Utility of multiparametric pre-operative magnetic resonance imaging in differentiation of chordoid meningioma from the other histopathological subtypes of meningioma-a retrospective study.

PURPOSE: To determine the magnetic resonance imaging (MRI) features which could pre-operatively differentiate chordoid meningioma (CM) from other histopathological subtypes of meningioma. METHODS: Retrospective analysis of pre-operative MRI of cases with histopathologically confirmed diagnosis of meningioma during the last 5 years at our institute was done. T1W, T2W, FLAIR sequences, and post-contrast enhancement were evaluated on a qualitative scale. Normalized ADC ratios (nADCR) and normalized fractional anisotropy ratios (nFAR) were derived. The intratumoral susceptibility score (ITSS), presence of sunburst pattern of vasculature, bone changes, tumour-parenchyma interface, and oedema-to-tumour ratio were also determined. RESULTS: A total of 81 lesions were analyzed out of which 15 were CM. CM showed a higher relative contrast enhancement as compared to all other subtypes except for angiomatous and microcystic meningioma. Relative signal intensity on FLAIR could differentiate CM from transitional meningioma. nFAR was found to be significantly higher in fibroblastic meningioma and significantly lower in microcystic meningiomas as compared to CM. Anaplastic meningiomas were remarkable for bone changes and an ill-defined tumour-brain interface in significantly higher proportion of cases as compared to CM. nADCR > 1.5 was found to be an independent predictor of CM with a sensitivity of 84.6%, specificity of 89.8%, positive predictive value of 64.7%, and negative predictive value of 96.4%. CONCLUSION: Routine pre-operative MRI may be able to differentiate CM from other meningioma subtypes and a cut-off value of greater than 1.5 for nADCR could be predictive of > 50% chordoid histology of meningioma with a high sensitivity, specificity, and negative predictive value.

"Trapped labelled spins"-related signal on arterial spin labelling in the assessment of flow-diverted aneurysms: preliminary experience.

PURPOSE: To investigate ASL-MRI features of flow-diverted aneurysms, review their haemodynamic surrogates, and discuss their pertinent clinical implications. METHODS: Retrospective single institutional analysis was performed on the clinical and imaging data of patients who underwent digital subtraction angiography (DSA) and ASL-MRI after endovascular flow diversion for cerebral aneurysms. Pseudo-continuous ASL-MRI was performed with post-label delays of 1525-1800 ms. Intra-aneurysmal "trapped labelled spins" (TLS)-related hypersignal, as seen on cerebral blood flow (CBF)-weighted maps of ASL-MRI, was investigated. Intermodality equivalence with DSA [O'Kelly-Marotta (OKM) grading for occlusion], 3D-TOF-MRA, and 3D spin-echo T1-weighted ("black-blood") images was assessed. RESULTS: Ten cases were included. "TLS" signal was demonstrable in 7/8 (87.5%) of the DSA-visible flow-diverted aneurysms (OKM grade B3, n = 6; OKM grade A3, n = 2). No TLS was seen in both OKM-D (excluded) aneurysms. TLS was not visualised in an OKM-B3 aneurysm with < 3 mm opacifying remnant. 3D-TOF-MRA and ASL-MRI were discordant at 5 instances (45.4%; TOF-MRA false negative, n = 4; false positive, n = 1). Loss of flow void on black-blood images corresponded to the absence of TLS and vice versa in all cases but one. CONCLUSION: "Trapped labelled spins"-related signal on ASL-MRI occurs in patent large aneurysms that have undergone successful endovascular flow diversion. This phenomenon likely represents an interplay of a multitude of haemodynamic factors including decelerated intra-aneurysmal inflow and outflow restriction. Serial intra-saccular TLS signal changes may hold diagnostic value, including contexts where 3D-TOF-MRA interpretation becomes dubious. "Trapped labelled spins"-related signal as a non-invasive proxy marker of aneurysm patency can possibly obviate unnecessary DSA.

Diffusion and perfusion imaging biomarkers of H3 K27M mutation status in diffuse midline gliomas.

PURPOSE: H3K27M-mutant diffuse midline gliomas (M-DMGs) exhibit a clinically aggressive course. We studied diffusion-weighted imaging (DWI) and perfusion (PWI) MRI features of DMG with the hypothesis that DWI-PWI metrics can serve as biomarkers for the prediction of the H3K27M mutation status in DMGs. METHODS: A retrospective review of the institutional database (imaging and histopathology) of patients with DMG (July 2016 to July 2020) was performed. Tumoral apparent diffusion coefficient (ADC) and peritumoral ADC (PT ADC) values and their normalized values (nADC and nPT ADC) were computed. Perfusion data were analyzed with manual arterial input function (AIF) and leakage correction (LC) Boxerman-Weiskoff models. Normalized maximum relative CBV (rCBV) was evaluated. Intergroup analysis of the imaging variables was done between M-DMGs and wild-type (WT-DMGs) groups. RESULTS: Ninety-four cases (M-DMGs-n = 48 (51%) and WT-DMGs-n = 46(49%)) were included. Significantly lower PT ADC (mutant-1.1 ± 0.33, WT-1.23 ± 0.34; P = 0.033) and nPT ADC (mutant-1.64 ± 0.48, WT-1.83 ± 0.54; P = 0.040) were noted in the M-DMGs. The rCBV (mutant-25.17 ± 27.76, WT-13.73 ± 14.83; P = 0.018) and nrCBV (mutant-3.44 ± 2.16, WT-2.39 ± 1.25; P = 0.049) were significantly higher in the M-DMGs group. Among thalamic DMGs, the min ADC, PT ADC, and nADC and nPT ADC were lower in M-DMGs while nrCBV (corrected and uncorrected) was significantly higher. Receiver operator characteristic curve analysis demonstrated that PT ADC (cut-off-1.245), nPT ADC (cut-off-1.853), and nrCBV (cut-off-1.83) were significant independent predictors of H3K27M mutational status in DMGs. CONCLUSION: DWI and PWI features hold value in preoperative prediction of H3K27M-mutation status in DMGs.

Transcriptional modulation of calcium-permeable AMPA receptor subunits in glioblastoma by MEK-ERK1/2 inhibitors and their role in invasion.

Glioblastoma is the most common primary brain tumor. Glioblastoma cells secrete a significant amount of glutamate, which serve as a potential growth factor in glioma pathobiology through their specific receptor subtypes including α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR). Glioblastoma express AMPAR subunits; however, its regulation and activation with downstream intracellular signaling are not well-understood. Phosphorylated-extracellular signaling-regulated kinase (ERK)1/2 is known to regulate the ionotropic glutamate receptors in cortical neurons. The mitogen-activated protein kinase cascade is frequently activated in several tumors, including glioma. Nonetheless, the association of ERK signaling with AMPAR subunits in glioblastoma is undetermined. Here, we demonstrated potential role of AMPAR in invasion, and the modulation of AMPAR subunits at transcript level by ERK signaling in glioblastoma cells. Inhibition of ERK signaling specifically downregulated the expression of calcium-permeable AMPAR subunits, GluA1 and GluA4, and upregulated calcium-impermeable AMPAR subunit GluA2 implying differential regulation of the expression of calcium-permeable AMPAR subunits of glioblastoma. Concomitantly, it significantly decreased the invasion of U87MG cells. Taken together, these findings suggest that the AMPAR enhances invasion of glioblastoma, and ERK signaling modulates the differential expression of calcium-permeable AMPAR phenotype that might play a crucial role in the invasive propensity of glioblastoma cells.

Conventional and Advanced Magnetic Resonance Imaging Features of Supratentorial Extraventricular Ependymomas.

OBJECTIVE: To describe the magnetic resonance imaging characteristics of supratentorial ependymomas. METHODS: The magnetic resonance imaging and computed tomography imaging characteristics of 49 cases of supratentorial ependymomas were analyzed retrospectively. The location, size, degree of perilesional edema, gross appearance, computed tomography attenuation characteristics, T1 and T2 signal intensity characteristics, degree of diffusion restriction, presence of calcification, and hemorrhage were documented for each lesion. The intratumoral susceptibility scores (ITSS), apparent diffusion coefficient (ADC) values, relative cerebral blood volume, and choline/N-acetyl aspartate ratios were documented where available. RESULTS: The frontal lobe was the most common location with a mean size of 6.37 × 4.8 cm. Severe perilesional edema was evident in 30%. Heterogenous, solid-cystic appearance was present in 96% lesions, with 95% of extraventricular lesions extending from pial surface to the ventricular margin. Calcification was seen in 55% of cases. The ITSS was 3 in 85.7% of lesions. The mean ADC value calculated was 600 × 10 mm/s. The mean relative cerebral blood volume on dynamic susceptibility contrast perfusion was 4.83. The mean choline/N-acetyl aspartate ratio was 5.87. Leptomeningeal dissemination was demonstrable in 5 lesions. Four lesions were abutting the dura with frank dural invasion in one. One patient presented with disseminated disease without evidence of a primary lesion. CONCLUSIONS: A large lesion with relatively well-defined margins, heterogeneous solid cystic appearance, extending from the pial surface to the ventricular margin, presence of calcification, and ADC values approaching those of white matter should raise a suspicion of supratentorial ependymoma. High ITSS, MR perfusion parameters, and magnetic resonance spectroscopy characteristics are similar to those of other high-grade gliomas.

TNF-α mediated MEK-ERK signaling in invasion with putative network involving NF-κB and STAT-6: a new perspective in glioma.

Glioblastoma is the most common malignant primary brain tumor with poor prognosis. Invasion involves pro-inflammatory cytokines and major signaling hubs. Tumor necrosis factor-α (TNF-α) acts as a master switch in establishing an intricate link between inflammation and cancer. The present study attempted to explore the possible implication of MAPK extracellular signaling-regulated kinase kinase (MEK)-extracellular signaling-regulated kinase (ERK) signaling pathway and expression of nuclear factor-κB (NF-κB), signal transducers and activators of transcription-6 (STAT-6), ERK, and phosphorylated-ERK (p-ERK) signaling proteins in TNF-α microenvironment. U0126 and PD98059 were used to inhibit the MEK-ERK1/2 pathway. TNF-α stimulation enhanced invasion in U87MG, U251MG and patient-derived primary glioma cells, whereas cell viability was not altered. Matrix metalloproteinase-2 (MMP-2) activity was increased only in U251MG glioma cells. These data suggest that TNF-α microenvironment plays an important role in the invasion of U251MG, U87MG, and patient-derived primary glioma cells, without any cytotoxic effect. The MMP-2 activity is differentially regulated by TNF-α stimulation in these cells. TNF-α stimulation upregulated the protein expression of ERK-1, ERK-2 and also increased the level of p-ERK1/2. TNF-α stimulation further upregulated the expression of NF-κB1, STAT-6 in tandem with Ras-MEK signaling system in U87MG cells, which emphasized the possible involvement of these signaling hubs in the glioma microenvironment. MEK-ERK inhibitors significantly attenuated the invasion of U87MG cells mediated by the TNF-α stimulation, probably through their inhibitory impact on p-ERK1/2 and ERK-2. This study provides the possible rationale of invasion by glioma cells in a TNF-α-induced pro-inflammatory milieu, which involves direct role of MEK-ERK signaling, with possible implication of NF-κB and STAT-6.

Neuronal Intranuclear Inclusion Disease: A Rare Etiology for Rapidly Progressive Dementia.

INTRODUCTION: Neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative disorder pathologically characterized by localized neuronal loss, and presence of eosinophilic intranuclear inclusions in neurons and glial cells. CASE REPORT: A 50-year-old man presented with rapidly progressive dementia, behavioral changes, gait disturbances, and incontinence of 3 months duration. His brain magnetic resonance imaging showed diffuse T2/FLAIR hyperintensity of basal ganglia, thalami, cerebral peduncles, ventral pons, and supratentorial white matter with a frontal predominance. Hyperintensity was noted along the corticosubcortical junction on diffusion-weighted images. NIID was suspected and the patient underwent triple biopsy of the sural nerve with adjacent skin and biceps biopsy. Biopsy revealed ubiquitin-positive intranuclear inclusions surrounding the myofibers, and vascular smooth muscles suggestive of NIID. CONCLUSIONS: NIID is a rare neurodegenerative disorder usually diagnosed postmortem. The rectal and skin biopsy had proved helpful in antemortem diagnosis. We have increased the diagnostic armamentarium by showing the presence of intranuclear inclusions in smooth muscle cells of the muscle. Hence, a high degree of suspicion, magnetic resonance imaging features, with nerve/muscle/skin biopsy can help in diagnosis of NIID.

Incidence of deep venous thrombosis in patients undergoing elective neurosurgery - A prospective cohort based study.

INTRODUCTION: The exact incidence of deep vein thrombosis (DVT) in the Indian neurosurgical patient population is uncertain. This situation is quite different from its well-documented incidence in the Caucasian population.This study aims to analyze the incidence, etiopathogenesis, and risk factors in the development of DVT in Indians. This will enable us to formulate country-specific guidelines for its appropriate and timely prophylaxis. AIMS AND OBJECTIVES: To study the incidence of deep venous thrombosis in patients undergoing elective neurosurgery. MATERIALS AND METHODS: This was a prospective cohort based study analyzing a total of 273 adult (>18 years) patients who underwent elective neurosurgery during a period of 1 year from November 2013 to December 2014.A preoperative baseline Doppler ultrasonography and coagulation profile was performed, followed by postoperative surveillance Doppler ultrasonography biweekly until discharge. Statistical analysis was performed using chi-square test and Pearson's correlation analysis. RESULTS: A total of 33 patients (12.08%) developed DVT in the postoperative period. Hypertension, frequent alcohol intake, smoking, and obesity were found to be the risk factors (P = 0.001). Significant association was observed between malignant tumors, meningiomas, and DVT (P = 0.001). Intraoperative supine and lateral position for more than 5 h, the severity of postoperative motor deficit, and ambulation delay of more than 2 days were significant risk factors (P = 0.001). CONCLUSION: Our study, one of the first of its kind, details the incidence and etiopathogenesis of DVT in the Indian neurosurgical population. We recommend an early usage of prophylaxis (mechanical and/or pharmacological) in the perioperative period for the high risk category of patients. We hope that this data can be used for preparing country-specific guidelines for DVT prophylaxis.

Family with Ehlers-Danlos syndrome (combined classic and vascular type) with rare presentation of progressive myopathy and unusual association of severe facial and trigeminal motor weakness.

We report the clinical, radiological, biochemical, muscle histology, and electron microscopic features of two members of a family with combined Ehlers-Danlos syndrome (EDS) [classic and vascular type] and progressive myopathy as the primary manifestation. A 35-year old lady presented with severe gluteal and thigh muscle pain and easy fatigability for 5 years. She developed weakness and wasting of pelvic and pectoral girdles and thighs for 3 years and severe neck flexor and truncal weakness for 6 months. She had a history of recurrent jaw dislocation, easy bruising with hyperpigmentation, hyperextensibility of joints, translucent skin, and papyraceous scars. She had high myopia with astigmatism. She had wasting of temporalis, masseters, sternocleidomastoids and trapezius. There was moderate weakness of temporalis, masseters, and facial muscles. Muscle power was Medical Research Council (MRC) grade 4 at shoulders and arms, and grade 3+ at pelvis and thighs. Serum homocysteine level was normal, and creatine kinase (CK) was 275 IU. Two dimensional echocardiogram (2D Echo) showed myxomatous degeneration of mitral valves. Electromyography (EMG) was suggestive of a myopathic pattern. Muscle magnetic resonance imaging (MR) revealed severe fatty infiltration of paraspinal muscles, gluteus maximus and medius, quadriceps, hamstrings, and gastrocnemius. Electron microscopy showed an occasional distorted fibril with mild increase in oxytalan fibers and variation in thickness of blood vessel basement membrane. Her 15-year old daughter had exertion-induced myalgias, right hemifacial hypoplasia, myopia, hyperextensible joints, hyperelastic skin, and neck muscle weakness. However, her CK and 2D Echo were normal. This report presents the rare combination of classic and vascular type of EDS primarily presenting as muscle weakness and associated with facial and trigeminal motor weakness.

Imaging features of rosette-forming glioneuronal tumours (RGNTs): A Series of seven cases.

OBJECTIVE: Rosette-forming glioneuronal tumours (RGNTs) are a recently described, rare, distinct nosological entity of the glioneuronal family. We describe imaging findings (CT and MRI) in seven patients with RGNTs. MATERIALS AND METHODS: This retrospective study includes seven RGNT patients (4 male, 3 female; age range: 7-42 years; mean age: 25 years) diagnosed and treated at our institute. MR studies were performed on 3 T and 1.5-T clinical MR systems. All patients were reviewed by two experienced neuroradiologists and imaging findings were tabulated. RESULTS: Five tumours were located in the posterior fossa, and two were in the pineal region. One of the tumours demonstrated multiple satellite lesions, which involved the midbrain, pons, medulla as well as the cervical cord. Tumours located in the pineal region compressed the 3rd ventricle/aqueduct and extended below the tentorium cerebelli. All the tumours demonstrated enhancement, and susceptibility was evident in six of the seven patients. CSF dissemination was present in two patients. CONCLUSION: RGNTs are usually solid-cystic tumours and frequently demonstrate peripheral/heterogeneous enhancement upon post-contrast study. Haemorrhage is a common feature which may not be evident on CT. Cerebrospinal fluid (CSF) dissemination is a feature and appropriate imaging should be performed whenever an RGNT is suspected. KEY POINTS: CT and MRI findings of seven RGNT cases were retrospectively reviewed. RGNTs are predominantly posterior fossa tumours. RGNTs are typically T1 hypointense and T2 hyperintense. Haemorrhage and peripheral/heterogeneous enhancement are common features of RGNTs. CSF dissemination is a feature of RGNTs and requires appropriate imaging.

Functional cortical reorganization in cases of cervical spondylotic myelopathy and changes associated with surgery.

OBJECTIVE The physiological mechanisms underlying the recovery of motor function after cervical spondylotic myelopathy (CSM) surgery are poorly understood. Neuronal plasticity allows neurons to compensate for injury and disease and to adjust their activities in response to new situations or changes in their environment. Cortical reorganization as well as improvement in corticospinal conduction happens during motor recovery after stroke and spinal cord injury. In this study the authors aimed to understand the cortical changes that occur due to CSM and following CSM surgery and to correlate these changes with functional recovery by using blood oxygen level-dependent (BOLD) functional MRI (fMRI). METHODS Twenty-two patients having symptoms related to cervical cord compression due to spondylotic changes along with 12 age- and sex-matched healthy controls were included in this study. Patients underwent cervical spine MRI and BOLD fMRI at 1 month before surgery (baseline) and 6 months after surgery. RESULTS Five patients were excluded from analysis because of technical problems; thus, 17 patients made up the study cohort. The mean overall modified Japanese Orthopaedic Association score improved in patients following surgery. Mean upper-extremity, lower-extremity, and sensory scores improved significantly. In the preoperative patient group the volume of activation (VOA) was significantly higher than that in controls. The VOA after surgery was reduced as compared with that before surgery, although it remained higher than that in the control group. In the preoperative patient group, activations were noted only in the left precentral gyrus (PrCG). In the postoperative group, activations were seen in the left postcentral gyrus (PoCG), as well as the PrCG and premotor and supplementary motor cortices. In postoperative group, the VOA was higher in both the PrCG and PoCG as compared with those in the control group. CONCLUSIONS There is over-recruitment of sensorimotor cortices during nondexterous relative to dexterous movements before surgery. After surgery, there was recruitment of other cortical areas such as the PoCG and premotor and supplementary motor cortices, which correlated with improvement in dexterity, but activation in these areas was greater than that found in controls. The results show that improvement in dexterity and finer movements of the upper limbs is associated with recruitment areas other than the premotor cortex to compensate for the damage in the cervical spinal cord.

Dengue encephalitis with predominant cerebellar involvement: report of eight cases with MR and CT imaging features.

OBJECTIVES: CNS dengue infection is a rare condition and the pattern of brain involvement has not been well described. We report the MR imaging (MRI) features in eight cases of dengue encephalitis. MATERIALS AND METHODS: We retrospectively searched cases of dengue encephalitis in which imaging was performed. Eight cases (three men, five women; age range: 8-42 years) diagnosed with dengue encephalitis were included in the study. MR studies were performed on 3-T and 1.5-T MR clinical systems. Two neuroradiologists retrospectively reviewed the MR images and analysed the type of lesions, as well as their distribution and imaging features. RESULTS: All eight cases exhibited MRI abnormalities and the cerebellum was involved in all cases. In addition, MRI signal changes were also noted in the brainstem, thalamus, basal ganglia, internal capsule, insula, mesial temporal lobe, and cortical and cerebral white matter. Areas of susceptibility, diffusion restriction, and patchy post-contrast enhancement were the salient imaging features in our cohort of cases. CONCLUSION: A pattern of symmetrical cerebellar involvement and presence of microbleeds/haemorrhage may serve as a useful imaging marker and may help in the diagnosis of dengue encephalitis.

Novel imaging findings in two cases of biotinidase deficiency-a treatable metabolic disorder.

Biotinidase deficiency is one of the few treatable inborn errors of metabolism. We describe unique MRI features in two patients with biotinidase deficiency. Brain MRI in case one demonstrated symmetrical diffusion restriction in bilateral hippocampi, parahippocampal gyri, central tegmental tracts, and cerebellar white matter besides other structures that have been reported previously. The second patient was noted to have bilateral symmetrical T2 hyperintensities involving the anterior, lateral and posterior columns of the entire spinal cord on MRI. Knowledge of the varied MRI features of biotinidase deficiency will aid the prompt diagnosis and treatment of a potentially disabling illness, especially in countries where newborn screening is not routinely performed.

Variant course of bilateral anterior cerebral artery in semilobar holoprosencephaly.

We report an unusual case of semilobar holoprosencephaly with variant course of bilateral anterior cerebral arteries (ACA) in a 1-year-old child. This is a very rare arterial variant, given that holoprosencephalic brains are usually associated with azygous ACAs.

Bell's mania as a clinical presentation in a neurosurgical setting from a tertiary care neuropsychiatric hospital in India.

Bell's mania is the co-occurrence of delirium and mania. We present two cases of Bell's mania in a neurosurgical setting. The first case is of a 52-year-old male who presented with holocranial headache, disorientation, and manic symptoms for five months. He was found to have suprasellar craniopharyngioma. He significantly improved with olanzapine, but re-emergence of mood symptoms was noted after surgery. The second case is of a 42-year-old male who presented with a 15-day history of seizures and disorientation. He was found to have a dural arteriovenous fistula. He developed Bell's mania in the post-procedural period, which improved with olanzapine. Compression of the hypothalamo-pituitary stalk in the first case and vascular and inflammatory changes in the second case could have led to Bell's mania. Atypical age of onset and presence of neurological symptoms in patients presenting with psychiatric symptoms should raise the suspicion of an underlying organicity. Atypical anti-psychotics can be a useful management strategy for Bell's mania.

Monomelic Amyotrophy/Hirayama Disease: Surgical Outcome in a Large Cohort of Indian Patients.

BACKGROUND: Hirayama disease (HD) is a cervical compressive myelopathy. Anterior cervical discectomy and fusion (ACDF) is identified as the best surgical approach. We evaluated surgical outcomes and factors influencing ACDF in HD. METHODS: Between 2015 and 2019, 126 patients with HD underwent ACDF. Contrast magnetic resonance imaging of the cervical spine in full flexion was performed. Clinical examination and preoperative/postoperative assessment of hand function using Fugl-Meyer assessment, Jebsen-Taylor hand function test, and handheld dynamometry were performed at 3-monthly intervals for 1 year. Surgical outcomes were assessed as per the Odom criteria and Hirayama outcome questionnaire. RESULTS: Age at onset and duration of illness were 12-31 years (mean, 18 ± 2.7) and 1-96 months (32.7 ± 24.4), respectively. All patients had progressive weakness and wasting of the affected limb. Cord atrophy was seen in 97.1%, with epidural detachment and engorgement of the posterior epidural venous plexus in all. All patients underwent ACDF. Of these patients, 54% had an excellent/good outcome and 39% had a satisfactory outcome as per the Odom scale at last follow-up (mean, 44.9 ± 16.5 months) after surgery. Handheld dynamometry showed improvement from preoperative values to 1 year follow-up. Duration of illness and age at onset had a negative correlation and the preoperative Fugl-Meyer score had a positive correlation with improvement. CONCLUSIONS: ACDF resulted in remarkable improvement or stabilization in neurologic deficits in many patients with HD. Because motor disability ensues over time, early surgical intervention during the progressive phase is advocated.

Transarterial treatment of direct carotico-cavernous fistulas with coils and Onyx.

INTRODUCTION: The purpose of this study was to evaluate the role of combination of liquid embolic agent ethylene vinyl alcohol copolymer (Onyx) and detachable coils in the treatment of direct carotico-cavernous fistulas (CCFs). METHODS: We prospectively collected clinical and radiological data of all patients who underwent embolization of direct CCFs at our institution over a period of 21 months. The clinical parameters, angioarchitecture, presence of cortical venous reflux, volume of Onyx used, number of coils used, extent of embolization and complications were recorded. RESULTS: A total of 21 consecutive patients (18 men and 3 women, 14 to 48 years) with direct CCF underwent embolization with a combination of coils and Onyx. Embolization was done through the arterial route in all cases. Complete obliteration of the fistula was achieved in 19 of 21 cases. Cast embolization in middle cerebral artery occurred in one patient; however, the cast was completely retrieved with Solitaire device, and the patient did not have any neurological deficit. All completely treated patients reported relief of symptoms at varying intervals. At 6-month follow-up, none of the patients with complete occlusion of the fistula showed any recurrence. CONCLUSION: The adjuvant use of Onyx with detachable coils in direct CCF through the arterial route is a safe and effective method for embolization with immediate and complete occlusion of the fistula. To the best of our knowledge, this is the first case series of demonstration of arterial use of Onyx with coils in the treatment of direct CCFs.

Comparison of arterial spin labeling perfusion with dynamic susceptibility contrast perfusion in Moyamoya disease.

Objectives: Moyamoya disease (MMD) leads to frequent ischemic/hemorrhagic manifestations. Our aim was to compare findings of arterial spin labeling (ASL) with dynamic susceptibility contrast (DSC) perfusion in patients of MMD. Materials and Methods: Patients diagnosed as MMD underwent magnetic resonance imaging with ASL and DSC perfusion sequences. Perfusion in bilateral anterior cerebral artery and middle cerebral artery territories at two levels (level of thalami and centrum semiovale) was graded as normal (score 1), or reduced (score 2) on DSC and ASL cerebral blood flow (CBF) maps by comparison with normal cerebellar perfusion. Time to peak (TTP) maps of DSC perfusion were also qualitatively scored as normal (score 1), or increased (score 2) similarly. Correlation between scores of ASL, CBF, DSC, CBF, and DSC, TTP maps was assessed by using Spearman's rank correlation. Results: Among the 34 patients, we did not find any significant correlation between the ASL CBF maps and DSC CBF maps (r = -0.028, P = 0.878), mean matching index 0.39 ± 0.31, whereas significant correlation was noted between the ASL CBF maps and DSC TTP maps (r = 0.58, P = 0.0003), mean matching index 0.79 ± 0.26. ASL CBF underestimated the perfusion compared to DSC perfusion. Conclusion: ASL perfusion CBF maps do not match the DSC perfusion CBF maps and rather match the TTP maps of DSC perfusion. This is explained by inherent problems in estimation of CBF in these techniques because of delay in arrival of label (in ASL perfusion) or contrast bolus (in DSC perfusion) due to the presence of stenotic lesions.

Acute Severe Hypovolemic Hyponatremia in a Patient on Intravenous Dexamethasone.

Hyponatremia is a commonly encountered electrolyte imbalance with varied etiology. Hyponatremia can be broadly classified as hypotonic, isotonic, and hypertonic hyponatremia based on the tonicity of plasma. Hypotonic hypovolemia is further classified as hypovolemic, euvolemic, and hypervolemic hyponatremia based on the volume status. Gastrointestinal fluid and electrolyte losses, secondary to vomiting and diarrhea, is an important predisposition to hypotonic hypovolemic hyponatremia. The renin-angiotensin-aldosterone system (RAAS) and antidiuretic hormone (ADH) play a pivotal role in maintaining intravascular volume and serum sodium concentration. Dexamethasone is a potent glucocorticoid with minimal mineralocorticoid activity. It negatively affects the hypothalamic-pituitary-adrenal axis and the renin-angiotensin-aldosterone system, particularly with prolonged administration. In the index case, acute severe hypovolemic hyponatremia ensued on the third post-procedure (endovascular embolization of traumatic carotico-cavernous fistula (CCF)) day while the patient was on intravenous dexamethasone. This case underscores that even small fluid and electrolyte imbalance in the setting of dexamethasone therapy may lead to severe hypovolemic hyponatremia, which requires specific therapy.