A 47-year-old woman presented with a 4-week history of headaches. These were present from waking, and the preceding night's sleep had been disturbed by a sudden popping sensation associated with tinnitus. She described pounding frontal headaches on sitting or standing which were associated with nausea and vomiting, but relieved with bed rest. She had a past history of migraine without aura, which were qualitatively different, lacking a postural component associated with sensory sensitivity (photophobia and phonophobia). There was no history of trauma. Detailed neurological examination was normal. There was no evidence of nasal or auditory meatal CSF leakage. Magnetic resonance imaging of brain demonstrated bilateral subdural effusions and there was diffuse enhancement of the pachymeninges following gadolinium (Figures 1 and 2). Magnetic resonance imaging (MRI) of cervical spine showed a small extradural collection of CSF density at the level of C6. The patient was treated with bed rest and intravenous caffeine sodium benzoate (500 mg). Her headaches reduced in severity post caffeine such that she was able to sit and mobilize. Caffeine gave immediate but temporary benefit. Her headaches resolved completely over a further 4 weeks and a repeat MRI showed resolution of her collections and gadolinium enhancement. At 6-month review she remains free of postural headache.