You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Griesinger's sign is seen in - and explain in detail?
Lateral Sinus Thrombophlepitis

It is inflammation of the walls of sigmoid sinus (lateral sinus) with the formation of thrombus - Complication of acute coalescent mastoiditis or masked mastoiditis
Aetiology - Chronic SOM with cholesteatoma