A Relationship Between the Supratrochlear Nerve and Trochlea: Anatomical Study and Application to Migraine Headaches

Supratrochlear nerve (STN) is a terminal branch of the frontal nerve arising from the ophthalmic nerve (V1). Compression of the STN by adjacent structures might result in migraine headaches. The aim of this study was to explore the relationship of the STN and trochlea for a better understanding of potential entrapment of the STN. Nineteen orbits from ten fresh-frozen cadaveric heads were dissected. The relationship of the STN and the trochlea was classified into three types: In type I, the STN passed lateral to the trochlea; In type II, the STN passed through the trochlea; In type III, the STN passed medial to the trochlea. Type I was found in 52.6% (10/19 sides), type II was found in 42.1% (8/19 sides), and type III was seen in 3.4% (1/19 sides). In type III, both the STN and infratrochlear nerve were identified as separate branches. The authors propose a new classification of the pathway of the STN based on its relationship with the trochlea. This study might shed light on headaches emanating from this region.