Obstetrics and Gynaecologymiddle twist
A 29-year-old woman presents ten days after an uncomplicated vaginal delivery under epidural analgesia with four days of worsening headache, which she says is worst when she lies down at night. This morning she vomited twice, and her husband then witnessed two minutes of stiffening and jerking of all four limbs. On examination she is drowsy but rousable, temperature 36.8°C, blood pressure 118/76 mmHg, and there is no neck stiffness; urine dipstick shows no protein. Fundoscopy shows indistinct optic disc margins on both sides. Which one of the following is the most likely diagnosis?