The cerebrospinal fluid pressure as determined by lumbar puncture is used as a routine as a measure of intracranial pressure. For otolaryngologic purposes, the Queckenstedt or Tobey-Ayer1 test is used to ascertain the degree of obliteration of the lateral sinus by thrombosis in cases of mastoiditis. In a summary of results obtained during twelve years at the Massachusetts Charitable Eye and Ear Infirmary, Meltzer2 found the Tobey-Ayer test valuable and reliable in approximately from 70 to 80 per cent of the cases and a complete failure in 18.2 per cent. He considered this test one of the best diagnostic aids in cases of thrombosis of the lateral sinus.
The Queckenstedt and Tobey-Ayer tests are of special importance in the differentiation between the two lateral sinuses when both mastoids are involved. Under these conditions the percentage of failure is highest and the tests less accurate in determining