Disorders of the Nervous System
Author: axel omar colombo | Email: axelcolombo59@gmail.com
axel omar colombo1°, Tomas Picone1°, Julieta Rodriguez Valdivia1°, Catalina Dolccimelli1°, Valeria Trofa1°, Julian Cicler1°, Gonzalo Bonilla1°, Facundo Villamil1°2°
1° Neuroanatomy Laboratory, III Department of Anatomy, School of Medicine, University of Buenos Aires, Paraguay 2155, C1121, Buenos Aires, Argentina.
2° Surgical Neuroanatomy Laboratory, Neurosurgery Department, FLENI, Montañeses 2325, C1428 Buenos Aires, Argentina.
Introduction Mackenzie’s Nerve (MN) is a communicating branch from the accessory nerve to the ventral
branch of the first spinal nerve, it transports sternocleidomastoid’s motor fibers and this is of
major significance in rizhotomy surgeries to treat spasmodic torticollis. It has a vertical variation
of greater length and a transverse of shorter. The objective is to describe trough dissections the
variations of length and appearance percentage.
Materials and Methods9 heads (18 sides) were used in a 10% formalin solution. The squamous of the temporal bone
and the posterior arch of the first two cervical vertebrae were removed using a drill. For the MN
dissection were used dissecting forceps, iris scissors, scalpel with 24-blade; and measured with a
precision of 0,1mm.
ResultsThe MN on 8 out of 9 heads was going through the first dentate ligament, precisely on 8 sides
(44,4%). Out of those, there were 3 on right (16,6%) and 5 on left (27,7%). Also no findings of
bilateral MN nor communications. The vertical variation was on 6 sides (33,3%), 2 on right
(11,1%) and 4 on left (22,2%), measuring 7mm to 9mm; the transverse was on 2 cadaveric corps
(11,1%), 1 on each side measuring 4mm to 6mm.
ConclusionsVariations regarding length and direction of MN were detailed but particularly one, in opposition
to the most reported by other authors, was notable because of its side of origin. Considering this
may be useful in avoiding undesirable lesions during selective d