Antiphospholipid syndrome (APS) is an autoimmune disease where the presence of antiphospholipid antibodies leads to the development of arterial and/or venous thromboses and obstetric complications. Amongst the myriad of presentations, APS can manifest in the form of cerebrovascular stroke. However, overlapping clinico-radiological findings and a lack of classic APS features can sometimes pose a diagnostic dilemma.

A 31-year-old female presented with occipital headache and difficulty in walking. Neurological examination revealed ataxia, dysdiadochokinesia and intention tremor. Preliminary laboratory findings revealed raised ESR along with normal CRP, aPTT and PT levels. MRI brain showed an acute infarct in the right cerebellar hemisphere and right postero-lateral upper medulla. MRA Head & Neck revealed an occluded intracranial right vertebral artery with an extracranial segment showing multifocal occlusions with aorta and its major branches unaffected. These features and the absence of fever, rash, joint pain or obstetric complications led to the consideration of stroke due to Takayasu Arteritis. Treatment was initiated with corticosteroids, anticoagulants and antiplatelet drugs. However, on review of other laboratory tests, notably the auto-immune profile showed the presence of anti-ß2 glycoprotein-I antibodies with negligible titres of lupus anticoagulant and anti-cardiolipin antibody. This pointed towards a diagnosis of Primary Antiphospholipid Syndrome, which was confirmed after 12 weeks when repeat laboratory tests indicated the presence of IgM anti-ß2 glycoprotein-I antibodies. The patient is now on lifelong Warfarin therapy and is leading a symptom-free life. 

This case illustrates the potential of anti-β2 glycoprotein-1 antibody to cause a cerebellar stroke in the absence of other commonly involved antibodies. It also highlights the value of a holistic stroke workup. Recognition of APS is imperative for the timely administration of treatment and to prevent a recurrence.