Short communication
Intracutaneous sterile water injections do not relieve pain in cervicogenic headache Sand T, Bovim G, Helde G. Intracutaneous sterile water injections do not relieve pain in cervicogenic headache. Acta Neurol Scand 1992: 86: 526-528. 0 Munksgaard 1992.
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Intracutaneous sterile water injections have been reported to relieve acute labor pain and cervical pain in whip-lash patients. A double blind cross-over trial has presently been conducted in 10 women with cervicogenic headache in order to investigate whether sterile water injections were effective in this disorder. No benefit was observed for either treatment (isotonic saline or sterile water), neither on pain during the first 14 days nor on neck mobility. We conclude that intracutaneous sterile water injections is not effective in cervicogenic headache.
Intracutaneous sterile water injections do seemingly have some effect on low back labor pain (1). It has also recently been claimed that such injections may be effective in patients suffering from neck pain following a neck distorsion of the whiplash type (2). The latter report has gained attention in the media, and patients with various pain syndromes have wanted to try this treatment, although its effect remains to be proven. Cervicogenic headache has recently been defined (3). It is a unilateral headache supposedly stemming from the neck. The patients experience an episodic headache (afterwards regularly a more continuous pain with fluctuating intensity) with signs of neck involvement (e.g. ipsilateral neck and shoulder pain and reduced range of motion in the neck). A whiplash trauma has frequently occurred in the history of patients with cervicogenic headache (4). The pathogenesis of cervicogenic headache is still unknown and probably multifactorial. The aim of the present study was to investigate the effect of sterile water injections in a group of cervicogenic headache patients, using a double-blind, cross-over design. Methods
Ten women with unilateral headache fulfilling the criteria of cervicogenic headache (3) were entered into the study. Six of the patients had experienced trauma of possible whiplash type preceeding the onset of headache. The purpose of the study was 526
T. Sand, G. Bovim, G. Helde Department of Neurology, University Hospital of Trondheim, Norway
Key words: headache: whiplash; neck pain; water; saline Trond Sand, Nevrologisk avdeling, Regionsykehuset, N 7006 Trondheim, Norway
1
Accepted for publication May 12, 1 9 9 2
explained in writing, and they signed an informed consent. The design was randomised double-blind crossover. Pain levels were self-rated daily (morning, afternoon, and evening) on a VAS-form during the run-in phase (13 days), during the 13 days following the first injection (0.9% NaC1, n = 5, or sterile water (SW), n = 5 ) and during the 13 days after the second injection (SW or NaCl). During the day of injection, patients rated the pain level after injection on a VAS form every 30th min for 12 h. The following variables were analyzed: Pain level (VAS) before and immediately after injection, the minimum pain level during the first 12 h and the pain level 12 h after injection. The range of motion in the neck was measured with an electronic digital inclinometer (Cybex ED1 320) in three planes (mean of three replications) before and a few minutes after the injection. Rotation was measured with the patients supine while flexion/extension and lateral flexion was measured in a sitting position. The tender points were identified by palpation (mean number of points per patient = 16, range 5-27), and 0.3 ml of fluid was injected intracutaneously over each tender point. Results were assessed with the Student’s t-test, and a p value of 0.05 was regarded as significant. Results
No significant benefit was found for either treatment. The mean maximal pain reductions during the first
Water injection in cervicogenic headache 12 hours were 7.5% (sd 16%) following NaCl injection and 11% (sd 27%) following sterile water injection (Fig. 1). At the end of the first 12 h, slight but insignificant increase of mean pain levels were observed for both treatments (NaCl: 6.5 % ; SW: 3 % , Fig. 1). Mean pain levels during the three 13-day periods (run-in phase, following NaCl, and following SW injections) were of equal magnitude (Table 1). , Both improvement and deterioration of neck mobility was found in the individual patient after both NaCl and SW injections (Fig. 2). Mobility differences were not significantly different from zero in any of the groups in Fig. 2. Significant mobility differences between NaCl and SW groups after injection were not found.
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Discussion
Anesthetic blockade of the greater occipital nerve is frequently effective in cervicogenic headache in contrast to what is the case in migraine and tension I
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Fig. 2. Distribution of neck mobility change in three planes (mobility 5 min after injection minus mobility before injection of isotonic saline (NaCl) or sterile water (SW). Increased mobility is plotted upwards (positive values). Flexion-extension (FE), lateral flexion (Lat), and rotation (Rot) are shown. Group medians are shown as filled circles.
0 0 0
0
0
0
0 0
0
0 0
0 0
0
0
Fig. 1. Distribution of pain change (VAS after minus VAS before) during the first 12 hours after injection of isotonic saline (NaCI) or sterile water (W). Reduced pain is plotted downwards (negative values). The immediate effect (IMM), the maximal effect (Max), and the effect after 12 hours (End) are shown. Group medians are shown as filled circles.
Table 1. VAS values in percent during the three 13-day self-rating periods (run-in, following NaCl injections, and following sterile water injections).
Mean SD Max Min
Run-in
NaCl
Sterile Water
44.2 25.8 88.5 12.3
41.0 25.7 87.7 5.4
38.6 26.8 82.3 a. 1
headache, while injections of saline cause no relief (5). The present pathogenetic model for cervicogenic headache is based on the intimate anatomical relationship between fibers in the spinal trigeminal nucleus and the upper cervical roots (6). It has also been proposed that sterile water injections modulate pain gating mechanisms in the dorsal horn (1). Hence it seemed reasonable to investigate the effect of such injections in cervicogenic headache. In this double-blind cross-over study, however, neither intracutaneous sterile water injections nor NaCl injections had any effect on pain intensity. The nature of pain in cervicogenic headache is of course different from the acute pain during labor and during urolithiasis (7). Neck pain following a whiplash trauma may possibly share some common causal mechanism with cervicogenic headache. Increased vibration and thermal sensitivity tresholds in the trigeminal area have been found in whiplash patients (8). The open uncontrolled design of the study which reported beneficial effect in 8 of 10 whiplash patients (2) does not allow any definite conclusions as to the effect of injections in this syndrome. The complete lack of effect, even of a slight positive trend, in the present study should not create any basis for undue optimism about the possible effect of sterile water injections in other chronic pain syndromes. The possibility remains however, that the pain-mechanism in patients (at least in a subgroup) with a whiplash syndrome may be different from the mechanism in 521
Sand et al. cervicogenic headache. The whiplash syndrome may indeed be a more heterogeneous disorder than cervicogenic headache (9). We conclude that intracutaneous, sterile water injections are in-effective in cervicogenic headache. It’s use can not be recommended in this patient grOUPReferences 1. TROLLE B, MOLLER M, KRONBORG H, THOMSEN S. The
effect of sterile water blocks on low back labor pain. Am J Obstet Gyn 1991: 164: 1277-1281. 2. BYRNC , BORENSTEIN P, LINDERLE. Treatment of neck and shoulder pain in whip-lash syndrome patients with intracutaneous sterile water injections. Acta Anaesthesiol Scand 1991: 35: 52-53. 3. SJAASTAD 0, FREDRIKSEN T, PFAFFENRATH V. Cervico-
528
genic headache: Diagnostic criteria. Headache 1990: 30: 725726. 4. FREDERIKSEN T, HOVDALH, SJAASTAD 0. Cervicogenic headache: Clinical manifestations. Cephalalgia 1987: 7: 147160. 5. BOVIMG, SANDT. Cervicogenic headache, migraine with-
out aura, and tension headache: Diagnostic blockades of greater occipital and supraorbital nerves. Pain, (in press). 6. KERRFWL,OLAFSON RA. Trigeminal and cervical volleys. Convergence on single units in the spinal grays at C-1 and C-2. Arch Neurol 1961: 5: 171-178. J, WORNING AM, GERTZJ. Urolithiasissmerter 7. BENGTSON behandlet med intrakutane sterilvandspapler. Ugeskr Laeger 1981: 143: 3463-3465. 8. KNIBESTOL M, HILDINGSON C , TOOLANEN G. Trigeminal
sensory impairment after soft-tissue injury of the cervical spine. Acta Neurol Scand 1990: 82: 271-276. 9. Pearce JMS Whiplash injury: a reappraisal. J Neurol Neurosurg Psychiat 1989: 52: 1329-1331.
Intracutaneous sterile water injections do not relieve pain in cervicogenic headache Sand T, Bovim G, Helde G. Intracutaneous sterile water injections do not relieve pain in cervicogenic headache. Acta Neurol Scand 1992: 86: 526-528. 0 Munksgaard 1992.
I
Intracutaneous sterile water injections have been reported to relieve acute labor pain and cervical pain in whip-lash patients. A double blind cross-over trial has presently been conducted in 10 women with cervicogenic headache in order to investigate whether sterile water injections were effective in this disorder. No benefit was observed for either treatment (isotonic saline or sterile water), neither on pain during the first 14 days nor on neck mobility. We conclude that intracutaneous sterile water injections is not effective in cervicogenic headache.
Intracutaneous sterile water injections do seemingly have some effect on low back labor pain (1). It has also recently been claimed that such injections may be effective in patients suffering from neck pain following a neck distorsion of the whiplash type (2). The latter report has gained attention in the media, and patients with various pain syndromes have wanted to try this treatment, although its effect remains to be proven. Cervicogenic headache has recently been defined (3). It is a unilateral headache supposedly stemming from the neck. The patients experience an episodic headache (afterwards regularly a more continuous pain with fluctuating intensity) with signs of neck involvement (e.g. ipsilateral neck and shoulder pain and reduced range of motion in the neck). A whiplash trauma has frequently occurred in the history of patients with cervicogenic headache (4). The pathogenesis of cervicogenic headache is still unknown and probably multifactorial. The aim of the present study was to investigate the effect of sterile water injections in a group of cervicogenic headache patients, using a double-blind, cross-over design. Methods
Ten women with unilateral headache fulfilling the criteria of cervicogenic headache (3) were entered into the study. Six of the patients had experienced trauma of possible whiplash type preceeding the onset of headache. The purpose of the study was 526
T. Sand, G. Bovim, G. Helde Department of Neurology, University Hospital of Trondheim, Norway
Key words: headache: whiplash; neck pain; water; saline Trond Sand, Nevrologisk avdeling, Regionsykehuset, N 7006 Trondheim, Norway
1
Accepted for publication May 12, 1 9 9 2
explained in writing, and they signed an informed consent. The design was randomised double-blind crossover. Pain levels were self-rated daily (morning, afternoon, and evening) on a VAS-form during the run-in phase (13 days), during the 13 days following the first injection (0.9% NaC1, n = 5, or sterile water (SW), n = 5 ) and during the 13 days after the second injection (SW or NaCl). During the day of injection, patients rated the pain level after injection on a VAS form every 30th min for 12 h. The following variables were analyzed: Pain level (VAS) before and immediately after injection, the minimum pain level during the first 12 h and the pain level 12 h after injection. The range of motion in the neck was measured with an electronic digital inclinometer (Cybex ED1 320) in three planes (mean of three replications) before and a few minutes after the injection. Rotation was measured with the patients supine while flexion/extension and lateral flexion was measured in a sitting position. The tender points were identified by palpation (mean number of points per patient = 16, range 5-27), and 0.3 ml of fluid was injected intracutaneously over each tender point. Results were assessed with the Student’s t-test, and a p value of 0.05 was regarded as significant. Results
No significant benefit was found for either treatment. The mean maximal pain reductions during the first
Water injection in cervicogenic headache 12 hours were 7.5% (sd 16%) following NaCl injection and 11% (sd 27%) following sterile water injection (Fig. 1). At the end of the first 12 h, slight but insignificant increase of mean pain levels were observed for both treatments (NaCl: 6.5 % ; SW: 3 % , Fig. 1). Mean pain levels during the three 13-day periods (run-in phase, following NaCl, and following SW injections) were of equal magnitude (Table 1). , Both improvement and deterioration of neck mobility was found in the individual patient after both NaCl and SW injections (Fig. 2). Mobility differences were not significantly different from zero in any of the groups in Fig. 2. Significant mobility differences between NaCl and SW groups after injection were not found.
60
I
I
I
I
I
I
0
40
t
0
-ea
8
0
20
0
E
W
0
0
0
0
0
$
0
8 -2 0
8
-40
Discussion
Anesthetic blockade of the greater occipital nerve is frequently effective in cervicogenic headache in contrast to what is the case in migraine and tension I
I
I
I
I
I
Fig. 2. Distribution of neck mobility change in three planes (mobility 5 min after injection minus mobility before injection of isotonic saline (NaCl) or sterile water (SW). Increased mobility is plotted upwards (positive values). Flexion-extension (FE), lateral flexion (Lat), and rotation (Rot) are shown. Group medians are shown as filled circles.
0 0 0
0
0
0
0 0
0
0 0
0 0
0
0
Fig. 1. Distribution of pain change (VAS after minus VAS before) during the first 12 hours after injection of isotonic saline (NaCI) or sterile water (W). Reduced pain is plotted downwards (negative values). The immediate effect (IMM), the maximal effect (Max), and the effect after 12 hours (End) are shown. Group medians are shown as filled circles.
Table 1. VAS values in percent during the three 13-day self-rating periods (run-in, following NaCl injections, and following sterile water injections).
Mean SD Max Min
Run-in
NaCl
Sterile Water
44.2 25.8 88.5 12.3
41.0 25.7 87.7 5.4
38.6 26.8 82.3 a. 1
headache, while injections of saline cause no relief (5). The present pathogenetic model for cervicogenic headache is based on the intimate anatomical relationship between fibers in the spinal trigeminal nucleus and the upper cervical roots (6). It has also been proposed that sterile water injections modulate pain gating mechanisms in the dorsal horn (1). Hence it seemed reasonable to investigate the effect of such injections in cervicogenic headache. In this double-blind cross-over study, however, neither intracutaneous sterile water injections nor NaCl injections had any effect on pain intensity. The nature of pain in cervicogenic headache is of course different from the acute pain during labor and during urolithiasis (7). Neck pain following a whiplash trauma may possibly share some common causal mechanism with cervicogenic headache. Increased vibration and thermal sensitivity tresholds in the trigeminal area have been found in whiplash patients (8). The open uncontrolled design of the study which reported beneficial effect in 8 of 10 whiplash patients (2) does not allow any definite conclusions as to the effect of injections in this syndrome. The complete lack of effect, even of a slight positive trend, in the present study should not create any basis for undue optimism about the possible effect of sterile water injections in other chronic pain syndromes. The possibility remains however, that the pain-mechanism in patients (at least in a subgroup) with a whiplash syndrome may be different from the mechanism in 521
Sand et al. cervicogenic headache. The whiplash syndrome may indeed be a more heterogeneous disorder than cervicogenic headache (9). We conclude that intracutaneous, sterile water injections are in-effective in cervicogenic headache. It’s use can not be recommended in this patient grOUPReferences 1. TROLLE B, MOLLER M, KRONBORG H, THOMSEN S. The
effect of sterile water blocks on low back labor pain. Am J Obstet Gyn 1991: 164: 1277-1281. 2. BYRNC , BORENSTEIN P, LINDERLE. Treatment of neck and shoulder pain in whip-lash syndrome patients with intracutaneous sterile water injections. Acta Anaesthesiol Scand 1991: 35: 52-53. 3. SJAASTAD 0, FREDRIKSEN T, PFAFFENRATH V. Cervico-
528
genic headache: Diagnostic criteria. Headache 1990: 30: 725726. 4. FREDERIKSEN T, HOVDALH, SJAASTAD 0. Cervicogenic headache: Clinical manifestations. Cephalalgia 1987: 7: 147160. 5. BOVIMG, SANDT. Cervicogenic headache, migraine with-
out aura, and tension headache: Diagnostic blockades of greater occipital and supraorbital nerves. Pain, (in press). 6. KERRFWL,OLAFSON RA. Trigeminal and cervical volleys. Convergence on single units in the spinal grays at C-1 and C-2. Arch Neurol 1961: 5: 171-178. J, WORNING AM, GERTZJ. Urolithiasissmerter 7. BENGTSON behandlet med intrakutane sterilvandspapler. Ugeskr Laeger 1981: 143: 3463-3465. 8. KNIBESTOL M, HILDINGSON C , TOOLANEN G. Trigeminal
sensory impairment after soft-tissue injury of the cervical spine. Acta Neurol Scand 1990: 82: 271-276. 9. Pearce JMS Whiplash injury: a reappraisal. J Neurol Neurosurg Psychiat 1989: 52: 1329-1331.
