Dr Takanashi's neonatal patient also shows splenium signal changes with an increased diffusion-weighted image signal and a decreased ADC value. Neonatal brain magnetic resonance imaging at Swedish Medical Center, Seattle, Wash, a busy birthing center, shows that perinatal asphyxia, germinal matrix hemorrhage, ischemic stroke, or neonatal seizure rarely results in splenium signal change. Takanashi et al's findings are intriguing and may suggest that myelin may have nothing to do with why diffusion-weighted image signals are altered. As most patients improve clinically, proving inflammatory involvement will likely remain difficult. Perhaps their neonate had a genetic risk similar to a recently described patient1 with a splenium signal change? This patient showed a mitochondrial mutation within an adenosine triphosphate synthesis gene. I wonder if an adenosine triphosphate synthesis defect might also have predisposed the patient of Takanashi et al to neonatal asphyxia.
Doherty M. Neonate Showing Reversible Splenial Lesion—Reply. Arch Neurol. 2005;62(9):1482. doi:10.1001/archneur.62.9.1482