailed McNemar test.

RESULTS

There was no difference in the frequency of VR spaces at the levels of the midbrain, lenticulostriate vessels and supraventricular white matter between MS patients and controls. In the supraventricular region, however, there were 91 dilated VR spaces in 26 (32%) of the MS patients while in the control group, there were 8 dilated VR spaces in 6 (7.5%) patients and the difference was statistically significant (p < 0.0001).

CONCLUSION

The data showed that dilated VR spaces in the supraventricular region could potentially be used as a marker for MS and as a prognostic tool. However, further studies with a larger population are needed to further evaluate and confirm this observation.

Changes in the subarachnoid space precede ventriculomegaly in idiopathic normal pressure hydrocephalus (iNPH)

We report on an 80-year-old woman who had shunt-responsive idiopathic normal pressure hydrocephalus (iNPH). Her brain MRI showed an initial change in the subarachnoid space (a disproportional narrowing of the subarachnoid space at the cerebral high convexities) at the age of 70 years, followed by enlargement of the ventricles (Evans index: 0.31) at the age of 78. The observation suggests that changes in the subarachnoid space may precede ventricular enlargement in iNPH.

Blastic plasmacytoid dendritic cell neoplasm: cytopathologic findings

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare, aggressive hematopoietic neoplasm, which in the past was also known variously as blastic NK cell lymphoma, agranular CD4+ natural killer cell leukemia, and CD4+/CD56+ hematodermic neoplasm. BPDCN is now believed to arise from plasmacytoid dendritic cells, but its exact etiology is still unknown. We report here on the cerebrospinal fluid (CSF) cytology of a BPDCN, a hypercellular specimen comprised of malignant, singly dispersed cells with scant to moderate amounts of pale blue, agranular cytoplasm, and uniform round to oval nuclei, fine chromatin, prominent nucleoli, occasional cytoplasmic microvacuoles, and pseudopodia. Neither mitoses nor karyorrhexis were identified. Flow cytometry of the CSF demonstrated that the malignant cells expressed bright CD45, HLA-DR and CD33, dim CD4, heterogeneous CD56, and partial CD123. The importance of clinical, histopathological, and phenotypic correlation is emphasized. Clinical and histopathological correlation and a literature review are also presented. The poor clinical outcome makes it important to accurately report this rare tumor in a CSF specimen.

Neoplastic meningitis from solid tumors: new diagnostic and therapeutic approaches

Neoplastic meningitis is a result of the spread of malignant cells to the leptomeninges and subarachnoid space and their dissemination within the cerebrospinal fluid. This event occurs in 4%-15% of all patients with solid tumors and represents an important prognostic factor for poor survival. Neoplastic meningitis should be diagnosed in the early stages of disease to prevent important neurological deficits and to provide the most appropriate treatment. Despite new diagnostic approaches developed in recent years, such as positron emission tomography-computed tomography and new biological markers, the combination of magnetic resonance imaging without and with gadolinium enhancement and cytology still has the greatest diagnostic sensitivity. Recently, no new randomized studies comparing intrathecal (i.t.) with systemic treatment have been performed, yet there have been a few small phase II studies and case reports about new molecularly targeted substances whose successful i.t. or systemic application has been reported. Trastuzumab, gefitinib, and sorafenib are examples of possible future treatments for neoplastic meningitis, in order to better individualize therapy thus allowing better outcomes. In this review, we analyze the most recent and interesting developments on diagnostic and therapeutic approaches.

Ruptured intracranial dermoid cyst manifesting as new onset seizure: a case report

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.

[Pneumocephalus and pneumorrhachis after chest wall injury]

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.

Outcome correlates with blood distribution in subarachnoid hemorrhage of unknown origin

PURPOSE

Between 15 and 30 % of patients with subarachnoid hemorrhage (SAH) have no bleeding source and usually have a benign clinical course and outcome. The objectives of this study were to classify the pattern of blood distribution on initial computed tomography (CT) and to correlate it with clinical outcome in aneurysmal (ASAH) and SAH of unknown origin (SAHuO).

METHODS

We reviewed 112 CTs of SAHuO and 104 CTs of ASAH patients. Blood distribution was classified according to a new grading system (type 0-4) and correlated to Hunt and Hess (H&H) grade and modified Rankin scores (MRS) at short- and long-term follow-up.

RESULTS

Fifty percent of 112 SAHuO patients were classified as type 0 (no visible blood on CT) or 1 (blood restricted to prepontine cisterns). Most ASAH patients presented with bleeding into the lateral Sylvian fissure (66%; type 3) or with intracerebral hemorrhage (27%; type 4) whereas types 0 and 1 were not observed. SAHuO patients were in better clinical condition on admission than ASAH patients (p < 0.0001). H&H grades of SAHuO patients correlated with the amount of subarachnoid blood according to the new classification (p = 0.004). Short-term outcome was obtained from 100% and long-term outcome from 95% patients (follow-up 29 +/- 31 months). Short- and long-term MRS correlated with blood distribution in SAHuO patients (p = 0.012) and was significantly better than in ASAH patients (p < 0.0001). No correlation was observed between blood distribution, H&H grade, and short- and long-term outcome in aneurysmal patients.

CONCLUSIONS

In SAH of unknown origin, a new classification allows to predict outcome based on the extent of blood on CT.

Aneurysmal subarachnoid hemorrhage diagnosis with computed tomographic angiography and OsiriX

PURPOSE

Recent advances in computed tomographic angiography (CTA) have resulted in its replacing digital subtraction angiography (DSA). However, CTA requires a powerful workstation and experienced technicians for image postprocessing. OsiriX, a free open-source medical imaging software with powerful three-dimensional (3D) capability, enables neurosurgeons to perform 3D rendering without extensive training. In this study, we examined the sensitivity and specificity of CTA with OsiriX as the primary diagnostic tool for intracranial aneurysms.

METHOD

From May 2006 to March 2009, 121 patients with spontaneous subarachnoid hemorrhage (SAH) underwent CTA. The CTA source images were 3D rendered by neurosurgeons using OsiriX. All the possible locations for aneurysms were carefully reviewed. DSA was performed on every patient in any of the following conditions: for negative CTA findings, after surgical clipping of aneurysms or before transarterial embolization of aneurysms.

RESULT

Of the 121 patients, 8 were excluded because DSA data were not available. In the remaining 113 patients, 20 patients had negative CTA findings. CTA with OsiriX detected 106 aneurysms in 93 patients, of which 103 were confirmed by DSA or postoperative DSA; 3 infundibular dilated pouches of small arteries were mistaken for aneurysms. Two anterior communicating artery aneurysms (1.5 mm and 1 mm) were missed by CTA from among all 113 patients. The sensitivity and specificity of CTA for detecting aneurysms on a per-patient basis were 98.9% and 100%, respectively. The sensitivity and specificity of CTA for detecting aneurysms on a per-aneurysm basis for detecting aneurysms were 98.1% and 86.3%, respectively.

CONCLUSION

CTA with OsiriX enables accurate detection of intracranial aneurysms. Cerebral DSA should be reserved for those patients with negative CTA findings.

Rheumatoid leptomeningitis: radiological alteration of cerebral hypoperfusion and subarachnoid lesions

A 56-year-old man with rheumatoid arthritis developed emotional lability and myoclonic seizure in the left arm, followed by fever and generalized convulsion. Brain magnetic resonance imaging (MRI) revealed leptomeningeal lesions with abnormal enhancement. MRI lesions were localized predominantly in the right cerebral subarachnoid spaces. Electroencephalogram showed epileptogenic focus at the right frontal and central points. After administration of valproate sodium improved convulsion and myoclonus, single photon emission computed tomography (SPECT) using N-isopropyl-p-(123)I-iodoamphetamine was performed. Brain SPECT displayed hypoperfusion predominantly in the right cerebral hemisphere. Cerebrospinal fluid (CSF) disclosed mild pleocytosis and marked elevations of interleukin-6 levels. Repeated CSF analyses showed cytology of class I and negative results for infectious pathogens. Methylprednisolone pulse therapy (1 g for 3 days, iv) and subsequent prednisolone administration (daily 50 mg, po) ameliorated neurological symptoms dramatically. Prednisolone was tapered to 20 mg/day for 5 months. Leptomeningeal MRI lesions were attenuated gradually followed by restoration of cerebral hypoperfusion on SPECT. He was diagnosed as rheumatoid leptomeningitis (RLM). Although clinical features of RLM exhibited variable deficits of the central nervous system (CNS), MRI failed to detect the corresponding CNS lesions. We first highlighted neuroradiological changes of cerebral hypoperfusion and leptomeningeal lesions in RLM. These neuroimages of our patient supported that leptomeningeal inflammation and the adjacent cerebrocortical ischemia could cause encephalitis-like symptoms in RLM patients.