Use of multiplex PCR based molecular diagnostics in diagnosis of suspected CNS infections in tertiary care setting-A retrospective study

OBJECTIVES

CNS infections like meningitis and encephalitis pose enormous healthcare challenges due to mortality, sequelae and socioeconomic burden. In tertiary setting, clinical, microbiological, cytological and radiological investigations are not distinctive enough for diagnosing microbial etiology. Molecular diagnostics is filling this gap. We evaluated the clinical impact of a commercially available multiplex molecular diagnostic system - SES for diagnosing suspected CNS infections.

PATIENTS AND METHODS

This study was conducted in our tertiary level Neurology ICU. 110 patients admitted during Nov-2010 to April-2014 were included. CSF samples of patients clinically suspected of having CNS infections were subjected to routine investigation in our laboratory and SES test at XCyton Diagnostics. We studied the impact of SES in diagnosis of CNS infections and its efficacy in helping therapeutic management.

RESULTS

SES showed detection rate of 42.18% and clinical specificity of 100%. It had 10 times higher detection rate than conventional tests. Streptococcus pneumoniae and Mycobacterium tuberculosis were two top bacterial pathogens. VZV was most detected viral pathogen. SES results elicited changes in therapy in both positive and negative cases. We observed superior patient outcomes as measured by GCS scale. 75% and 82.14% of the patients positive and negative on SES respectively, recovered fully.

CONCLUSION

Detecting causative organism and ruling out infectious etiology remain the most critical aspect for management and prognosis of patients with suspected CNS infections. In this study, we observed higher detection rate of pathogens, target specific escalation and evidence based de-escalation of antimicrobials using SES. Institution of appropriate therapy helped reduce unnecessary use of antimicrobials.

Combined Efficacy of Adrenal Vein Sampling and Imaging Findings in Predicting Clinical Outcomes Following Unilateral Adrenalectomy for Primary Aldosteronism

The objective of this study was to investigate the combined efficacy of adrenal vein sampling (AVS) and imaging findings in predicting successful clinical outcomes following unilateral adrenalectomy for primary aldosteronism (PA). A retrospective chart review of 137 patients who underwent AVS between 2009 and 2014 at two hospitals in a single academic institution was performed. Preprocedure demographic, imaging, medication, and laboratory values were reviewed. In general, patients were considered for adrenalectomy when lateralization was suggested on AVS. Clinical outcomes such as improved blood pressure control and preserved renal function after adrenalectomy were correlated with preprocedure variables. AVS was technically successful in 120 out of 137 patients. Lateralization was seen in 64 patients and 48 out of 64 patients underwent adrenalectomy. Out of 48, 43 patients had an adrenal nodule on preoperative imaging, while 5 did not. 28 patients showed improvement in blood pressure after adrenalectomy, all of which had a nodule on imaging. Of the 28 patients, 22 also showed preservation of renal function. None of the remaining 5 (out of 48) patients who demonstrated lateralization on AVS and had no nodule on imaging showed clinical improvement following adrenalectomy. The presence of an adrenal nodule on preoperative imaging was also associated with improved blood pressure control (p = 0.022) and preserved renal function (p = 0.048) following adrenalectomy. Improved blood pressure control and preserved renal function in patients with PA who underwent adrenalectomy following lateralization on AVS are associated with the identification of an adrenal nodule on preoperative imaging.

Acenocoumarol: A Review of Anticoagulant Efficacy and Safety

Anticoagulant treatment is required for the treatment and prevention of thromboembolic disorders. Vitamin K antagonists are commonly used oral anticoagulants worldwide. Acenocoumarol is mono-coumarin derivative with racemic mixture of R (+) and S (-) enantiomers. Efficacy and safety of acenocoumarol has been evaluated in atrial fibrillation, cardiac valve replacement, after myocardial infarction, treatment of deep vein thrombosis, after major surgeries and after critical illness requiring prolonged hospitalization. Acenocoumarol is effective and safe in all age groups. It offers an advantage over warfarin in terms of better stability of anti-coagulant effect. Due to its economic advantage acenocoumarol may be suitable oral anticoagulant for long term use in countries like India.

Effect of technical parameters on transjugular intrahepatic portosystemic shunts utilizing stent grafts

AIM: To assess the effect of technical parameters on outcomes of transjugular intrahepatic portosystemic shunt (TIPS) created using a stent graft.

METHODS: The medical records of 68 patients who underwent TIPS placement with a stent graft from 2008 to 2014 were reviewed by two radiologists blinded to the patient outcomes. Digital Subtraction Angiographic images with a measuring catheter in two orthogonal planes was used to determine the TIPS stent-to-inferior vena cava distance (SIVCD), hepatic vein to parenchymal tract angle (HVTA), portal vein to parenchymal tract angle (PVTA), and the accessed portal vein. The length and diameter of the TIPS stent and the use of concurrent variceal embolization were recorded by review of the patient’s procedure note. Data on re-intervention within 30 d of TIPS placement, recurrence of symptoms, and survival were collected through the patient’s chart. Cox proportional regression analysis was performed to assess the effect of these technical parameters on primary patency of TIPS, time to recurrence of symptoms, and all-cause mortality.

RESULTS: There was no significant association between the SIVCD and primary patency (P = 0.23), time to recurrence of symptoms (P = 0.83), or all-cause mortality (P = 0.18). The 3, 6, and 12-mo primary patency rates for a SIVCD ≥ 1.5 cm were 82.4%, 64.7%, and 50.3% compared to 89.3%, 83.8%, and 60.6% for a SIVCD of < 1.5 cm (P = 0.29). The median time to stenosis for a SIVCD of ≥ 1.5 cm was 19.1 mo vs 15.1 mo for a SIVCD of < 1.5 cm (P = 0.48). There was no significant association between the following factors and primary patency: HVTA (P = 0.99), PVTA (P = 0.65), accessed portal vein (P = 0.35), TIPS stent diameter (P = 0.93), TIPS stent length (P = 0.48), concurrent variceal embolization (P = 0.13) and reinterventions within 30 d (P = 0.24). Furthermore, there was no correlation between these technical parameters and time to recurrence of symptoms or all-cause mortality. Recurrence of symptoms was associated with stent graft stenosis (P = 0.03).

CONCLUSION: TIPS stent-to-caval distance and other parameters have no significant effect on primary patency, time to recurrence of symptoms, or all-cause mortality following TIPS with a stent-graft.

Association of 3.0-T brain magnetic resonance imaging biomarkers with cognitive function in the Dallas Heart Study

IMPORTANCE

Understanding the relationships between age-related changes in brain structure and cognitive function has been limited by inconsistent methods for assessing brain imaging, small sample sizes, and racially/ethnically homogeneous cohorts with biased selection based on risk factors. These limitations have prevented the generalizability of results from brain morphology studies.

OBJECTIVE

To determine the association of 3.0-T structural brain magnetic resonance (MR) imaging measurements with cognitive function in the multiracial/multiethnic, population-based Dallas Heart Study.

DESIGN, SETTING, AND PARTICIPANTS

Whole-brain, 2-dimensional, fluid-attenuated inversion recovery and 3-dimensional, magnetization-prepared, rapid acquisition with gradient echo MR imaging at 3.0 T was performed in 1645 Dallas Heart Study participants (mean [SD] age, 49.9 [10.5] years; age range, 19-85 years) who received both brain MR imaging and cognitive screening with the Montreal Cognitive Assessment between September 18, 2007, and December 28, 2009. Measurements were obtained for white matter hyperintensity volume, total brain volume, gray matter volume, white matter volume, cerebrospinal fluid volume, and hippocampal volume. Linear regression and a best predictive model were developed to determine the association of MR imaging biomarkers with the Montreal Cognitive Assessment total score and domain-specific questions.

MAIN OUTCOMES AND MEASURES

High-resolution anatomical MR imaging was used to quantify brain volumes. Scores on the screening Montreal Cognitive Assessment were used for cognitive assessment in participants.

RESULTS

After adjustment for demographic variables, total brain volume (P < .0001, standardized estimate [SE] = .1069), gray matter volume (P < .0001, SE = .1156), white matter volume (P = .008, SE = .0687), cerebrospinal fluid volume (P = .012, SE = -.0667), and hippocampal volume (P < .0001) were significantly associated with cognitive performance. A best predictive model identified gray matter volume (P < .001, SE = .0021), cerebrospinal fluid volume (P = .01, SE = .0024), and hippocampal volume (P = .004, SE = .1017) as 3 brain MR imaging biomarkers significantly associated with the Montreal Cognitive Assessment total score. Questions specific to the visuospatial domain were associated with the most brain MR imaging biomarkers (total brain volume, gray matter volume, white matter volume, cerebrospinal fluid volume, and hippocampal volume), while questions specific to the orientation domain were associated with the least brain MR imaging biomarkers (only hippocampal volume).

CONCLUSIONS AND RELEVANCE

Brain MR imaging volumes, including total brain volume, gray matter volume, cerebrospinal fluid volume, and hippocampal volume, were independently associated with cognitive function and may be important early biomarkers of risk for cognitive insult in a young multiracial/multiethnic population. A best predictive model indicated that a combination of multiple neuroimaging biomarkers may be more effective than a single brain MR imaging volume measurement.

Polyvinylidene fluoride film based nasal sensor to monitor human respiration pattern: an initial clinical study

Design and development of a piezoelectric polyvinylidene fluoride (PVDF) thin film based nasal sensor to monitor human respiration pattern (RP) from each nostril simultaneously is presented in this paper. Thin film based PVDF nasal sensor is designed in a cantilever beam configuration. Two cantilevers are mounted on a spectacle frame in such a way that the air flow from each nostril impinges on this sensor causing bending of the cantilever beams. Voltage signal produced due to air flow induced dynamic piezoelectric effect produce a respective RP. A group of 23 healthy awake human subjects are studied. The RP in terms of respiratory rate (RR) and Respiratory air-flow changes/alterations obtained from the developed PVDF nasal sensor are compared with RP obtained from respiratory inductance plethysmograph (RIP) device. The mean RR of the developed nasal sensor (19.65 ± 4.1) and the RIP (19.57 ± 4.1) are found to be almost same (difference not significant, p > 0.05) with the correlation coefficient 0.96, p < 0.0001. It was observed that any change/alterations in the pattern of RIP is followed by same amount of change/alterations in the pattern of PVDF nasal sensor with k = 0.815 indicating strong agreement between the PVDF nasal sensor and RIP respiratory air-flow pattern. The developed sensor is simple in design, non-invasive, patient friendly and hence shows promising routine clinical usage. The preliminary result shows that this new method can have various applications in respiratory monitoring and diagnosis.

A comparative study of brainstem auditory evoked potentials in preterm and full-term infants

BACKGROUND

Preterm infants can have many neurological problems. An enormous amount of fetal brain development occurs during the last trimester of pregnancy. They include myelination, glial cell migration and the development of a complex gyral pattern. The brain doesn't show the normal growth after birth in preterm infants. Brainstem auditory evoked potentials (BAEPs) are a noninvasive neurophysiologic assessment of brainstem maturation in babies.

METHODS

BAEPs in 25 preterm and 25 full-term infants were considered for the study. Infants having history of birth trauma, metabolic disorders or intracranial infection were excluded. BAEP waveforms (absolute and interpeak latencies) were recorded and analyzed. Student t test was used to analyze the data thus acquired.

RESULTS

Analysis of data revealed a significant increase in latency of BAEP waveform V (P<0.05). Other latencies and interpeak latencies of BAEP waveforms were comparable.

CONCLUSION

The preterm infants have a prolonged latency of BAEP waveform V suggestive of a retarded myelination of the central auditory pathway. Thus BAEP could be a useful electrophysiological test to assess neuronal myelination and maturation in preterm infants.