Thanks for using the forum. I am happy to address your questions, and my answer will be based on the information you provided here. Please make sure you recognize that this forum is for educational purposes only, and it does not substitute for a formal office visit with your doctor.
Without the ability to examine you and obtain a detailed history, I can not tell you what the exact cause of your headaches is or how to treat it. However I will try to provide you with some useful information.
Headache is a common symptom, however it may be concerning in some patients, specially when is a new headache with a different pattern, worsens or presents with focal neurologic problems. It is important to determine if there is an underlying cause, and if not, treat it accordingly depending on the type of headache. I cannot tell you what type of headache you have as I do not have a good description from your post, and I cannot obtain a detailed history, but I can provide some examples. Migraine usually is a unilateral headache, pounding, lasts for few hours up to 72 hours, usually severe and the patient stops doing what they were doing at the moment. Light and noise bothers, and patients may complain of nausea and vomiting. If the headache is infrequent, treatment is for the attacks, however if the headaches are frequent, the patient may need preventive treatment, and there are specific medications for this, as well as for the attacks. A cluster headache, is usually unilateral, behind the eye, with lacrimation and “runny nose”. In this case, oxygen helps, and there is specific treatment. Hemicrania continua or paroxysmal hemicrania may be intermittent or continuous, with a dull and a sharp component, and usually on one side or on the top. It sometimes comes and goes. This type of headache responds to a medication called indometacin.
As I said, with headaches is important to determine if there is an underlying neurologic problem. A detailed history is needed, as well as a good physical and neurologic examination, in order to determine if there is a neurologic problem. Imaging studies are helpful, and an MRI can tell if there are tumors or something else causing the headache. It is reassuring that your MRI, at least from your description, does not show a tumor or other brain structural abnormality. Regarding the basilar artery problem, it is difficult for me to comment on this without being able to see the image and the configuration of the artery. Many times basilar artery problems can be concerning and need to be addressed, but sometimes it could just be an anatomical configuration with no significance. MRIs are very helpful to see the vascular structures, but sometimes other studies may be performed, such as an angiogram, to have a better picture of the vessels.
Without being able to obtain myself a good assessment, and to see the MRI image, I cannot tell you what the cause of your headaches is, if the basilar artery abnormality is significant or not, or if you need further studies.
I think you should discuss your concerns and the MRI findings with your neurologist, to determine if there is a cause for your headaches, if they fit a specific type of headache that requires specific treatment, or if you need further studies.
I hope this information is useful.
I don't know why the Doctor here has not responded to my last post. Makes me worry!