How valid is a CT scan result? Isn’t it possible that if , let’s say an aneurysm, is very tiny it may not show up? I have a metal clip, so MRI’s are no good for me. I had an AVM removed years ago. I had a migraine last year that was the worse I had. Imitrex took care of it in 24 hours, but I was left off balance, side vision in one eye gone for 2 wks & a busting headache that came sporadically for over a month. After 3 wks I finally went for a CT scan. That headache nailed the same groove on the surgery. A few months ago I had a grand mal seizure w/ Todd’s Syndrome. Ct scan came back fine, but the daily headache on the groove has returned, although it’s not as severe as the prior one. No migraine this time w/ the grand mal. I just find it odd that it picks that spot. I have milder headaches on the other side.
Dr. Joshua’s Answer:
A regular CT scan is not sufficient to rule out aneurysms. A CT-angiogram would be needed for that. However, aneurysms in general, and small aneurysms in particular, do not cause headaches except when they bleed. If there is a bleed, a CT scan is about 95% accurate in detecting one. If a bleed is strongly suspected (SUDDEN - momentary - onset of severe headache), and a CT turns out negative for blood (which is rare), a lumbar puncture is done to check the cerebrospinal fluid for blood, in order to achieve 100% reliability.
Migraine is not generally a sufficient explanation of persisting neurological symptoms. Usually, with migraines, the neuro symptoms (loss of vision etc) appear before the headache, and resolve within hours. If the symptoms persist for longer than that, other causes should be considered. In any case, such neuro symptoms should always be evaluated by a neurologist, unless a diagnosis of hemiplegic or hemianopic migraine has been done previously, and the recurring symptoms are typical in severity and course, and the neurologist has OK’d home treatment of such episodes.
Headaches appearing near the site of previous operation are common, and almost always harmless if the operation itself was succesful. The main question in your case is - is the AVM gone and has this been verified by an angiogram? What is the cause of your epilepsy? AVMs can sometimes cause seizures, and often when the AVM is taken out, the seizures are also cured. Not always, though.
Sometimes, epileptic seizure may manifest as partial loss of vision especially if the seizure originates in the back of the brain (occipital lobes). Any problem in the occipital lobe may disturb the vision (occipital AVM etc). However, in such a case the vision would be lost on one side of both eyes, instead of just one eye as you describe.
Also, when was your operation done? Are you sure that you have such a metal clip that would prevent an MRI? The vast majority of clips used in recent years are safe with MRI. Check with your doctor.
For the benefit of other readers: Todd’s palsy means transient motor weakness on one side (hemiparesis) after a seizure.
My comments here only apply in the most general sense - I cannot say what’s causing what in your specific case. I recommend that you discuss these issues with your own doctor, and I’m sure he’ll be able to answer these questions for you.
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