{
  "abstract": "Case We present a case of an 18 year-old non-obese woman with a four-week history of headaches, and blurred vision. Although she had a remote history of acne treated with Roaccutane, the latter was ceased six months prior. Her examination was notable for a normal body mass index (21kg/m 2) with Frisen grade four papilloedema.Investigations CSF opening pressure was 40.5cmH2O with normal constituents. MRI brain and venogram demonstrated features of raised intracranial pressure, without venous sinus thrombosis. Given her normal body habitus, secondary causes of raised ICP were explored and aside from long-standing high platelet count of 612x10^9/L, none identified. Subsequently Jak2v617f mutation was detected.Diagnosis The patient’s clinical course was in keeping with IIH secondary to ET given the rarity of ET in this demographic, absence of typical risk factors for IIH and response to ET specific treatment.Progress Initially, her ICP remained high despite high dose acetazolamide and serial lumbar punctures. Upon treatment with hydroxyurea, aspirin and peginterferon, there was reduction in the platelet count with simultaneous improvement in papilloedema. Acetazolamide was ceased. At one year, she remained asymptomatic on ongoing treatment for ET.Conclusion/Discussion IIH in the context of ET without venous sinus thrombosis has been reported. Previously postulated mechanisms include partially occlusive venous sinus or impaired CSF absorption at arachnoid granulations. Herein, we hypothesize that congestion of the glymphatic system especially in the presence of a myeloproliferative disorder possibly resulted in impaired drainage of the dural venous sinuses triggering the hydrodynamic cascade of IIH.",
  "authors": [
    {
      "affiliations": [
        "Neurology, Royal Perth Hospital, Perth, WA, Australia",
        "Ophthalmology department, Sir Charles Gairdner Hospital, Perth, WA, Australia"
      ],
      "name": "Sarah K Morgan"
    },
    {
      "affiliations": [
        "Haematology, Fiona Stanley Hospital, Perth, WA, Australia"
      ],
      "name": "Matthew Wright"
    },
    {
      "affiliations": [
        "Lions Eye Institute, Perth, WA, Australia"
      ],
      "name": "William H Morgan"
    },
    {
      "affiliations": [
        "Neurology, Royal Perth Hospital, Perth, WA, Australia",
        "Ophthalmology department, Sir Charles Gairdner Hospital, Perth, WA, Australia",
        "Neurology, Joondalup Health Campus, Perth, WA, Australia"
      ],
      "name": "Neha Irani"
    }
  ],
  "title": "3584 Case report. Essential thrombocythemia: a risk factor for IIH",
  "uid": "82ea8b95-14f8-52bc-a514-6bbc06afde4e"
}