Cognitive effects of pituitary tumours and their treatments: twocase studies and an investigation of 90 patients

摘要

OBJECTIVES—Two case studies are reported of patients with pituitary adenomas who had been treated with trans-sphenoidal surgery, one with and one without adjunctive radiotherapy, in whom memory impairment was found. Further to this, neuropsychological investigations of 90 patients were carried out (1) to establish the prevalence of such deficits, and (2) to try to determine their cause.
METHODS—Two case studies are described. For the expanded study, patients were recruited from the data base of the endocrinology department of St Thomas's Hospital, London, if they had previously been treated for a pituitary adenoma in the past 30 years. Ninety patients were contacted and assessed with a wide range of neuropsychological tests. They were divided into five treatment groups: those who had received transfrontal surgery with radiotherapy, trans-sphenoidal surgery with or without radiotherapy, radiotherapy only, and a bromocriptine therapy group, as well as a group of 19 healthy control subjects matched for age and sex.
RESULTS—In the two patients presented, both showed severe memory impairments compared with their intact intellectual ability. The more severely affected patient had received adjunctiveradiotherapy, and superimposition of the 90% isodose fields on apostoperative MRI examination suggested involvement of the diencephalicstructures. In the group study, significant deficits in anterogradememory were also obtained on two measures (WMS-R, RMT) for all patient groups when compared with the healthy controls, although these impairments varied in degree and were less in the bromocriptine group.However, the individual surgical and radiotherapy treatment groups didnot differ significantly from one another. By contrast, generalintellectual function (IQ) remained intact for all groups, as didperformance on supplementary cognitive tests, including measures offrontal lobe or "executive" function, language comprehension, andspeed of mental processing. Psychiatric morbidity and tumour aetiologydid not seem to relate to the presence of memory deficits.
CONCLUSIONS—Anterograde memory deficits were seenin the two case studies and in all our treatment groups when comparedwith the healthy controls, and these occurred in the context ofpreserved intellectual function. The present findings suggest thatthese memory deficits result from treatment rather than from theunderlying tumour, but there was no difference between the effects ofsurgery and radiotherapy. It is suggested that they result from damageto diencephalic structures implicated in memory.