Late recovery of pituitary function following traumatic brain injury
J Ryan, A Agha, M Sherlock & CJ Thompson
Anterior pituitary dysfunction is a well-recognized complication of traumatic brain injury (TBI) but recovery is an exceptional event, with only three previously published case reports.
We report a case of a 25 year old man who suffered severe TBI in a road traffic accident in 1997. His neurological recovery was slow and incomplete with significant cognitive deficit and recurrent seizures. He developed polyphagia and his weight increased by 20 Kilograms in the 12 months following his TBI. He also complained of excessive tiredness and was referred to our service for assessment 16 months following the accident. The glucagon stimulation test (GST) revealed severe growth hormone (GH) and cortisol deficiencies with GH peak of 3 micrograms per litre (normal response, greater than 5 ) and a cortisol peak of 307 nanomole per litre ( normal response, greater than 500 ) . His IGF-1 level was 0.9 standard deviation below mean age-matched value. The gonadotrophin-releasing hormone and the thyrotrophin releasing hormone tests showed normal responses and he had normal basal testosterone and free thyroxine levels. He was treated with hydrocortisone and GH. In 2002 (5 years post TBI) his IGF-1 level started to rise which prompted re-evaluation. His repeat GST showed a normal GH peak response of 7.96 micrograms per litre and a normal cortisol peak response of 514 nanomole per litre . His hormonal treatment was stopped and he remained well.
This is the first case report to show recovery of adult post-traumatic GH deficiency. Clinicians should be aware of the possibility of recovery of post-traumatic hypopituitarism even years after the event, and of the need for periodic pituitary assessments in those patients.