Factor XII deficiency and recurrent sixth nerve palsy

Factor XII deficiency is associated with thrombosis.1–3 Severe deficiency increases an individual’s prothrombotic tendency but with a mild reduction in levels there is less certainty.4 We present a case of recurrent sixth cranial nerve palsy due to severe factor XII deficiency. To our knowledge, this is the first reported case of a recurrent cranial nerve palsy associated with factor XII deficiency. A 58 year old white male presented with an acquired constant incomitant horizontal diplopia. He had had a previous episode of horizontal diplopia of 3 weeks’ duration 6 months previously with spontaneous resolution and a further similar episode 18 years before that but had been otherwise …