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[The anatomy of the surgical treatment of migraine].

OBJECTIVE
The transpalpebral resection of the corrugator and depressor supercilii muscles is a new treatment option for migraine headaches. Hyperactive contractility of these muscles can provoke the peripheral compression of the supratrochlear nerve and induce a neurogenic inflammation triggering the symptoms of migraine. In order to gather detailed knowledge of the respective anatomy in the eyebrow region, a macroscopic cadaver study was conducted.


MATERIALS AND METHODS
The relevant muscles of the forehead, glabella and eyebrow were dissected in five fresh, non-preserved heads. The supracanthal origins and dermal points of insertion were marked. Following the preparation of the neurovascular structures, the muscles were measured and weighed. The course of the supraorbital and supratrochlear nerves was demonstrated from the forehead to the orbital cavity.


RESULTS
There are three, paired groups of muscles in the superomedial region of the orbital rim. They can be divided into the superficial frontalis and procerus muscle, the orbicularis muscle in a middle layer and the corrugator and depressor supercilii in a deeper layer. The corrugator measured approximately 4.5 cm, whose origin is superior and posterior to the depressor origin situated cranial to the medial canthus. The corrugator inserts lateral to the exit of the supraorbital nerve in the dermis above the eyebrow after penetrating the orbicularis and frontalis muscles and a subgaleal fat pad. The length and weight of the muscles is highly variable. The muscle is penetrated by the supratrochlear nerve whereas the supraorbital nerve runs underneath it. The corrugator is innervated medially and laterally by branches of the facial nerve.


CONCLUSION
A detailed knowledge of the complex arrangement of the muscles acting upon the glabella and the different communicating subgaleal and preseptal fat pads allow the identification and resection of the corrugator and depressor muscles without damaging the supratrochlear nerve. The course of the specific nerves is variable. The double-innervation of the corrugator suggests its complete resection instead of the selective denervation of the muscle.