Occipital nerve stimulation in medically intractable, chronic cluster headache. The ICON study: Rationale and protocol of a randomised trial

Background

About 10% of cluster headache patients have the chronic form. At least 10% of this chronic group is intractable to or cannot tolerate medical treatment. Open pilot studies suggest that occipital nerve stimulation (ONS) might offer effective prevention in these patients. Controlled neuromodulation studies in treatments inducing paraesthesias have a general problem in blinding. We have introduced a new design in pain neuromodulation by which we think we can overcome this problem.

Methods/design

We propose a prospective, randomised, double-blind, parallel-group international clinical study in medically intractable, chronic cluster headache patients of high- versus low-amplitude ONS. Primary outcome measure is the mean number of attacks over the last four weeks. After a study period of six months there is an open extension phase of six months. Alongside the randomised trial an economic evaluation study is performed.

Discussion

The ICON study will show if ONS is an effective preventive therapy for patients suffering medically intractable chronic cluster headache and if there is a difference between high- and low-amplitude stimulation. The innovative design of the study will, for the first time, assess efficacy of ONS in a blinded way.

Cost-effectiveness of minimal interventional procedures for chronic mechanical low back pain: design of four randomised controlled trials with an economic evaluation

BACKGROUND

Minimal interventional procedures are frequently applied in patients with mechanical low back pain which is defined as pain presumably resulting from single sources: facet, disc, sacroiliac joint or a combination of these. Usually, these minimal interventional procedures are an integral part of a multidisciplinary pain programme. A recent systematic review issued by the Dutch Health Insurance Council showed that the effectiveness of these procedures for the total group of patients with chronic low back pain is yet unclear and cost-effectiveness unknown. The aim of the study is to evaluate whether a multidisciplinary pain programme with minimal interventional procedures is cost-effective compared to the multidisciplinary pain programme alone for patients with chronic mechanical low back pain who did not respond to conservative primary care and were referred to a pain clinic.

METHODS

All patients with chronic low back pain who are referred to one of the 13 participating pain clinics will be asked to participate in an observational study. Patients with a suspected diagnosis of facet, disc or sacroiliac joint problems will receive a diagnostic block to confirm this diagnosis. If confirmed, they will be asked to participate in a randomized controlled trial (RCT). For each single source a separate RCT will be conducted. Patients with a combination of facet, disc or sacroiliac joint problems will be invited for participation in a RCT as well. An economic evaluation from a societal perspective will be performed alongside these four RCTs. Patients will complete questionnaires at baseline, 3 and 6 weeks, 3, 6, 9 and 12 months after start of the treatment. Costs will be collected using self-completed cost questionnaires.

DISCUSSION

No trials are yet available which have evaluated the cost-effectiveness of minimal interventional procedures in patients with chronic mechanical low back pain, which emphasizes the importance of this study.

TRIAL REGISTRATION NUMBER

National Trial Register: NTR3531.

Multiplex bead array assay for detection of 25 soluble cytokines in blister fluid of patients with complex regional pain syndrome type 1

Inflammatory processes are known to be involved at least in the early phase of complex regional pain syndrome type 1 (CRPS1). Blister fluid obtained from the involved extremities displayed increased amounts of proinflammatory cytokines IL-6 and TNFα compared with the noninvolved extremities. The aim of this paper is to investigate the involvement of mediators by measurement of several other cytokines using new detection techniques that enable multiple cytokine measurement in small samples. The use of a multiplex-25 bead array cytokine assay and Luminex technology enabled simultaneous measurement of representative (1) proinflammatory cytokines such as GM-CSF, IL-1β, IL-1RA, IL-6, IL-8, and TNF-α; (2) Th1/Th2 distinguishing cytokines IFN-γ, IL-2, IL-2R, IL-4, IL-5, and IL-10; (3) nonspecific acting cytokines IFN-α, IL-7, IL-12p40/p70, IL-13, IL-15, and IL-17; and (4) chemokines eotaxin, IP-10, MCP-1, MIP-1α, MIP-1β, MIG, and RANTES. Although minimal detection levels are significantly higher in the bead array system than those in common ELISA assays, in blister fluid, IL-1RA, IL-6, IL-8, TNF-α, IL-12p40/p70, MCP-1, and MIP-1β were detectable and increased in CRPS1 affected extremities. Levels of IL-6 and TNF-α simultaneously measured by ELISA (Sanquin Compact kit) and by multiplex-25 bead array assay (Biosource) were highly correlated (r = 0.85, P < .001 for IL-6 and r = 0.88, P < .001 for TNF-α). Furthermore, IP-10 and eotaxin were detectable but diminished in CRPS1, whereas detectable amounts of IL-10 were similar in involved and noninvolved extremities. Multiplex bead array assays are useful systems to establish the involvement of cytokines in inflammatory processes by measurements in blister fluids of CRPS1. Ten representative cytokines were detectable. However, detection levels and amounts measured are at least 3 times higher in the multiplex-25 array assay than in the ELISA assays used simultaneously for the measurement of cytokines.

Increased endothelin-1 and diminished nitric oxide levels in blister fluids of patients with intermediate cold type complex regional pain syndrome type 1

Background

In complex regional pain syndrome type 1 (CRPS1) pro-inflammatory mediators and vascular changes play an important role in the sustained development and outcome of the disease. The aim of this study was to determine the involvement of vasoactive substances endothelin-1 (ET-1) and nitric oxide (NO) during early chronic CRPS1.

Methods

Included were 29 patients with CRPS 1 who were diagnosed during the acute stage of their disease and observed during follow-up visits. Disease activity and impairment were determined and artificial suction blisters were made on the CRPS1 and the contralateral extremities for measurements of IL-6, TNF-α, ET-1 and nitrate/nitrite (NOx).

Results

The levels of IL-6, TNF-α and ET-1 in blister fluid in the CRPS1 extremity versus the contralateral extremity were significantly increased and correlated with each other, whereas NOx levels were decreased.

Conclusion

The NOx/ET-1 ratio appears to be disturbed in the intermediate stage of CRPS, resulting in vasoconstriction and consequently in a diminished tissue blood distribution.

Thermography imaging during static and controlled thermoregulation in complex regional pain syndrome type 1: diagnostic value and involvement of the central sympathetic system

Background

Complex Regional Pain Syndrome type 1 (CRPS1) is a clinical diagnosis based on criteria describing symptoms of the disease.

The main aim of the present study was to compare the sensitivity and specificity of calculation methods used to assess thermographic images (infrared imaging) obtained during temperature provocation. The secondary objective was to obtain information about the involvement of the sympathetic system in CRPS1.

Methods

We studied 12 patients in whom CRPS1 was diagnosed according to the criteria of Bruehl. High and low whole body cooling and warming induced and reduced sympathetic vasoconstrictor activity. The degree of vasoconstrictor activity in both hands was monitored using a videothermograph. The sensitivity and specificity of the calculation methods used to assess the thermographic images were calculated.

Results

The temperature difference between the hands in the CRPS patients increases significantly when the sympathetic system is provoked. At both the maximum and minimum vasoconstriction no significant differences were found in fingertip temperatures between both hands.

Conclusion

The majority of CRPS1 patients do not show maximal obtainable temperature differences between the involved and contralateral extremity at room temperature (static measurement). During cold and warm temperature challenges this temperature difference increases significantly. As a result a higher sensitivity and specificity could be achieved in the diagnosis of CRPS1. These findings suggest that the sympathetic efferent system is involved in CRPS1.

Neuroimmune alterations in the complex regional pain syndrome

This review focuses on some clinical aspects of the complex regional pain syndrome, such as oedema, local temperature changes and chronic pain, as a result of supposed neurogenic inflammation. Involvement of the immune system could imply the subsequent release of neuropeptides, pro-inflammatory cytokines and eicosanoids, which in turn leads to a complex cross-talk of primary and secondary generated mediators of inflammation. The development and application of drugs that act through selective receptor antagonism or enzymatic synthesis inhibition to prevent further stimulation of this cascade that could inevitably lead to chronicity of this disease are extensively discussed.

Is the breast best for children with a family history of atopy? The relation between way of feeding and early childhood morbidity

BACKGROUND

Previous studies reported that breast-feeding protects children against a variety of diseases, but these studies were generally conducted on "high-risk" or hospitalized children. This paper describes the results of our study on the effects of breast-feeding on rate of illness in normal children with a family history of atopy.

METHODS

A historic cohort approach of 794 children with a family history of atopy was used to assess the effects of breast-feeding on illness rates. Family history of atopy was based on allergic diseases in family members as registered by the family physician. Illness data from birth onwards were available from the Continuous Morbidity Registration of the Department of Family Medicine. Information on breast-feeding was collected by postal questionnaire. We then compared rates of illness between children with a family history of atopy who were and who were not breast-fed.

RESULTS

Breast-feeding was related to lower levels of childhood illness both in the first and the first three years of life. In the first year of life they had fewer episodes of gastroenteritis, lower respiratory tract infections, and digestive tract disorders. Over the next three years of life they had fewer respiratory tract infections and skin infections.

CONCLUSIONS

Our results suggest a protective effect of breast-feeding among children with a family history of atopy that is not confined to the period of breast-feeding but continues during the first three years of life. Breast-feeding should be promoted in children with a family history of atopy.

Infusion of propofol versus midazolam for sedation in the intensive care unit following coronary artery surgery

The use and the hemodynamic effects of propofol and midazolam were studied during titrated continuous infusions to deep sedation (sedation level 5: asleep, sluggish response to light glabellar tap or loud auditory stimulus) following coronary artery surgery. The drugs were compared in 30 ventilated patients in an open randomized study. The duration of infusion was approximately 570 minutes in both groups. After a loading dose of propofol (1 mg/kg) or midazolam (0.07 mg/kg), the infusion rates were 2.71 +/- 1.13 mg/kg/h and 0.092 +/- 0.028 mg/kg/h, respectively. An analgesic infusion of sufentanil was also given in both groups. In the midazolam group, to maintain the predetermined level of sedation, more frequent additional bolus doses (4.7 +/- 1.8; P < 0.001) and infusion rate adjustments (5.3 +/- 1.6; P < 0.001) were required than for similar sedation in the propofol group (2.3 +/- 1.0 bolus doses and 3.3 +/- 1.2 adjustments). The time from stopping sedation to patient responsiveness was 11 +/- 8 minutes in the propofol group and 72 +/- 70 minutes in the midazolam group (P < 0.001), and the time from stopping sedation to extubation was 250 +/- 135 minutes and 391 +/- 128 minutes (P < 0.014), respectively. Following the loading dose of propofol, there was a fall in blood pressure (BP) (mean from 80 +/- 11 mmHg to 67.5 +/- 10 mmHg; P < 0.05). After approximately 15 minutes, BP started to rise but remained below pretreatment level throughout sedation.(ABSTRACT TRUNCATED AT 250 WORDS)

Morbidity in early childhood: family patterns in relation to sex, birth order, and social class

BACKGROUND AND OBJECTIVES

This study investigated family patterns of morbidity in early childhood related to different degrees of severity of morbidity, sex, birth-order position, and social class.

METHODS

The study was performed using data collected by the Continuous Morbidity Registration Project of the Department of Family Practice of the Nÿmegen University in the Netherlands. All recorded morbidity and a number of sociodemographic data (sex, birth order, and social class) were available. The study population included children (783 boys, 730 girls) born in the four practices from 1971 to 1985 and their parents. The children were followed until age five. Morbidity of children during the first five years of life and their parents during the same five years was categorized into three levels of seriousness and 10 morbidity groups.

RESULTS

Correlations between morbidity of children and their mothers were high, particularly for nonserious morbidity (0.45-0.49). Correlations between morbidity of fathers and their children were similar for moderate and nonserious morbidity (0.30). Logistic regression analysis showed that the morbidity of the mother was the most important factor in predicting childhood morbidity.

CONCLUSIONS

Although morbidity in early childhood was associated with sex, birth order, and social class, the morbidity of the parents, in particular the mother, was by far the most important factor.

Morbidity from childhood to adulthood. The medical life history of 103 patients

The aim of the study was to investigate the relationship between presented morbidity in consecutive periods of time in the first 35 years of life. Data were collected in a large rural general practice from 1946 to 1990 and covered 103 persons born between 1946 and 1959 in a general practice in the east of The Netherlands. Morbidity scores were calculated for all registered diagnoses in 5-year periods. Morbidity was allocated to three degrees of seriousness, to all atopic disorders, and to eight important diagnosis groups. There were strong correlations between consecutive time periods for all but serious morbidity. The same pattern was found between 0-4 years of age and consecutive periods till the age of 20-25. After this age no significant correlations could be established. Atopic disorders were inter-related in the first 20 years of life. Strong correlations were also found for eczema and lower respiratory tract infections in the first 20 years, while strong correlations were found for accidents and nervous complaints between the ages of 20 and 35. We conclude that causes of morbidity presented in general practice in childhood and adulthood are strongly inter-related over consecutive 5-year periods.

Morbidity in early childhood: differences between girls and boys under 10 years old

The aim of the study was to investigate the differences in presented morbidity and use of health services among boys and girls in early childhood. The study was performed using data collected by the continuous morbidity registration project of the department of general practice at Nijmegen University. All recorded morbidity, referrals to specialists and admissions to hospitals were recorded by the registration project. The study population included children born in four practices from 1971 to 1984. The children were followed up until the age of five years and if possible until the age of 10 years. The morbidity of the children had been categorized into three levels of seriousness of diagnosis and 15 diagnostic groups as part of the registration project. Boys presented more morbidity than girls in the first years of their lives. For the age group 0-4 years this was true for all levels of seriousness of diagnosis except the most serious. In this younger age group significantly more boys than girls suffered respiratory diseases, behaviour disorders, gastroenteritis and accidents. Girls suffered from more episodes of urinary infection than boys in both age groups. More boys were referred to specialists and admitted to hospital than girls. The findings of this study suggest that not only inborn factors can explain the sex differences in presented morbidity and use of health services in early childhood. In particular, differences between girls and boys in terms of non-serious morbidity and referral and admission rates suggest a different way of handling health problems in boys and girls in early childhood both by parents and doctors.(ABSTRACT TRUNCATED AT 250 WORDS)

Morbidity in early childhood, sex differences, birth order and social class

STUDY OBJECTIVE

The aim of the study was to investigate the relationship between morbidity in early childhood and gender, birth order, and social class.

DESIGN

The study used data collected in the Nijmegen Continuous Morbidity Registration. All presented morbidity and a number of personal data were available.

SETTING

The survey population was regional; four general practices in the east of The Netherlands.

PARTICIPANTS

The study population included all children born in the four practices from 1971 to 1984. They were followed up till the age of five (1537 children).

MEASUREMENTS AND MAIN RESULTS

Morbidity of children in the first five years was allocated to three degrees of seriousness and to 14 diagnosis groups. The morbidity of all children was analysed for boys and girls, first-born, second-born, and later-born children, and low, middle, and high social class. Boys presented more morbidity than girls; in particular, nervous disorders, lower respiratory tract infections, and accidents. First-born children presented more morbidity than later-born children; in particular, non-serious diseases, nervous disorders, and colds. Lower social class children presented more moderately serious and non-serious morbidity, colds, lower respiratory tract infections, and skin diseases. Logistic regression analysis showed that high social class, being the first-born child, and male gender were the most important factors related to presented morbidity in general practice.

CONCLUSIONS

High social class, low social class, gender, and being the first-born child were, in this sequence, related to morbidity in early childhood presented to the general practitioner in this study population.

Relationship between the working styles of general practitioners and the health status of their patients

The aim of this study was to relate the working style of general practitioners to the health status of a sample of their patients. From a large regional sick fund forming part of the national health insurance system in the Netherlands a stratified sample was taken of general practitioners with at least 1000 patients on their list, taking into account the degree or urbanization of the area in which they practised and their annual referral rates to specialists. These 75 general practitioners were observed for two days in their surgeries by trained doctors and rated according to criteria defined beforehand. Taking into account these ratings and the annual figures from the sick fund for prescribing selected drugs and referrals to specialists, the general practitioners were classified into styles of practice - integrated, interventionist or minimal diagnostic. Twenty randomly selected women, aged 50-65 years, from each general practitioner's list, were interviewed and examined by independent doctors. The patients of general practitioners with the integrated practice style appeared to feel more healthy and to have more realistic expectations about the possibilities of professional help for common ailments. They tended to visit their doctor less frequently and to have fewer symptoms. The results showed an association between the quality of general practitioners and patients' health, and it may therefore be concluded that good general practitioners can further the health and well being of their patients.

The relationship between breast-feeding and early childhood morbidity in a general population

This study investigated the relationship between breast-feeding and early childhood morbidity. Data on morbidity had been recorded in the Continuous Morbidity Registration of the Department of Family Medicine of the University of Nijmegen, the Netherlands, since 1967. Information on early childhood feeding was collected retrospectively by questionnaires mailed to the parents of all the children; the response rate was 94%. Exposure and outcome data of 1,347 children were available for analyses. Duration of breast-feeding was categorized as follows: 0 days (no breast-feeding), 1-14 days, 15-30 days, 31-90 days, 91-180 days, and more than 180 days. Two thirds of the children had been breast fed. Generally there was an inverse relationship between breast-feeding and morbidity. This was most prominent in the first year of life but was also present in the first three years. After adjustment for potential confounding variables, duration of breast-feeding was associated with fewer morbidity episodes and lower rates of several specific illnesses during the first three years of life. The findings suggest some modest health benefits of breast-feeding for children in the Netherlands.

Handling of confidentiality in general practice: a survey among general practitioners in The Netherlands

This paper describes the results of a study of the handling of confidentiality by general practitioners. A sample of 272 general practitioners in the eastern part of the Netherlands was interviewed. The general practitioners were presented with 10 cases involving confidentiality and were asked what course of action they would pursue. Twenty-eight per cent of the general practitioners would never disclose information to others without the patient's consent, while 14% would disclose information to other physicians, members of non-medical professions and relatives. The largest proportion (38%) would disclose information only to other physicians. General practitioners were less likely to divulge information if they were: younger, female or practising in group practices. In particular, general practitioners who involved patients in decision making were less likely to disclose information to third parties. A plea is made for more education about confidentiality in the medical curriculum.

Longitudinal studies of family units

In this paper the transmission of illness and illness behaviour from grandparents to their children and grandchildren is discussed. Maternal grandmothers are found to have most influence. Some prediction of the frequency of new periods of illness among the grandchildren was possible by making use of the number of nervous disorders of the grandparents for which medical help was requested. As family doctors, general practitioners are in a favourable position to anticipate and try to prevent the transmission of inadequate illness behaviour from generation to generation.

The relation between overweight and subjective health according to age, social class, slimming behavior and smoking habits in Dutch adults

Subjective health status was assessed in relation to overweight by administering a list of 51 health complaints to adult men and women who were either chronically overweight as defined by Body Mass Index (BMI) or not overweight, in a continuous morbidity registration in four general practices during the period 1967-83. Responses were received from 455 men (182 overweight) and 790 women (386 overweight), ages 26-66 years. Response rate (71 per cent) and age distribution (mean age 48) were similar in overweight and non-overweight groups of both sexes. BMI was correlated with the total number of complaints in women (r = 0.15) but not in men (r = 0.07). Multiple regression analysis revealed, however, that age was an effect modifier in this relation, there being a negative association between BMI and subjective health in younger men and a positive association in older men, whereas in women the association between BMI and subjective health was much more pronounced at younger ages than at older ages. In addition, current smoking habits and social class (in men and women) and reported slimming behavior (in women) had an independent relation to the total number of health complaints. BMI was also related to specific complaints and groups of complaints, particularly in women.

[Possibilities for prevention in the aged in primary health care]

A systematic periodic check-up of all aged by the general practitioner would result in an impracticable workload of the GP, while the benefits of this check-up have never been proved irrefutably. Good arguments can be brought forward however for regular visits by the health visitor to survey the social and medical conditions, referring to the GP and social work agencies if necessary. This kind of surveillance has been proved to be feasible. The most important task in preventive respect for the GP is to forestall unnecessary deterioration of health and validity by optimal diagnosis and treatment of the aged under his care, by surveillance and anticipatory care. The new possibilities of data automation with personal computers offer important perspectives in this respect. The use of these possibilities will help the GP to learn to look at his practice population as a population at risk in which the category of the aged is prone to particular risks. As the GP has contact with 85% of the aged in his practice during one year, a systematization of the surveillance of these risk categories should be easily practicable.

Home deliveries in Holland. Dutch maternity care and home confinements

In the Netherlands a majority of all deliveries take place at home. The perinatal mortality rate is better than that reported from the United ffiingdom, probably because obstetric care in hospital is more active and aggressive. Dutch midwives play an important role and the specially trained home helps are most successful. I believe that, provided case selection is rigorous, many women are best delivered at home.