Role of spinal ultrasound in diagnosis of meningitis in infants younger than 6 months

Abstract

Background: Spinal ultrasound (US) can detect changes in CSF echogenicity and decreased cord pulsations which reflect the inflammatory changes in meningitis. Till date, there is no published data about the prospective accuracy of spinal US in meningitis.

Objective: To assess accuracy of spinal US in diagnosis of meningitis in infants younger than 6 months.

Methods: This was an institute ethics committee approved prospective study carried out in infants less than 6 months of age with clinical suspicion of meningitis who presented to pediatric emergency unit. 60 infants each in study and control group were enrolled. US of thoraco-lumbar spine were performed prior to lumbar puncture in all cases. We looked for the presence of echogenicity or trabeculations in posterior subarachnoid space and for presence or absence of spinal cord and nerve root pulsations on real time ultrasound. The results of spinal US were evaluated in correlation with cerebrospinal fluid analysis. Follow up ultrasounds were done in infants who showed abnormal findings after the initiation of treatment and findings compared with initial results.

Results: The study group comprised of 40 boys and 20 girls with mean age of 47.85 days. The control group comprised of 36 boys and 24 girls with a mean age of 60.53 days. 34/60 cases in study group had CSF findings suggestive of meningitis. Based on imaging parameters, spinal US had sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 67.16%, 92.3%, 93.1% and 74.64%, respectively. Chi-square test showed a statistically significant association between infants with meningitis and positive US findings (p<0.05).

Conclusion: Spinal US findings of CSF debris, septations and decreased spinal cord pulsations can be seen in infants with meningitis.

Keywords: Infants; Meningitis; Spinal; Ultrasound.