An anatomico-radiological study of the grooves for occipital sinus in the posterior cranial fossa.
BACKGROUND
The occipital sinus (OS) lies in the attached margin of the faix cerebelli in the internal occipital crest of the occipital bone. The OS extends from the foramen magnum to the confluence of sinuses. Standard textbooks and research reports do not describe in detail any variation in the groove for the occipital sinus.


METHODS
In the present study, we examined a total of 50 human dried skulls for the groove of OS and its possible variations. We also performed an osteological study supplemented with digital X ray and CT scan.


RESULTS
Out of 50 skull specimens, a single case with two grooves for OS was observed (2%). The two grooves for OS traversed as two limbs from the foramen magnum to join the other at the internal occipital protuberance. An accessory faint groove was also found at the lateral aspect of the left limb. Interestingly, in the same specimen, the superior sagittal sinus instead of continuing as right transverse sinus, continued as left transverse sinus. The X ray and CT scan of the anomalous bone specimen were compared to those of the normal bone specimen.


CONCLUSIONS
To the best of our knowledge, this is the first anatomico-radiological study of multiple OS groove with associated anomalies. Surgeons should be aware of the variations of the OS in order to check any inadvertent injury during skull surgeries. Presence of such variations may also result in erroneous interpretation of radiological findings (Tab. 1, Fig. 7, Ref. 17).
Das
Srijit
S
Department of Anatomy, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, Kuala Lumpur, Malaysia. das_srijit23@rediffmail.com
Abd Latiff
Azian
A
Suhaimi
Farihah Haji
FH
Othman
Faizah Bt
FB
Yahaya
Mohd F
MF
Ahmad
Fairus
F
Abdul Hamid
Hamzaini
H
D003388:Cranial Fossa, Posterior / Q000002:abnormalities / Q000033:anatomy & histology*; D006801:Humans; D009777:Occipital Bone / Q000002:abnormalities / Q000033:anatomy & histology*