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Neuroradiology Case of the Week

Case 273

Ashwani K. Sharma, MD, and P-L Westesson, MD, PhD, DDS

Clinical Presentation: Patient is a 2-week-old full-term infant presenting with history of apnea and seizures.

Imaging Findings:

Diagnosis: Germinal matrix hemorrhage

Discussion: Subependymal germinal matrix with intraventricular hemorrhage (GMIVH) is the most common type of neonatal intracranial hemorrhage and is characteristic of premature infants. Most GMIVHs occur within the first 72 hours of life. The germinal matrix is considered to be friable and fragile in the preterm period and highly susceptible to hypoxemia and anoxia, acidosis, and changes in blood pressure associated with delivery [1].
     Subsequent reperfusion to the ischemic tissues in the setting of weakened capillaries and increased venous pressure result in germinal matrix hemorrhage, ranging in severity from subependymal hemorrhage (grade 1) to intraventricular hemorrhage without (grade 2) and with (grade 3) ventricular dilatation, to parenchymal extension and coexisting periventricular venous infarction (grade 4).
     Periventricular parenchymal changes, especially encephalomalacia and PVL associated with GMIVH, contribute significantly to neonatal mortality and long-term neurodevelopmental deficits in the premature infant [2].
     Hypoperfusion Injury in preterm Infants affects periventricular white matter, with ischemic parenchyma manifesting as PVL. As severity increases thalami, brainstem, and cerebellum are affected.
     Hypoperfusion Injury in term Infants affects intervascular watershed zones between the anterior and middle cerebral arteries and between the middle and posterior cerebral arteries and the border zone. Both the cortex and the underlying subcortical white matter in the parasagittal locations demonstrate restricted diffusion. With increasing severity metabolically active tissues in the brain of the term neonate lateral thalami, posterior putamina, hippocampi, brainstem, corticospinal tracts, and the sensorimotor cortex are affected.

References:

1. Volpe JJ: Intraventricular hemorrhage in the preterm infant - current concepts. Part I. Ann Neurol. 1989 Jan;25(1):3-11. [Medline]
2. Aida N, Nishimura G, Hachiya Y, Matsui K, Takeuchi M, Itani Y: MR imaging of perinatal brain damage: comparison of clinical outcome with initial and follow-up MR findings. AJNR Am J Neuroradiol. 1998 Nov-Dec;19(10):1909-21. [Medline]