Striking fluctuation in the temperature curve is recognized as the outstanding clinical symptom of lateral sinus thrombosis. In the more typical cases, these fluctuations range from subnormal to 104 and 106 F., and down to subnormal, often within a period of less than twenty-four hours; they are usually associated with chills and a corresponding increase in pulse rate. The clinical phenomenon is explained by the morbid change taking place within the sinus, the sudden pyrexia indicating the entrance into the blood stream of septic material from the broken down thrombus.
An afebrile type of sinus thrombosis occasionally occurs. In such cases, when an obliterating thrombus is present, symptoms may be produced which are traceable to disturbed intracranial circulation, such as headache, nausea, vomiting and optic neuritis. But in the absence of these symptoms, thrombosis may not be recognized unless discovered accidentally at the time of mastoid operation or revealed at