Lumbar puncture: expectation of a headache caused one.

Clinical bottom line (level 1b)

  1. Patients who require a lumbar puncture and were told to expect a headache after the procedure, were more likely to have a headache than those not told to expect one (NNH = 3 at 24 hours) .
Daniels : Lancet 1981; : 1003-1003
Expires January 2004

The study

Single-blinded ?concealed randomised trial ?with intention-to-treat
Setting: medical and surgical wards, Kiribati

28 patients (aged ?, ?% male) schizophrenics (15 patients) and controls who gave consent for lumbar puncture
Control Group: (n = 13, 13 analysed): not told to expect a headache
Experimental Group: (n = 15, 15 analysed): told to expect a headache after the procedure
Lumbar puncture was done under local anaesthetic with a 20F disposable needle and 5 ml of CSF drawn off. All patients were ambulant immediately after the lumbar puncture.
100% followed for 24 hours

The evidence

Outcome Time to outcome CEREERRRR
(95% CI)		ARR
(95% CI)		NNH
(95% CI)
headache after lumbar puncture 24 hours 1
(7.69%)		 7
(46.7%)		 -507%
(-4204% to 14.0%)		 -39.0%
(-68.1% to -9.87%)		 3
(1 to 10)

Comments

  1. Patients were from remote islands and so were unlikely to have cultural expectations about the lumbar puncture procedure.
  2. There was no difference in the number of patients who have headaches between the schizophrenia group and the control group.
  3. There is a difficulty in balancing the results of the study with the need to give information to obtain informed consent to the procedure.

Citation

  1. Daniels AM, : Headache, lumbar puncture, and expectation. Lancet 1981; : 1003-1003
Contributor: Clare Wotton and Musab Hayatli, January 2000
Reviewer: Steve Kisely

Clinical Question.
Patient undergoing lumbar puncture
Intervention or Exposure told to expect a headache
Comparison not told to expect a headache
Outcome occurrence of headache