What is the most likely diagnosis for a woman experiencing severe headache and seizures shortly after a normal vaginal delivery?

The most likely diagnosis for a woman experiencing severe headache and seizures shortly after a normal vaginal delivery is subarachnoid hemorrhage. This condition is characterized by the sudden onset of a severe headache, often described as a "thunderclap" headache, which can occur in the postpartum period. Women are at an increased risk of developing this condition following a delivery, particularly if there are predisposing factors such as hypertension or a predisposition to vascular issues.

The presence of seizures alongside the severe headache further supports this diagnosis. Seizures can occur due to the irritation of the brain's surface from the bleeding, leading to cortical irritation and the potential for convulsions.

In the context of other potential diagnoses, bacterial meningitis would typically present with more classic signs such as fever, neck stiffness, and altered consciousness. Pre-eclamptic toxaemia, while it can cause headaches and seizures, usually presents with other symptoms like hypertension and proteinuria during pregnancy or shortly after delivery rather than as immediate post-delivery sequelae. Venous sinus thrombosis can present with headache and neurological symptoms, but the acute onset of severe headache and seizures aligns more closely with the presentation of subarachnoid hemorrhage.

Thus, given the timing and