Prevalence and evolution of intracranial hemorrhage in asymptomatic term infants

Abstract

Background and purpose: Subdural hemorrhage (SDH) is often associated with infants experiencing nonaccidental injury (NAI). A study of the appearance and natural evolution of these birth-related hemorrhages, particularly SDH, is important in the forensic evaluation of NAI. The purpose of this study was to determine the normal incidence, size, distribution, and natural history of SDH in asymptomatic term neonates as detected by sonography (US) and MR imaging within 72 hours of birth.

Materials and methods: Birth history, delivery method, duration of each stage of labor, pharmaceutic augmentation, and complications during delivery as well as postnatal physical examination were recorded. Brain MR imaging and US were performed on 101 asymptomatic term infants at 3-7 days, 2 weeks, 1 month, and 3 months. Clinical follow-up at 24 months was recorded.

Results: Forty-six neonates had SDH by MR imaging within 72 hours of delivery. SDH was seen in both vaginal and cesarean deliveries. All neonates were asymptomatic, with normal findings on physical examination. All 46 had supratentorial SDH seen in the posterior cranium. Twenty (43%) also had infratentorial SDH. US detected 11 of the 20 (55%) infratentorial SDHs and no supratentorial SDH. Most SDHs present at birth were <or=3 mm and had resolved by 1 month, and all resolved by 3 months on MR imaging. Most children with SDHs had normal findings on developmental examinations at 24 months.

Conclusion: SDH in asymptomatic term neonates after delivery is limited in size and location.

Fig 1.

Posterior fossa SDH in a neonate delivered via SVD. A, Axial MPGR at <72 hours of life demonstrates lobular symmetric low signal intensity with blooming in the posterior fossa (arrows). B, Follow-up T1 images show high-signal-intensity SDH (arrowheads) by 7 days.

Fig 2.

Neonate delivered via SVD with both supratentorial and infratentorial SDH. A and B, Initial examination shows the lobular occipital SDH to be very low signal intensity on MPGR (arrows, A) and isointense to gray matter and difficult to detect on the SE T1-weighted MR image (B). C and D, Five-day follow-up shows high T1 SDH (arrowheads) in 2 locations in 2 planes, axial supratentorial (C) and coronal, both supra- and infratentorial (D). E and F, Two-week follow-up shows complete resolution of hemorrhage on T1 images.

Fig 3.

Neonate delivered via SVD with posterior fossa SDH seen on US and confirmed on MR imaging. A, Axial sonogram of the posterior fossa through the mastoid fontanel demonstrates initial curvilinear echogenic focus adjacent to the transverse sinus (arrow). B, Axial T1-weighted MR image confirms high-signal-intensity posterior fossa SDH (arrowhead) on day 7 of life.

Fig 4.

Images obtained at 7 and 26 days postnatal age for follow-up of bilateral occipital SDH in a neonate with extra-axial collections. Axial T2, T1, gradient-refocused echo (GRE), and FLAIR images (left to right, top row) show CSF-intensity frontal subarachnoid collections that were present since birth. Also note a thin linear T1 hyperintense GRE hypointense bilateral posterior occipital SDH. At 26 days postnatal age (bottom row), left frontal subdural collections that do not conform to CSF signal intensity are present, consistent with spontaneous SDH. The patient had no history of trauma and had a negative evaluation for NAI.