Acute Encephalitis Syndrome in Children and Adolescents: A Five-Year Descriptive Study From South India.

OBJECTIVE: Acute encephalitis syndrome (AES) in children results in significant neurocognitive deficits or mortality. It is pertinent to study the AES patterns periodically to identify the changes in the etiological trends and outcomes. Our objective was to find the etiological agents of AES, mode of diagnosis, treatment given, and outcomes. METHODS: We reviewed the electronic records of children aged 1 month to 15 years who were admitted with AES in our centre from January 2015 to December 2019. We analyzed the the clinical, laboratory, and radiological profile of these children and adolescents in relation to their outcome. Poor outcome was defined as death, discharge against medical advice with neurological deficits, or Glasgow Outcome Score Extended (GOS-E) d≤ 5 at the time of discharge. RESULTS: Among 250 patients admitted with AES during the study period, a definitive etiological diagnosis was established in 56.4% of children (30.4% viral, 22% bacterial). Scrub typhus (11.2%) and dengue (9%) were the two most common underlying illnesses. Serology helped in clinching the diagnosis in 30% of children. A surge in AES cases in the post-monsoon season was observed in our cohort. Third-generation cephalosporin drugs (85.7%) and acyclovir (77.7%) were the most commonly used empiric antimicrobial drugs. About one-third of children (n = 80) had a poor outcome. GCS ≤ 8 at presentation and requirement for invasive ventilation were found to be significant predictors of poor outcome. CONCLUSION: A definitive diagnosis was obtained in about half of the children with AES. Viral (30.4%) and rickettsial infections (22%) were the common etiologies identified. Poor outcome was observed in 32% of patients.

Topographical distribution and prevalence of basal duct-like recess sign in a cohort of Papillary Craniopharyngioma-novel findings and implications.

PURPOSE: Basal duct-like recess (DR) sign serves as a specific marker of papillary craniopharyngiomas (PCPs) of the strictly third-ventricular (3 V) topography. Origins of this sign are poorly understood with limited validation in external cohorts. METHODS: In this retrospective study, MRIs of pathologically proven PCPs were reviewed and evaluated for tumor topography, DR sign prevalence, and morphological subtypes. RESULTS: Twenty-three cases with 24 MRIs satisfied our inclusion criteria. Median age was 44.5 years with a predominant male distribution (M/F ratio 4.7:1). Overall, strictly 3 V was the commonest tumor topography (8/24, 33.3%), and tumors were most commonly solid-cystic (10/24, 41.7%). The prevalence of DR sign was 21.7% (5/23 cases), all with strictly 3 V topography and with a predominantly solid consistency. The sensitivity, specificity and positive and negative predictive value of the DR sign for strict 3 V topography was 62.5%, 100%, 100% and 84.2% respectively. New pertinent findings associated with the DR sign were observed in our cohort. This included development of the cleft-like variant of DR sign after a 9-year follow-up initially absent at baseline imaging. Additionally, cystic dilatation of the basal tumor cleft at the pituitary stalk-tumor junction and presence of a vascular structure overlapping the DR sign were noted. Relevant mechanisms, hypotheses, and implications were explored. CONCLUSION: We confirm the DR sign as a highly specific marker of the strictly 3 V topography in PCPs. While embryological and molecular factors remain pertinent in understanding origins of the DR sign, non-embryological mechanisms may play a role in development of the cleft-like variant.

Idiopathic intracranial hypertension as the initial presenting manifestation of systemic lupus erythematosus in a child.

Idiopathic intracranial hypertension (IIH) is a diagnosis of exclusion characterized by features of raised intracranial pressure (ICP) in the absence of brain parenchymal lesion, vascular malformations, hydrocephalus, or central nervous system (CNS) infection. Commonly used other terms for this entity include benign intracranial hypertension (BIH) or pseudotumor cerebri. Few case reports of systemic lupus erythematosus (SLE) presenting as IIH are available in the literature. We report a 12-year-old girl presented with chronic holocranial headache and occasional episodes of projectile vomiting for the last 6 months and then developed blurring of vision for the last month. She fulfilled the criteria for IIH. Subsequent evaluation revealed a diagnosis of SLE. The occurrence of IIH in SLE is not coincidental and is reported in 1%-5.4% of patients with SLE. Though corticosteroids have not been widely used in IIH, underlying SLE warranted administering corticosteroids with subsequent complete resolution of IIH. Pediatricians, neurologists, intensivists, and ophthalmologists should consider SLE as a differential diagnosis in children presenting with IIH.

Is radiomics a useful addition to magnetic resonance imaging in the preoperative classification of PitNETs?

BACKGROUND: The WHO 2021 introduced the term pituitary neuroendocrine tumours (PitNETs) for pituitary adenomas and incorporated transcription factors for subtyping, prompting the need for fresh diagnostic methods. Current biomarkers struggle to distinguish between high- and low-risk non-functioning PitNETs. We explored if radiomics can enhance preoperative decision-making. METHODS: Pre-treatment magnetic resonance (MR) images of patients who underwent surgery between 2015 and 2019 with available WHO 2021 classification were used. The tumours were manually segmented on the T1w, T1-contrast enhanced, and T2w images using 3D Slicer. One hundred Pyradiomic features were extracted from each MR sequence. Models were built to classify (1) somatotroph and gonadotroph PitNETs and (2) high- and low-risk subtypes of non-functioning PitNETs. Feature were selected independently from the MR sequences and multi-sequence (combining data from more than one MR sequence) using Boruta and Pearson correlation. Support vector machine (SVM), logistic regression (LR), random forest (RF), and multi-layer perceptron (MLP) were the classifiers used. Data imbalance was addressed using the Synthetic Minority Oversampling TEchnique (SMOTE). Performance of the models were evaluated using area under the receiver operating curve (AUC), accuracy, sensitivity, and specificity. RESULTS: A total of 222 PitNET patients (train, n = 149; test, n = 73) were enrolled in this retrospective study. Multi-sequence-based LR model discriminated best between somatotroph and gonadotroph PitNETs, with a test AUC of 0.84, accuracy of 0.74, specificity of 0.81, and sensitivity of 0.70. Multi-sequence-based MLP model perfomed best for the high- and low-risk non-functioning PitNETs, achieving a test AUC of 0.76, accuracy of 0.67, specificity of 0.72, and sensitivity of 0.66. CONCLUSIONS: Utilizing pre-treatment MRI and radiomics holds promise for distinguishing high-risk from low-risk non-functioning PitNETs based on the latest WHO classification. This could assist neurosurgeons in making critical decisions regarding surgery or alternative management strategies for PitNETs after further clinical validation.

Clinico-Radiological Evaluation for Longitudinal Assessment in Central Skull Base Osteomyelitis: Proposal of Novel Scoring System.

This study aims to evaluate clinical, radiological and laboratory parameters for longitudinal assessment and prognostication in central skull base osteomyelitis (CSBO). Novel radiological score and cranial nerve assessment score (CNAS) have been proposed and analysed along with pain score (VAS), ESR, CRP, WBC count, and HbA1c for utility in disease-monitoring and predicting outcome in CSBO. CSBO cases managed in a tertiary care centre from January 2018 to November 2020, with a minimum follow-up of 6 months were included. The parameters were recorded at presentation, 3-month, 6-month postoperative follow-up, and at completion of therapy, for statistical analysis. Significant positive correlation was found amongst pain score, CNAS, radiological score, ESR, and CRP at different timelines. On longitudinal assessment, there was a statistically significant reduction in above-mentioned parameters, in the cases who recovered. Those with initial radiological score < 30, pain score ≤ 7, and CNAS < 10 showed early clinical improvement, required shorter duration of antimicrobial therapy, and exhibited higher probability of becoming disease-free at an earlier time, compared to those presenting with higher scores. We propose the use of pain score, a novel cranial nerve assessment score, and a novel radiological score for longitudinal assessment in CSBO. The trend in these parameters along with ESR and CRP are useful to monitor the disease process. The initial assessment scores can predict duration of antimicrobial therapy and probability of early recovery. WBC count and HbA1c were neither useful for disease-monitoring nor predicting outcome.

Clinico-Etiological Spectrum and Functional Outcomes of Children with Pre-Status Dystonicus and Status Dystonicus (SD): A Descriptive Study.

Background: Status dystonicus (SD) is a life-threatening movement disorder emergency characterized by increasingly frequent and severe episodes of generalized dystonia, requiring urgent hospital admission. The diverse clinico-etiological spectrum, high risk of recurrence, and residual disabilities complicate functional outcomes. Aim: We aim to describe the clinico-etiological spectrum, radiology, therapeutic options, and follow-up of patients with pre-status dystonicus (pre-SD) and SD. Methodology: A cross-sectional retrospective study was carried out in a tertiary care referral center. The clinical, laboratory, and radiology data of all patients aged less than 18 years with pre-SD and SD from January 2010 to December 2020 were collected. The Dystonia Severity Assessment Plan (DSAP) scale for grading severity and the modified Rankin Scale (mRS) for assessing outcome were used at the last follow-up visit. Results: Twenty-eight patients (male:female: 2.1:1) experiencing 33 episodes of acute dystonia exacerbation were identified. The median age at the onset of dystonia and SD presentation was 8.71 (range: 0.25-15.75) and 9.12 (range: 1-16.75) years, respectively. Four patients experienced more than one episode of SD. The etiological spectrum of SD includes metabolic (Wilson's disease-13, L-aromatic amino acid decarboxylase deficiency-one, and Gaucher's disease-one), genetic (neurodegeneration with brain iron accumulation-three and KMT2B and THAP 1 gene-related-one each), structural-three, post-encephalitic sequelae (PES)-four, and immune-mediated (anti-NMDA receptor encephalitis-one). Five patients had pre-SD (DSAP grade 3), and 23 patients had established SD (DSAP grade 4-17 and DSAP grade 5-six). The Rapid escalation of chelation therapy precipitated SD in 11 patients with Wilson's disease. Febrile illness or pneumonia precipitated SD in nine patients. Twenty-three episodes of SD required midazolam infusion in addition to anti-dystonic medications. The median duration of hospital stay was 10 days (range: 3-29). Twenty-three patients had resolution of SD but residual dystonia persisted, while two patients had no residual dystonia at follow-up. Three patients succumbed owing to refractory SD and its complications. Conclusion: Early identification of triggers, etiology, and appropriate management are essential to calm the dystonic storm.

Effectiveness of Adjunctive High-Dose Infliximab Therapy to Improve Disability-Free Survival Among Patients With Severe Central Nervous System Tuberculosis: A Matched Retrospective Cohort Study.

BACKGROUND: Few treatment options exist for patients with severe central nervous system (CNS) tuberculosis (TB) worsening due to inflammatory lesions, despite optimal antitubercular therapy (ATT) and steroids. Data regarding the efficacy and safety of infliximab in these patients are sparse. METHODS: We performed a matched retrospective cohort study based on Medical Research Council (MRC) grading system and modified Rankin Scale (mRS) scores comparing 2 groups of adults with CNS TB. Cohort A received at least 1 dose of infliximab after optimal ATT and steroids between March 2019 and July 2022. Cohort B received only ATT and steroids. Disability-free survival (mRS score ≤2) at 6 months was the primary outcome. RESULTS: Baseline MRC grades and mRS scores were similar between the cohorts. Median duration before initiation of infliximab therapy from start of ATT and steroids was 6 (IQR: 3.7-13) months and for neurological deficits was 4 (IQR: 2-6.2) months. Indications for infliximab were symptomatic tuberculomas (20/30; 66.7%), spinal cord involvement with paraparesis (8/30; 26.7%), and optochiasmatic arachnoiditis (3/30; 10%), worsening despite adequate ATT and steroids. Severe disability (5/30 [16.7%] and 21/60 [35%]) and all-cause mortality (2/30 [6.7%] and 13/60 [21.7%]) at 6 months were lower in cohort A versus cohort B, respectively. In the combined study population, only exposure to infliximab was positively associated (aRR: 6.2; 95% CI: 2.18-17.83; P = .001) with disability-free survival at 6 months. There were no clear infliximab-related side effects noted. CONCLUSIONS: Infliximab may be an effective and safe adjunctive strategy among severely disabled patients with CNS TB not improving despite optimal ATT and steroids. Adequately powered phase 3 clinical trials are required to confirm these early findings.

Correlation Between Post-Radiosurgery Perinidal Hyperintensity and AVM Obliteration Following LINAC-Based Stereotactic Radiosurgery.

OBJECTIVE: We studied the correlation between new-onset perinidal hyperintensity (PH) on T2-weighted magnetic resonance imaging and obliteration of intracranial arteriovenous malformation (AVM) after stereotactic radiosurgery (SRS). METHODS: A retrospective study of 148 patients with an intracranial AVM who underwent SRS between September 2005 and June 2018 and had ≥1 radiological follow-up (early magnetic resonance imaging) 12-18 months after SRS was performed to analyze the correlation between PH (graded from 0 to 2) and AVM obliteration. RESULTS: Of the 148 patients, 95 were male. The mean patient age was 27.7 ± 12.4 years. Of the 148 AVMs, 105 (70.9%) were obliterated at a median follow-up of 27 months (interquartile range, 14-48 months). The cumulative 3-, 5-, 10-year obliteration rate was 51.8%, 70.8%, and 91.8%, respectively. New-onset PH was observed in 58 AVMs (39.2%; 50 obliterated and 8 not obliterated). No association was found between the pretreatment variables or dose delivered and the development of PH. Grade 2 PH was associated with the risk of symptoms developing compared with grade 1 PH (37.5% vs. 4%; P = 0.002). Symptomatic PH was more likely to develop in patients with a larger AVM (P = 0.05). On multivariate analysis, the presence of a single draining vein (odds ratio [OR], 2.9; 95% confidence interval [CI], 1.3-6.8), a lower median AVM volume (OR, 0.97; 95% CI, 0.6-0.89), a mean marginal radiation dose (OR, 1.29; 95% CI, 1.02-1.64), and the presence of PH (OR, 3.16; 95% CI, 1.29-7.71) were independent predictors of AVM obliteration. CONCLUSIONS: The incidence of PH after SRS for AVM was 39.2%. PH was an independent predictor of AVM obliteration after SRS. Grade 2 PH and a larger AVM volume were associated with symptomatic PH.

Morphometric analysis of Corpus Callosum in autistic and typically developing Indian children.

Corpus callosum (CC) is the largest commissural white matter bundle in the brain, responsible for the integration of information between hemispheres. Reduction in the size of the CC structure has been predominantly reported in children with autism spectrum disorder (ASD) compared to typically developing children (TD). However, most of these studies are based on high-functioning individuals with ASD but not on an inclusive sample of individuals with ASD with varying abilities. Our current study aimed to examine the CC morphometry between children with ASD and TD in the Indian population. We also compared CC morphometry in autistic children with autism severity, verbal IQ (VIQ) and full-scale IQ (FSIQ). T1-weighted structural images were acquired using a 3T MRI scanner to examine the CC measures in 62 ASD and 17 TD children. The length and height of the CC and the width of genu were decreased in children with ASD compared to TD. There was no significant difference in CC measures based on autism severity, VIQ or FSIQ among children with ASD. To our knowledge, this is the first neuroimaging study to include a significant number (n = 56) of low-functioning ASD children. Our findings suggest the atypical interhemispheric connectivity of CC in ASD.

Haemodynamic stroke in a rare adult presentation of osteopetrosis.

Osteopetrosis refers to a collection of metabolic bone diseases with impaired osteoclastic activity resulting in abnormally dense and dysplastic bone. Cranial involvement results in severe complications, including compressive nerve palsies, hydrocephalus and tonsillar herniation. Ischaemic stroke is very rarely reported in osteopetrosis, resulting from vascular impingement. We report a young adult woman with CLCN7 (Chloride Voltage-Gated Channel 7) gene-related osteopetrosis and ischaemic stroke resulting from diffuse and focal arterial stenosis and severe myelophthisic anaemia. Acute management included blood transfusions, lay-flat positioning and fever treatment, which resulted in partial recovery of her initial neurological deficits. Our case highlights this very rare stroke syndrome's unique mechanisms and treatment challenges.

MR findings suggestive of idiopathic intracranial hypertension in 117 patients with spontaneous cerebrospinal fluid rhinorrhea.

PURPOSE: The purpose of this study is to document the prevalence of MR findings suggestive of idiopathic intracranial hypertension (IIH) in patients undergoing endoscopic repair of spontaneous CSF rhinorrhea (SCSFR). METHODS: In a retrospective study, MR images of 117 consecutive patients who had undergone endoscopic repair of SCSFR were evaluated for features suggestive of IIH (empty sella, widened optic nerve sheath, tortuous optic nerve, flattened posterior globe, and enlarged Meckel's cave). Pituitary height was used to diagnose partial and complete empty sella. MR images were independently evaluated by two of the authors without knowledge of the clinical findings. Consensus method was used to resolve differences between the two evaluators. RESULTS: Empty or partially empty sella was diagnosed in the MR of 105 (89.7%) patients. In 38/105 (36.2%) patients with empty/partial empty sella, no additional MR findings were present. In 43/105 (41%) patients, one or more of the MR features with high specificity for diagnosis of IIH (flattened posterior globe and enlarged Meckel's cave) were seen. In the other 24 (22.9%) additional MR findings, less specific for IIH (widened optic nerve sheath, tortuous optic nerve) were noted. Papilledema was seen in 11 of 60 (18.3%) patients who underwent funduscopic examination. All patients with papilledema had empty/partial empty sella, and 9/11 (81.8%) had an additional MR finding suggestive of IIH. CONCLUSION: The majority of patients with SCSFR have MR imaging features of IIH. These imaging features should be a major component of previously published modified diagnostic criteria for IIH in patients with SCSFR.

Evaluation of intracranial vasculitis in tuberculous meningitis using magnetic resonance vessel wall imaging technique.

Background: Tuberculous meningitis (TBM) is a global health problem with important complications such as acute infarcts secondary to vasculitis contributing to adverse outcomes. The objective of this study is to assess intracranial vasculitis in patients with TBM, either during their initial diagnosis or during follow-up while on standard antituberculous therapy. Methods: Ten patients with TBM underwent magnetic resonance (MR) based vessel wall imaging (VWI) to identify intracranial vasculitis (five patients during their initial presentation and the other five patients during their follow-up visit). Results: Vasculitis was seen in 60% of the patients wherein 70% of their intracranial vessels were affected. Acute and chronic infarcts were seen in four and two patients respectively, one of whom had both acute and chronic infarcts. Leptomeningeal enhancement and basal cisternal tuberculomas were frequently seen in patients with vasculitis. Vasculitis was also seen many days after the commencement of the antituberculous therapy thus explaining late-onset infarcts in this disease. Conclusion: Intracranial vasculitis is common in the patient with TBM. MR-based VWI technique has the potential for infarct risk assessment and to help guide the treatment for its possible prevention.

Diffuse Infiltrative Non-mass-like Brain Parenchymal Lesions on MRI: Differentiating Lymphomatosis Cerebri from its Mimics.

OBJECTIVES: Diffuse infiltrative "non-mass-like" parenchymal lesions on MRI brain are a known presentation of an aggressive condition called lymphomatosis cerebri (LC) but are often misdiagnosed due to its non-specific clinical and imaging findings. We aim to identify clues to differentiate lymphomatosis from its less aggressive mimics based on imaging features. MATERIAL AND METHODS: MRI brain studies showing diffuse infiltrative "non-mass-like" parenchymal lesions between January 2013 and March 2020 were retrospectively identified and read for lesion location, signal characteristics, and enhancement pattern by two radiologists. Additional findings on MRI spine and whole-body fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) were recorded wherever available. The clinical diagnosis, patient demographics, symptoms, laboratory and histopathology results, treatment details, and follow-up details were also noted. RESULTS: Of the 67 patients, 28 (41.7%) were diagnosed with lymphomatosis. The remaining 39 (13.4%) patients were classified as non-lymphomas (infective, vasculitis, and inflammatory conditions). Diffusion restriction on MRI (20/67, P = 0.007) and increased regional activity on FDG PET-CT (12/31, P = 0.017) were the two imaging parameters found to significantly favor lymphomatosis over other conditions, whereas the presence of microhemorrhages on susceptibility-weighted imaging was significantly associated with vasculitis (P = 0.002). Rapid clinical or imaging deterioration on a short trial of steroids (P = 0.00) was the only relevant clinical factor to raise an early alarm of lymphomatosis. Positive serological markers and non-central nervous system systemic diseases were associated with non-lymphomatous diseases. CONCLUSION: LC and its less aggressive mimics can be differentiated on diffusion-weighted imaging-MRI and PET-CT when read in conjunction with rapid progression of clinical features, serological workup, and systemic evaluation.

Phenotypic variability of a TREX1 variant in Aicardi-Goutieres type 1 patients from the Indian subcontinent.

Aicardi-Goutieres Syndrome (AGS) is a heterogeneous genetic syndrome, manifesting early as encephalopathy and is associated with abnormal neurologic findings, hepatosplenomegaly, elevated liver enzymes, thrombocytopenia and intracranial calcification. The most severe neonatal type, AGS1, is caused by biallelic disease-causing variants in TREX1. In this study, we describe four patients with TREX1-related AGS1 whose phenotype overlaps with intra-uterine infections and neonatal lupus. Exome sequencing identified a previously reported TREX1 variant, c.223dup (NM_016381.5; p. Glu75GlyfsTer82) in all the four patients belonging to the Indian subcontinent. The functional consequence of the disease-causing variant was predicted by using a new combination of bioinformatics softwares. The recurrence of this pathogenic variant indicates a possible founder effect in TREX1 for AGS1 in this population. The phenotypic variability in those with this founder mutation can mimic intrauterine infections and neonatal lupus, thereby leading to misdiagnosis warranting a targeted genetic testing approach to be a part of the diagnostic workup to obtain a definite, early and cost-effective diagnosis in patients from Indian subcontinent with early onset encephalopathy.

Imaging criteria to predict Shamblin group in carotid body tumors - revisited.

PURPOSE: This study aims to compare the imaging findings of carotid body tumors on contrast-enhanced computed tomography (CT) with the intraoperative Shamblin grade and to evolve an imaging-based scoring system that can accurately predict the Shamblin grade. METHODS: Preoperative contrast-enhanced CT scans of 40 patients who underwent surgical excision of carotid body tumors in our institution between 2004 and 2017 were retrospectively reviewed. The angle of contact with the internal carotid artery (ICA), tumor volume, presence of peritumoral tuft of veins, loss of tumor adventitia interface and distance from the skull base were assessed and compared with the intraoperative Shamblin grades of the tumor. Ordinal logistic regression was used to determine which parameters could be predictors of the Shamblin grades. Receiver operator characteristic (ROC) curves were used to score the tumor volumes. RESULTS: Among the 42 tumors evaluated, 6 (14.3%) were surgically classified as Shamblin I, 15 (35.7%) as Shamblin II, and 21 (50%) as Shamblin III tumors. Pairwise comparison between the three Shamblin groups showed a statistically significant difference for angle of contact with ICA, maximum tumor dimension, presence of peritumoral tuft of veins and loss of tumor adventitia interface (p = 0.001, p = 0.001, p = 0.038 and p = 0.003, respectively). However, tumor volumes and distance from skull base were not significantly different between the Shamblin groups (p = 0.136 and p = 0.682). A scoring system, including four of the above mentioned parameters (angle of contact with ICA, tumor volume, presence of peritumoral tuft of veins, and loss of tumor adventitia interface) was developed with a maximum score of 8 and a minimum of 2. A statistically significant difference was found between the final scores among the three Shamblin groups (p < 0.001). Using ROC curves, a final score of ≥6 was found to separate Shamblin grade III tumors from grade I and II tumors (sensitivity, 95.24%; specificity, 71.43%). All patients with documented intraoperative estimated blood loss of >1000 mL had Shamblin grade III tumors. Postoperative complications like stroke, ICA thrombosis and lower cranial nerve palsies were seen only with Shamblin grade II and III tumors. CONCLUSION: The simple scoring system we have proposed correlates well with the Shamblin grade and helps in identifying patients who have a higher risk of developing complications.

The role of imaging in skull base osteomyelitis - Reviewed.

PURPOSE: Skull base osteomyelitis (SBO) is difficult to diagnose due to a wide array of clinical presentations. It can be life threatening if not treated promptly. The objective of this study is to identify the various neck spaces involved in skull base osteomyelitis, correlate them with the possible source of infection and identify the related complications. METHODS: Eighty nine consecutive either culture proven cases of skull base osteomyelitis, or culture negative cases with inflammation on histopathology responding to antibiotic therapy, presenting at a single non-government hospital in south India between January 2016 and December 2018 were included in this study. Images were reviewed by two radiologists and imaging findings were documented by consensus. RESULTS: Involvement of the parotid space, retromastoid space and (temporomandibular) TM joint was associated with otogenic source of infection (p value < 0.05); while, retropharyngeal/prevertebral involvement was associated with sphenoid and nasopharyngeal sources (p value < 0.05). Complications such as cavernous sinus thrombosis (p value = 0.023) and ICA involvement (p value = 0.014) were more commonly seen with central skull base osteomyelitis. Abscess formation was seen in all three groups of patients without a significant difference between the groups. CONCLUSION: Imaging plays an important role in determining the possible source of infection by identifying the involved neck spaces and this in turn can guide the clinician to a site for biopsy. Complications related to SBO can also be identified on imaging and can guide appropriate management.

Varicella Zoster Virus Infection of the Central Nervous System - 10 Year Experience from a Tertiary Hospital in South India.

INTRODUCTION: Varicella zoster virus is an exclusively human neurotrophic virus. The primary infection with the virus causes varicella. The virus remains latent in nervous tissue and upon secondary activation causes a variety of syndromes involving the central nervous system (CNS) including meningoencephalitis and cerebellitis. MATERIALS AND METHODS: In this study, we looked at the epidemiology, clinical and laboratory features, and outcomes of patients who were admitted with varicella zoster of the CNS from 2005 to 2014. RESULTS: There were 17 patients. Fever was present in 13 patients, seizures in 9 patients and headache and vomiting in 4 patients each. A generalized varicella rash was present in 8 out of 17 patients. A single dermatomal herpes zoster was present in seven patients. Two patients had no rash. Varicella zoster polymerase chain reaction (PCR) in cerebrospinal fluid (CSF) was done in 5 patients of which 4 were positive and 1 was negative. Nine patients had diabetes with an average glycated hemoglobin of 8.6%. Total number of deaths was five. CONCLUSIONS: Patients with diabetes who develop varicella or herpes zoster may be at risk for CNS complications. The diagnosis of varicella encephalitis has to rest on a combination of clinical findings and CSF PCR, as neither the rash nor the PCR is sensitive enough to diagnose all the cases with varicella encephalitis.

Can Pixel Value Ratio be Used in the Assessment of Ceramic Bone Substitute Incorporation? Observations from a Pilot Study.

BACKGROUND: Assessment of bone graft substitute incorporation is critical in the clinical decision making process and requires special investigations. We examined if the pixel value ratio (PVR) obtained in routine follow-up digital radiographs could be used for such assessment. MATERIAL/METHODS: Radiographic images were acquired using either computed radiography or flat panel digital radiography systems. The PVR from radiographs of thirty children with ceramic bone substitute grafting were analyzed using the software from the picture archival and communication system (PACS) workstation. Graft incorporation was also assessed using the van Hemert scale. Three independent observers (A, B, C) measured PVRs at two different time points during the first and the last follow-up visits. PVR was compared with the van Hemert scale scores and analyzed using Spearman's rank correlation. RESULTS: The mean intra-observer reliability was 0.8996, and inter-observer reliabilities were 0.69 (A vs. C), 0.78 (A vs. B), and 0.85 (B vs. C) for the first follow-up visit and 0.74 (A vs. C), 0.82 (A vs. B), and 0.70 (B vs. C) for the last follow-up measurements. Spearman's correlation showed a strong negative association between PVR values and van Hemert scale scores, as the healing process advanced on serial measurements at each follow-up (r=-0.94, n=60, z=-7.24, p≤0.0001). The reliability of the PVR measurements was assessed using an aluminum step wedge and ceramic graft. CONCLUSIONS: PVR is potentially a reliable indicator of bone graft incorporation and can aid in clinical decision making provided standard radiographic techniques are used.

Non-Invasive and Minimally Invasive Imaging Evaluation of CSF Rhinorrhoea - a Retrospective Study with Review of Literature.

BACKGROUND: Localization of a cerebrospinal fluid [CSF] fistula is a diagnostic challenge. The choice of an optimal imaging technique is necessary to locate the site of CSF leak which is required for surgical/endoscopic repair of the CSF fistula. MATERIAL/METHODS: Retrospective analysis of imaging was performed in 33 patients who presented with symptoms suggestive of CSF rhinorrhoea over a period of two years. Either a bone defect on high resolution CT [HRCT] or CSF column extending extracranially from the subarachnoid space with or without brain/ meningeal herniation on magnetic resonance [MR] cisternography was considered positive for CSF leak. The MR imaging technique included 1-mm heavily T2-weighted [TR 2000 ms; TE-200 ms] fast spin echo study in coronal and sagittal planes. HRCT sections involved 0.625 to 0.8-mm sections in the coronal plane, with or without axial planes, through the paranasal sinuses, reconstructed in a sharp algorithm and acquired with the patient in prone position. Imaging findings were compared with endoscopic findings, being the gold standard for the assessment of CSF rhinorrhea. RESULTS: A total of 25 patients had a combination of HRCT and MR cisternography. The sensitivity, specificity, positive predictive value [PPV] and negative predictive value [NPV] of both MR cisternography and HRCT together were 93%, 100%, 100% and 50% respectively. Two patients underwent only MR cisternography, 5 patients underwent only HRCT and one patient underwent HRCT, MR cisternography and CT cisternography. Though PPV was 100% in the groups with HRCT alone, MR cisternography alone and combined CT cisternography, HRCT and MR cisternography, the results were not statistically significant as the number of patients in those groups was lower. CONCLUSIONS: Combination of MR cisternography and HRCT appears to be complementary, accurate and non-invasive and should be considered as optimal imaging modality for pre-op imaging in the evaluation of CSF rhinorrhoea.