Review: Neuropathology findings in autonomic brain regions in SUDEP and future research directions

Autonomic dysfunction is implicated from clinical, neuroimaging and experimental studies in sudden and unexpected death in epilepsy (SUDEP). Neuropathological analysis in SUDEP series enable exploration of acquired, seizure-related cellular adaptations in autonomic and brainstem autonomic centres of relevance to dysfunction in the peri-ictal period. Alterations in SUDEP compared to control groups have been identified in the ventrolateral medulla, amygdala, hippocampus and central autonomic regions. These involve neuropeptidergic, serotonergic and adenosine systems, as well as specific regional astroglial and microglial populations, as potential neuronal modulators, orchestrating autonomic dysfunction. Future research studies need to extend to clinically and genetically characterized epilepsies, to explore if common or distinct pathways of autonomic dysfunction mediate SUDEP. The ultimate objective of SUDEP research is the identification of disease biomarkers for at risk patients, to improve post-mortem recognition and disease categorisation, but ultimately, for exposing potential treatment targets of pharmacologically modifiable and reversible cellular alterations

Polyglucosan bodies in medullary catecholaminergic neurones in SUDEP

Polyglucosan bodies have been reported in the context of hypoxic-ischaemic perinatal brain injury, mainly in the pallidum but with rare reports in brainstem neurones. We report a case of a five year old boy with cerebral palsy, complex neurology and epilepsy with a sudden nocturnal death. At post-mortem long-standing bilateral necrosis of basal ganglia and hippocampal atrophy was identified in keeping with hypoxic-ischaemic perinatal injury. In addition numerous polyglucosan bodies, which were PAS, p62 and ubiquitin positive, were noted in brainstem neurones and dendrites, primarily involving the ventrolateral and dorsomedial medulla. Immunohistochemistry confirmed relative preservation of medullary neuronal populations in the reticular formation, including catecholaminergic (tyrosine hydroxylase, TH), serotonergic (tryptophan hydroxylase) and neurokinin1 receptor/somatostatin positive neurones. The polyglucosan bodies predominated in catecholaminergic neurones which could indicate their selective vulnerability and a functional deficiency, which during a critical peri-ictal period contributed to the sudden death in epilepsy

Scale Inside-Out: Rapid Mitigation of Cloud DDoS Attacks

The distributed denial of service (DDoS) attacks in cloud computing requires quick absorption of attack data. DDoS attack mitigation is usually achieved by dynamically scaling the cloud resources so as to quickly identify the onslaught features to combat the attack. The resource scaling comes with an additional cost which may prove to be a huge disruptive cost in the cases of longer, sophisticated, and repetitive attacks. In this work, we address an important problem, whether the resource scaling during attack, always result in rapid DDoS mitigation? For this purpose, we conduct real-time DDoS attack experiments to study the attack absorption and attack mitigation for various target services in the presence of dynamic cloud resource scaling. We found that the activities such as attack absorption which provide timely attack data input to attack analytics, are adversely compromised by the heavy resource usage generated by the attack. We show that the operating system level local resource contention, if reduced during attacks, can expedite the overall attack mitigation. The attack mitigation would otherwise not be completed by the dynamic scaling of resources alone. We conceived a novel relation which terms “Resource Utilization Factor” for each incoming request as the major component in forming the resource contention. To overcome these issues, we propose a new “Scale Inside-out” approach which during attacks, reduces the “Resource Utilization Factor” to a minimal value for quick absorption of the attack. The proposed approach sacrifices victim service resources and provides those resources to mitigation service in addition to other co-located services to ensure resource availability during the attack. Experimental evaluation shows up to 95 percent reduction in total attack downtime of the victim service in addition to considerable improvement in attack detection time, service reporting time, and downtime of co-located services

DDoS victim service containment to minimize the internal collateral damages in cloud computing

Recent Distributed Denial of Service (DDoS) attacks on cloud services demonstrate new attack effects, including collateral and economic losses. In this work, we show that DDoS mitigation methods may not provide the expected timely mitigation due to the heavy resource outage created by the attacks. We observe an important Operating System (OS) level internal collateral damage, in which the other critical services are also affected. We formulate the DDoS mitigation problem as an OS level resource management problem. We argue that providing extra resources to the victim's server is only helpful if we can ensure the availability of other services. To achieve these goals, we propose a novel resource containment approach to enforce the victim's resource limits. Our real-time experimental evaluations show that the proposed approach results in reduction in the attack reporting time and victim service downtime by providing isolated and timely resources to ensure availability of other critical services

A RAPID, SENSITIVE AND VALIDATED ULTRA PERFORMANCE LIQUID CHROMATOGRAPHY AND TANDEM MASS SPECTROMETRY METHOD FOR DETERMINATION OF PAROMOMYCIN IN MICE PLASMA: APPLICATION TO PHARMACOKINETIC STUDY

Objective: To develop and validate simple, sensitive, accurate and selective UPLC-MS/MS method for quantification of paromomycin (PARO) in mice plasma.Methods: Precipitation method was used for the extraction of plasma samples, an aliquot of 25 µl plasma samples was extracted using 10% perchloric acid in water. Chromatographic separation was performed using waters acquity ultra-performance liquid chromatography (UPLC) columns, BEH HILIC (50 mm× 2.1 mm, 1.7 µm) by a gradient mixture of acetonitrile and water (both containing 0.005% v/v trifluro acetic acid) as a mobile phase at the flow rate of 0.2 ml/min. The analyte was protonated in the positive electrospray ionization (ESI) interface and detected in multiple reactions monitoring (MRM) modes using the transition m/z 308.60-455.30.Results: The method had a short chromatographic run time of 3 min. Calibration curves were linear over wide ranges of 50.51-5019.22 ng/ml. The between and within-batch precision and accuracy of the method was determined by using 4 quality control samples, the highest % CV observed was 11.06. The mean recovery values are 78.17, 101.17 and 92.58 at low, medium and high-quality control levels; respectively.Conclusion: It was concluded that the developed and validated UPLC-MS/MS method was rapid, sensitive, accurate, precise, linear, and specific. Therefore, this method can be used for quantification of PARO in mice plasma with various advantages over the reported methods

Cognitive and psychomotor effects of adjunctive aripiprazole or paliperidone in patients of schizophrenia receiving olanzapine: a double blind placebo controlled clinical study

Background: Emergence of atypical antipsychotics has revolutionized the treatment of schizophrenia by exploiting dual actions on serotonin as well as dopaminergic receptors. Still, monotherapy with these agents is insufficient to control cognitive and psychomotor as well as positive and negative symptoms. Hence combination therapy with antipsychotics is common in clinical practice. Objective of current study is to compare the effects of addition of aripiprazole or paliperidone on cognition and psychomotor functions in schizophrenia receiving olanzapine.Methods: This is prospective, double blind, placebo controlled, parallel group study in 90 patients of schizophrenia showing partial or no response to olanzapine measured by Positive And Negative Symptoms Score (PANSS) scale. They were randomly divided to receive adjuvant aripiprazole, paliperidone or placebo for 6 weeks.Results: Combination of aripiprazole and olanzapine shows significant improvement in most of the cognition and psychomotor parameters like attention, perception, verbal memory, thinking and processing as well as motor speed while combination of paliperidone and olanzapine is associated with improvement in only some of the cognitive and psychomotor parameters such as attention, perception and verbal memory only. Both the combinations are efficacious in controlling positive and negative symptoms of schizophrenia as assessed by PANSS scale.Conclusions: The best augmenting strategy with for olanzapine nonresponsive patients will be D2 receptor partial agonist like aripiprazole rather than D2 antagonist like paliperidone and other atypical antipsychotic agents for better improvement in cognition and psychomotor domains

Characterisation of medullary astrocytic populations in respiratory nuclei and alterations in sudden unexpected death in epilepsy

Central failure of respiration during a seizure is one possible mechanism for sudden unexpected death in epilepsy (SUDEP). Neuroimaging studies indicate volume loss in the medulla in SUDEP and a post mortem study has shown reduction in neuromodulatory neuropeptidergic and monoaminergic neurones in medullary respiratory nuclear groups. Specialised glial cells identified in the medulla are considered essential for normal respiratory regulation including astrocytes with pacemaker properties in the pre-Botzinger complex and populations of subpial and perivascular astrocytes, sensitive to increased pCO2, that excite respiratory neurones. Our aim was to explore niches of medullary astrocytes in SUDEP cases compared to controls. In 48 brainstems from three groups, SUDEP (20), epilepsy controls (10) and non-epilepsy controls (18), sections through the medulla were labelled for GFAP, vimentin and functional markers, astrocytic gap junction protein connexin43 (Cx43) and adenosine A1 receptor (A1R). Regions including the ventro-lateral medulla (VLM; for the pre-Bötzinger complex), Median Raphe (MR) and lateral medullary subpial layer (MSPL) were quantified using image analysis for glial cell populations and compared between groups. Findings included morphologically and regionally distinct vimentin/Cx34-positive glial cells in the VLM and MR in close proximity to neurones. We noted a reduction of vimentin-positive glia in the VLM and MSPL and Cx43 glia in the MR in SUDEP cases compared to control groups (p < 0.05-0.005). In addition, we identified vimentin, Cx43 and A1R positive glial cells in the MSPL region which likely correspond to chemosensory glia identified experimentally. In conclusion, altered medullary glial cell populations could contribute to impaired respiratory regulatory capacity and vulnerability to SUDEP and warrant further investigation

Comparing the findings of clinical examination versus magnetic resonance imaging for the diagnosis of ligamentous injuries of knee in rural area

Background: The knee is a complex synovial joint allowing flexion, extension, anteroposterior gliding and internal-external rotation. The major articular surfaces are the medial and lateral condyles of the femur and patellar surface. The aim of the study was to compare the findings of clinical examination versus magnetic resonance imaging (MRI) for the diagnosis of ligamentous injuries of knee in rural area.Methods: Present study was an observational study carried out at rural medical college under orthopaedic department. All patients coming with ligamentous injury to orthopaedic department were studied. Thus such 50 cases were studied. All cases were referred to radiology department for MRI of knee. MRI reports and clinical reports were compared and analysis was done. Cases contraindicated for MRI examination were excluded from study. General demoghraphic history, clinical presentation and MRI reports were recorded. All data was compiled in Microsoft excel and analysed using OpenEPi 2.3.1.Results: Mean age was 46.4±11.2 years. Majority were males 70% and 30% were females. Swelling 62% was most commonly seen followed by knee pain. Majority 58% cases had grade 3 tear on MRI, followed by 36% had grade II and only 6% had grade I.  Conclusions: MRI is an excellent, non-invasive, radiation free imaging modality with multilane capabilities and excellent soft tissue delineation. It can accurately detect, localize and characterize various internal derangements of the knee joint and help in arriving at a correct anatomical diagnosis thereby guiding further management of the patient

Neuropeptide depletion in the amygdala in sudden unexpected death in epilepsy: A postmortem study

OBJECTIVE: Sudden unexpected death in epilepsy (SUDEP) is typically unwitnessed but can be preceded by seizures in the period prior to death. Peri-ictal respiratory dysfunction is a likely mechanism for some SUDEP, and central apnea has been shown following amygdala stimulation. The amygdala is enriched in neuropeptides that modulate neuronal activity and can be transiently depleted following seizures. In a postmortem SUDEP series, we sought to investigate alterations of neuropeptidergic networks in the amygdala, including cases with recent poor seizure control. METHODS: In 15 SUDEP cases, 12 epilepsy controls, and 10 nonepilepsy controls, we quantified the labeling index (LI) for galanin, neuropeptide Y (NPY), and somatostatin (SST) in the lateral, basal, and accessory basal nuclei and periamygdala cortex with whole slide scanning image analysis. Within the SUDEP group, seven had recent generalized seizures with recovery 24 hours prior to death (SUDEP-R). RESULTS: Galanin, NPY, and SST LIs were significantly lower in all amygdala regions in SUDEP cases compared to epilepsy controls (P < .05 to P < .0005), and galanin LI was lower in the lateral nucleus compared to nonepilepsy controls (P < .05). There was no difference in the LI in the SUDEP-R group compared to other SUDEP. Higher LI was noted in epilepsy controls than nonepilepsy controls; this was significant for NPY in lateral and basal nuclei (P < .005 and P < .05). SIGNIFICANCE: A reduction in galanin in the lateral nucleus in SUDEP could represent acute depletion, relevant to postictal amygdala dysfunction. In addition, increased amygdala neuropeptides in epilepsy controls support their seizure-induced modulation, which is relatively deficient in SUDEP; this could represent a vulnerability factor for amygdala dysfunction in the postictal period

Medullary tyrosine hydroxylase catecholaminergic neuronal populations in sudden unexpected death in epilepsy

Sudden unexpected death in epilepsy (SUDEP) is mechanistically complex and one probable cause is seizure‐related respiratory dysfunction. Medullary respiratory regulatory nuclei include the pre‐Bötzinger complex (pre‐BötC) in the ventrolateral medulla (VLM), the medullary raphé nuclei (MR) and nucleus of solitary tract in the dorsomedial medulla (DMM). The region of the VLM also contains intermingled tyrosine hydroxylase (TH) catecholaminergic neurones which directly project to the pre‐BötC and regulate breathing under hypoxic conditions and our aim was to evaluate these neurones in SUDEP cases. In post‐mortem cases from three groups [SUDEP (18), epilepsy controls (8) and non‐epilepsy controls (16)] serial sections of medulla (obex + 2 to + 13 mm) were immunolabeled for TH. Three regions of interest (ROI) were outlined (VLM, DMM and MR) and TH‐immunoreactive (TH‐IR) neurones were evaluated using automated detection for overall labeling index (neurones and processes) and neuronal densities and compared between groups and relative to obex level. C‐fos immunoreactivity was also semi‐quantitatively evaluated in these regions. We found no significant difference in the density of TH‐IR neurones or labeling index between the groups in all regions. Significantly more TH‐IR neurones were present in the DMM region than VLM in non‐epilepsy cases only (P < 0.01). Regional variations in TH‐IR neurones with obex level were seen in all groups except SUDEP. We also identified occasional TH neurones in the MR region in all groups. There was significantly less c‐fos labeling in the VLM and MR in SUDEP than non‐epilepsy controls but no difference with epilepsy controls. In conclusion, in this series we found no evidence for alteration of total medullary TH‐IR neuronal numbers in SUDEP but noted some differences in their relative distribution in the medulla and c‐fos neurones compared to control groups which may be relevant to the mechanism of death