Botulinum toxin is increasingly advocated as effective treatment in chronic tension-type headache. We conducted a randomized, placebo-controlled clinical trial to prove efficacy of botulinum toxin in chronic tension-type headache. Patients were randomly assigned to receive botulinum toxin (maximum 100 units) or placebo (saline) in muscles with increased tenderness. After 12 weeks there was no significant difference between the two treatment groups in decrease of headache intensity on VAS (-3.5 mm, 95% confidence interval (CI) - 20 to +13), mean number of headache days (-7%; 95% CI - 20 to +4), headache hours per day (-1.4%; 95% CI - 3.9 to +1.1), days on which symptomatic treatment was taken (-1.9%; 95% CI - 11 to +7) and number of analgesics taken per day (-0.01; 95% CI -0.25-0.22). There was no significant difference in patient's assessment of improvement after week 4, 8 and 12. Botulinum toxin was not proven effective in treatment of chronic tension-type headache. Increased muscle tenderness might not be as important in pathophysiology of chronic tension-type headache as hitherto believed.

To evaluate changes occurring in the neuromuscular junction after injection with botulinum neurotoxin type A (BoTx), three healthy volunteers were injected with 10 U BoTx in the right extensor digitorum brevis muscle. In agreement with previous observations, amplitude of compound muscle action potential (CMAP) decreased to approximately 30% of the initial value at approximately day 8 and slowly returned to baseline values around day 250. Values of the acetylcholine receptor (AChR) open time were determined by spectral analysis of end-plate noise and from single exponential fits to the decay phase of individual miniature end-plate potentials (MEPPs). At baseline, the mean channel open times determined by end-plate noise analysis and the exponential fits were 1.1 +/- 0.2 ms and 1.20 +/- 0.04 ms, respectively. After BoTx injection, initially no end-plate noise could be recorded. From day 9 onwards, however, a gradual recurrence of end-plate noise was observed, with mean channel open times of approximately 2-5 ms, being maximal between days 20 to 140. In addition, the shape of many recorded MEPPs was different from the typical fast rising MEPPs observed at baseline. After day 80, end-plate noise gradually returned to normal and mean channel open times decreased slowly to baseline values. Our findings reflect the changed AChR characteristics of newly formed neuromuscular junctions, which are created after BoTx injection and gradually removed after restoration of the original neuromuscular junctions.

Objective: High affective reactivity to pain (i.e., increased negative affect in response to pain) can have an adverse impact on the well-being of individuals with chronic pain. The present study examined the role of momentary and average positive affect and trait mindfulness in protecting against affective reactivity to chronic migraine-related pain. Methods: The sample included 61 adults with chronic migraine. Following the experience sampling method, participants completed smartphone-based assessments of momentary pain intensity (PI), positive affect (PA), and negative affect (NA) at nine random moments a day for 7 consecutive days. The Five-Facet Mindfulness Questionnaire was used to assess two dimensions of mindfulness: nonjudging and nonreactivity. Results: Momentary PA inversely predicted the strength of the concurrent but not the time-lagged associations between PI and NA. Average PA predicted neither the strength of the concurrent nor the time-lagged associations between PI and NA. Furthermore, the concurrent associations between PI and NA were weaker in individuals who reported higher "nonjudging" while "nonreactivity" did not significantly moderate these associations. Conclusions: Results provide partial support for the dynamic model of affect in the context of chronic migraine. State PA seems to play a larger role in momentary affective reactivity to chronic migraine-related pain than trait PA. Results also suggest that the ability to take a nonjudgmental stance toward negative experiences may lower momentary affective reactivity to pain. These factors seem promising targets for interventions aimed at improving the well-being of individuals with chronic migraine.

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Goal management is a dynamic process that may contribute to the development of, and recovery from, headache-related disability. Rehabilitation services offered to individuals with CH should target this process to promote optimal functioning. Implications for Rehabilitation Individuals with chronic headache use assimilative and accommodative goal management strategies to be able to pursue personal goals despite the limitations of chronic headache. Before accommodating goals to the limitations of chronic headache, many patients go through a phase of persistence, characterized by the use of resource-depleting assimilative strategies. A reorientation phase, characterized by accommodation of goals to the limitations of chronic headache, allows patients to adopt a more balanced way of pursuing personal goals.