Hypothalamic and pituitary pathology.

This article details the intricate anatomy and elegant physiology of the hypothalamic-pituitary axis. The discussion is meant to confer an understanding of the principles of neuroendocrinology appropriate for the radiologist interpreting imaging studies of this region. The clinical presentations of the diseases that occur in this area of the central nervous system are unique and therefore are discussed in some detail. The radiologic features of the diseases affecting the hypothalamic-pituitary axis are described and correlated with the relevant pathology.

Hypothalamic-pituitary region: computed tomography imaging.

High resolution CT with dynamic scanning, demonstrating the pituitary tuft, the pituitary enhancement and the related vascular structures, is of major benefit for the diagnosis of pituitary lesions. Perfection of examination techniques is essential for accurate application of the modality to detect subtle diagnostic signs. A good knowledge of normal anatomy and variants of the sella turcica and pituitary gland permits one to avoid most of the misdiagnoses. Since the CT findings are often non-specific to tissues, clinical endocrinological correlation is essential. The technique also allows consistent assessment of the extent of the disease to permit better treatment planning and effective follow-up of patients after therapy.

Association of adverse perinatal events with an empty sella turcica in children with growth hormone deficiency.

High-resolution computed tomography (HR-CT) of the hypothalamo-pituitary region was performed in 26 consecutive children presenting with growth hormone deficiency (GHD) at one clinic. 58% had an empty sella turcica (ES) and 42% a full sella turcica (FS). There was no difference between the ES and FS groups for mean (+/- 95% confidence limits) presentation age (ES 6.7 (+/- 1.8) years, FS 5.6 (+/- 2.2) years), height standard deviation score (SDS) (ES -3.9 (+/- 0.8), FS -3.3 (+/- 0.5] nor head circumference SDS (ES -1.9 (+/- 1.1), FS -0.7 (+/- 1.1]. There were significant associations between the ES group and a history of adverse perinatal events (p less than 0.001) and multiple pituitary deficiency (p = 0.014). Growth hormone response to an acute growth hormone releasing factor test showed no association with HR-CT diagnosis. Sella turcica volumes were calculated from the HR-CT scans. All sella volumes were small; mean SDS for height was -2.6 (+/- 0.2). There was no difference in sella volume SDS between the ES and FS groups (ES -2.9 (+/- 0.3), FS -2.5 (+/- 0.4]. Adverse perinatal events may cause an ES and GHD by compromising the blood supply to the pituitary gland or infundibulum.

Hypothalamic-pituitary dysfunction in primary empty sella syndrome in childhood.

In a series of 37 consecutive CT scans performed in children referred to our pediatric endocrine unit, an empty (eight) or partially empty (one) sella turcica was found in nine (24%) patients with short stature or delay in sexual maturation, precocious puberty, or hypoparathyroidism. The size and contour of the sella were abnormal in only three patients. Five of the nine children had evidence of decreased growth hormone secretion as determined by subnormal GH secretory responses to provocative tests (peak GH concentration less than 7 ng/ml) or assessment of endogenous 24-hour GH secretion (mean 24-hour GH concentration less than 3 ng/ml). Two children had multiple pituitary hormone deficiencies. Although primary empty sella syndrome was often associated with hypothalamic-pituitary dysfunction in this series, the prevalence of an empty sella in normal children is unknown. Further identification and evaluation of children with empty sella may provide new information regarding the cause of pituitary dysfunction in childhood.

[Panhypopituitarism and dwarfism in a man with a primary empty sella turcica (author's transl)]. / Panhypopituitarisme et nanisme chez un homme ayant une selle turcique vide primitive.

Endocrine features associated with the primary empty sella turcica syndrom are rare; they are usually related to a pituitary microadenoma and more rarely to an idiopathic panhypop ituitarism. A pituitary dwarfism with an idiopathic panhypopituitarism of hypothalamic origin, associated with an "empty" sella turcica containing functional and stimulable pituitary tissue, is reported in a 27 year old male Moraccan.

Computed tomography in the evaluation of sella and parasella lesions: the value of sagittal and coronal reconstructions.

A method is described whereby contiguous, thin-section (3 mm) axial CT scans are obtained followed by computer manipulation of the data to reconstruct good quality images in sagittal and coronal planes. The application of this technique in the evaluation of sella and parasella abnormalities is discussed. In our experience, this has resulted in an increased sensitivity of CT scanning for the detection of abnormalities around the sella. In addition, it has been possible to more accurately define the true extrasella extension of pituitary tumors.