A prospective study of the cognitive and psychiatric effects of pituitary tumours and their treatments.

Neurocognitive complaints are common in patients with pituitary tumours, particularly in memory and concentration. Past studies have shown impairments in executive function and memory, but it is not clear whether these result from direct effects of the tumour (pressure or hormonal secretion), incidental damage from radiotherapy or surgical treatments, and/or mediating psychiatric factors. This study assessed cognitive function and psychiatric state of 86 pituitary tumour patients and 18 healthy controls, pre and post-treatment, to examine the effects of tumour aetiology and treatment type. No significant cognitive impairments were found, except on verbal recognition memory. Patients with Cushing's disease showed lower verbal recognition memory than the other groups pre-treatment, but improved at follow-up. This was (at least partially) accounted for by an improvement in depression scores. Patients who were treated with surgery showed poorer verbal recognition memory than controls across all (pre- and post-treatment) time-points. Overall findings of minimal cognitive impairment in patients with pituitary tumours may reflect improved diagnostic and treatment techniques in recent years. We suggest that the verbal memory impairments identified in the Cushing's group may result from increased cortisol (directly, or mediated by depression). In the surgical groups, verbal memory impairments appeared to pre-date treatment. This may relate to treatment selection factors, rather than harmful effects of surgery itself.