Spinal Ultrasound Assessment of Correlation Between Intraventricular Hemorrhage Severity and Cerebrospinal Fluid Volume in Preterm Infants.

Objective: Intraventricular hemorrhage (IVH) affects >15% of preterm infants. Severe IVH disrupts cerebrospinal fluid (CSF) flow dynamics, causing post-hemorrhagic ventricular dilation (PHVD) and further brain injury. Although lumbar puncture (LP) may reduce CSF volume and intracranial pressure, its effectiveness depends on brain-to-spine CSF flow dynamics and spinal CSF volume, which remain underexplored. This study correlates IVH severity with spinal CSF volume of preterm infants using spinal ultrasound (SUS).

Methods: This prospective study enrolled infants (<33 weeks gestational age [GA]) with head ultrasounds (HUS) done at 7-15 days of life. SUS was performed within 2 days of HUS and repeated if another HUS was done. Exclusion criteria were congenital, chromosomal, or spinal anomalies. Using SUS clips, an automated algorithm calculating the proportion of anechoic CSF area within the spinal canal at the L3-L4 intervertebral space, termed the CSF-to-Spinal Canal Index (CSCI) was developed. Clinical data and IVH grades were analyzed.

Results: Twenty-five infants (mean GA: 28 ± 3 weeks) were enrolled, with 46 SUS studies performed. We found no correlation between IVH grade and CSCI (R2 = 0.13, P = .57). The CSCI did not correlate with birth GA, birth weight, corrected GA, current weight, day of life, and previous 24-hour weight change at the time of SUS. The CSCI decreased after each LP in 4 infants with PHVD. Four infants needed surgical CSF diversion.

Conclusions: SUS is a non-invasive method to estimate spinal CSF volume. The lack of correlation with IVH severity suggests multifactorial mechanisms besides previously proposed CSF outflow obstruction. Further research is necessary to understand the pathophysiology of PHVD.