Crystal clear cerebral ultrasound images mimicking acute asphyxia in an infant with primary hyperoxaluria.

Genetic deficiencies in enzymes involved in glyoxylate metabolism lead to primary hyperoxaluria (PH) type I, typically characterized by deposition of oxalate crystals in kidneys. A 2-month-old infant was admitted, and was diagnosed with renal failure. Abdominal ultrasound images revealed enlarged and hyperechoic kidneys. Additionally, on cerebral ultrasound (CUS) hyperechoic changes of thalami and basal ganglia were noted, reminiscent of perinatal hypoxic-ischemic brain damage. However, MRI of the brain did not show any abnormal signal intensities compatible with asphyxia. The hyperechoic appearance of deep grey matter, in particular putamen, was therefore not due to asphyxiated brain damage but seemed related to the deposition of oxalate salts. Moreover, macular crystals were detected at ophthalmoscopy. Our case report shows the potential of US imaging to detect deposition of crystals not only in kidneys but also in brain mimicking, perinatal asphyxia.