The study is designed as a crossover trial, which means that participants will receive both the active medication and placebo at different times, with periods in between where no study medication is given to wash out the previous treatment. The study begins with a two-week period where participants keep track of their headache attacks in a diary before starting any treatment. Then participants will go through two four-week treatment periods where they take either candesartan or placebo, with the order being randomly assigned. Between these treatment periods there is a wash-out phase. After completing these phases, there is an optional open treatment period where participants may continue with candesartan.

Throughout the study, participants will record their headache attacks, including how severe they are and how often they occur. The study will measure changes in the number of severe and very severe attacks per week, how many people experience at least a 50 percent reduction in attacks, and changes in headache intensity. Other measurements include how much rescue medication participants need to use, improvements in quality of life and disability related to cluster headaches, and overall impression of improvement. The study will also monitor for any side effects and changes in mood or suicidal thoughts using specific questionnaires.

The study involves several phases that participants will go through over time. First, there is a one-week period before treatment starts where participants keep a diary of their headache attacks to establish a starting point. Then comes a three-week blinded phase where participants take either candesartan up to 32 milligrams daily or placebo, with neither the participants nor the doctors knowing which treatment is being given. During this time, participants continue to record their headache attacks, how severe they are, and what medications they use to treat them. After the three-week blinded phase, there is an optional treatment period where participants may continue taking the study medication, followed by a wash-out phase where the medication is stopped to see what happens.

Throughout the study, participants will be asked to complete questionnaires about how much their condition has improved, how the headaches affect their daily life, and how they are feeling emotionally. The study will track how often severe and very severe attacks occur, how intense the attacks are, and how much rescue medication participants need to use. Researchers will also monitor how long it takes for attacks to stop completely and whether attacks return after treatment ends. The study is designed to gather information about whether candesartan can effectively prevent cluster headache attacks and improve the quality of life for people living with this condition.

The purpose of the study is to evaluate the effectiveness and safety of taking 25 micrograms of LSD every three days over a period of three weeks. Participants in the study will be randomly assigned to receive either the LSD treatment or a placebo. The study aims to determine if the treatment can reduce the frequency of headache attacks in individuals with chronic cluster headache.

Throughout the study, participants will be monitored to assess any changes in their headache patterns and to ensure their safety while taking the medication. The study will help researchers understand if this treatment can provide relief for those suffering from chronic cluster headache and if it is safe for use in this context.

The purpose of the study is to evaluate the effectiveness of this treatment approach. Participants will receive the treatment through an intravenous infusion, which means the medication is delivered directly into the bloodstream. The study will monitor changes in the frequency and intensity of headache attacks over several weeks following the infusion. Participants will also be assessed for any side effects and their overall response to the treatment.

Throughout the study, researchers will collect data on how often and how severe the headaches are, as well as any changes in anxiety and depression levels. The study aims to provide insights into whether this combination of medications can offer a new option for those suffering from chronic cluster headaches who have not benefited from existing treatments.

The purpose of the study is to determine if these injections can safely and effectively reduce the frequency of headache attacks over the long term. Participants will receive injections over a period of time and will be monitored to see how often they experience headaches, how severe the headaches are, and how long they last. The study will also look at the overall quality of life of participants and any side effects they may experience.

Throughout the study, participants will be asked about their experiences and whether they believe they received the actual treatment or a placebo. The study aims to provide valuable information on whether this treatment can be a convenient and cost-effective option for managing chronic cluster headaches.

The purpose of the study is to assess the differences in brain activity and blood flow between the active and inactive periods of cluster headaches. Participants will undergo imaging sessions where the Befiradol (18F) will help highlight areas of the brain that are active during these periods. The study aims to provide insights into how the brain’s activity changes before, during, and after a headache attack.

Throughout the study, participants will receive injections of Befiradol (18F) and undergo PET-MRI scans. These scans will help researchers compare brain activity and blood flow during different phases of the headache. The study will not only look at the immediate effects but also how these changes correlate with the overall pattern of the headaches. This research hopes to contribute to a better understanding of cluster headaches and potentially lead to improved treatments in the future.

Participants in the study will receive either the active treatment with Botulinum toxin type A or a placebo. The study will monitor changes in the frequency and intensity of headache attacks over a period of time. The goal is to see if the treatment can reduce the number of headache attacks and improve the quality of life for those suffering from chronic cluster headaches. The study will also compare the occurrence of any side effects between those receiving the active treatment and those receiving the placebo.

The study will take place over several weeks, with participants being closely monitored by healthcare professionals. The results will help determine if Botulinum toxin type A is a viable treatment option for people who have not found relief from other medications. This research could provide new insights into managing chronic cluster headaches and offer hope for those affected by this challenging condition.