Botulinumtoxin in der Schmerztherapie

Zusammenfassung

Botulinumtoxin (BTX) wird seit mehr als 20 Jahren erfolgreich bei Erkrankungen mit muskulären Hyperaktivitäten eingesetzt. In den letzten Jahren kam es zu einer deutlichen Ausweitung der Anwendung bei autonomen Erkrankungen und in der Schmerztherapie. Die analgetischen Wirkungen von BTX-Injektionen werden vor dem Hintergrund erheblicher Plazeboeffekte und teilweise methodischer Mängel der vorgelegten Studien kontrovers diskutiert. Weiterhin bestehen noch unzureichende Konzepte zur Schmerzphysiologie allgemein sowie zu den spezifischen analgetischen Wirkmechanismen von Botulinumtoxin. Neben der Schmerzreduktion durch die bekannte BTX-Wirkung an der neuromuskulären Endplatte werden weitere lokale schmerzreduzierende Mechanismen und Wirkungen an anderen synaptischen Systemen postuliert. Derzeit kann BTX zur Schmerztherapie bei Dystonien und Spastiksyndromen sowie bei Analfissuren und Achalasie empfohlen werden. Bei myofaszialen Schmerzen, Migräne, Kopfschmerzen vom Spannungstyp und anderen seltenen Kopfschmerzsyndromen wurde eine Schmerzreduktion durch BTX berichtet, aber der definitive Beleg nach Kriterien der evidenzbasierten Medizin steht noch aus. Bei Fibromyalgie scheint keine sichere klinische Wirkung vorzuliegen. Es ist zu erwarten, dass in Zukunft die Bedeutung von BTX in der Schmerztherapie zunehmen wird.

Abstract

Botulinum toxin (BTX) has been used for more than 20 years to treat various muscle hyperactivity syndromes. Over the past years its use has expanded into the treatment of autonomic disorders and pain. Analgesic effects of BTX have been discussed controversially due to substantial placebo effects and flaws of the study designs used. Additionally, pathophysiological concepts of pain as well as specific analgesic mechanisms of BTX remain largely unclear. Apart from a pain reduction through the well documented BTX effects at the neuromuscular endplate, additional analgesic mechanisms including other synaptic and local effects have been suggested. Currently, BTX can be recommended for pain treatment in dystonia and spasticity as well as in analfissures and achalasia. In myofascial pain syndromes, migraine, tension-type headache and other rare headache syndromes pain relief by BTX has been reported, but definite proof according to evidence based medicine criteria is still lacking. In fibromyalgia there seems to be no analgesic effect. The role of BTX in pain therapy is likely to increase in the future.

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