Use of ¹⁸F-Fluorodeoxyglucose–Positron Emission Tomography/Computed Tomography to successfully diagnose central nervous system vasculitis in systemic lupus erythematosus and antiphospholipid syndrome: a case report

Abstract

A 53-year-old woman was admitted to our hospital for headache secondary to an acute subdural haematoma in the right cerebellar tentorium. She had been diagnosed with systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS) two years before presentation and was initiated on prednisolone (PSL) 40 mg/day as induction therapy, which was subsequently tapered to 5 mg/day. Her thrombocytopenia and renal impairment were managed by warfarin with a target prothrombin time-international normalised ratio of 2–3. Her history also included 5 instances of triggerless acute subdural haematoma in the right cerebellar tentorium in the preceding 8 months. Warfarin therapy was suspected as the cause of her bleeding; however, dose adjustment was ineffective. During the current admission, neither magnetic resonance imaging nor cerebral angiography could reveal the cause of the bleeding. However, spinal fluid IL-6 was 25.7 pg/mL, and ¹⁸F-Fluorodeoxyglucose–Positron Emission Tomography/Computed Tomography showed fluorodeoxyglucose accumulation in the right medial occipital lobe cortex in the proximity of the haemorrhage site. Based on these two findings, we suspected vasculitis as the cause of recurrent bleeding. After ruling out malignancy, re-induction therapy with intravenous cyclophosphamide 500 mg/m²/month and PSL 30 mg/day was initiated. PSL was tapered to 2 mg/day and no signs of relapse have developed at 2 years after discharge. Her clinical course also supported vasculitis as the cause of recurrent central nervous system (CNS) bleeding and we discuss the usefulness of ¹⁸F-Fluorodeoxyglucose–Positron Emission Tomography in the diagnosis and treatment of CNS vasculitis in SLE and/or APS.

Keywords:

• Recurrent acute subdural haematoma
• central nervous system vasculitis
• fluorodeoxyglucose–positron emission tomography
• systemic lupus erythematosus
• antiphospholipid syndrome

Patient consent

Written informed consent to publish this case report was obtained from the patient.

Ethical approval

Not applicable.

Conflict of interest

None.

Additional information

Funding

This work was supported in part by Japan Society for the Promotion of Science under Grant number JSPS KAKENHI 19K17887, in order to measure spinal fluid IL-6 concentration.