Post Lumbar Puncture Headache
Background
- Normal volume of CSF ( adult) is 150 mL, intracranial pressure 5 - 15 mmHg
- >400ml produced secreted and reabsorbed by the choroid plexus each day
- Post LP headache is possibly due to intracranial hypotension post a CSF leak
- Headache alleviated by lying down or increasing CSF volume (saline)
- Headache prominent in those with low substance P levels (lost during CSF leak)
Features
- Post LP headache incidence varies (2% with small bore needles, 40% post puncture with large bore)
- Usually occurs immediately, may be delayed for weeks
NB - minimal or absent supine, triggered by sitting/standing (MUST be present to make Dx)
- Usually frontal, burning, radiates to neck / shoulders
- Most resolve within 1 week
Risk factors
- 20-40 yo (x3 risk in older patients)
- M: F = 2:1
- Previous post LP headache or Hx chronic headaches
- Low BMI
- Larger needles, especially cutting type
- Stylet not replaced during needle removal
Treatment
- Please use smaller bore, traumatic (blunt) needles and replace stylet [BestBets] prior to removal
- Bed rest has no influence in risk of post LP headache. But . symptoms resolve lying down.
- Hydration post LP - no evidence either way, though pre-LP headache reported in dehydrated patients
- Sumatriptan - no convincing evidence for or against
- Caffeine - evidence inconclusive - worth a try
- Epidural blood patch
- (20ml patient's own blood) - indicated for more severe / debilitating symptoms.
- Best used early post symptom onset.
