Endocrine Abstracts

Introduction: Cranial Diabetes Insipidus (DI) presenting in children beyond infancy is most commonly associated with sellar/suprasellar tumours and severe traumatic brain injury or haemorrhage. Less frequent causes may be genetic or idiopathic. Exceptional cases may be associated with minor head injury. We present a case of post-concussive head injury with DI, and anterior pituitary hormone deficits.

Case: 15 year old malesustained a concussive head injury (foot to head) playing rugby. Probable brief loss of conscious, and noted to have transient divergent squints before promptly transferred to local hospital emergency department. Neurological examination there reportedly normal; CT head no evidence haemorrhage/contusion injury.Patient allowed home. Overnight he developed nocturia, excessive thirst and progressive polyuria. Over next 3 months he would drink ˜ 2.5 l water overnight, and 4–5 l daytime. He developed progressive daytime fatigue, stopped all sports and gym, would sleep in the afternoon after school, come home early or miss school through lack of energy. He experienced diffuse headaches, often felt nauseated on rising in the morning, and dizziness on standing. He shaved less frequently, lost appetite and weight. Referred to local Paediatrician at 3 months post-injury; investigations consistent with DI (Na 146 mmol/l x2, SeOsmo297/UOsmo 101), with normal Calcium and Glucose. Cortisol(1000 h) 61 nmol/l (Normal>150). While undergoing these tests he was admitted as an emergency with tonsillitis, tachycardic and prolonged capillary refill,looking exceptionally unwell. Overnight IV fluids were required to stabilise. MRI brain/pituitary revealed absent posterior pituitary bright signal; no other significant abnormality. On referral to our Endocrine service: Height 181.2 cm Weight 70 kg Additional investigations: Na 145 mmol/l, fT4 7 pmol/l/TSH 0.1 mIU/l, Cortisol<30 nmol/l (1300 h),Testosterone 0.3 nmol/l, Prolactin 1900 mIU/l(NR<410), IGF-1 16 nmol/l(6–68); BHCG/AFP undetectable. Pituitary MDT conclusion: Panhypopituitarism with DI secondary to stalk transection; raised Prolactin resulting from loss of dopaminergic inhibitory tone.Highly probable secondary to concussive head injury in view of coincident timing of DI symptom onset and lackof other pathology. Management:Hydrocortisone, DDAVP and Levothyroxine replacement with symptomatic relief; awaiting addition of testosterone and growth hormone.

Conclusion: Sports injury related concussion may rarely be associated with potential life threatening sequelae. Appropriate post-injury surveillance may be required.