A Rare Anatomical Variation of the Lesser Occipital Nerve

The lesser occipital nerve (LON) is a cutaneous branch of the cervical plexus that arises from the second and sometimes the third spinal nerve and innervates the scalp. During routine dissection of the neck, the LON was observed to arise directly from the spinal accessory nerve. The aberrant nerve measured 1.9 mm in diameter and 10.2 cm in length. Although anatomical variations of the LON such as duplication and triplication have been observed, we believe the origination of this nerve directly and exclusively from the spinal accessory nerve is exceedingly rare. The current case adds to the sparse literature on the variations of the LON and might be of interest to clinicians treating neurological conditions or surgeons operating in the area.