Vertebrobasilar dolichoectasia is one of the causes of neurovascular compression syndrome (NVCS) as presented in this case where it is seen compressing the trigeminal nerve and presumably causing trigeminal neuralgia. 

It is important to note, however, that vascular ectasia and even distortion of the trigeminal nerve by an elongated vertebral artery is not an uncommon finding in asymptomatic individuals and as such the causal link in this instance is presumptive.