Abstract Situs inversus is a rare condition in which the position of the thoracic and the abdominal viscera are exchanged from the left to the right sides. A possible in- version of normal dominant intracranial anatomy, has however, rarely been discussed. We examine here the gross anatomy of an elderly cadaveric female for a possi- ble “situs inversus” of the intracranial contents. This study has found that many structures commonly domi- nant on one side in the intracranial compartment were re- versed in this specimen. These findings support the con- cept that a reversal of more commonly found intracranial anatomy may occur in situs inversus totalis, and this should alert the clinician performing invasive procedures in this population. These data will also hopefully provide further insight into possible mechanisms that contribute to situs inversus totalis. Keywords Anatomy · Symmetry · Cerebral dominance · Cranium · Transposition Introduction Situs inversus is a rare condition in which the position of the thoracic and the abdominal viscera are exchanged from the left to the right sides. Incidences of this condi- tion range from 1 in 10,000 to 1 in 50,000 (Casey 1998; Stoler and Holmes 1992; Uragoda 1977). We have found few accounts in the literature of the reversal of dominant gross intracranial structures of humans and the condition of situs inversus (Kennedy et al. 1999; Tanaka et al. 1999; Woods 1986). Materials and methods A formalin-fixed, 102-year-old white female cadaver with known situs inversus totalis was dissected. This individual had died from natural causes. The calvaria was removed with an oscillating bone saw, and the dura mater was opened in a cruciate manner so as to expose the cerebral cortex. All cranial nerves were sequentially excised, and the spinal cord was transected at the level of the fora- men magnum. The circle of Willis and its proximal branches were defined and dissected free from the brain. Next, the tentorium cer- ebelli was incised anterolaterally, and the brain was carefully re- moved. The brain was weighed as a whole, then sagittally sec- tioned, and each hemisection was weighed separately. Selected measurements of various intracranial structures were made with calipers, and sketches of the specimen were made (Figs. 1 and 2). Structures were chosen for measurement and as specimens if there was sufficient literature supporting their laterality in the general population. Table 1 lists major structures and their normally later- R.S. Tubbs ( ✉ ) Pediatric Neurosurgery, Children’s Hospital, 1600 7th Avenue South Acc 400, Birmingham, AL 35233, USA e-mail: richard.tubbs@ccc.uab.edu Tel.: +1-205-9399914; Fax: +1-205-9399972 R.S. Tubbs · G. Salter Department of Cell Biology, University of Alabama, Birmingham, Alabama, USA J.C. Wellons III · J.P. Blount · W.J. Oakes Department of Pediatric Neurosurgery, Children’s Hospital, Birmingham, Alabama, USA Anat Embryol (2003) 206:199–202 DOI 10.1007/s00429-002-0286-1 ORIGINAL ARTICLE R. Shane Tubbs · John C. Wellons III George Salter · Jeffrey P. Blount · W. Jerry Oakes Intracranial anatomic asymmetry in situs inversus totalis Accepted: 11 October 2002 / Published online: 18 January 2003 © Springer-Verlag 2003 Table 1 Contrasts between our findings and normally lateralized structures. ICA Internal carotid artery, ACA anterior carotid artery, MCA middle cerebral artery, VA vertebral artery, ACF anterior cra- nial fossa, MCA middle cranial fossa Normally Current specimen lateralized side Vasculature Supraclinoid ICA Left Right A1 segment of ACA Left Right M1 segment of MCA Left Right Intradural VA Left Right Vein of Labbé Left Right Vein of Trolard Right Left Transverse sinus Right Left Osseous ACF Left Right MCF Left Right Other Sylvian sulcus Right superior Left superior Artery of Adamkiewicz Left Right