LAUSR

The lentiform fork sign (LFS) is an uncommon imaging finding. Accepted hypotheses include vasogenic edema and metabolic acidosis affecting the lentiform nuclei.1,2 MRI imaging in a 46-year-old woman undergoing regular hemodialysis showed 3 stages of the LFS over 9 months. Her initial neurologic examination revealed severe dystonia (Video 1). Laboratory testing revealed mild compensated metabolic acidosis with nearly normal bicarbonate and anion gap (Table). MRI sequence scans demonstrated symmetric hyperintensities of the BG and hyperintense rim delineating the lentiform (Figure). This case demonstrates that LFS can exist without metabolic acidosis. Vasogenic edema is considered a likely underlying mechanism.