The chest was clear. Investigations are shown. What is the most probable cause of the stroke?

A 29-year-old woman presented with sudden onset of weakness affecting the left side of the body. There was no history of headaches or head injury. She had previously been well with the exception of having mild Raynaud’s disease. The patient had a history of two previous miscarriages four years ago but had had a successful pregnancy six months previously that was complicated by a below-knee deep vein thrombosis. She worked as a clerk in a large business firm prior to her pregnancy. Her appetite was good and her weight was stable. On examination she had a left facial palsy and obvious left-sided weakness. Her heart rate was 80 beats/min and regular. The blood pressure was 150/88 mmHg. The temperature was 36.8°C (98.2°F). Both heart sounds were normal; there was a soft systolic murmur in the pulmonary area. The chest was clear. Investigations are shown.
What is the most probable cause of the stroke?

a. Atrial septal defect complicated by paradoxical embolus.
b. Atrial myxoma.
c. Saggital vein thrombosis complicating recent pregnancy.
d. Lupus anticoagulant syndrome.
e. Cerebral abscess.

Hb 11 g/dl WCC 11 109/l Platelets 152 109/l ESR 11 mm/h CT scan brain Infarct in right middle cerebral artery territory Trans-thoracic echocardiogram Normal.

Answer:

d. Lupus anticoagulant syndrome

The patient has a predisposition to arterial and venous thromboses. She has had miscarriages in the second trimester. She also has Raynaud’s phenomenon and thrombocytopenia, all of which are characteristic of lupus anticoagulant syndrome. The normal echocardiogram in this context rules out an atrial septal defect and hence a paradoxical embolus as a cause of the stroke. Echocardiography may show evidence of verrucous (Libmann–Sack) endocarditis. The manifestations of antiphospholipid syndrome are tabulated.
Manifestations of antiphospholipid syndrome • Predisposition to arterial and venous thromboses • Mid-trimester miscarriages in females • Migraines • Depression • Chorea • Epilepsy • Livedo reticularis • Thrombocytopenia • Haemolysis • Avascular necrosis of head of femur • Pulmonary hypertension • Libmann–Sack endocarditis