Affiliations: Departments of Pediatric Neurology, Arkansas
Children's Hospital, Little Rock, AR, USA | Departments of Pediatric Neurosurgery, Arkansas
Children's Hospital, Little Rock, AR, USA | Departments of Pediatric Radiology, Arkansas
Children's Hospital, Little Rock, AR, USA
Note: [] Correspondence: Dr. Aimee F. Luat, Department of Pediatric
Neurology, Arkansas Children's Hospital, University of Arkansas for Medical
Sciences, No 1 Children's Way, Little Rock, AR 72202, USA. Tel.: +1 501 364
1850; Fax: +1 501 364 6077; E-mail: ALuat@uams.edu
Abstract: We report an 8-year-old girl who presented with acute right foot
drop with preserved reflex following minor trauma. Brain magnetic resonance
imaging showed a large pial arterio-venous malformation (AVM) over the left
frontal paramedian convexity with a large varix draining into the superior
sagittal sinus. On post-contrast T1-weighted imaging, the AVM showed a swirling
pattern with sharply marginated outer hypo-intense area and inner hyper-intense
area reminiscent of the Chinese "yin-yang" symbol. A partially thrombosed varix
in an AVM nidus was suspected which was confirmed on histopathology following
resection. Unilateral foot drop with preserved reflex is one of the rare
clinical presentations of a frontal paramedian AVM. "Yin-yang" sign is a unique
magnetic resonance imaging finding suggestive of a partially thrombosed
AVM.
