Synopsis
Recognise cerebrospinal-fluid volume loss, distinguish post-dural-puncture headache from spontaneous intracranial hypotension, and arrange safe imaging and definitive leak-directed care without relying on opening pressure alone.
- Low-pressure headache usually reflects loss of cerebrospinal-fluid volume through a dural leak or a cerebrospinal-fluid venous fistula; measured lumbar opening pressure is often normal.
- The classic symptom is headache that develops or worsens after becoming upright and improves after lying flat, but the delay and recovery time vary and chronic cases can lose obvious orthostatic behaviour.
- Ask about recent lumbar puncture, spinal or epidural anaesthesia, spinal surgery, vigorous stretching or minor trauma, and features suggesting an underlying connective-tissue disorder.
- Neck pain, nausea, tinnitus, muffled hearing, photophobia, diplopia and a sense of imbalance are common accompaniments; cranial-nerve palsy or cognitive change indicates more severe traction.
- Brain MRI with gadolinium may show diffuse smooth pachymeningeal enhancement, venous engorgement, pituitary enlargement, subdural collections and downward brain sag, yet a normal scan does not exclude a leak.
- Do not perform lumbar puncture simply to demonstrate low pressure when the history and imaging suggest spontaneous intracranial hypotension, because another dural puncture may worsen the syndrome.
- Post-dural-puncture headache is a clinical diagnosis after a known procedure; inspect for infection or neurological complication and involve the relevant anaesthetic service early when symptoms are disabling.
- Short initial measures include recumbency for comfort, oral fluids to avoid dehydration and simple analgesia, but prolonged bed rest does not close a persistent spontaneous leak.
- An epidural blood patch is both a therapeutic seal and a specialist procedure; spontaneous disease may need repeated non-targeted patching, leak localisation and targeted patch, embolisation or surgery.
- Current pathways differ between post-procedural and spontaneous disease, so discuss timing, imaging technique, anticoagulation and procedural preparation with anaesthesia or a specialist neuroradiology service.
Key red flags
New focal deficit, seizure, somnolence or a changing non-postural headache may reflect subdural haematoma, venous thrombosis or marked brain sag and needs urgent neuroimaging.
Investigation priorities
Define the postural timing, precipitant and possible complication.
Management branches
A new headache has a convincing upright-worse pattern or follows dural puncture.
- Record onset, postural latency, procedure and medicines, then assess observations, mental state, focal neurology, meningism and features of raised intracranial pressure or infection.
- Send thunderclap headache, seizure, reduced consciousness, new deficit, fever or severe progressive symptoms through urgent same-day imaging and specialty assessment.
- For a neurologically stable patient, give safety-net advice, avoid dehydration, provide suitable simple analgesia and arrange review rather than promising spontaneous resolution.
Key medicines
ParacetamolUse the usual adult oral dose according to the BNF, reducing or avoiding it where low body weight, liver disease or excess alcohol changes the safe maximum.Check combination products and total daily exposure; analgesia must not delay assessment of neurological deterioration or replace definitive treatment of a persistent leak.
CaffeineOral caffeine is sometimes used for brief symptomatic relief at a locally agreed dose; intravenous regimens require anaesthetic or specialist prescribing and monitoring.Benefit is short lived and evidence is limited; consider pregnancy or breastfeeding, arrhythmia, anxiety, insomnia and toxicity from repeated or concentrated preparations.