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Significant reduction of post-lumbar puncture headaches by the use of a 29-gauge spinal needle
Significant Reduction of Post-lumbar Puncture Headaches by the Use of a 29-gauge Spinal Needle Claire McConaha, Andrea M. Bastiani, and Walter H. Kaye Key Words:
L u m b a r puncture, 2 9 - g a u g e needle, 2 2 - g a u g e needle, spinal h e a d a c h e
BIOL PSYCHIATRY 1996;39:1058--1060
Introduction There are limitations to the tools that can be used to study neurotransmitter activity in vivo in humans. One option is the measurement of levels of neurotransmitters and their metabolites in spinal fluid; however, there has been some reluctance to use this methodology for several reasons. First, studies of concentrations of neurotransmitters and neuromodulators in cerebrospinal fluid (CSF) invariably raise the question of the physiological relevance of such measurements. For example, alterations might not reflect changes in neurotransmission, but might reflect alterations in metabolism or clearance of neurochemicals from CSF. Alternatively, findings are difficult to interpret because of the multiplicity of pathways of any neurochemical system. Moreover there is no methodology presently available that can identify the specific pathways that contribute to levels of a neurochemical in CSF. It should be noted, however, that the ability to determine CSF monoamine levels has been very useful in studies of human central nervous system disease. For example, dopamine has been shown to be low in postmortem brain studies of Parkinson's disease (Bernheimer et al 1973) and such findings are reflected in vivo in lumbar CSF (Johanson and Roos 1967; Miachon et al 1974). Moreover, a considerable number of studies have found that low levels of CSF 5-hydroxyindoleacetic acid (5-HIAA) are associated with impulsive, suicidal, and aggressive behavior (Asberg et al 1976; van Praag 1983; Brown et al 1979; Linnoila et al 1983). Despite the limitations inherent in CSF studies, little alternative
From the Center for Overcoming Problem Eating, Western Psychiatric Institute and Clinic, Pittsburgh, Pennsylvania. Address reprint requests to Walter H. Kaye, M.D., Western Psychiatric Institute and Clinic, 3811 O'Hara Street, Pittsburgh, PA 15213. Received August 1, 1994; revised July 27, 1995.
© 1996 C. McConaha et al
technology exists at present to directly study these brain neuromodulators in humans in vivo. Second, professionals and the lay public tend to regard studies incorporating lumbar punctures as dangerous or painful; however, serious complications with simple lumbar puncture (LP) procedures are extremely rare (Dripps and Vandam 1954). In addition, when performed correctly, little discomfort is involved in the actual procedure. Perhaps the most common complication of LPs is post-lumbar puncture headache. For example, Ballenger and colleagues (1979) reported the performance of 1341 lumbar punctures with substantial CSF withdrawal (26-30 mL) without complications other than headaches. In a recent study, we performed LPs to obtain CSF in order to compare concentrations of brain neurochemicals between women who had recovered from an eating disorder and matched healthy volunteer women. During the initial part of the study we used only a 22-gauge needle to obtain CSF. Despite precautions, such as post-LP bedrest, a large percentage of subjects experienced post-lumbar puncture headache symptoms. A search of the literature revealed a new technique, using a 29-gauge needle, which was reported to dramatically reduce the incidence of post-LP headaches. This article compares post-LP headaches after using either a 22- or 29-gauge needle for a psychiatric research procedure.
Methods
Subjects Subjects included 20 healthy volunteer women and 50 women who had recovered from an eating disorder (R-ED). R-ED subjects consisted of women who had previously been diagnosed with anorexia or bulimia nervosa (American Psychiatric Association 1987). At the time of the present study, these R-ED subjects 0006-3223/96 SSDI 0006-3223(95)00417-3
Brief Reports
BtOL PSYCHIATRY
1059
1996;39:1058-1060
Table 1. Comparison of Women Who Had Recovered from an Eating Disorder and Healthy Volunteer Women
Age (years) Height (cm) Weight (kg) Average body weight (%) Headaches with 22-gauge needle Headaches with 29-gauge needle
Recovered eating disorder women (N = 44)
Healthy volunteer women (N = 19)
25.5 _+ 5.1 162.6 _+ 6.2 57.7 _+ 7.7 104.8 _+ 7.42 30% (8/27) 6% (1/17)
23.2 -+ 4.2 165.7 +- 5.4 60.5 -4- 5.31 105.7 -+ 7.4 33% (2/6) 0% (0/13)
t=1.74, ns t=1.89, ns t= 1.44, ns t=0.39, ns X2= .098,ns ×2= .019,ns
Note: Statistics are based on successful/completed LP procedures only. ns = not significant.
had been at a normal weight (i.e., within 15% of ideal body weight) for at least 1 year. All control subjects were screened for any DSM-III-R axis I or II diagnoses. Potential participants were excluded if they had any medical or neurological problems. All subjects were medication free at the time of the procedure. Each gave informed consent for the study.
who reported headaches at this time were then contacted 24 hours later for reassessment. If at the time of reassessment a position-dependent headache was present, subjects were advised to return to the research facilities for reevaluation and analogous blood patch procedure. In this study, we considered subjects to have a post-LP headache if they continued to have a posturally dependent headache more than 72 hours after the LP procedure.
Procedure Subjects were admitted to the Eating Disorder Research Lab (EDRL) the evening prior to the lumbar puncture procedure. They each fasted from midnight until the procedure was completed (between 8 AM and 10 AM). Lumbar punctures were performed at the L 3 - 4 interspace with subjects in a left lateral position. Skin and subcutaneous tissues were infiltrated with 1% lidocaine hydrochloride. When only the 22-gange needle was used, it was advanced into the subdural lumbar space. When the 29-gauge needle was used, the procedure was as follows: A 22-gauge spinal needle (Becton Dickinson brand Quinck type point) was advanced through the interspinous ligament until it just penetrated the ligamentum flavum with a slight "pop." The stilette of the 22-gauge needle was then withdrawn and a 29-gauge spinal needle was fed through the lumen of the 22-gauge introductory needle until it just penetrated the dura (Lynch et al 1992; Dittman and Renkl 1989; Flaatten et al 1989; Fishman 1977; Patten 1977). Position was confirmed by the appearance of CSF in the hub of the 29-gauge needle after its stilette was removed. The protocol involved slow (1 cc/min) aspiration of CSF samples (20 cc total) using a syringe over a 30-min interval while the subject was kept in the left lateral position. Identical pre- and post-lumbar-puncture procedures were used for subjects involved in both the traditional 22-gauge needle method group, and the group in which both the 22- and the 29-gauge needle methods were employed. All subjects were kept prone for 3 hours following the full procedure, and then allowed out of bed to toilet only. Subjects were then restricted to bed rest in the EDRL overnight, then discharged within 24 hours after the procedure. Each participant was contacted by telephone between 48 and 72 hours after the procedure, and questioned about the presence of a severe position-dependent headache. If subjects reported a headache, they were advised moderate interventions including bed rest, and increased oral fluid and caffeine intake. Subjects
Results Women who had recovered from an eating disorder and healthy control women were of similar ages, heights, and weights (Table 1). Both groups of women had similar rates of post-LP headaches when compared for use of either the 22-gauge or 29-gauge needles. Thus, we combined these groups of women. For both groups of women considered together, the overall rate of post-LP headache using only the 22-gauge needle was 30%. In comparison, significantly fewer (×2 = 6.44, df = l, p = .01) headaches occurred when the procedure was carried out using the 29-gauge needle (3.3%). We were not able to obtain CSF at the time of all studies. In fact, with the 22-gauge needle, 15.2% or 5 out of 33 were unsuccessful, whereas with the 29-gauge needle, only 6.7% or 2 out of 30 were unsuccessful (X2 = 1.15, df = 1, not significant).
Discussion We have found that use of a 29-gauge spinal needle dramatically reduces the incidence of post-LP headache. Although the present study is the first, to our knowledge, to use the 29-gauge needle with a 22-gange introducer, our results are similar to those of previous researchers who have used a 20-gauge introducer in their method. For example, Flaatten and colleagues (1989) performed LPs with 29-gauge needles on 149 male and female patients under 30 years old using a 20-gauge needle as an introducer. They found that whereas 6.7% of their subjects had developed symptoms of post-LP headache when a 26-gauge needle was used, no subjects developed post-LP headache using the present procedure with the 29-gauge needle. Geurts and colleagues (1990) found a 25% post-LP headache frequency using a 25-gauge needle and 0% post-LP headaches using a 29-gauge needle. It appears that using a smaller diameter LP needle reduces the
1060
BIOL PSYCHIATRY
Brief Reports
1996;39:1058 1060
incidence of post-LP headaches. In fact, a correlation between the diameter of the needle and the incidence of headache has been demonstrated (Moore 1982; Charlton 1983). Although a 22-gauge needle is commonly used in lumbar puncture procedures, the use of even smaller sized needles, e.g., 25-gauge, has been identified as a measure for preventing headaches (Flaatten et al 1989; Geurts et al 1990). Thus, the diameter of the puncture cite in the dura, and not the amount of spinal fluid withdrawn, may be a major factor contributing to post-LP headache. It is thought that the continued escape of CSF may be the cause of headache after lumbar puncture (Lee et al 1985; Geurts et al 1990). Not only is the rate of fluid lost through a smaller puncture cite less, but the smaller puncture cite should heal more quickly. It is also worth noting that young women have the highest incidence of post-LP headaches (Raskin 1990; Geurts et al 1990). The fact that the subjects in the present study were all young women may account for our higher rate of post-LP headaches. The major problem with the insertion of a 29-gauge needle is
that this needle is extremely flexible, which in turn increases the difficulty of performing a successful LP. To some extent, the problem of needle flex is reduced by using a 22-gauge introducer; however, it is sometimes difficult to know exactly where to end the insertion of the 22-gauge needle and when to introduce the 29-gauge. Nonetheless, the incidence of failed LP attempts was similar using 22- and 29-gauge needles in this study. In summary, the use of the 29-gauge needle reduces the incidence of post-LP headaches and thus may contribute to the wider acceptance of the LP procedure.
This work was supported in part by grants from NIMH (#MH46001 01, MH42984 01) and the Children's Hospital Clinical Research Center (#5MOIRROOO84), Pittsburgh Pennsylvania. We wish to thank Amelia Cabrera and Corrina Pavetto for their secretarial and editorialassistance, and Radhi Rao for her assistance with data analysis.
References American Psychiatric Association (1987): Diagnostic and Statistical Manual of Mental Disorders, 3rd ed rev. Washington, DC: American Psychiatric Press. Asberg M, Traskman L, Thoren P (1976): 5-HIAA in the cerebrospinal fluid: A biochemical suicide predictor? Arch Gen Psychiatry 33:1193-1197. Ballenger JC, Post RM, Stember DE, Van Kammen DP, Cowdry RW, Goodwin FK (1979): Headaches after lumbar puncture and insensitivity to pain in psychiatric patients [letter]. N Engl J Med 301:110. Bernheimer H, Birkmayer W, Hornykiewicz O, Jellinger K, Seitelberger F (1973): Brain dopamine and the syndromes of Parkinson and Huntington. J Neurol Sci 20:415-455. Brown GL, Goodwin FK, Ballenger JC, Goyer PF, Major LF (1979): Aggression in humans correlates with cerebrospinal fluid amine metabolites. Psychiatry Res 1:131-139. Charlton JE (1983): Correspondence: Hazards of lumbar puncture. Br Med J (Clin res ed) 286(6362):392. Dittman M, Renkl F (1989): Spinal anesthesia with extremely fine needles. Anaesthesiology 70:1035-1036. Dripps RD, Vandam LD (1954): Long-term follow-up of patients who received 10 098 spinal anesthetics: Failure to discover any neurological sequelae. JAMA 156:1486-1491. Fishman RA (1977): Recent advances in clinical neurology. In Baker AB, Baker LH (eds), Clinical Neurology, Maryland: Harper and Row, vol 1, pp 1-40. Flaatten H, Rodt SA, Vames J (1989): Postdural puncture headache. Anaesthesia 44:147-149.
Geurts JW, Haanschoten MC, Haanschoten RM, Kraak H, Besse TC (1990): Post-dural puncture headache in young patients. Acta Anaesthesiol Scand 34:350-353. Johanson B, Roos BE (1967): 5-Hydroxyindoleacetic acid and homovanillic acid levels in the cerebrospinal fluid of healthy volunteers and patients with Parkinson's syndrome. Life Sci 6:1449-1454. Lee JA, Atkinson RS, Watt MJ (1985): Lumbar Puncture and Spinal Analgesia: lntradural and Extradural. New York: Churchill Livingstone, pp 278-301. Linnoila M, Virkkunen M, Scheinin M, Nuutila A, Rimon R, Goodwin FK (1983): Low cerebrospinal fluid 5-HIAA concentration differentiates impulsive from non-impulsive violent behavior. Life Sci 33:2609-2614. Lynch J, Arhelger S, Krings-Ernst I (1992): Post dural puncture headache in young orthopaedic inpatients. Acta Anaesthesiol Scand 36:58-61. Miachon S, Dalmaz Y, Cottet-Emard JM, Peyrin L (1974): Cerebrospinal homovanillic acid and parkinsonism. Biomedicine 20:303-308. Moore DC (1982): Factors influencing spinal anesthesia. Reg Anesthesia 7:20. Patten J (1977): Neurological Differential Diagnosis. New York: Springer-Verlag, pp 259-266. Raskin NH (1990): Lumbar puncture headache: A review. Headache 30:197-200. van Praag HM (1983): CSF 5-HIAA and suicide in nondepressed schizophrenics. Lancet 977-978.
L u m b a r puncture, 2 9 - g a u g e needle, 2 2 - g a u g e needle, spinal h e a d a c h e
BIOL PSYCHIATRY 1996;39:1058--1060
Introduction There are limitations to the tools that can be used to study neurotransmitter activity in vivo in humans. One option is the measurement of levels of neurotransmitters and their metabolites in spinal fluid; however, there has been some reluctance to use this methodology for several reasons. First, studies of concentrations of neurotransmitters and neuromodulators in cerebrospinal fluid (CSF) invariably raise the question of the physiological relevance of such measurements. For example, alterations might not reflect changes in neurotransmission, but might reflect alterations in metabolism or clearance of neurochemicals from CSF. Alternatively, findings are difficult to interpret because of the multiplicity of pathways of any neurochemical system. Moreover there is no methodology presently available that can identify the specific pathways that contribute to levels of a neurochemical in CSF. It should be noted, however, that the ability to determine CSF monoamine levels has been very useful in studies of human central nervous system disease. For example, dopamine has been shown to be low in postmortem brain studies of Parkinson's disease (Bernheimer et al 1973) and such findings are reflected in vivo in lumbar CSF (Johanson and Roos 1967; Miachon et al 1974). Moreover, a considerable number of studies have found that low levels of CSF 5-hydroxyindoleacetic acid (5-HIAA) are associated with impulsive, suicidal, and aggressive behavior (Asberg et al 1976; van Praag 1983; Brown et al 1979; Linnoila et al 1983). Despite the limitations inherent in CSF studies, little alternative
From the Center for Overcoming Problem Eating, Western Psychiatric Institute and Clinic, Pittsburgh, Pennsylvania. Address reprint requests to Walter H. Kaye, M.D., Western Psychiatric Institute and Clinic, 3811 O'Hara Street, Pittsburgh, PA 15213. Received August 1, 1994; revised July 27, 1995.
© 1996 C. McConaha et al
technology exists at present to directly study these brain neuromodulators in humans in vivo. Second, professionals and the lay public tend to regard studies incorporating lumbar punctures as dangerous or painful; however, serious complications with simple lumbar puncture (LP) procedures are extremely rare (Dripps and Vandam 1954). In addition, when performed correctly, little discomfort is involved in the actual procedure. Perhaps the most common complication of LPs is post-lumbar puncture headache. For example, Ballenger and colleagues (1979) reported the performance of 1341 lumbar punctures with substantial CSF withdrawal (26-30 mL) without complications other than headaches. In a recent study, we performed LPs to obtain CSF in order to compare concentrations of brain neurochemicals between women who had recovered from an eating disorder and matched healthy volunteer women. During the initial part of the study we used only a 22-gauge needle to obtain CSF. Despite precautions, such as post-LP bedrest, a large percentage of subjects experienced post-lumbar puncture headache symptoms. A search of the literature revealed a new technique, using a 29-gauge needle, which was reported to dramatically reduce the incidence of post-LP headaches. This article compares post-LP headaches after using either a 22- or 29-gauge needle for a psychiatric research procedure.
Methods
Subjects Subjects included 20 healthy volunteer women and 50 women who had recovered from an eating disorder (R-ED). R-ED subjects consisted of women who had previously been diagnosed with anorexia or bulimia nervosa (American Psychiatric Association 1987). At the time of the present study, these R-ED subjects 0006-3223/96 SSDI 0006-3223(95)00417-3
Brief Reports
BtOL PSYCHIATRY
1059
1996;39:1058-1060
Table 1. Comparison of Women Who Had Recovered from an Eating Disorder and Healthy Volunteer Women
Age (years) Height (cm) Weight (kg) Average body weight (%) Headaches with 22-gauge needle Headaches with 29-gauge needle
Recovered eating disorder women (N = 44)
Healthy volunteer women (N = 19)
25.5 _+ 5.1 162.6 _+ 6.2 57.7 _+ 7.7 104.8 _+ 7.42 30% (8/27) 6% (1/17)
23.2 -+ 4.2 165.7 +- 5.4 60.5 -4- 5.31 105.7 -+ 7.4 33% (2/6) 0% (0/13)
t=1.74, ns t=1.89, ns t= 1.44, ns t=0.39, ns X2= .098,ns ×2= .019,ns
Note: Statistics are based on successful/completed LP procedures only. ns = not significant.
had been at a normal weight (i.e., within 15% of ideal body weight) for at least 1 year. All control subjects were screened for any DSM-III-R axis I or II diagnoses. Potential participants were excluded if they had any medical or neurological problems. All subjects were medication free at the time of the procedure. Each gave informed consent for the study.
who reported headaches at this time were then contacted 24 hours later for reassessment. If at the time of reassessment a position-dependent headache was present, subjects were advised to return to the research facilities for reevaluation and analogous blood patch procedure. In this study, we considered subjects to have a post-LP headache if they continued to have a posturally dependent headache more than 72 hours after the LP procedure.
Procedure Subjects were admitted to the Eating Disorder Research Lab (EDRL) the evening prior to the lumbar puncture procedure. They each fasted from midnight until the procedure was completed (between 8 AM and 10 AM). Lumbar punctures were performed at the L 3 - 4 interspace with subjects in a left lateral position. Skin and subcutaneous tissues were infiltrated with 1% lidocaine hydrochloride. When only the 22-gange needle was used, it was advanced into the subdural lumbar space. When the 29-gauge needle was used, the procedure was as follows: A 22-gauge spinal needle (Becton Dickinson brand Quinck type point) was advanced through the interspinous ligament until it just penetrated the ligamentum flavum with a slight "pop." The stilette of the 22-gauge needle was then withdrawn and a 29-gauge spinal needle was fed through the lumen of the 22-gauge introductory needle until it just penetrated the dura (Lynch et al 1992; Dittman and Renkl 1989; Flaatten et al 1989; Fishman 1977; Patten 1977). Position was confirmed by the appearance of CSF in the hub of the 29-gauge needle after its stilette was removed. The protocol involved slow (1 cc/min) aspiration of CSF samples (20 cc total) using a syringe over a 30-min interval while the subject was kept in the left lateral position. Identical pre- and post-lumbar-puncture procedures were used for subjects involved in both the traditional 22-gauge needle method group, and the group in which both the 22- and the 29-gauge needle methods were employed. All subjects were kept prone for 3 hours following the full procedure, and then allowed out of bed to toilet only. Subjects were then restricted to bed rest in the EDRL overnight, then discharged within 24 hours after the procedure. Each participant was contacted by telephone between 48 and 72 hours after the procedure, and questioned about the presence of a severe position-dependent headache. If subjects reported a headache, they were advised moderate interventions including bed rest, and increased oral fluid and caffeine intake. Subjects
Results Women who had recovered from an eating disorder and healthy control women were of similar ages, heights, and weights (Table 1). Both groups of women had similar rates of post-LP headaches when compared for use of either the 22-gauge or 29-gauge needles. Thus, we combined these groups of women. For both groups of women considered together, the overall rate of post-LP headache using only the 22-gauge needle was 30%. In comparison, significantly fewer (×2 = 6.44, df = l, p = .01) headaches occurred when the procedure was carried out using the 29-gauge needle (3.3%). We were not able to obtain CSF at the time of all studies. In fact, with the 22-gauge needle, 15.2% or 5 out of 33 were unsuccessful, whereas with the 29-gauge needle, only 6.7% or 2 out of 30 were unsuccessful (X2 = 1.15, df = 1, not significant).
Discussion We have found that use of a 29-gauge spinal needle dramatically reduces the incidence of post-LP headache. Although the present study is the first, to our knowledge, to use the 29-gauge needle with a 22-gange introducer, our results are similar to those of previous researchers who have used a 20-gauge introducer in their method. For example, Flaatten and colleagues (1989) performed LPs with 29-gauge needles on 149 male and female patients under 30 years old using a 20-gauge needle as an introducer. They found that whereas 6.7% of their subjects had developed symptoms of post-LP headache when a 26-gauge needle was used, no subjects developed post-LP headache using the present procedure with the 29-gauge needle. Geurts and colleagues (1990) found a 25% post-LP headache frequency using a 25-gauge needle and 0% post-LP headaches using a 29-gauge needle. It appears that using a smaller diameter LP needle reduces the
1060
BIOL PSYCHIATRY
Brief Reports
1996;39:1058 1060
incidence of post-LP headaches. In fact, a correlation between the diameter of the needle and the incidence of headache has been demonstrated (Moore 1982; Charlton 1983). Although a 22-gauge needle is commonly used in lumbar puncture procedures, the use of even smaller sized needles, e.g., 25-gauge, has been identified as a measure for preventing headaches (Flaatten et al 1989; Geurts et al 1990). Thus, the diameter of the puncture cite in the dura, and not the amount of spinal fluid withdrawn, may be a major factor contributing to post-LP headache. It is thought that the continued escape of CSF may be the cause of headache after lumbar puncture (Lee et al 1985; Geurts et al 1990). Not only is the rate of fluid lost through a smaller puncture cite less, but the smaller puncture cite should heal more quickly. It is also worth noting that young women have the highest incidence of post-LP headaches (Raskin 1990; Geurts et al 1990). The fact that the subjects in the present study were all young women may account for our higher rate of post-LP headaches. The major problem with the insertion of a 29-gauge needle is
that this needle is extremely flexible, which in turn increases the difficulty of performing a successful LP. To some extent, the problem of needle flex is reduced by using a 22-gauge introducer; however, it is sometimes difficult to know exactly where to end the insertion of the 22-gauge needle and when to introduce the 29-gauge. Nonetheless, the incidence of failed LP attempts was similar using 22- and 29-gauge needles in this study. In summary, the use of the 29-gauge needle reduces the incidence of post-LP headaches and thus may contribute to the wider acceptance of the LP procedure.
This work was supported in part by grants from NIMH (#MH46001 01, MH42984 01) and the Children's Hospital Clinical Research Center (#5MOIRROOO84), Pittsburgh Pennsylvania. We wish to thank Amelia Cabrera and Corrina Pavetto for their secretarial and editorialassistance, and Radhi Rao for her assistance with data analysis.
References American Psychiatric Association (1987): Diagnostic and Statistical Manual of Mental Disorders, 3rd ed rev. Washington, DC: American Psychiatric Press. Asberg M, Traskman L, Thoren P (1976): 5-HIAA in the cerebrospinal fluid: A biochemical suicide predictor? Arch Gen Psychiatry 33:1193-1197. Ballenger JC, Post RM, Stember DE, Van Kammen DP, Cowdry RW, Goodwin FK (1979): Headaches after lumbar puncture and insensitivity to pain in psychiatric patients [letter]. N Engl J Med 301:110. Bernheimer H, Birkmayer W, Hornykiewicz O, Jellinger K, Seitelberger F (1973): Brain dopamine and the syndromes of Parkinson and Huntington. J Neurol Sci 20:415-455. Brown GL, Goodwin FK, Ballenger JC, Goyer PF, Major LF (1979): Aggression in humans correlates with cerebrospinal fluid amine metabolites. Psychiatry Res 1:131-139. Charlton JE (1983): Correspondence: Hazards of lumbar puncture. Br Med J (Clin res ed) 286(6362):392. Dittman M, Renkl F (1989): Spinal anesthesia with extremely fine needles. Anaesthesiology 70:1035-1036. Dripps RD, Vandam LD (1954): Long-term follow-up of patients who received 10 098 spinal anesthetics: Failure to discover any neurological sequelae. JAMA 156:1486-1491. Fishman RA (1977): Recent advances in clinical neurology. In Baker AB, Baker LH (eds), Clinical Neurology, Maryland: Harper and Row, vol 1, pp 1-40. Flaatten H, Rodt SA, Vames J (1989): Postdural puncture headache. Anaesthesia 44:147-149.
Geurts JW, Haanschoten MC, Haanschoten RM, Kraak H, Besse TC (1990): Post-dural puncture headache in young patients. Acta Anaesthesiol Scand 34:350-353. Johanson B, Roos BE (1967): 5-Hydroxyindoleacetic acid and homovanillic acid levels in the cerebrospinal fluid of healthy volunteers and patients with Parkinson's syndrome. Life Sci 6:1449-1454. Lee JA, Atkinson RS, Watt MJ (1985): Lumbar Puncture and Spinal Analgesia: lntradural and Extradural. New York: Churchill Livingstone, pp 278-301. Linnoila M, Virkkunen M, Scheinin M, Nuutila A, Rimon R, Goodwin FK (1983): Low cerebrospinal fluid 5-HIAA concentration differentiates impulsive from non-impulsive violent behavior. Life Sci 33:2609-2614. Lynch J, Arhelger S, Krings-Ernst I (1992): Post dural puncture headache in young orthopaedic inpatients. Acta Anaesthesiol Scand 36:58-61. Miachon S, Dalmaz Y, Cottet-Emard JM, Peyrin L (1974): Cerebrospinal homovanillic acid and parkinsonism. Biomedicine 20:303-308. Moore DC (1982): Factors influencing spinal anesthesia. Reg Anesthesia 7:20. Patten J (1977): Neurological Differential Diagnosis. New York: Springer-Verlag, pp 259-266. Raskin NH (1990): Lumbar puncture headache: A review. Headache 30:197-200. van Praag HM (1983): CSF 5-HIAA and suicide in nondepressed schizophrenics. Lancet 977-978.