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Intracranial fluid dynamics changes in idiopathic intracranial hypertension: pre and post therapy [article]

Nivedita Agarwal, Christian Contarino, Nicola Limbucci, Laura Bertazzi, Eleuterio Toro
2018 bioRxiv   pre-print
Idiopathic intracranial hypertension (IIH) is a condition of unknown etiology frequently associated with dural sinus stenosis. There is emerging evidence that venous sinus stenting is an effective treatment. We use phase contrast cine MRI to observe changes in flow dynamics of multiple intracranial fluids and their response to different treatments in a patient with IIH. We quantified the following parameters at the level of the aqueduct of Sylvius and the cervical C2C3: cerebrospinal fluid
more » ... , arterial and venous flow; CSF velocity amplitude; artero-venous delay (AVD); artero-CSF delay and percentage of venous outflow normalized to total arterial inflow (tIJV/tA). Analyses were run before lumbar puncture (LP) (A), after LP (B), after medical therapy (C) and after venous stent placements deployed at two separate times (D and E). AVD and tIJV/tA improved only after CSF removal and after stent placements. CSF velocity amplitude remained elevated. Arterial flow profile showed a dramatic reduction after LP with improvement in mean venous flow. This report is the first to demonstrate interactive changes in intracranial fluid dynamics that occur before and after different therapeutic interventions in IIH. We discuss how increased intracranial venous blood could be "tumoral" in IIH and facilitating its outflow could be therapeutic.
doi:10.1101/245894 fatcat:wzv4xzfho5b7bfguqurmr2snxq

Cervical spinal degenerative disease in multiple sclerosis

Simran Chhugani, Nivedita Agarwal, Faraz Sheikh, Florina Borca, Aginor Spanoulis, Ian Galea
2021 European Journal of Neurology  
Root and cord irritation from cervical spinal degenerative disease may share clinical features with progressive multiple sclerosis (MS), so diagnostic overshadowing may occur. We hypothesized that cervical stenotic spinal degenerative disease is commoner in progressive MS, compared to controls. A retrospective case-control study of 111 cases (56 with progressive MS and 55 controls) was conducted. Five types of cervical spinal degenerative disease (disc degeneration, posterior disc protrusion,
more » ... dplate changes, canal stenosis and foraminal stenosis) were assessed objectively on magnetic resonance imaging using published scales. Multivariable regression analysis was performed. Moderate-to-severe cervical spinal degeneration occurred more frequently in progressive MS, compared to controls. In multivariable regression, foraminal stenosis was three times more likely in progressive MS (odds ratio = 3.20 (95% CI:1.27, 8.09), p=0.014), and was more severe (p=0.009). This finding was confirmed on retrospective evaluation of clinical radiology reports in the same population. Foraminal stenosis was twice as likely in progressive MS, compared to relapsing-remitting MS. People with progressive MS are susceptible to foraminal stenosis. A higher index of suspicion for cervical spinal degenerative disease is required when appropriate neurological symptoms occur in the setting of progressive MS, to guide appropriate treatment or monitoring.
doi:10.1111/ene.14855 pmid:33817913 fatcat:orpsuvdm6fespbk6no7de6fjee

Brain function monitoring during off-pump cardiac surgery: a case report

Paolo Zanatta, Enrico Bosco, Piero Di Pasquale, Agarwal Nivedita, Carlo Valfrè, Carlo Sorbara
2008 Cases Journal  
Early postoperative stroke is an adverse syndrome after coronary bypass surgery. This report focuses on overcoming of cerebral ischemia as a result of haemodynamic instability during heart enucleation in off-pump procedure. Case presentation: A 67 year old male patient, Caucasian race, with a body mass index of 28, had a recent non-Q posterolateral myocardial infarction one month before and recurrent instable angina. His past history includes an uncontrolled hypertension, dyslipidemia, insulin
more » ... ependent diabetes mellitus, epiaortic vessel stenosis. The patient was scheduled for an off-pump procedure and monitored with bilateral somatosensory evoked potentials, whose alteration signalled the decrement of the cardiac index during operation. The somatosensory evoked potentials appeared when the blood pressure was increased with a pharmacological treatment. Conclusion: During the off-pump coronary bypass surgery, a lower cardiac index, predisposes patients, with multiple stroke risk factors, to a reduction of the cerebral blood flow. Intraoperative somatosensory evoked potentials monitoring provides informations about the functional status of somatosensory cortex to reverse effects of brain ischemia.
doi:10.1186/1757-1626-1-94 pmid:18706094 pmcid:PMC2531095 fatcat:oongrzjme5djfnrqdieayg2mku

Strategic business transformation through technology convergence: implications from General Electric's industrial internet initiative

Nivedita Agarwal, Alexander Brem
2015 International Journal of Technology Management  
Agarwal (September 8, 2013) The industrial internet is a phenomenon that involves the merging of the digital world with the world of machines.  ...  Agarwal (October 23, 2013) Overall, each phase of this technology convergence appears to have been time consuming, involving significant capital investment.  ... 
doi:10.1504/ijtm.2015.068224 fatcat:6yini322s5h4jhk6syp2vm6qwu

Intracranial Fluid Dynamics Changes in Idiopathic Intracranial Hypertension: Pre and Post Therapy

Nivedita Agarwal, Christian Contarino, Nicola Limbucci, Laura Bertazzi, Eleuterio Toro
2018 Current Neurovascular Research  
Keywords: Idiopathic intracranial hypertension, Cerebrospinal fluid, Phase contrast-cine magnetic resonance imaging, dural venous stenosis, papilledema Running title: MR fluid analysis in IIH Abbreviations: AaCD=artero-aqueduct CSF delay; AcCD= artero-cervical CSF delay; aCSF=CSF through the AoS; AoS=aqueduct of Sylvius; AVD=arterovenous delay; CC= cardiac cycle; cCSF=CSF in the cervical subarachnoid space; CSF=cerebrospinal fluid; CVO=cerebral venous outflow; ICA=internal carotid artery; ICP =
more » ... intracranial pressure; IIH = idiopathic intracranial hypertension; IJV=internal jugular vein; tA=total cerebral arterial inflow; tIJV=total outflow from internal jugular veins; LP=lumbar puncture; RFNL = retinal fiber nerve layer; PCC-MR=phase contrast cine magnetic resonance; SAS=subarachnoid space; TS=transverse sinus; VA= vertebral artery peer-reviewed) Abstract Idiopathic intracranial hypertension (IIH) is a condition of unknown etiology frequently associated with dural sinus stenosis. There is emerging evidence that venous sinus stenting is an effective treatment. We use phase contrast cine MRI to observe changes in flow dynamics of multiple intracranial fluids and their response to different treatments in a patient with IIH. We quantified the following parameters at the level of the aqueduct of Sylvius and the cervical C2C3: cerebrospinal fluid (CSF), arterial and venous flow; CSF velocity amplitude; artero-venous delay (AVD); artero-CSF delay and percentage of venous outflow normalized to total arterial inflow (tIJV/tA). Analyses were run before lumbar puncture (LP) (A), after LP (B), after medical therapy (C) and after venous stent placements deployed at two separate times (D and E). AVD and tIJV/tA improved only after CSF removal and after stent placements. CSF velocity amplitude remained elevated. Arterial flow profile showed a dramatic reduction after LP with improvement in mean venous flow. This report is the first to demonstrate interactive changes in intracranial fluid dynamics that occur before and after different therapeutic interventions in IIH. We discuss how increased intracranial venous blood could be "tumoral" in IIH and facilitating its outflow could be therapeutic. peer-reviewed) Buell TJ, Raper DMS, Pomeraniec IJ, Ding D, Chen C-J, Taylor DG, et al. Transient resolution of venous sinus stenosis after high-volume lumbar puncture in a patient with idiopathic intracranial hypertension. J. Neurosurg. 2017: 1-4. Doepp F, Schreiber SJ, Münster von T, Rademacher J, Klingebiel R, Valdueza JM. How does the blood leave the brain? A systematic ultrasound analysis of peer-reviewed)
doi:10.2174/1567202615666180528113616 pmid:29807514 fatcat:5zlyyuyweza3fjlqyrymqeoxhy

Cerebral Vessels: An Overview of Anatomy, Physiology, and Role in the Drainage of Fluids and Solutes

Nivedita Agarwal, Roxana Octavia Carare
2021 Frontiers in Neurology  
The cerebral vasculature is made up of highly specialized structures that assure constant brain perfusion necessary to meet the very high demand for oxygen and glucose by neurons and glial cells. A dense, redundant network of arteries is spread over the entire pial surface from which penetrating arteries dive into the cortex to reach the neurovascular units. Besides providing blood to the brain parenchyma, cerebral arteries are key in the drainage of interstitial fluid (ISF) and solutes such as
more » ... amyloid-beta. This occurs along the basement membranes surrounding vascular smooth muscle cells, toward leptomeningeal arteries and deep cervical lymph nodes. The dense microvasculature is made up of fine capillaries. Capillary walls contain pericytes that have contractile properties and are lined by a highly specialized blood–brain barrier that regulates the entry of solutes and ions and maintains the integrity of the composition of ISF. They are also important for the production of ISF. Capillaries drain into venules that course centrifugally toward the cortex to reach cortical veins and empty into dural venous sinuses. The walls of the venous sinuses are also home to meningeal lymphatic vessels that support the drainage of cerebrospinal fluid, although such pathways are still poorly understood. Damage to macro- and microvasculature will compromise cerebral perfusion, hamper the highly synchronized movement of neurofluids, and affect the drainage of waste products leading to neuronal and glial degeneration. This review will present vascular anatomy, their role in fluid dynamics, and a summary of how their dysfunction can lead to neurodegeneration.
doi:10.3389/fneur.2020.611485 pmid:33519691 pmcid:PMC7838613 fatcat:elhfi5lyazffrjviwbcfpnt7ia

Neurofluids: A holistic approach to their physiology, interactive dynamics and clinical implications for neurological diseases

Nivedita Agarwal, Christian Contarino, Eleuterio F. Toro
2019 Veins and Lymphatics  
There is increasing interest in understanding the physiology of the extracellular fluid compartments in the central nervous system and their dynamic interaction. Such interest has been in part prompted by a vigorous resurgence of the role of the venous system, the recent discoveries of the meningeal lymphatics, the brain waste removal mechanisms and their potential link to neurological diseases, such as idiopathic intracranial hypertension, Ménière's disease, migraine, small vessel disease, and
more » ... most neurodegenerative diseases. The rigid cranial cavity houses several space-competing material compartments: the brain parenchyma (BP) and four extracellular fluids, namely arterial, venous, cerebrospinal fluid (CSF) and interstitial fluid (ISF). During cardiac pulsations, the harmonious, temporal and spatial dynamic interaction of all these fluid compartments and the BP assures a constant intracranial volume at all times, consistent with the Monro-Kellie hypothesis. The dynamic interaction involves high-pressure input of arterial blood during systole and efflux of CSF into the spinal subarachnoid space (SSAS) followed by venous blood exiting directly into the vertebral and internal jugular veins towards the heart and intraventricular CSF displacing caudally towards the SSAS. Arterial pulsatile energy is transmitted to the BP that contributes to the smooth movement of fluids in and out of the brain. Perturbing any of these fluid compartments will alter the entire brain dynamics, potentially increase intracranial pressure, affect perfusion and hamper clearance capacity of metabolic waste. This review of all major extracellular fluid compartments within the brain, advocates a holistic approach to our understanding of the fluid dynamics, rather than focusing on a single compartment when analyzing neurological diseases. This approach may contribute to advance our comprehension of some common neurological disorders, paving the way to newer treatment options.
doi:10.4081/vl.2019.8470 fatcat:hkaqiziydfep3k34467ggitl3e

Multifaceted progressive neurotuberculosis in a single patient: from miliary tuberculomas to cortical venous infarct

Nivedita Agarwal, Lorenza Lenzi, Nicoletta Dorigoni, Susanna Cozzio, Sabino Walter Della Sala
2018 BJR|case reports  
Neurotuberculosis is a potentially fatal disease which requires prompt diagnosis and immediate multidrug antitubercular treatment as per international guidelines. There is evidence that the bacterial spread can continue even during therapy at least in its initial stages. We monitored our patient not only with chest X-rays but with brain MRI during the first 6 weeks. To our surprise on serial MRI, during treatment, we found several new localization of the disease in a pauci-symptomatic patient.
more » ... hese included vessel wall inflammation (vasculitis), arachnoiditis and hypophysitis. At 4 weeks of treatment, the patient complained of dizziness and vomiting which were first dismissed as treatment side-effects but MRI revealed multiple cortical venous hemorrhagic infarcts. We report this case to emphasize the importance of neuroimaging even in case of the most subtle symptoms and that disease can continue to progress in the initial phase of treatment which may require additional therapeutic intervention.
doi:10.1259/bjrcr.20180020 pmid:31131115 pmcid:PMC6519487 fatcat:3r3asbdbpjek5lyyhyv2bjooci

An Analysis of a Crowdfunding System in North Africa Based on the Actor-Network Theory

Khaoula Behi, Nivedita Agarwal, Alexander Brem
2020 International Journal of Global Business and Competitiveness  
Appendix Interview guide for platforms founders and actors involved in the development of crowdfunding in the North African Region Nivedita Agarwal is an assistant professor at the Chair of Technology  ... 
doi:10.1007/s42943-020-00007-3 fatcat:4oadxq73cvgx3b4wq2qaahmg3y

Managing Dilemmas of Resource Mobilization Through Jugaad : A Multi‐Method Study of Social Enterprises in Indian Healthcare

Nivedita Agarwal, Ronika Chakrabarti, Jaideep Prabhu, Alexander Brem
2020 Strategic Entrepreneurship Journal  
ORCID Nivedita Agarwal https://orcid.org/0000-0002-6806-4399 ENDNOTE 1 The significant event for each dilemma is provided briefly here and highlighted in the respective concrete models.  ...  ., 2009 ) to achieve greater social impact, thus driving the societal change that can ideally lead to more inclusive markets (Agarwal, Chakrabarti, Brem, & Bocken, 2018) .  ... 
doi:10.1002/sej.1362 fatcat:ebte3clcnzhwxar2qinyx4kedi

The Cardiolipin Transacylase Tafazzin Regulates Basal Insulin Secretion and Mitochondrial Function in Pancreatic Islets from Mice [article]

Laura K. Cole, Prasoon Agarwal, Christine Doucette, Mario Fonseca, Bo Xiang, Genevieve C. Sparagna, Nivedita Seshadri, Marilyne Vandel, Vernon Dolinsky, Grant Hatch
2021 bioRxiv   pre-print
Objective: Tafazzin (TAZ) is a cardiolipin (CL) biosynthetic enzyme important for maintaining mitochondrial function. TAZ impacts both the species and content of CL in the inner mitochondrial membrane which are essential for normal cellular respiration. In pancreatic β-cells, mitochondrial function is closely associated with insulin secretion. However, the role of TAZ and CL in the secretion of insulin from pancreatic islets remains unknown. Methods: Male 4-month-old doxycycline-inducible TAZ
more » ... ock-down (TAZ KD) mice and wild-type littermate controls were utilized. Immunohistochemistry was used to assess β-cell morphology in whole pancreas sections, while ex vivo insulin secretion, CL content, RNA-Seq analysis and mitochondrial oxygen consumption were measured from isolated islet preparations. Results: Ex vivo insulin secretion under non-stimulatory low-glucose concentrations was reduced ~52% from islets isolated from TAZ KD mice. Mitochondrial oxygen consumption under low-glucose conditions was also reduced ~58% in islets from TAZ KD animals. TAZ-deficiency in pancreatic islets was associated with significant alteration in CL molecular species and reduced oxidized CL content. In addition, RNA-Seq of isolated islets showed that TAZ KD increased expression of extracellular matrix genes which are linked to pancreatic fibrosis, activated stellate cells and impaired β-cell function. Conclusion: These data indicate a novel role for TAZ in regulating normal β-cell function, particularly under low-glucose conditions.
doi:10.1101/2021.01.15.426880 fatcat:u5d7xu7ka5airlpwoa7inpxpkq

Elucidating the nature and mechanism of tic improvement in tourette syndrome: a pilot study

David R Shprecher, Keenan Gannon, Nivedita Agarwal, Xianfeng Shi, Jeffrey S Anderson
2014 Tremor and Other Hyperkinetic Movements  
Tic Improvement in Tourette Syndrome Shprecher DR, Gannon K, Agarwal N, et al.  ... 
doi:10.7916/d8th8jqq pmid:24757584 pmcid:PMC3983677 fatcat:6vuvm3io7jgqzd4l2hcvns32yu

The human brain pacemaker: Synchronized infra-slow neurovascular coupling in patients undergoing non-pulsatile cardiopulmonary bypass

Paolo Zanatta, Gianna Maria Toffolo, Elisa Sartori, Anna Bet, Fabrizio Baldanzi, Nivedita Agarwal, Eugene Golanov
2013 NeuroImage  
Abbreviations: BFV: blood flow velocity; EEG-PV: EEG power; ISO: infra-slow oscillations; CBF: cerebral blood flow; NP-CPB: non-pulsatile cardiopulmonary bypass; CSA: compressed spectral analysis; TCD: transcranial Doppler; AR: autoregressive; MVAR: multivariate autoregressive; C-ApEn: cross-approximate entropy. Abstract In non-pulsatile cardiopulmonary bypass surgery, middle cerebral artery blood flow velocity (BFV) is characterized by infra-slow oscillations of approximately 0.06 Hz, which
more » ... paralleled by changes in total EEG power (EEG-PV), measured in 2 s intervals. Since the origin of these BFV oscillations is not known, we explored their possible causative relationships with oscillations in EEG-PV at around 0.06 Hz. We monitored 28 patients undergoing non-pulsatile cardiopulmonary bypass using transcranial Doppler sonography and scalp electroencephalography at two levels of anaesthesiadeep (prevalence of burst suppression rhythm) and moderate (prevalence of theta rhythm). Under deep anaesthesia, the EEG bursts suppression pattern was highly correlative with BFV oscillations. Hence, a detailed quantitative picture of the coupling between electrical brain activity and BFV was derived, both in deep and moderate anaesthesia, via linear and non linear processing of EEG-PV and BFV signals, resorting to widely used measures of signal coupling such as frequency of oscillations, coherence, Granger causality and cross-approximate entropy. Results strongly suggest the existence of coupling between EEG-PV and BFV. In moderate anaesthesia EEG-PV mean dominant frequency is similar to frequency of BFV oscillations (0.065 ± 0.010 Hz vs 0.045 ± 0.019 Hz); coherence between the two signals was significant in about 55% of subjects, and the Granger causality suggested an EEG-PVBFV causal effect direction. The strength of the coupling increased with deepening anaesthesia, as EEG-PV oscillations mean dominant frequency virtually coincided with the BFV peak frequency (0.062 ± 0.017 Hz vs 0.060 ± 0.024 Hz), and coherence became significant in a larger number (65%) of subjects. Cross-approximate entropy decreased significantly from moderate to deep anaesthesia, indicating a higher level of synchrony between the two signals. Presence of a subcortical brain pacemaker that triggers vascular infra-slow oscillations in the brain is proposed. These findings allow to suggest an original hypothesis explaining the mechanism underlying infra-slow neurovascular coupling. Keywords: infra-slow oscillations, non-pulsatile cardiopulmonary bypass, multimodality neuromonitoring, brain blood flow velocity, EEG power The human brain pacemaker: Synchronized infra-slow neurovascular coupling in patients undergoing non-pulsatile cardiopulmonary bypass
doi:10.1016/j.neuroimage.2013.01.033 pmid:23357071 fatcat:j665gjevfvfjphdlprqrpqibb4

SARS-CoV-2 re-infection: development of an epidemiological definition from India

Aparna Mukherjee, Tanu Anand, Anup Agarwal, Harpreet Singh, Pranab Chatterjee, Jitendra Narayan, Salaj Rana, Nivedita Gupta, Balram Bhargava, Samiran Panda
2021 Epidemiology and Infection  
The current investigation was conducted with the objective to develop an epidemiological case definition of possible severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) re-infection and assess its magnitude in India. The epidemiological case definition for SARS-CoV-2 re-infection was developed from literature review of data on viral kinetics. For achieving second objective, the individuals who satisfied the developed case definition for SARS-CoV-2 re-infection were contacted
more » ... lly. Taking available evidence into consideration, re-infection with SARS-CoV-2 in our study was defined as any individual who tested positive for SARS-CoV-2 on two separate occasions by either molecular tests or rapid antigen test at an interval of at least 102 days with one negative molecular test in between. In this archive based, telephonic survey, 58 out of 1300 individuals (4.5%) fulfilled the above-mentioned definition; 38 individuals could be contacted with healthcare workers (HCWs) accounting for 31.6% of the cases. A large proportion of participants was asymptomatic and had higher Ct value during the first episode. While SARS-CoV-2 re-infection is still a rare phenomenon, there is a need for epidemiological definition of re-infection for establishing surveillance systems and this study contributes to such a goal.Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) re-infection is an emerging concern and there is a need to define it. Therefore, working epidemiological case definition for re-infection was developed and its magnitude was explored via archive-based, telephonic survey. Re-infection with SARS-CoV-2 was defined as two positive tests at an interval of at least 102 days with one interim negative test. Thirty-eight of the 58 eligible patients could be contacted with 12 (31.6%) being HCWs. Majority of the participants were asymptomatic and had higher Ct value during their first episode. To conclude, a working epidemiological case definition of SARS-CoV-2 re-infection is important to strengthen surveillance. The present investigation contributes to this goal and records reinfection in 4.5% of SARS-CoV-2 infected individuals in India.
doi:10.1017/s0950268821000662 pmid:33766185 pmcid:PMC8027559 fatcat:rko3joil5jgfbhpvvkhmrtvdhm

The Frugal Innovation Case of Solar-powered Automated Teller Machines (ATMs) of Vortex Engineering in India

Nivedita Agarwal, Alexander Brem
2017 Journal of Entrepreneurship and Innovation in Emerging Economies  
Table 2 describes the identifying characteristics of these innovations (Agarwal & Brem, 2014 ).  ...  these affordable or constraintbased innovations garnered a lot of attention in both business and academia and resulted in various subtypes of innovations differentiated by the underlying motivation (Agarwal  ... 
doi:10.1177/2393957517717895 fatcat:ipeqh6hvjjczzhrstv67vvpiq4
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