Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Empty sella syndrome ?
    ### Response:
    Empty sella syndrome (ESS) is a condition that involves the sella turcica, a bony structure at the base of the brain that protects the pituitary gland. There is a primary and secondary form of the condition. The primary form occurs when a structural defect above the pituitary gland increases pressure in the sella turcica and causes the gland to flatten.
    