Banavathu Daya Bharath Singh Naik1, B. Hayagriva Rao2, T. Sandeep3, P. Krishna Rajiv4
Anastomosis found in the adulthood between the carotid and vertebro-basilar systems, apart from the posterior communicating artery, are extremely infrequent and are due to the persistence of vessels that joined both systems during the fetal period. This carotid-vertebrobasilar anastomosis are the trigeminal, otic, and hypoglossal and proatlantal arteries. Persistent trigeminal artery is the commonest of the above mentioned four arteries. The reported incidence is about 0.2%. Patients may be asymptomatic or present symptoms due to low flow of posterior circulation or carotid microembolization from posterior circulation. PTA can cause trigeminal neuralgia. We report in this paper a case of a persistant trigeminal artery found in an adult female with a para pcom aneurysm who had persistent trigeminal artery which was seen in CT angiogram.