<prompt> Picket fence fever is a feature of-Acute mastoiditisLateral sinus thrombophlebitisBells PalsyAtticoantral CSOM  <response>: Ans. is b i.e., Lateral sinus thrombophlebitis Signs of lateral sinus thrombosis sigmoid sinus thrombosiso Hectic Picket-Fence type of fever with rigor.o Headache, Progressive anemia and emaciation.o Griesingers sign:- odema over the posterior part of mastoid due to thrombosis of mastoid emissary veinso Papilloedemao Tobey-Ayer testo Crowe-Beck test:- Pressure on jugular vein of healthy side produces engorgement of retinal veins. Pressure on affected side does not produce such changeo Tenderness along jugular vein 