Pituitary function in patients with normal pressure hydrocephalus before and after neurosurgical correction

Little is known about pituitary function in patients with normal pressure hydrocephalus (NPH). This study evaluated pituitary function in a large series of patients awaiting neurosurgical correction for NPH. We also sought to ascertain whether surgical correction of hydrocephalus would result in improvement of any noted pituitary dysfunction.

Patients with NPH referred for neurosurgical evaluation between February 2010 and January 2011 were eligible for recruitment. Pituitary endocrine evaluation including serum prolactin, free thyroid hormone, TSH, IGF-I, FSH, LH, estradiol, testosterone, cortisol, and ACTH was preformed at baseline and 1 and 3 months after surgery.

Of the 63 patients referred for possible NPH, 32 met study criteria, 20 could provide informed consent, and laboratory evaluation was obtainable in 16. The mean age of these patients was 62±14 yr, and 75% were men. The overall incidence of NPH-associated pituitary dysfunction was 31% (five of 16 patients) at baseline laboratory assessment. Hypogonadism was the most common type of pituitary dysfunction detected.

NPH is associated with pituitary dysfunction, observed in a significant proportion (31%) of patients. As such, we recommend that pituitary screening should be considered in all NPH patients. In two patients with hypogonadism, surgical correction of NPH was associated with improved testosterone levels. Therefore, not all patients with NPH-associated pituitary dysfunction will require hormone replacement therapy because surgical correction may correct pituitary deficiencies in some instances.