“…Our observations demonstrate that the finding of a normal ICP during wakefulness is not sufficient to rule out an actual increase in ICP, since a rise in the CRF pressure can occur during sleep. Our data also demonstrated a correlation between an abnormal rise in ICP and an absent or blunted nocturnal increment in PRL secretion.The 'primary empty sella' (PES) is defined as an exten sion of the subarachnoid space into the sella turcica in sub jects who have not received surgical or radiotherapeutic procedures [6,17], The pituitary fossa is enlarged and par tially filled with cerebrospinal fluid, while the pituitary gland is compressed against the posterior rim of the fossa.Although it has been suggested, on the basis of clinical signs (headache, with or without papilledema), that a chron ic or intermittent intracranial hypertension can cause the development of the PES [12], an actual increase in cerebro spinal fluid (CSF) pressure has rarely been documented in patients who have developed this syndrome [7,8,10,11,20], It is known, however, that in some pathological conditions (such as normotensive hydrocephalus) an increase in intra cranial pressure (ICP) was revealed only by prolonged re cordings during nocturnal sleep. In particular, the highest ICP was recorded during REM episodes [19],…”