Chiari malformation type 1 presenting as unilateral progressive foot drop: a case report and review of literature

Abstract Background Foot drop is a disabling clinical condition with multiplicity of causes, which requires detailed evaluation to identify the exact aetiology. Here, we report an extremely rare cause of foot drop in a child, which if not recognized early, could lead to multiple complications. Case presentation A 6-year-old girl presented with difficulty in walking and left sided foot droop for1-month duration. On examination she had reduced muscle power in dorsiflexors and plantar flexors and diminished knee and absent ankle jerk in the left side. Sensory loss was noted in L4 and L5 dermatomes on the left side. Superficial abdominal reflex was absent on the left side while preserved in the right. Nerve conduction and electromyography revealed nerve root or spinal cord cause for the foot drop. These results prompted ordering MRI spine and brain which revealed Chiari malformation type-1 with holocord syrinx extending from the cervicomedullary junction to conus medullaris. Conclusions This case highlights the importance of considering broad differential diagnosis for foot drop and value of the complete neurological examination including superficial reflexes in arriving at a diagnosis. Prompt diagnosis helped to early neurosurgical referral and intervention which is an important prognostic factor

Predictive value of persistent NS1 antigen positivity beyond 3rd day for dengue haemorrhagic fever in Sri Lankan children

Abstract Objective Dengue haemorrhagic fever (DHF) is a major public health concern responsible for significant morbidity in both adult and paediatric populations in Sri Lanka. This study examined if persistent non structural protein 1 (NS1) antigen positivity beyond day 3 was predictive of the occurrence of dengue haemorrhagic fever. The patients were followed up during their in-hospital stay and the severity of the illness was classified according to the WHO classification. The NS1 antigen test was repeated after day 3 of the onset of illness, at least 2 days after the initial test. Results One hundred and fifty-seven patients were enrolled. Persistent NS1 antigen test positivity after day 3 of the illness was not predictive of subsequent development of DHF. Out of multiple other demographic and illness related factors assessed, only having a secondary dengue infection was associated with a high risk of DHF (relative risk = 3.077, 95% CI 1.361, 6.954). Persistent NS1 positivity on day 3 may not be indicative of disease severity. However results need to be confirmed by a larger study with quantitative NS1 testing

Genetic Variation in the Domain II, 3′ Untranslated Region of Human and Mosquito Derived Dengue Virus Strains in Sri Lanka

Genetic variations in dengue virus (DENV) play a distinct role in epidemic emergence. The DENV 3′ UTR has become a recent interest in research. The objective of the study was to examine the genetic variation in the domain II, 3′ UTR region of human and mosquito-derived DENV. DENV-infected human sera were orally infected to laboratory reared Aedes aegypti mosquitoes. The domain II, 3′ UTR of each human- and mosquito-derived sample was amplified. The nucleotide sequence variation, phylogenetic and secondary structure analysis was carried out incorporating respective regions of so far recorded Sri Lankan and the reference genotype strains of the DENV3 and DENV1 serotypes. The human- and mosquito-derived domain II, 3′ UTR were identical in nucleotide sequences within the serotypes isolated, indicating the conserved nature of the region during host switch. The sequence analysis revealed distinct variations in study isolates compared to so far recorded Sri Lankan isolates. However, despite single nucleotide variations, the maintenance of structural integrity was evident in related strains within the serotypes in the secondary structure analysis. The phylogenetic analysis revealed distinct clade segregation of the study sequences from so far reported Sri Lankan isolates and illustrated the phylogenetic relations of the study sequences to the available global isolates of respective serotypes

Effect of Climatic Factors and Population Density on the Distribution of Dengue in Sri Lanka: A GIS Based Evaluation for Prediction of Outbreaks

<div><p>Dengue is one of the major hurdles to the public health in Sri Lanka, causing high morbidity and mortality. The present study focuses on the use of geographical information systems (GIS) to map and evaluate the spatial and temporal distribution of dengue in Sri Lanka from 2009 to 2014 and to elucidate the association of climatic factors with dengue incidence. Epidemiological, population and meteorological data were collected from the Epidemiology Unit, Department of Census and Statistics and the Department of Meteorology of Sri Lanka. Data were analyzed using SPSS (Version 20, 2011) and R studio (2012) and the maps were generated using Arc GIS 10.2. The dengue incidence showed a significant positive correlation with rainfall (<i>p</i><0.0001). No positive correlation was observed between dengue incidence and temperature (<i>p</i> = 0.107) or humidity (<i>p</i> = 0.084). Rainfall prior to 2 and 5 months and a rise in the temperature prior to 9 months positively correlated with dengue incidence as based on the auto-correlation values. A rise in humidity prior to 1 month had a mild positive correlation with dengue incidence. However, a rise in humidity prior to 9 months had a significant negative correlation with dengue incidence based on the auto-correlation values. Remote sensing and GIS technologies give near real time utility of climatic data together with the past dengue incidence for the prediction of dengue outbreaks. In that regard, GIS will be applicable in outbreak predictions including prompt identification of locations with dengue incidence and forecasting future risks and thus direct control measures to minimize major outbreaks.</p></div

ARIMA models for 12 districts.

<p>A—Anuradapura; B—Badulla; C—Batticaloa; D—Colombo; E -Hambantota; F—Jaffna; G—Kandy; H—Kurunegala; I–Nuwara Eliya; J—Puttalam; K—Ratnapura and L—Trincomalee Districts.</p

Auto-correlation of series ‘X’ by lag–dengue vs humidity.

<p>Y axis–CCF—Cross correlation function; X axis–Lag time in months.</p

Auto-correlation of series ‘X’ by lag–dengue vs rainfall.

<p>Y axis–CCF- Cross correlation function; X axis–Lag time in months.</p

Meteorology stations according to the agro-climatic zones,elevation above sea level (given in metres (m)) andglobal positioning system (GPS) coordinates oflatitude and longitude for each meteorological station (DD) (Meteorology Department of Sri Lanka, 2006).

<p>Meteorology stations according to the agro-climatic zones,elevation above sea level (given in metres (m)) andglobal positioning system (GPS) coordinates oflatitude and longitude for each meteorological station (DD) (Meteorology Department of Sri Lanka, 2006).</p

Correlation between total annual dengue incidence with climatic factors and population density.

<p>Correlation of annual dengue incidence from 2009–2014 with population density (A), temperature and rainfall (B), temperature and humidity (C) and humidity and rainfall (D).</p

Auto-correlation of series ‘X’ by lag–dengue vs temperature.

<p><b>Y</b> axis–CCF—Cross correlation function; X axis–Lag time in months.</p