<prompt> A patient presented with headache and fever for 7 days. While doing a lumbar puncture, it was noticed that the opening CSF pressure increased on jugular vein compression and became normal on relieving the pressure on jugular vein. What is the interpretation of this?Subdural blockageSubarachnoid blockageArachnoid villi blockagePatent subarachnoid space  <response>: Queckenstedt maneuver IJV: Venous outflow Brain ICP: Patent subarachnoid space i.e. no spinal block present If presence of sagittal vein thrombosisspinal block then this maneuver will not increase in the pressure of manometer reading because entire circuit is blocked. Queckenstedt or Tobey- Ayer test: Compression of I.J.V. - rapid rise of C.S.F. pressure 50-100 mm water - rapid fall on release of compression. In L.S.T. no rise rise by only 10-20 mm water. Low sensitivity and specificity 