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Biomedical subjects

T Howlett

Publications and source records attributed to T Howlett.

6 recordsLinked to original sources

Evaluation of the effect of radiotherapy for pituitary tumours on cognitive function and quality of life.

AIMS: Pituitary tumours are often treated with radiotherapy, which can cause cognitive impairment when given in high doses. It is assumed that current regimens do not cause damage, but this has not been established. The aim was to determine whether radiotherapy given to people with pituitary tumours was associated with cognitive impairment and reduced quality of life. MATERIAL AND METHODS: We retrospectively compared two outcome groups (patients with pituitary tumours who had undergone radiotherapy and surgery and patients with pituitary tumours who had surgery alone), and carried out standardised tests of cognitive function and quality of life. RESULTS: The data suggested that patients with pituitary tumours treated with surgery, with or without radiotherapy, had cognitive impairment compared with the normal population. Patients receiving radiotherapy performed significantly worse than those receiving only surgery on the Stroop test, a measure of executive function. They also scored significantly lower on the Physical Health composite of the SF36, although this difference was no longer significant when account was taken of baseline differences between the groups. There were no significant differences in other cognitive functions, mood, general well-being or the Mental Health Composite of the SF36. CONCLUSIONS: Patients treated for pituitary disease may have cognitive impairment. A decrease in cognitive function was found regardless of treatment type. The decrease seemed to be greater in the radiotherapy group and was mainly on executive function. This impairment of executive function could affect daily life. Further prospective studies are required to assess the effect of pituitary disease on cognitive function and the safety of radiotherapy.

Adult↗

Cushing's disease cycling over ten years.

Cycles of excessive cortisol secretion have been reported interposed with phases of remission lasting from few days to several months. In this study we report a ten year follow up on a patient who had four episodes of hypercortisolism and Cushing's syndrome associated with hypokalemia and edema and three long lasting spontaneous remissions. This was all caused by corticotroph pituitary adenoma. She demonstrated the longest phase of remission yet recorded in this condition, 4.5 years. The precipitating factors for the recurrence in cyclical Cushing's syndrome are not well defined, but the last recurrence in our patient appeared two months after delivery. We have discussed the continuing uncertainty of the standard dynamic tests in the differential diagnosis of Cushing's syndrome.

Adenoma↗

The interrelationship of beta endorphin, ACTH and cortisol in depressive illness: a controlled study.

Plasma cortisol, ACTH and beta endorphin were measured before and after dexamethasone in 8 severely depressed patients and 8 age- and sex-matched controls to examine the relationship of ACTH and endogenous opioids to cortisol in depression. Despite having significantly higher plasma levels of cortisol than the controls, the depressed patients did not have correspondingly elevated plasma levels of ACTH. Beta-endorphin levels were also similar in the two groups. All three hormones suppressed to some degree after dexamethasone, but cortisol suppressed less in patients than controls. Our findings suggest that in severe depressive illness abnormalities exist in the hypothalamic-pituitary-adrenal axis peripherally as well as centrally.

Adrenocorticotropic Hormone↗