E1122. The Subpial Space: An Uncommon Site of Hemorrhage in Term Infants
  1. Joseph Junewick; Advanced Radiology Services PC
  2. Andrew Zbojniewicz; Advanced Radiology Services PC
  3. M. Bercu; Helen DeVos Children's Hospital
  4. Christopher Therasse; Advanced Radiology Services PC
  5. Ellen Junewick; Spectrum Health
  6. Mark DeLano; Advanced Radiology Services PC
Pia mater is the deepest meningeal layer covering the brain. Pia also invaginates into the brain parenchyma along the perivascular spaces of penetrating arteries and veins. The subpial space is a potential space between the inner layer of the pia mater (pia intima) and the outer layer of the cortex (glia limitans). Reticular processes and elastic fibers responsible for adherence of the pia mater to the cortex may not be well developed in infancy and consequently the subpial space may be more easily exposed. Subpial hemorrhage is typically manifested as contained blood over the cortex but atypical manifestations of blood in the peripheral cortex and along the perivascular spaces and medullary veins may also be seen. Understanding pial anatomy, clinical presentations and predisposing factors are important to facilitate recognition of subpial hemorrhage and differentiation from other forms of intracranial hemorrhage in infancy.

Educational Goals / Teaching Points
Review pial anatomy. Define diagnostic criteria and differential diagnoses for subpial hemorrhage. Understand clinical presentations and predisposing factors for subpial hemorrhage. Illustrate various manifestations of subpial hemorrhage.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Typical subpial hemorrhage: contained blood over the cortex with no RBCs or xanthochromia on lumbar puncture. Atypical subpial hemorrhage: peripheral parenchymal hemorrhage along the perivascular spaces often with subjacent cytotoxic edema.

Recognition of subpial hemorrhage as an entity distinct from other forms of intracranial hemorrhage is important in understanding pathophysiological mechanism and directing appropriate patient care.