Age / Sex : 17 / M

What is your impression?

Two weeks later, you can see the final diagonosis with a brief discussion of this case (Please submit only one answer).

Courtesy : Jang Gyu Cha, Soonchunhyang University Bucheon Hospital

Discussion

Discussion

Answer: right vertebral artery dissection, cerebellar infarction caused by Os odontoideum

Findings:

Seperation of odontoid process of C2 vertebra and complete fusion of C2-4.

Loss of flow void artifact of right vertebral artery, showing T2 high SI, due to vertebral artery insufficiency.

High SI lesion on DW and low SI on ADC showing vermis infarction

Differential Diagnosis:

Diagnosis:  

Os odontoideum and right vertebral artery dissection, cerebellar infarction

Discussion:

Os odontoideum presenting as atlantoaxial instability may cause symptomatic cord compression; thus, posterior fusion for stabilization is recommended in some cases. Roentogenographically, the presence of translation instability of 10 mm or

more between the atlas and the axis is considered an indication for fusion if the spinal cord symptoms are progressive.

Five cases of os odontoideum associated with pediatric cerebellar infarction have been reported.

Singer et al proposed that repeated subluxation of the atlas on axis may produce kinking, compression, stretching, and

tearing of the intima of the vertebral arteries leading to thromboembolic vertebrobasilar occlusions.

Atlantoaxial instability may cause mechanical stress to the vertebral artery as well as spinal cord injury. More

attention should be paid to the possible relation between atlantoaxial instability and vertebrobasilar artery insufficiency.

References:

Os Odontoideum With Cerebellar Infarction A Case Report

SPINE 2000;25(9): 1178–1181