Endocrine Abstracts

We report a case of severe postradiation encephalitis presenting 6 months following pituitary radiotherapy for pituitary adenoma. Our patient (78 years old female) was diagnosed with non-functioning pituitary ademona compromising the optic chiasm in 1999 at the age of 66 years. She underwent transphenoideal decompression in 2000. Over the next 8 years there was slow re-growth of the pituitary adenoma and by 2008 it was causing optic chiasm compression. At this stage, the patient opted for pituitary radiotherapy. Four months post radiotherapy she experienced progressive problems with memory, mobility and falls. Her 9 am cortisol level measured 259 nmol/l and although in normal range team opted to start hydrocortisone replacement therapy given her symptoms. Deterioration in her condition culminated in admission 5 months post-radiotherapy. MRI performed during her admission showed a reduction in the size of the pituitary adenoma and delineated marked diffuse white matter changes in the medial temporal lobe and basal ganglia. High doses dexamethasone was initiated with no clinical improvement. As the patient did not improve, she required nursing care on discharge and sadly died shortly thereafter. This patient displayed typical symptoms of late delayed post-radiation encephalopathy which is a rare complication of irradiation therapy. MRI revealed extensive white matter changes in the temporal lobe and basal ganglia. Unexplained changes in cognition and mobility should raise suspicion of this rare complication in pituitary patients who have undergone pituitary irradiation and urgent brain MRI should be performed. Outcome is often very guarded as brain changes in late delayed encephalopathy are due to necrosis and therefore irreversible. Late delayed post-radiation encephalopathy usually occurs 4 months post radiotherapy. It is well recognised following whole brain irradiation but is very rarely associated with focused beam irradiation to pituitary fossa. Clinically it can manifest as a progressive dementia sometimes accompanied by gait apraxia.

Declaration of interest: There is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported.

Funding: No specific grant from any funding agency in the public, commercial or not-for-profit sector.