The Analysis Of Pituitary Function And Imaging Characteristics In Patients With Primary Empty Sella

OBJECTIVE: Primary empty sella(PES)is characterized by the herniation of the subarachnoid space within the sella turcica in patients with no history of pituitary surgery,trauma,tumor or radiotherapy.Classically,PES was regarded as a normal physiological alteration and without any influence on pituitary function.With the development of imaging techniques,the incidence of PES has been apparent.So more and more people pay attention on health hazard from the disease of PES.The main objective of the study is to describe the changes in pituitary function and the size of pituitary gland and sella turcica by analyzing the clinical manifestations and laboratory findings along with imaging features of 108 patients with PES.METHODS: The data for this retrospective study had been collected from the department of Endocrinology and Metabolic Diseases of Tianjin Medical University General Hospital between January 2011 and October 2016.For all the subjects in the study,the general information such as the age,gender,BMI,clinical features and other comorbid diseases like diabetes mellitus,hypertension and coronary heart disease were accurately obtained from their medical records.All subjects were scanned using a MRI which obtained contiguous sagittal and coronal imaging through the sellar region.The measurement of pituitary gland and sella turcica was performed by the well-trained and reliable radiologists who were blinded to the clinical diagnosis.Patients with the radiological findings of herniation of the subarachnoid space into the sella turcica,causing compression of the pituitary gland and normal or expanded sella turcica in subjects with no history of pituitary surgery,trauma,tumor or radiotherapy were all included.Exclusion criteria of the subjects comprised of an absence of any hormonal evaluation or imaging data,PRL>100 ng/ml and growth hormone(GH)or cortisol hypersecretion.In our study,61 patients had normal pituitary function,whereas 47 had different degrees of anterior pituitary hormone deficiency.We divided 108 patients into two groups: partial empty sella group(less than 50% of the sellar cavity is replaced by cerebrospinal fluid and pituitary height more than 2 mm)and total empty sella group(more than 50% of the sellar cavity is replaced by cerebrospinal fluid and pituitary height less than 2 mm).We selected 43 subjects as the age and gender matched controls with an intact hypothalamo-pituitary region and normal pituitary function.RESULTS: 1.Baseline data: Of the 108 patients(65 women and 43 men),the ratio of male to female was 1:1.5,accounting for 1.4% of the total hospitalized patients in our department during the same period.The average age at diagnosis was 61.5 ± 12.9 years.Out of the 65 women,63 of them(96.9%)had a history of pregnancy,of whom 60.3% were multiparous.2.Clinical characteristic: Of 108 patients,54.6% patients had fatigue and 37% had non-specific headache.26.9% patients had poor appetite and 14.8% had dry skin and intolerance to cold.27.9% male patients had diminished sexual capacity and 18.5% of female patients appeared with hypogonadism.Visual disturbances were found in 10.2% patients,including decreased visual acuity(9.3%)and visual field defects(0.9%).3.7% patients experienced adrenal crisis.10 patients of diabetes mellitus were diagnosed with PES due to polyuria and polydipsia.3.Evaluation of pituitary function: Among the 108 patients,61 patients(56.5%)had normal pituitary function and 47 patients(43.5%)had different degrees of anterior pituitary hormone deficiency.In this study,although the incidence of PES in males was lower than in females,the rate of males with hypopituitarism(60.5%)was significantly more than the females(32.3%)(P<0.05).The prevalance of hypogonadotropic hypogonadism,central hypothyroidism and central hypoadrenalism were 33.3%,18.5%,13.9%.The rate of hypopituitarism in total empty sella group(60.7%)was higher than that in partial empty sella group(21.3%)(P<0.05).20.5% had hypopituitarism in 39 asymptomatic patients.In addition,3.1% patients had hyperprolactinaemia and 10.2% had central diabetes insipidus.4.Imaging Evaluation: All subjects were examined by MRI which showed the characteristic cerebrospinal fluid signal was filled within the sella turcica,the pituitary gland was compressed and the sella turcica appeared normal or expanded.The results of measurements of the pituitary gland and sella turcica were shown: The volume of pituitary was significantly lower in PES patients in contrast to that of the controls(P<0.05).Interestingly,the pituitary volume was significantly lower in the group of hypopituitarism than those in group of normal pituitary function(P<0.05).Meanwhile,the prevalance of hypopituitarism in total empty sella group was significantly higher than that in partial empty sella group.The mean sella anterior-posterior diameter,depth and width were higher in PES group than those in controls and mean sella cross-sectional area was significantly higher in anterior group(P<0.05).However,Respectively to compare the normal pituitary function group with hypopituitarism group and total empty sella group with partial empty sella group,there were no significant differences in the sella size(P>0.05).5.Correlation:There is a positive correlation between pituitary function and volume.6.Follow-up: 74 PES patients were undergone follow-up in pituitary function for 26±14 months and 8.1% patients had new pituitary-target axes hypofunction.CONCLUTION: 1.The prevanlence of PES is higher in females than in males,expecially in old and middle-aged females.2.The clinical manifestations of PES are diverse and atypical.The main symptoms present as headache,fatigue,endocrine disorders and visual impairments.3.Hypopituitarism in PES is more common than what has been previously thought.Therefore,an overall evaluation of the pituitary function is essential for the new diagnosed empty sella patients.If they have been diagnosed with hypopituitarism,the hormone replacement therapy should be given in time.PES has a particular risk of a worsening progression.So all patients with PES must be kept under long-term follow-up to prevent the occurrence of pituitary crisis.4.Empty sella not only cause pituitary shape change,but also make pituitary volume shrinking.Meanwhile,there is a correlation of pituitary function with its volume.Empty sella can make the sella turcica expanded.However,it has no relationship with the pituitary function and size.