P50 Hypertrophic pachymeningitis a revealing manifestation of systemic lupus erythematosus: a case report

Objective Hypertrophic pachymeningitis (HP) is a relatively uncommon disease associated with focal or diffuse thickening of the dura mater secondary to underlying chronic inflammation. Methods We report a case of pachymeningitis revealing systemic lupus erythematosus (SLE) in a Tunisian male patient. Results A 46 year old patient presented with headaches and decreased visual acuity in the left eye. On further examination it was deemed to be secondary to underlying optic neuritis. Magnetic resonance imaging (MRI) revealed patchy pachymeningeal thickening and enhancement with areas of nodular thickening, pronounced around the left cavernous sinus. Our patient had a non specific small-joint arthritis and a papular rash of photosensitive distribution. A lumbar puncture was normal (one lymphocyte and no other cells, normal glucose (2.7mmol/l – serum level 4.2 mmol/l), normal protein (0.32 g/l), cryptococcal latex antigen test (CLAT) and India Ink negative, tuberculosis (TB) polymerase chain reaction negative and negative bacterial and TB culture). Further blood work-up revealed a lymphopaenia and an elevated erythrocyte sedimentation rate (90 mm in one hour) with normal complement 3, complement 4, treponema palladium antibody negative, ANCAs negative, normal IgG and IgG4 levels, normal serum calcium and other electrolytes. positive serology (antinuclear antibody positive (titre 1600 with speckled pattern), doublestranded DNA positive (100 IU/ml)), anti smith antibody was positive and a persistent lymphopaenia. A biopsy, done by neurosurgeons, have eliminated a cancer specillay lymphoma and granulomatosis. In light of the above findings, a diagnosis of SLE pachymeningitis was made using 2019 ACR EULAR Criteria. Our patient was treated with IVI methylprednisolone (750 mg daily for three days) and started on maintenance oral prednisone (60 mg), which was later weaned down, as well as a monthly dose of IVI cyclophosphamide (750 mg every month for six months). Our patient had an excellent, rapid response with complete resolution of headaches and neurology (excluding the optic atrophy) within one month. The patient showed good response to steroids and cyclophosphamide therapy. One should maintain a high index of suspicion to make the diagnosis in patients with SLE presenting with neurological dysfunction. Conclusion HP in patients with SLE is an extremely rare condition. At our knowledge, eight cases, three among them are Tunisians, were reported having HP in SLE. Steroids remain the backbone of treatment for HP in SLE with good success in isolated case reports. Other disease-modifying agents may be added based on response. It is imperative that the diagnosis is made early and treatment initiated to prevent further neurological sequelae.