Relationship between subjectively-rated and objectively-tested physical function across six different medical diagnoses

OBJECTIVE

To quantify and compare associations and relationships between self-rated and tested assessments of mainly mobility-related physical function in different diagnoses.

DESIGN

Six longitudinal cohort studies before and after inpatient rehabilitation.

PATIENTS

Patients with whiplash-associated disorder (n = 71), low back pain (n = 121), fibromyalgia (n = 84), lipoedema (n = 27), lymphoedema (n = 78), and post-acute coronary syndrome (n = 64).

METHODS

Physical function was measured with the self-rated Short-Form 36 Physical functioning (SF-36 PF) and with the tested 6-Min Walk Distance (6MWD) and assessed by correlation coefficients. Across the 6 cohorts, the relationship between the 2 scores was compared using the ratio between them.

RESULTS

The correlations between the 2 scores were mostly moderate to strong at baseline (up to r = 0.791), and weak to moderate for the changes to follow-up (up to r = 0.408). The ratios SF-36 PF to 6MWD were 1.143-1.590 at baseline and 0.930-3.310 for the changes, and depended on pain and mental health.

CONCLUSION

Moderate to strong cross-sectional and moderate to weak longitudinal correlations were found between the 6MWD and the SF-36 PF. Pain and mental health should be considered when interpreting physical function. For a comprehensive assessment in clinical practice and research, the combination of self-rated and tested physical function measures is recommended.

Occipital transcranial direct current stimulation in episodic migraine patients: effect on cerebral perfusion

Cerebral blood flow differs between migraine patients and healthy controls during attack and the interictal period. This study compares the brain perfusion of episodic migraine patients and healthy controls and investigates the influence of anodal transcranial direct current stimulation (tDCS) over the occipital cortex. We included healthy adult controls and episodic migraineurs. After a 28-day baseline period and the baseline visit, migraine patients received daily active or sham anodal tDCS over the occipital lobe for 28 days. All participants underwent a MRI scan at baseline; migraineurs were also scanned shortly after the stimulation period and about five months later. At baseline, brain perfusion of migraine patients and controls differed in several areas; among the stimulated areas, perfusion was increased in the cuneus of healthy controls. At the first visit, the active tDCS group had an increased blood flow in regions processing visual stimuli and a decreased perfusion in other areas. Perfusion did not differ at the second follow-up visit. The lower perfusion level in migraineurs in the cuneus indicates a lower preactivation level. Anodal tDCS over the occipital cortex increases perfusion of several areas shortly after the stimulation period, but not 5 months later. An increase in the cortical preactivation level could mediate the transient reduction of the migraine frequency.Trial registration: NCT03237754 (registered at clincicaltrials.gov; full date of first trial registration: 03/08/2017).

Guideline on multimodal rehabilitation for patients with post-intensive care syndrome

BACKGROUND

Intensive Care Unit (ICU) survivors often experience several impairments in their physical, cognitive, and psychological health status, which are labeled as post-intensive care syndrome (PICS). The aim of this work is to develop a multidisciplinary and -professional guideline for the rehabilitative therapy of PICS.

METHODS

A multidisciplinary/-professional task force of 15 healthcare professionals applied a structured, evidence-based approach to address 10 scientific questions. For each PICO-question (Population, Intervention, Comparison, and Outcome), best available evidence was identified. Recommendations were rated as "strong recommendation", "recommendation" or "therapy option", based on Grading of Recommendations, Assessment, Development and Evaluation principles. In addition, evidence gaps were identified.

RESULTS

The evidence resulted in 12 recommendations, 4 therapy options, and one statement for the prevention or treatment of PICS.

RECOMMENDATIONS

early mobilization, motor training, and nutrition/dysphagia management should be performed. Delirium prophylaxis focuses on behavioral interventions. ICU diaries can prevent/treat psychological health issues like anxiety and post-traumatic stress disorders. Early rehabilitation approaches as well as long-term access to specialized rehabilitation centers are recommended. Therapy options include additional physical rehabilitation interventions. Statement: A prerequisite for the treatment of PICS are the regular and repeated assessments of the physical, cognitive and psychological health in patients at risk for or having PICS.

CONCLUSIONS

PICS is a variable and complex syndrome that requires an individual multidisciplinary, and multiprofessional approach. Rehabilitation of PICS should include an assessment and therapy of motor-, cognitive-, and psychological health impairments.

The longitudinal influence of tDCS on occipital GABA and glutamate/glutamine levels in episodic migraineurs

This study investigated differences in the concentration of gamma-aminobutyric acid (GABA) and the combination of glutamine and glutamate (as GLX) in the early visual cortex of patients with episodic migraine and the influence of transcranial direct current stimulation (tDCS) on GABA and GLX. In this single-blind, sham-controlled trial, we randomly assigned patients with episodic migraine to receive daily anodal tDCS or sham stimulation. In addition, we included healthy controls. We acquired proton MR spectroscopy data of the visual cortex with 3 Tesla MRI at baseline and from migraine patients directly after the stimulation period and 4 months later. In 22 migraineurs and 25 controls, the GABA and the GLX concentrations did not differ at baseline between the groups. tDCS resulted in reduced concentrations of GABA but not GLX or the migraine frequency directly after the stimulation period, but not 4 months later. The changes in the levels of GABA in the early visual cortex of patients with episodic migraine in the interictal period suggest an effect of tDCS that allowed for subsequent changes in the migraine frequency. However, we might have missed relevant variations in the concentrations of these neurotransmitters during the follow-up period, as changes in migraine frequency appeared after the first MRI and disappeared before the second.

Comparison of Swiss versus Standard Acupuncture in Patients with Chronic Low Back Pain. A Study Protocol for a Randomized, Controlled, Single-Blind, Parallel Trial

Introduction

Chronic low back pain (CLBP) cannot sufficiently be treated by pharmacological therapy and generates substantial health-care costs worldwide. Acupuncture, a cost-effective, safe and non-pharmacological therapy, has shown promising results in relieving acute low back pain; however, the optimal acupuncture therapy for CLBP remains controversial. This study will compare two acupuncture methods for pain relief in CLBP.

Methods and Analysis

This randomized, controlled, single-blind, parallel trial will be conducted in patients with clinically diagnosed CLBP with a disease duration ≥3 months and an average pain intensity of ≥4 points on an 11-point Pain Intensity Numerical Rating Scale (pain-NRS) on the previous 7 days. Patients will be randomized to 9-week acupuncture therapy using Jiu Gong Points (termed Swiss low back acupuncture, SLBA) or standard acupuncture (SA) therapy (weeks 1-6: two sessions/week, weeks 7-9: one session/week, 15 sessions/patient in total). Measurements will be conducted before the first session (T1), at the end of the 9-week therapy (T2) and after 3- and 6-month follow-up (T3 and T4). The primary hypothesis is that 9 weeks of SLBA will be superior in reducing the pain severity assessed by the pain-NRS compared to SA therapy for CLBP. Secondary outcomes will be derived from the Short-Form 36, Oswestry Disability Index, Multidimensional Pain Inventory questionnaire, Symptom Checklist-90 - Revised questionnaire and a daily pain diary. Assuming a minimal clinically important difference in the pain-NRS of 0.39 and an effect size of ≥0.6 between SLBA and SA, 80% power, 0.05 alpha level and 20% dropouts, a total of 55 patients/arm will be required. The primary outcome will be analyzed in the intention-to-treat population using chained linear regression models. Patients, outcome assessors and data analysts will be blinded to the treatment arm.

Trial Registration

Clinicaltrials.gov Identifier: NCT05232487.

Cluster Headache and the Comprehension Paradox

Patients with primary headache disorders such as cluster headache cycle between being entirely healthy and almost completely incapacitated. Sick leave or reduced performance due to headache attacks demands flexibility by their social counterparts. The objective of this study is to test the hypothesis that headache patients cause frustration that grows with the times colleagues have to take over their work. In this study, we analysed cluster headache patients’ answers to an online questionnaire. Participants self-reported their number of sick days, the number of days on which leisure activities were missed and whether they felt understood by colleagues and family. We then investigated the correlation between the number of sick days and the proportion of patients feeling understood by colleagues and friends. We found that feeling understood by colleagues and friends decreases with a growing number of sick days. However, when sick days accrue further, this proportion increases again. The number of sick days correlates similarly with both colleagues’ and friends’ understanding. The number of cluster headache patients feeling understood by others decreases with an increasing number of sick days. Their social circles’ frustration with the patients’ failure to meet obligations and expectations are a likely reason. With a growing number of sick days, however, the portion of patients feeling understood rises again despite patients meeting others’ expectations even less. This ‘comprehension paradox’ implies the influence of other factors. We suspect that growing numbers of sick days foster understanding as the disability of the disease becomes increasingly apparent.

Mental and psychosocial health and health related quality of life before and after cardiac rehabilitation: a prospective cohort study with comparison to specific population norms

Background

Data on mental health improvement after cardiac rehabilitation (CR) are contradictory. The aim was to examine the mental and psycho-social health of patients admitted to our rehabilitation center following hospital treatment for acute coronary syndrome, before and after multidisciplinary CR.

Methods

Outcome was measured at admission and discharge by the 36-Item Short Form Survey (SF-36), the Symptom Checklist-90 Revised (SCL-90R), the Coping Strategy Questionnaire (CSQ) and the 6-min-walking distance test. The patients’ health status was compared with norms of sex-, age- and comorbidity-matched data from the German general population. Score differences from norms were measured by standardized mean differences (SMDs); health changes were quantified by standardized effect sizes (ESs). Their importance for comprehensive assessment was quantified by explorative factor analysis.

Results

Of n = 70 patients followed-up (male: 79%; mean age: 66.6 years), 79% had ≥ 3 comorbidities. At baseline, SF-36 Physical functioning (SMD = − 0.75), Role physical (− 0.90), Social functioning (SMD = − 0.44), and Role emotional (SMD = − 0.45) were significantly worse than the norm. After CR, almost all scores significantly improved by ES = 0.23 (SCL-90R Interpersonal sensitivity) to 1.04 (SF-36 Physical functioning). The strongest factor (up to 41.1% explained variance) for health state and change was the mental health domain, followed by function & pain (up to 26.3%).

Conclusions

Normative deficits in physical and psycho-social health were reported at baseline. After CR, at follow-up, all scores, except phobia, showed significant improvement. The comprehensive measurement of bio-psycho-social health should not be limited to depression and anxiety but include, especially, the somatization and social participation dimensions.

Catastrophizing as a prognostic factor for pain and physical function in the multidisciplinary rehabilitation of fibromyalgia and low back pain

BACKGROUND

Quantitative data on longitudinal associations between catastrophizing and pain or physical function are patchy. The study aimed to quantify the prognostic value of catastrophizing for pain and function in fibromyalgia and low back pain before and after rehabilitation.

METHODS

The associations of state and change on the Multidimensional Pain Inventory (MPI) Pain severity scale, the Short Form 36 (SF-36) Physical functioning scale, and the Six-Minute Walking Distance (6MWD) with the Coping Strategies Questionnaire (CSQ) Catastrophizing scale were quantified by multiple regression modeling to adjust for confounders.

RESULTS

Sex- and age matched cohorts (n=71 each) were compared. Pain and catastrophizing were worse in fibromyalgia than in low back pain, whereas the function levels were comparable. Baseline catastrophizing predicted pain change by adjusted correlations of 0.552 (fibromyalgia) and 0.450 (low back pain), self-rated function by 0.403 and 0.308, and the 6MWD by 0.270 and -0.072. The change in catastrophizing was associated to the change in pain by 0.440 (fibromyalgia) and 0.614 (low back pain), self-rated function by 0.122 and 0.465, and the 6MWD by 0186 and 0.162.

CONCLUSIONS

Catastrophizing (pain-related worrying) was a potential prognostic factor, especially for pain and somewhat less for self-rated physical function but it was only weakly predictive for the walking distance in both conditions, independently of potential confounders, such as sex, age, baseline severity and others. Reduction of maladaptive coping should be integrated into the management of chronic pain.

Clinical features of migraine with onset prior to or during start of combined hormonal contraception: a prospective cohort study

Many studies have described the features of menstrually related migraines but there is a lack of knowledge regarding the features of migraine in combined hormonal contraceptive users (CHC). Hormone-withdrawal migraines in the pill-free period could differ from those in the natural cycle. Gynaecologic comorbidities, like dysmenorrhea and endometriosis, but also depression or a family history might modify the course of migraine. A better understanding of migraine features linked to special hormonal situations could improve treatment. For this prospective cohort study, we conducted telephone interviews with women using a CHC and reporting withdrawal migraine to collect information on migraine frequency, intensity, triggers, symptoms, pain medication, gynaecologic history and comorbidities (n = 48). A subset of women agreed to also document their migraines in prospective diaries. The mean number of migraine days per cycle was 4.2 (± 2.7). Around 50% of these migraines occurred during the hormone-free interval. Migraine frequency was significantly higher in women who suffered from migraine before CHC start (5.0 ± 3.1) (n = 22) in comparison to those with migraine onset after CHC start (3.5 ± 2.1) (n = 26). Menstrually related attacks were described as more painful (57.5%), especially in women with migraine onset before CHC use (72%) (p < 0.02). Comorbidities were rare, except dysmenorrhea. The majority of migraine attacks in CHC users occur during the hormone-free interval. Similar as in the natural cycle, hormone-withdrawal migraines in CHC users are very intense and the response to acute medication is less good, especially in those women, who developed migraine before CHC use.

Dealing with Headache: Sex Differences in the Burden of Migraine- and Tension-Type Headache

OBJECTIVE

The aim of this study was to investigate sex differences in the burden of migraine and tension-type headache (TTH).

BACKGROUND

Migraine and TTH are more common in women than in men, with differences in comorbidities, treatment responses, disease-modifying factors, and ictal and interictal burden of disease. Information about sex-related influences on ictal and interictal burden is limited, and an increased understanding is mandatory to provide tailored individual treatment for female and male patients.

METHODS

Participants answered an online survey based on the EUROLIGHT questionnaire. Inclusion criteria were the consent to participate, complete responses to the diagnostic questions, and information about their sex. Sex differences were investigated using the Mann-Whitney U test or Chi-square test. For detecting factors that influence the burden of disease, we built binary regression models.

RESULTS

We included 472 (74.6% female) migraineurs and 161 (59.6% female) participants with TTH. Women with migraine reported significantly more problems in their love lives, more self-concealment, less feelings of being understood by family and friends, more interictal anxiety, a higher pain severity, and more depression and anxiety symptoms than men. For TTH, we did not find significant sex-related differences. A higher headache frequency was the factor that increased the burden of disease in female but not in male migraneurs.

CONCLUSION

The burden of disease was higher in women than men with migraine in many aspects, but not with TTH. Therefore, according to our results, there is a need for sex-specific precision medicine for migraine but not TTH. Controlling the headache frequency with a proper acute or prophylactic treatment and treating comorbid depression and anxiety symptoms is crucial to ease migraine's burden, especially in women.

The impact of the disease burden on the quality of life of cluster headache patients

Background:

Cluster headache cannot be cured, and not all attacks can be aborted or prevented. Nevertheless, therapeutic guidelines focus solely on the attacks and ignore reverberations of the disorder on patients’ lives. However, it is likely that not only pain reduces patients’ quality of life (QoL).

Objective:

To investigate whether the interictal burden independently influence the QoL of subjects suffering from cluster headache.

Methods:

In this cross-sectional study, we asked patients with a self-reported cluster headache diagnosis to answer a modified EUROLIGHT questionnaire that included the EURO-HIS QoL scale. We built a generalised linear model and included the QoL as the dependent variable. Independent variables comprised both the ictal and the interictal burden.

Results:

The data of 625 participants entered the analysis. Several aspects of the interictal burden independently reduced the QoL. Among them were fear of pain, self-concealment, and private life difficulties due to the disorder.

Conclusion:

Both the ictal and the interictal burden of cluster headache independently reduce patients’ QoL. We advocate adopting a more holistic approach to cluster headache management extending the focus towards the afflicted person and their QoL, which would generate novel therapeutic goals and strategies, complementary to treating and preventing cluster headache attacks.

Comprehensiveness and validity of a multidimensional assessment in patients with chronic low back pain: a prospective cohort study

Background

Chronic low back pain is a multidimensional syndrome affecting physical activity and function, health-related quality of life and employment status. The aim of the study was to quantify the cross-sectional and longitudinal validity of single measurement scales in specific construct domains and to examine how they combine to build a comprehensive outcome, covering the complex construct of chronic low back pain before and after a standardized interdisciplinary pain program.

Methods

This prospective cohort study assessed 177 patients using the Short Form 36 (SF-36), the Multidimensional Pain Inventory (MPI), the Symptom Checklist-90-Revised (SCL-90-R), the Oswestry Disability Index (ODI), and 2 functional performance tests, the Back Performance Scale (BPS) and the 6-Minute Walking Distance (6MWD). The comprehensiveness and overlap of the constructs used were quantified cross-sectionally and longitudinally by bivariate correlations, exploratory factor analysis, and effect sizes.

Results

The mean age of the participants was 48.0 years (+/− 12.7); 59.3% were female. Correlations of baseline scores ranged from r = − 0.01 (BPS with MPI Life control) to r = 0.76 (SF-36 Mental health with MPI Negative mood). SF-36 Physical functioning correlated highest with the functional performance tests (r = 0.58 BPS, 0.67 6MWD) and ODI (0.56). Correlations of change scores (difference of follow-up – baseline score) were consistent but weaker. Factor analysis revealed 2 factors: “psychosocial” and “pain & function” (totally explained variance 44.0–60.9%). Psychosocial factors loaded strongest (up to 0.89 SCL-90-R) on the first factor, covering 2/3 of the explained variance. Pain and function (ing) loaded more strongly on the second factor (up to 0.81 SF-36 Physical functioning at follow-up). All scales showed improvements, with effect sizes ranging from 0.16–0.67.

Conclusions

Our results confirm previous findings that the chronic low back pain syndrome is highly multifactorial and comprises many more dimensions of health and quality of life than merely back-related functioning. A comprehensive outcome measurement should include the predominant psychosocial domain and a broad spectrum of measurement constructs in order to assess the full complexity of the chronic low back syndrome. Convergence and divergence of the scales capture the overlapping contents and nuances within the constructs.

Structural brain network characteristics in patients with episodic and chronic migraine

Background

Migraine is a primary headache disorder that can be classified into an episodic (EM) and a chronic form (CM). Network analysis within the graph-theoretical framework based on connectivity patterns provides an approach to observe large-scale structural integrity. We test the hypothesis that migraineurs are characterized by a segregated network.

Methods

19 healthy controls (HC), 17 EM patients and 12 CM patients were included. Cortical thickness and subcortical volumes were computed, and topology was analyzed using a graph theory analytical framework and network-based statistics. We further used support vector machines regression (SVR) to identify whether these network measures were able to predict clinical parameters.

Results

Network based statistics revealed significantly lower interregional connectivity strength between anatomical compartments including the fronto-temporal, parietal and visual areas in EM and CM when compared to HC. Higher assortativity was seen in both patients’ group, with higher modularity for CM and higher transitivity for EM compared to HC. For subcortical networks, higher assortativity and transitivity were observed for both patients’ group with higher modularity for CM. SVR revealed that network measures could robustly predict clinical parameters for migraineurs.

Conclusion

We found global network disruption for EM and CM indicated by highly segregated network in migraine patients compared to HC. Higher modularity but lower clustering coefficient in CM is suggestive of more segregation in this group compared to EM. The presence of a segregated network could be a sign of maladaptive reorganization of headache related brain circuits, leading to migraine attacks or secondary alterations to pain.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10194-021-01216-8.

Mitochondrial function and oxidative stress markers in higher-frequency episodic migraine

Increasing evidence points towards the role of mitochondrial functioning, energy metabolism, and oxidative stress in migraine. However not all previous research has been conclusive and some mitochondrial function/oxidative stress markers have not yet been examined. To this end, alpha-lipoic acid (ALA), total thiols, total plasma antioxidant capacity (TAC), lipid peroxide (PerOx), oxidised LDL (oxLDL), HbA1c and lactate were determined in the serum of 32 higher frequency episodic migraineurs (5-14 migraine days/ months, 19 with aura, 28 females) in this cross-sectional study. The majority of patients had abnormally low ALA and lactate levels (87.5% and 78.1%, respectively). 46.9% of the patients had abnormally high PerOx values, while for thiols and TAC over one third of patients had abnormally low values (31.2% and 37.5%, respectively). 21.9% of patients had abnormally low HbA1c and none had an HbA1c level above 5.6%. oxLDL was normal in all but one patient. This study provides further evidence for a role of oxidative stress and altered metabolism in migraine pathophysiology, which might represent a suitable therapeutic target. ALA, being too low in almost 90% of patients, might represent a potential biomarker for migraine. Further research is needed to replicate these results, in particular a comparison with a control group.This study is part of the trial registration: ClinicalTrials.gov: NCT03132233, registered on 27.04.2017, https://clinicaltrials.gov/ct2/show/NCT03132233 .

Green Flags and headache: A concept study using the Delphi method

OBJECTIVE

The aim of this study was to collect and rate Green Flags, that is, symptoms or pieces of information indicating that a patient is more likely to suffer from a primary than from a secondary headache.

BACKGROUND

When assessing headaches, a central question to be answered is whether the pain is primary or secondary to another disorder. To maximize the likelihood of a correct diagnosis, relevant signs and symptoms must be sought, identified, and weighed against each other.

METHODS

The project was designed as a Delphi study. In the first round, an expert panel proposed green flags that were rated anonymously in two subsequent rounds. Proposals with an average rating of 4.0 and higher on a scale from 0 to 5 reached consensus.

RESULTS

Five Green Flags reached consensus: (i) "The current headache has already been present during childhood"; (ii) "The headache occurs in temporal relationship with the menstrual cycle"; (iii) "The patient has headache-free days"; (iv) "Close family members have the same headache phenotype"; and (v) "Headache occurred or stopped more than one week ago."

CONCLUSIONS

We propose five Green Flags for primary headache disorders. None being a pathognomonic sign, we recommend searching for both Green Flags and Red Flags. If both are present, a secondary headache should be suspected. Overall, the application of the Green Flag concept in clinical practice is likely to increase diagnostic accuracy and improve diagnostic resource allocation. Prospective studies in clinical populations should be conducted to validate these Green Flags.

Long-Term Effects of Self-Administered Transcranial Direct Current Stimulation in Episodic Migraine Prevention: Results of a Randomized Controlled Trial

BACKGROUND

Migraine is a multifactorial neurovascular disorder, which affects about 12% of the general population. In episodic migraine, the visual cortex revealed abnormal processing, most likely due to decreased preactivation level. Transcranial direct current stimulation (tDCS) is able to modify cortical excitability and might result in an alleviation of migraine occurrence if used repetitively.

OBJECTIVE

To test the hypothesis that self-administered anodal tDCS over the visual cortex significantly decreases the number of monthly migraine days in episodic migraine.

MATERIALS AND METHODS

The study was single-blind, randomized, and sham-controlled. Inclusion criteria were age 18-80 years and an ICHD-3 diagnosis of episodic migraine. Exclusion criteria were pregnancy, presence of a neurodegenerative disorder, a contraindication against MRI examinations, and less than two migraine days during the 28-day baseline period. Patients in whom the baseline period suggested chronic migraine were excluded. After baseline, participants applied daily either verum (anodal-1 mA to 20 min) or sham tDCS (anodal-1 mA to 30 sec) at Oz (reference Cz electrode) for 28 days. Headache diaries were used to record the number of migraine days at baseline, during the stimulation period, and during four subsequent 28-day periods.

RESULTS

Twenty-eight patients were included; two were excluded after the baseline period because less than two migraine days occurred; three were excluded because their headache diaries suggested the diagnosis of chronic migraine. Twenty-three datasets were taken for further analysis. Compared to sham tDCS (n = 12), verum tDCS (n = 11) resulted in a lower number of migraine days (p = 0.010) across all follow-up periods. We found no significant change in total headache days (p = 0.165), anxiety (p = 0.884), or depression scores (p = 0.535). No serious adverse events occurred; minor side effects were similar in both groups.

CONCLUSIONS

This study provides Class II evidence that self-administered anodal tDCS over the visual cortex in episodic migraine results in a significantly lower number of monthly migraine days. However, it has neither an immediate nor a long-term effect.

Employee and Employer Benefits From a Migraine Management Program: Disease Outcomes and Cost Analysis

OBJECTIVE

To assess the impact of a migraine management program offered as a complimentary service by a company within its corporate well-being program.

BACKGROUND

Migraine imposes a substantial burden on patients, families, employers, and societies. As migraine primarily affects working-age adults, this has important implications for both employees and employers. Workplace educational and well-being programs positively contribute to employees' productivity, reduce costs related to absenteeism, and improve the quality of life of the employees living with migraine.

METHODS

This was a non-interventional cohort study, which followed employees and their family members over time. Participants received 1 telemedicine consultation to determine migraine diagnosis or a high probability of having migraine and 6 sessions of individualized telecoaching from a specialized nurse via a specially developed smartphone application to optimize their migraine management leveraging all appropriate medical and lifestyle options. Participants were evaluated during the program and at 3 months after completion through a series of validated questionnaires including Migraine Disability Assessment (MIDAS), Patient Activation Measure (PAM), and satisfaction with the services offered. A cost analysis was also performed to determine the economic benefit of the program considering the number of completers, dropouts, their associated program costs, MIDAS data, average salary of a Swiss employee in the pharma sector, and working days per year.

RESULTS

Of the 141 participants enrolled in the program, 79 completed 6-month and 42 completed 9-month assessments. The total MIDAS scores (mean, standard deviation [SD]) significantly improved from baseline by 54% at Month 6 (15.0 [13.6] vs 6.9 [8.2]; mean [SD] reduction: 8.1 [12.9], 95% confidence interval [CI]: 5.6-10.6; P < .0001) and by 64% at Month 9 (15.4 [14.7] vs 5.6 [6.0]; mean [SD] reduction: 9.8 [14.0], 95% CI: 6.6-13.0; P < .0001). The PAM scores also significantly improved from baseline by 8% at Month 6 (63.8 [10.9] vs 69.6 [12.8]; mean [SD] increase: 5.8 [12.8], 95% CI: 3.2-8.4; P = .003) and 11% at Month 9 (63.5 [10.7] vs 71.3 [12.2]; mean [SD] increase: 7.8 [11.0], 95% CI: 4.3-11.2; P = .003). At Month 6, common coaching lessons and respective action plans focused on progressive muscle relaxation, sleep, hydration, nutrition, general disease education, and stress management. The exit survey showed that the majority of the participants who completed the program had a meaningful and sustained improvement in their overall health and reported a high level of satisfaction with the program. The cost analysis revealed that on average participants gained 10.8 (95% CI: 9.3-12.3) working days/year that were previously lost due to migraine, resulting in a positive return on investment (ROI) of 490% (95% CI: 410%-570%), indicating a higher magnitude of savings that could be achieved by the implementation of such program. In addition to ROI and work productivity gained, participants also gained on average 13.6 (95% CI: 9.9-17.3) migraine-free days/year for their private and social life.

CONCLUSION

The employer-sponsored disease management program provided a better understanding of migraine, promoted methods and approaches to improve management by combining medical and lifestyle options leading to significant improvements in migraine symptoms that sustained beyond the intervention, supporting prolonged effectiveness of such programs. The program also provided a high ROI to the employer, supporting that the systematic inclusion of such programs into corporate well-being initiatives can be of significant benefit not only to the impacted individuals but to the employers as well.

Why is it important to diagnose hemicrania continua?

Hemicrania continua (HC) is an indomethacin-responsive primary headache which belongs to the trigeminal autonomic cephalalgias. Although the first description of HC was 35 years ago, there are still different views regarding the clinical course, the diagnostic criteria, and the treatment. The high clinical heterogeneity of HC, missed diagnosis, and the delay to the correct diagnosis are important in patient care. Central features of HC are continuous side-locked headaches (with superimposed exacerbations) and the response to indomethacin. We are describing the case of a 29-year-old women who developed right-sided headache 3 weeks after the excision of a right-sided vestibular schwannoma. She tried different painkillers and also was started on a prophylactic treatment with oxcarbazepine, acupuncture, and physiotherapy. But nothing really helped. She was then admitted for an inpatient withdrawal program for medication overuse headache. Again the pain did not change. She has then been treated with indomethacin 50-mg tds, where after the headache improved rapidly within 3 days. This educational case presentation and review of the literature aims to consider HC as a possible differential diagnosis in chronic headache, especially when side-locked and shows that indomethacin maybe a quick therapeutic option before putting the patients on a long treatment odyssey with analgesics and other drugs.

Case Report: New-Onset Retinal Migraine After Transseptal Catheterization

BACKGROUND

While new-onset migraine headaches and binocular visual aura have been reported after transseptal catheterization (TSC), this case suggests that retinal aura may emerge also after this procedure.

CASE DESCRIPTION

This 38-year-old male with paroxysmal atrial fibrillation had received TSC and cryoablation, and subsequently developed isolated monocular aura phenomena. The first episode happened a few hours after the intervention and was not accompanied by headache or other aura phenomena. The patient's history was negative for migraine. Brain magnetic resonance imaging demonstrated 2 lacunar diffusion restrictions in the left medial cerebral artery territory that were most likely catheterization related. Over the next 14 days, 3 additional, stereotyped episodes (duration = 20-30 minutes) with zigzag lines and flickering small bright dots in the central visual field of one eye (moving laterally) occurred. A central scotoma was noted during one episode.

CONCLUSIONS

This is the first case with retinal aura phenomena meeting International Classification of Headache Disorders diagnostic criteria for retinal migraine, suggesting that this rare migraine variant can be triggered by TSC.

The impact of depressive symptoms on the burden of cluster headache: Results of the EUROLIGHT Cluster Headache Project, an Internet-based, cross-sectional study of people with cluster headache

Many patients affected by cluster headache (CH) have a co-morbid depression. The aim of this study is to evaluate how the burden of disease is influenced by depressive symptoms measured by a depression score. The study was cross-sectional and Internet-based. We included individuals with a self-reported diagnosis of CH and asked them to fill out the EUROLIGHT questionnaire, which includes a depression score. The number of headache days was higher among patients with higher depression scores. In these participants, worrying about future attacks, avoiding triggers, believing to have earned less and avoiding to talk about the disease were more common as well. Individuals with higher depression scores reported a significantly higher burden of disease. It is possible that fear of pain, self-concealment and fear of impoverishment are consequences of the depression attributed to the headache disorder.

Interictal Hyperperfusion in the Higher Visual Cortex in Patients With Episodic Migraine

BACKGROUND

Migraine pathophysiology is complex and probably involves cortical and subcortical alterations. Structural and functional brain imaging studies indicate alterations in the higher order visual cortex in patients with migraine. Arterial spin labeling magnetic resonance imaging (ASL-MRI) is a non-invasive imaging method for assessing changes in cerebral blood flow (CBF) in vivo.

OBJECTIVE

To examine if interictal CBF differs between patients with episodic migraine (EM) with or without aura and healthy controls (HC).

METHODS

We assessed interictal CBF using 2D pseudo-continuous ASL-MRI on a 3 Tesla Philips scanner (University Hospital Zurich, Switzerland) in EM (N = 17, mean age 32.7 ± 9.9, 13 females) and HC (N = 19, mean age 31.0 ± 9.3, 11 females).

RESULTS

Compared to HC, EM showed exclusively hyperperfusion in the right MT+ and Cohen's d effect size was 0.99 (HC mean CBF ± SD: 33.1 ± 5.9 mL/100 g/minutes; EM mean CBF: 40.9 ± 9.4 mL/100 g/minutes). EM with aura (N = 13, MwA) revealed hyperperfusion compared to HC in the right MT+ and superior temporal gyrus. For MT, Cohen's d effect size was 1.34 (HC mean CBF ± SD: 33.1 ± 5.9 mL/100 g/minutes; MwA mean CBF: 43.3 ± 8.6 mL/100 g/minutes). For the superior temporal gyrus, Cohen's d effect size was 1.28 (HC mean CBF ± SD: 40.1 ± 4.9 mL/100 g/minutes; MwA mean CBF: 47.4 ± 6.4 mL/100 g/minutes). In EM, anxiety was positively associated with CBF in the parietal operculum and angular gyrus.

CONCLUSIONS

Our results suggest that extrastriate brain regions probably involved in cortical spreading depression are associated with CBF changes in the interictal state. We conclude that ASL-MRI is a sensitive method to identify local neuro-functional abnormalities in CBF in patients with EM in the interictal state.

The EUROLIGHT cluster headache project: Description of methods and the study population – An Internet-based cross-sectional study of people with cluster headache

Objective:

To present the methodology and to describe the sample of a large, Internet-based survey on the burden of cluster headache (CH).

Methods:

Participants filled out a questionnaire online. Inclusion criteria were a reported diagnosis of CH and a residency in a European country; exclusion criteria were refusal to give informed consent and to complete the questionnaire.

Results:

A total of 1514 participants completed the questionnaire. Of these, 66.2% were male and 31.2% reported suffering from chronic CH. The diagnosis was validated based upon the responses in 92.9% of the participants. Other diagnoses seemed more likely in 0.8%. Among the participants with self-reported chronic CH, the International Classification of Headache Disorders-3 beta criteria for chronicity were fulfilled by 90.8%.

Conclusions:

In this article, we discuss the applied methodology as well as the properties of the sample. The overall accuracy of the self-reported diagnoses was very good as judged by our questionnaire; women and chronic CH were slightly over-represented. We will present the results of more thorough analyses in future articles and believe that these data will provide deeper insights into the burden of CH and will help to give a voice to those who endure this painful disease.

Migräneprophylaxe 2019 – die Rolle der CGRP Antagonisten

Zusammenfassung. Das CGRP System ist Teil der Schmerzübertragung bei Migräne und Bestandteil eines komplexen pathophysiologischen Geschehens. Durch monoklonale Antikörper mit Wirkmechanismus im CGRP System wurde erstmals gezielt eine Substanzklasse entwickelt, deren Ziel die Reduktion der Attackenfrequenz und -intensität, also die Prophylaxe bei Migräne ist. Die Wirksamkeit ist vergleichbar mit etablierten Prophylaktika. Verträglichkeit und Sicherheit scheinen nach den publizierten Studiendaten und ersten klinischen Erfahrungen exzellent. Vor den Folgen des hohen Preises schützen sich die Kostenträger mit Limitationen. Die erste Substanz ist in der Schweiz zugelassen. Welche Rolle die neue Substanzklasse in der stratifizierten Behandlung der Betroffenen spielen wird, wird sich im Verlauf, insbesondere nach Zulassung mehrerer Substanzen, im klinischen Alltag zeigen.

Translation, cross-cultural adaptation and reliability of the German version of the migraine disability assessment (MIDAS) questionnaire

Background

The Migraine Disability Assessment (MIDAS) is a brief questionnaire and measures headache-related disability. This study aimed to translate and cross-culturally adapt the original English version of the MIDAS to German and to test its reliability.

Methods

The standardized translation process followed international guidelines. The pre-final version was tested for clarity and comprehensibility by 34 headache sufferers. Test-retest reliability of the final version was quantified by 36 headache patients completing the MIDAS twice with an interval of 48 h. Reliability was determined by intraclass correlation coefficients and internal consistency by Cronbach’s α.

Results

All steps of the translation process were followed, documented and approved by the developer of the MIDAS. The expert committee discussed in detail the complex phrasing of the questions that refer to one to another, especially exclusion of headache-days from one item to the next. The German version contains more active verb sentences and prefers the perfect to the imperfect tense. The MIDAS scales intraclass correlation coefficients ranged from 0.884 to 0.994 and was 0.991 (95% CI: 0.982–0.995) for the MIDAS total score. Cronbach’s α for the MIDAS as a whole was 0.69 at test and 0.67 at retest.

Conclusions

The translation process was challenged by the comprehensibility of the questionnaire. The German version of the MIDAS is a highly reliable instrument for assessing headache related disability with moderate internal consistency. Provided validity testing of the German MIDAS is successful, it can be recommended for use in clinical practice as well as in research.

Electronic supplementary material

The online version of this article (10.1186/s12955-018-0871-5) contains supplementary material, which is available to authorized users.

Rivaroxaban plasma levels in acute ischemic stroke and intracerebral hemorrhage

OBJECTIVE

Information about rivaroxaban plasma level (RivLev) may guide treatment decisions in patients with acute ischemic stroke (AIS) and intracerebral hemorrhage (ICH) taking rivaroxaban.

METHODS

In a multicenter registry-based study (Novel Oral Anticoagulants in Stroke Patients collaboration; ClinicalTrials.gov: NCT02353585) of patients with stroke while taking rivaroxaban, we compared RivLev in patients with AIS and ICH. We determined how many AIS patients had RivLev ≤ 100ng/ml, indicating possible eligibility for thrombolysis, and how many ICH patients had RivLev ≥ 75ng/ml, making them possibly eligible for the use of specific reversal agents. We explored factors associated with RivLev (Spearman correlation, regression models) and studied the sensitivity and specificity of international normalized ratio (INR) thresholds to substitute RivLev using cross tables and receiver operating characteristic curves.

RESULTS

Among 241 patients (median age = 80 years, interquartile range [IQR] = 73-84; median time from onset to admission = 2 hours, IQR = 1-4.5 hours; median RivLev = 89ng/ml, IQR = 31-194), 190 had AIS and 51 had ICH. RivLev was similar in AIS patients (82ng/ml, IQR = 30-202) and ICH patients (102ng/ml, IQR = 51-165; p = 0.24). Trough RivLev_{(≤137ng/ml)} occurred in 126/190 (66.3%) AIS and 34/51 (66.7%) ICH patients. Among AIS patients, 108/190 (56.8%) had RivLev ≤ 100ng/ml. In ICH patients, 33/51 (64.7%) had RivLev ≥ 75ng/ml. RivLev was associated with rivaroxaban dosage, and inversely with renal function and time since last intake (each p < 0.05). INR ≤ 1.0 had a specificity of 98.9% and a sensitivity of 25.7% to predict RivLev ≤ 100ng/ml. INR ≥ 1.4 had a sensitivity of 59.3% and specificity of 90.1% to predict RivLev ≥ 75ng/ml.

INTERPRETATION

RivLev did not differ between patients with AIS and ICH. Half of the patients with AIS under rivaroxaban had a RivLev low enough to consider thrombolysis. In ICH patients, two-thirds had a RivLev high enough to meet the eligibility for the use of a specific reversal agent. INR thresholds perform poorly to inform treatment decisions in individual patients. Ann Neurol 2018;83:451-459.

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Zusammenfassung. Chronische Kopfschmerzen stellen ein häufiges Problem in der Praxis dar. Die Behandlung beinhaltet eine Kombination von medikamentösen und nichtmedikamentösen Therapieverfahren im Rahmen eines multimodalen Settings. Neben der chronischen Migräne steht der Medikamentenübergebrauchskopfschmerz im Vordergrund. Hierbei ist ein zusätzliches Ziel, die Patienten vorausgehend im ambulanten oder stationären Setting von den übermässig konsumierten Schmerz- und Migränemittel zu entziehen. Mit der Kombination von einem Medikamentenentzug mit der nachfolgenden Optimierung der Migränebehandlung akut und prophylaktisch lässt sich in den allermeisten Fällen eine Verminderung der Kopfschmerzfrequenz und dadurch eine Verbesserung der Lebensqualität erreichen.

Neurorehabilitation bei Kopfschmerzen

Zusammenfassung. Medikamentenübergebrauchskopfschmerzen gehen häufig mit einer beträchtlichen Einschränkung und einem Partizipationsverlust im Leben der Patientinnen und Patienten einher. Nicht selten sind sowohl Berufs- als auch Privatleben kritisch kompromittiert. Komorbiditäten, Substanzabhängigkeit über die Schmerzmittel hinaus und ungünstige Kontextfaktoren beeinflussen die Therapierbarkeit. Die Therapie besteht aus einem Entzug akut wirksamer Schmerzmittel sowie einer anschliessenden Behandlung mit dem Ziel einer Stabilisierung. Diese reicht vom ambulanten Setting in der Sprechstunde bis hin zum stationären Entzug mit anschliessender stationärer kopfschmerzspezifischer Neurorehabilitation. Neurobiologische Erkenntnisse, insbesondere aus modernen bildgebenden Studien, helfen, das Krankheitsbild besser zu verstehen und Behandlungsansätze zu stratifizieren. Weitere klinische und pathophysiologische Studien sind notwendig.

[Unusual Migraine Manifestations]

Migraine is a complex neurologic disorder by which several systems of the central nervous system (autonomous system, affective, cognitive, sensoric and motoric system) may be affected on different levels. Around a fourth of the patients have migraine aura. The most common aura is the visual aura, followed by sensoric aura. But motoric deficits as well as deficits of higher cortical centers (disorders of thinking, orientation, coherence or concentration) may occur as well. In analogy with a headache calendar, an aura calendar can deliver important help in the diagnostic process of rare migraine manifestations and prevent underdiagnosis of unusual migraine manifestations. Complex migraine manifestations are diagnoses of exlusion, and a broad diagnostic work-up is warranted in order to exclude dangerous neurologic pathologies. There are no specific therapeutic recommendations, as there is a lack of randomized controlled studies.

Chirp stimulation: H-response short and dynamic

Background

Migraine patients have an increased photic-driving response. This ‘H-response’ (HR) has potential diagnostic value but it is time consuming.

Aim

The aim of the study was to establish a fast and standardized test for the study of migraine biology and treatment.

Methods

We studied 11 migraine patients and 11 matched control participants. We used stroboscope flashes with a ‘chirp’-like linear frequency-increase from 10 to 40 Hz. EEG was recorded from occipital electrodes. Power spectral density was calculated for the stimulus response and corrected for baseline. An HR-estimator was calculated as the average power between 18 and 26 Hz in the stimulation-frequency window.

Results

There was a significant difference for single ( p < 0.05) and for 10 averaged recordings ( p < 0.01) between migraineurs and controls, and a high inter-test reliability (Cronbach’s alpha = 0.94).

Conclusion

Chirp-like stimulation to study the H-response is reliable and efficient and might therefore have a potential for acute interventional studies in migraine research.

Prevalence of medication overuse headache in an interdisciplinary pain clinic

Background

Medication overuse headache (MOH) has been recognized as an important problem in headache patients although the pathophysiological mechanisms remain unclear. The diagnosis of MOH is based on clinical characteristics defined by the International Headache Society. The aim was the evaluation of the diagnostic criteria of MOH in a mixed population of chronic pain patients to gain information about the prevalence and possible associations with MOH.

Methods

Data of all patients referred to the interdisciplinary pain clinic at the University Hospital of Zurich between September 2005 and December 2007 were retrospectively analyzed. Demographic data (age, sex, history of migration), as well as data about duration of pain disease, category of pain disease (neurological, psychiatric, rheumatologic, other), use of medication, history of trauma, and comorbidity of depression and anxiety have been collected.

Results

Totally 178 of 187 consecutive chronic pain patients were included in the study. A total of 138 patients (78%) used analgesics on 15 or more days per month. Chronic headache was more prevalent among patients with analgesic overuse (39.8%) than without analgesic overuse (18%). The prevalence of MOH was 29%. The odds ratio (OR) for a patient with medication overuse to have chronic headache was 13.1 if he had a history of primary headache, compared to a patient without a primary headache syndrome. Furthermore, history of headache (OR 2.5, CI [1.13;5.44]), history of migration (OR 2.9, CI [1.31;6.32]) and comorbid depression (OR 3.5, CI [1.46;8.52]) were associated with overuse of acute medication, in general.

Conclusions

Primary headaches have a high risk for chronification in patients overusing analgesics for other pain disorders. Whereas history of headache, history of migration and comorbidity of depression are independentely associated with analgesic overuse in this group of patients.

Psychometric schizotypy modulates levodopa effects on lateralized lexical decision performance

Emergence of psychotic thought has been related to a breakdown in left-hemisphere language dominance. Dopamine (DA) is implicated in both psychotic pathology and modulation of the semantic system. The present study explored whether controlled DA administration modulates basic language functions: (1) in general and/or (2) as a function of schizophrenia-associated thought. Forty healthy men performed a tachistoscopic lexical decision task. Participants' performance was also analyzed as a function of their positive (magical ideation, MI) and negative (physical anhedonia, PHYSAN) schizotypal features. Half of the subjects received 200 mg levodopa, the other half a placebo. Our findings showed that pharmacological treatment per se did not influence task performance, but influenced laterality patterns as a function of participants' schizotypal features. In the placebo, but not in the levodopa group, right hemisphere language contribution increased as a function of increasing MI scores. In the levodopa, but not in the placebo group, superior left hemisphere lexical decision performance was related to increasing PHYSAN scores. The findings from both substance groups suggest that in the healthy brain, a DA agonist restores left-hemispheric dominance for language by reducing right-hemispheric contribution with respect to a positive schizotypal trait and by increasing left-hemispheric specialization with respect to a negative schizotypal trait. We conjecture that the healthy brain compensates through intact neurochemical mechanisms an increased DA concentration, in particular for persons with elevated positive psychotic-like features.

Nonstereotyped responding in positive schizotypy after a single dose of levodopa

Stereotyped behavior and left-sided orientation biases, associated with the dopamine (DA) system, were observed in populations of the schizophrenia spectrum disorders. We investigated whether heightened DA concentrations influence both side biases and stereotyped responding in a visuo-motor computer task, in which 90, 180, and 270 degrees rotated objects had to be brought into a target position. To account for the role of the schizophrenia spectrum, task performance was also analyzed as a function of healthy participants' high or low magical ideation (MI), a positive schizotypal feature. The first 36 participants (20 women) remained substance free. In a second sample, 20 men received levodopa and 20 men a placebo in a double-blind procedure. Results showed that high MI scorers responded more stereotyped than low MI scorers, without being specifically biased towards the left side. Rotation preferences toward one or the other side made high MI scorers less flexible for objects efficiently to be rotated into the opposite direction. This inflexibility may reflect impaired left hemisphere functioning. Unexpectedly, in the levodopa group, high MI scorers performed superior to low MI scorers. Since DA actions appear to follow an inverted U-shape function, the 'low' performing high MI scorers profited from the enhanced DA availability. Our observation in the levodopa group points to a dissociation between schizotypy and schizophrenia: while cognitive improvement in schizophrenia can occur after treatment with atypical neuroleptic agents, in our positive schizotypal participants a DA agonist resulted in improved task performance. This dissociation may point to protective neurochemical mechanisms preventing healthy schizotypes from developing full-blown psychotic symptoms.

Ergot and triptan overuse in Austria--an evaluation of clinical data and cost

Austria is one of the countries, in which ergots are still the most commonly used acute anti-migraine drugs. Overuse and chronification is a clinical problem for ergots, but also for the recently developed triptans. In a retrospective study for the year 1999 we evaluated clinical data from all Austrian neurological hospitals including cost of withdrawal as well as the estimated cost for ergots and triptans on the pharmaceutical retail market. We identified a total of 96 patients that underwent withdrawal, all of whom because of ergot overuse, and some with considerable long-term side-effects. The cost of withdrawal (more than 1300 000) together with direct cost of medication amounted to more than 11 million. In contrast, cost of medication for triptans was 12.8 million for the same year, without any cost for withdrawal. If only cost aspects were to be considered in the prescription of acute anti-migraine drugs, our data would suggest to choose ergots rather than triptans. However, as scientific evidence is clearly in favour of triptans, decision making for the prescribing clinicians is more complex and will primarily focus on optimizing patient care, but also depend on the respective socio-economic situation.

Reduced gating of middle-latency auditory evoked potentials (P50) in migraine patients: another indication of abnormal sensory processing?

Habituation of cortical evoked responses to repetitive stimuli is reduced in migraine between attacks. To explore another aspect of information processing, we measured auditory sensory gating. The amplitude of the P50 response to the second of two homologous stimuli was significantly less reduced in migraineurs than in healthy volunteers. This lack of auditory sensory gating may be due to a hypofunction of monoaminergic subcortico-cortical pathways, which is also supposed to cause the interictal deficit of cortical habituation to repetitive stimuli.

Short-term effects of early-acting and multilineage hematopoietic growth factors on the repair and proliferation of irradiated pure cord blood (CB) CD34+ hematopoietic progenitor cells

PURPOSE

Hematopoietic growth factor(s) (GF) may exert positive effects in vitro or in vivo on the survival of hematopoietic stem and progenitor cells after accidental or therapeutic total body irradiation.

METHODS AND MATERIALS

We studied the clonogenic survival and DNA repair of irradiated (0.36, 0.73, and 1.46 Gy) CD34+ cord blood (CB) cells after short-term incubation (24 h) with GFs. CD34+ cells were stimulated with basic fibroblast growth factor (bFGF), stem cell factor/c-kit ligand (SCF), interleukin-3 (IL-3), IL-6, leukemia inhibitory factor (LIF), and granulocyte-monocyte colony stimulating factor (GM-CSF) alone or in combination in short-term serum-free liquid suspension cultures (LSC) immediately after irradiation and then assayed for clonogenic progenitors. DNA repair was evaluated by analysis of DNA strand breaks using the comet assay. Survival of CFU-GM, BFU-E, and CFU-Mix was determined and dose-response curves were fitted to the data.

RESULTS

The radiobiological parameters (D[0] and n) showed significant GF(s) effects. Combination of IL-3 with IL-6, SCF or GM-CSF resulted in best survival for CFU-GM BFU-E and CFU-Mix, respectively. Combinations of three or more GFs did not increase the survival of clonogenic CD34+ cells compared to optimal two-factor combinations. The D[0] values for CFU-GM, BFU-E, and CFU-Mix ranged between 0.56-1.15, 0.41-2.24, and 0.56-1.29 Gy, respectively. As for controls, the curves remained strictly exponential, i.e., all survival curves were strictly exponential without any shoulder (extrapolation numbers n=1 for all tested GF(s). DNA repair capacity of CD34+ cells determined by comet assay, was measured before, immediately after irradiation, as well as 30 and 120 min after irradiation at 1 Gy. Notably, after irradiation the 2-h repair of cytokine-stimulated and unstimulated CD34+ cells was similar.

CONCLUSION

Our data indicate that increased survival of irradiated CB CD34+ cells after short-term GF treatment is mediated through proliferative GF effects on the surviving fraction but not through improved DNA repair capacity.