Interpeduncular Angle: A Possible Marker to Differentiate Atypical Parkinsonism from Idiopathic Parkinson's Disease. - Shivarthi, Tejas; Sriram, Mahima; Saraf, Udit; Kannan, Rajesh; Kannoth, Sudheeran; Sudhakar, Abish; Nambiar, Vivek; Gopinath, Siby; Unnikrishnan, Gopikrishnan; Anandakuttan, Anandkumar (Annals of Indian Academy of Neurology, 2026)