Cytomegalovirus in Congenital SNHL

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Questions and Answers

What technique was used to detect CMV in perilymphatic fluid?

ELISA

Serology

QRTPCR (correct)

Cul-ture

In how many patients was QRTPCR positive for CMV in perilymphatic fluid?

None of the patients

Two patients

Four patients (correct)

Six patients

What was the result of blood analysis for CMV using QRTPCR?

Not analyzed

Negative in all patients (correct)

Positive in all patients

Positive in some patients

What is the estimated volume of perilymph in the human cochlea?

50 μL Signup and view all the answers

What is the positive predictive value of viral culture for detecting CMV?

100% Signup and view all the answers

How does CMV theorized to reach the inner ear?

Hematogenous spread Signup and view all the answers

What condition is being investigated in relation to CMV presence in perilymphatic fluid?

Congenital sensorineural hearing loss Signup and view all the answers

What factor affects the sensitivity of the viral culture assay for CMV detection?

Volume of specimen available Signup and view all the answers

What is the estimated incidence of congenital cytomegalovirus (CMV) infection in neonates?

1% Signup and view all the answers

What percentage of congenitally infected infants with CMV are considered asymptomatic at birth?

90% Signup and view all the answers

What range of percentage does sensorineural hearing loss (SNHL) occur in asymptomatic congenital CMV infections?

7% to 15% Signup and view all the answers

What percentage of infants with congenital CMV are expected to have bilateral profound SNHL?

23% Signup and view all the answers

What method was used to analyze perilymphatic fluid for the presence of CMV?

Quantitative real-time polymerase chain reaction (QRTPCR) Signup and view all the answers

What percentage of all cases of congenital sensorineural hearing loss (SNHL) is attributed to CMV according to recent literature?

20% to 30% Signup and view all the answers

What is known about the pathogenesis of CMV-mediated hearing loss?

It is largely unknown Signup and view all the answers

What was the primary study design used to determine the presence of CMV in perilymphatic fluid?

Prospective case series Signup and view all the answers

What method was used to collect perilymphatic fluid during the procedure?

With a 27 gauge needle on a 1 mL syringe Signup and view all the answers

What was the purpose of centrifuging the perilymphatic fluid specimen?

To remove surgical contaminants Signup and view all the answers

What was the concentration of CMV in the blood for the studied patients?

Negative in all cases Signup and view all the answers

Which patient had a concentration of CMV higher than would be expected in a positive blood sample?

Patient 2 Signup and view all the answers

What was the primary technique used to detect the presence of CMV in perilymphatic fluid?

Quantitative reverse transcription PCR (QRTPCR) Signup and view all the answers

What was the sampling method for blood collection during the study?

From a peripheral vein Signup and view all the answers

What was the initial clinical presentation of the children involved in the study?

Hearing loss with no known etiology Signup and view all the answers

In what year was the study published?

2005 Signup and view all the answers

What is a significant factor in quantifying CMV DNA copy numbers in immune-suppressed individuals?

Viral target concentrations in plasma Signup and view all the answers

What complicating factor may affect molecular epidemiological studies related to CMV?

Intra-genetic variability of the virus strain Signup and view all the answers

Why might patients 1 and 4 have lower CMV concentrations compared to patients 2 and 6?

Variability in viral target concentrations Signup and view all the answers

What clinical condition has been linked to congenital cytomegalovirus infection according to the content?

CMV retinitis Signup and view all the answers

What limitation does QRTPCR have in the study of CMV?

It cannot identify specific viral strains Signup and view all the answers

What does the interaction of CMV with endothelial cells depend on?

The strain of the virus Signup and view all the answers

What was the outcome of the clinical pathologic study of hearing loss linked to congenital CMV?

It identified a correlation between CMV and hearing loss Signup and view all the answers

What aspect does the case study involving temporal bone histopathology focus on?

Long-term effects post-infection Signup and view all the answers

What percentage of cases of congenital nonsyndromic sensorineural hearing loss is suggested to be related to CMV infection?

50% to 60% Signup and view all the answers

What is the primary objective of using QRTPCR in this study?

To determine CMV presence in perilymphatic fluid Signup and view all the answers

How many children were identified during the precochlear implant evaluation process for this study?

Six Signup and view all the answers

What unique feature did one patient have among the identified cases?

Underwent sequential bilateral cochlear implantation Signup and view all the answers

What were the main findings on the MRI of two children in the study?

Radiologic evidence consistent with viral infection Signup and view all the answers

Which institution approved the project?

University of Texas Southwestern Medical Center Signup and view all the answers

What is the main benefit of using QRTPCR in this research context?

It gives a high specificity and sensitivity for detecting the virus Signup and view all the answers

What type of surgery were the children identified undergoing evaluation for?

Cochlear implantation Signup and view all the answers

Study Notes

Cytomegalovirus (CMV) in the Perilymphatic Fluid

CMV infection is an important cause of congenital sensorineural hearing loss (SNHL)
Approximately 1% of newborns are infected with CMV at birth
90% of congenitally infected infants are asymptomatic, meaning they show no signs or symptoms at birth
The prevalence of SNHL in asymptomatic, congenitally infected infants ranges from 7% to 15%
CMV is found in the perilymphatic fluid of some children with congenital SNHL
CMV can be detected and quantified in perilymphatic fluid using quantitative real-time polymerase chain reaction (QRTPCR)
Studying perilymphatic fluid after cochlear implantation can help to understand the cause of congenital SNHL
The study found that CMV was present in the perilymphatic fluid of four out of six children with congenital CMV infection
The blood of all six children tested negative for CMV, suggesting that the virus was present in the inner ear and not a contaminant
The concentration of CMV in perilymphatic fluid varied between patients
This study suggests that CMV may play a role in the pathogenesis of SNHL in some children with congenital CMV infection
More research is needed to determine the prevalence of CMV-mediated profound HL in children with unknown etiology

Materials and Methods

Six children were enrolled in the study: four with known congenital CMV infection and two with radiologic evidence suggestive of congenital viral infection
Perilymphatic fluid and blood samples were collected during cochlear implantation
The perilymphatic fluid was centrifuged to remove surgical contaminants
DNA was extracted from the perilymphatic fluid and blood samples
QRTPCR was used to detect and quantify CMV in both samples

Results

QRTPCR was positive for CMV in the perilymphatic fluid of four patients
All blood samples were negative for CMV using QRTPCR and culture

Conclusions

CMV can be detected and quantified in perilymphatic fluid using QRTPCR
The findings suggest that CMV may be present in the inner ear of children with congenital CMV infection
More research is needed to determine the prevalence of CMV-mediated profound HL in children with unknown etiology

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Description

This quiz explores the role of Cytomegalovirus (CMV) in congenital sensorineural hearing loss (SNHL), particularly its presence in perilymphatic fluid. Learn about the prevalence of CMV infection in newborns, its asymptomatic nature in most cases, and the implications for cochlear implantation studies. Test your knowledge on these vital topics in pediatric audiology.