Neurocognitive changes in pituitary adenoma patients after gamma knife radiosurgery: a preliminary study

We evaluated the effects of gamma-knife radiosurgery (GKRS) on the cognitive functioning of patients with a pituitary adenoma.

A total of 14 patients with pituitary adenomas were enrolled in this neurocognitive study. Nine patients had Cushing disease, and five had nonfunctioning pituitary adenomas. Five patients underwent GKRS for their pituitary adenomas. Other treatment modalities included transsphenoidal resection and conservative management. Comparisons were made between treatment groups and between those with Cushing disease versus those with a nonfunctioning adenoma by the use of psychometric tests of general intellectual functioning, memory, and current mood state. These tests were the Symptom Checklist 90 Revised, Wechsler Test of Adult Reading, Wechsler Memory Scale-third edition, selected subtests of the Wechsler Adult Intelligence Scale-third edition, and the Delis-Kaplan Executive Function System.

When analyzed collectively, the patient group showed deficits in immediate memory (t=-2.70, P=0.02) and high levels of psychological distress (46% of patients) in the presence of intact general intellectual functioning. No neurocognitive differences were found between the GKRS treated group versus participants not treated with GKRS (t≤0.70, P≥0.39). Similarly, no appreciable neurocognitive differences were demonstrated between those with nonfunctioning adenomas as compared with those with Cushing disease (t≤1.56, P≥0.15).

We found no evidence that GKRS impairs the neurocognitive functioning of patients with pituitary disease above any impairment caused by the disease itself. Further studies will require approximately 20 patients in each comparison group to confirm this result.