ESPE Abstracts

Introduction: Idiopathic intracranial hypertension (IIH) is a rare neurological condition characterized by raised intracranial pressure (ICP) in the absence of hydrocephalus, brain parenchymal lesion, vascular malformation, or central nervous system (CNS) infection. Hyperthyroidism is a rare but known cause of raised ICP in children and adults, with only a few case reports in the paediatric population. We describe a 7-year-old boy with IIH associated with hyperthyroidism.

Case Report: A 7-year-old boy presented with 6 weeks history of headaches, which had increased in severity over the previous 2 weeks. His headaches were not associated with nausea, vomiting or visual disturbance. On physical examination there was no exophthalmos or goitre. He was slightly tachycardic for his age with normal blood pressure. His weight & height were between 50th – 75th centile, with head circumference at 12th centile. Ophthalmologic examination showed bilateral normal optic discs. Investigations revealed elevated free thyroxine 39.2 (normal 11.0 – 21.2 pmol/L), free T3 21.4 (normal 3.1 – 6.8 pmol/L) and suppressed Thyroid stimulating hormone (TSH) <0.01 (0.27 – 4.20 mIU/L). The anti-TPO antibodies 84 (normal <34U/ml) & TSH Receptor antibodies 2.3 (normal <1.75U/L) were elevated. His computed tomography (CT) scan of head showed craniosynostosis, copper beaten appearance with no intracranial mass or bleed. Blood investigations for etiology of IIH including serum parathyroid hormone, vitamin D and iron studies were normal. There was no history of prolonged use of antibiotics or vitamin A supplements. He was reported to wear minimal clothes during winter months and had been hyperactive since the age of 4 years. Magnetic resonance imaging (MRI) of brain confirmed CT head findings of raised ICP. Cerebrospinal fluid (CSF) opening pressure in recumbent and relaxed position (under general anaesthesia with PCO2 of 4.5kPa) was elevated to 38mmHg (normal < 15mmHg). Subsequently he was commenced on anti-thyroid therapy (Carbimazole) as well as acetazolamide. As his hyperthyroidism improved over next eight weeks, the headaches subsided.

Conclusion: Hyperthyroidism is a rare cause of IIH. It should be considered in children presenting with headache and features of hyperthyroidism. In some case reports increased cerebral blood flow due to hyperthyroidism has been postulated to cause increased ICP. In view of CT scan findings of craniosynostosis and copper beaten appearance which signify long standing raised ICP, another hypothesis is hyperthyroidism leading to early fusion of sutures and subsequent brain growth causing development of raised ICP. Successful treatment of hyperthyroidism is required to reduce the complications associated with IIH.