Post lumbar puncture headache

• post-dural puncture headache (PDPH) is the commonest complication of LP, occurring in up to 46% of patients
  • pathophysiological mechanism likely involves the development of intracranial hypotension as CSF leaks through the dura with stretching and eventual rupture of subdural veins
  • clinical features
    • larger needles produce higher rates of postlumbar puncture headache
    • most headaches present within a few days after the procedure, some may not occur until 2 weeks afterwards. Headaches usually resolve within 5 days, although headaches lasting up to 1 year have been documented (2)
    • characteristically related to vertical posture and relieved by lying flat
      • occurs more commonly in women and in younger adults but infrequently in children
      • other symptoms of low CSF pressure and stretch of intracranial structures include upper cranial nerve dysfunction such as diplopia, vertigo and hearing loss may occur (1)
        
        
  • aetiology of PDPH
    • two major factors that determine the frequency of PDPH:
      • the size of the needle and the shape of the needle
      • size of needle
        • there is a reduction in the rate of headache when smaller needles are used
          • in vitro studies have also demonstrated a significant reduction in CSF leakage after dural puncture with smaller needles compared with larger needles
          • despite smaller needles having a lower incidence of PDPH, technical difficulties with these needles may make them unsuitable for use in the emergency department (ED)
          • CSF pressure measurements are still possible with normal CSF through small needles, the acquisition of CSF is slower and if the CSF has increased viscosity due to inflammation or blood it may be difficult to obtain diagnostic samples
      • shape of needle
        • two different types of LP needle:
          • a sharp beveled cutting tip (Quincke)
          • a round, pencil-point tip with a side hole (Sprotte or Whitacre)
          • theoretically, the pencil-point tip is less traumatic as it parts rather than cuts the dural fibres
        • most studies show a small reduction in the incidence of PDPH with the atraumatic needle but the impact of the type of needle is much less important than the size of the needle
        • although atraumatic needles are associated with a lower incidence PDPH, they are technically more difficult to use and have a higher rate of failed LP and therefore may not be suitable for use in the ED
      • orientation of the needle bevel parallel (rather than perpendicular) to dural fibres is also important in reducing the likelihood of PDPH. In theory, the parallel orientation parts, rather than cuts, the dural fibres
        • studies have shown reduced PDPH and reduced CSF leak when the bevel is parallel, although microscopic examination indicates that the dural fibres are cut with both parallel and perpendicular bevel puncture

Differential diagnosis:

• subdural haematoma
  • development of a subdural hematoma LP is extremely rare intracranial subdural hematoma has been reported after spinal anesthesia, lumbar myelography, and diagnostic lumbar puncture (2)
    • one must consider this diagnosis in patients with unremitting headaches after lumbar puncture (2)
      • in one case report the patient complained of severe non-positional headache located in the left forehead (3)

Management:

• bed rest for between 4 and 24 h has been recommended traditionally following LP to reduce the incidence of PDPH; however, the effect of bed rest on the incidence of PDPH remains unproven with conflicting results in different studies
• one study suggested that early mobilization may in fact reduce the incidence of PDPH (4)
• maintenance of good hydration with oral or intravenous fluids has also never been shown to be beneficial (5) but is recommended to avoid further lowering of CSF pressure by dehydration
• autologous epidural blood patch is a well-established treatment for PDPH with a greater than 90% success rate in experienced hands, provided it is not performed within 24 h of the original LP (5)
• intravenous caffeine benzoate has also been reported as a successful treatment (6)

Reference:

1. Holdgate A, Cuthbert K. Perils and pitfalls of lumbar puncture in the emergency department. Emerg Med (Fremantle). 2001 Sep;13(3):351-8
2. amdani A et al. Subdural hematoma after diagnostic lumbar puncture.Am J Emerg Med. 2004 Jul;22(4):316-7
3. Cohen S et al. Subdural hematoma following accidental dural puncture. Anesth Analg. 2005 Nov;101(5):1565
4. Vilming ST, Schrader H, Monstad I. Post-lumbar puncture headache: The significance of body posture. Cephalgia 1988; 8: 75–78
5. Olsen KS. Epidural blood patch in the treatment of post-lumbar puncture headache. Pain 1987; 30: 293–301
6. Ford CD, Ford DC, Koenigsberg MD. A simple treatment for post lumbar puncture headache. J. Emerg. Med. 1989; 7: 29–31.