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If you suffered a concussion, there is certainly the possibility that the new type of migraine is related. Post-concussive migraine headaches is a well-known phenomenon and is not uncommon. It commonly will start within a few days of the concussion and last for a few months (sometimes longer than a year).
However, it is probably more likely that if you have ocular migraines, they're just another manifestation of your migraine headaches in general--even if different from your previous migraines. In fact, most people with ocular migraines will have a prior history of migraine headache before such symptoms occur. I like to think of migraine not as a headache, but as a vascular phenomenon, with blood vessels constricting and dilating. The headache is just a symptom of the migraine, rather than being the migraine. This is evidenced by the fact that "acephalgic migraine" (i.e. "migraine without headache") exists. Just as nausea, vomiting, sensitivity to light, and sensitivity to sound are symptoms of migraine, the headache is a symptom of migraine.
That said, "geometric shapes in various colors" is less likely to be a true ocular migraine, but more likely to be a migraine aura--if it's related to migraine at all. (Occipital lobe seizures is another possibility for such an event, though I'm by no means saying that's what it is.) A true ocular migraine (also called "retinal migraine") is more classically associated with vision loss rather than with seeing extra things in your vision. True ocular migraines are somewhat rare and more serious (as they could result in permanent vision loss).
In the end, the treatment whether it's just migraine with a visual aura or a retinal migraine is usually very similar (though certain medications like triptans and dihydroergotamine are often avoided in true retinal migraine, as they can cause vasoconstriction and make vision loss worse or permanent). I'll defer to you and your neurologist/ophthalmologist for diagnosis and treatment, as I'm not able to examine you; but I hope the above answers your question and gives you a little more detail on ocular migraines.
Thanks for responding.
As far as I know, I didn't have symptoms of a concussion (although there may have been symptoms that I didn't recognize as such). However, within a day or two, I began experiencing what appears to be neuralgia (which persists - two years later). The 'ocular' migraines appeared more than a year later, although I did experience some visual disturbances shortly after the accident.
You indicated that geometric shapes/pastel colors aren't consistent with ocular migraines. This is surprising (and confusing) because, based on these symptoms, that was the diagnosis I received from both my neurologist and ophthalmologist. When I did some research online, many sites also describe geometric shapes/colors in connection with ocular migraine. Are they just applying the term 'ocular migraine' too broadly?
Have you heard of neuralgia developing following a blow to the head? In my case, it was a hard-impact, pinpointed blow near the temple. It's been a few years, and the character and pattern of the pain is essentially unchanged.
If the "ocular migraines" appeared more than a year later, they are extremely unlikely to be related to being hit in the head.
To answer your question, yes they are being overly broad in what they are characterizing as ocular migraine. While the International Headache Society's classification schema for ocular migraine is itself purposefully ambiguous (because unlike things like heart attack or HIV, primary headaches are based more on clinical history than a specific test that can prove it's X or Y), a truly "ocular" migraine would be limited to one eye and involve "negative symptoms" (i.e. loss of some normal function). An example of a negative symptom would be loss of vision (as the blood vessel constricts during the migraine). (Remember, headache is a symptom of migraine. Migraine is actually a vascular phenomenon--involving vessel constriction and dilatation.) One can have an aura with an ocular migraine; but a true ocular migraine will be unilateral (whereas auras may be bilateral or unilateral) and will almost always involve a loss of function (blurred vision, loss of vision, etc.). Pastel geometric shapes is a "positive symptom"--or a symptom that's a "gain of function," if you will. You're "gaining" things in your sight that aren't really there. The geometric shapes are more consistent with just a visual aura rather than "ocular migraine."
When explaining things to the laypublic, physicians sometimes try to associate similar conditions in their explanations to avoid being overly technical and maybe even confusing the patient. For example, when telling a patient he/she had a stroke, a physician might respond to the question "How did that happen?" with an answer like "You had a blood clot go to your brain." That's easily understandable for most of the laypublic's purposes. The most technically accurate answer may be "You had a soft plaque in your internal carotid artery that ruptured, causing platelets to aggregate and activate to form a clot. The clot then dislodged and traveled to your brain, blocking an artery and keeping oxygen from getting to the brain cells. So the brain cells died."
So I have seen that in cases where the "technical" aspect of a disorder doesn't so much matter in terms of treatment and such, many physicians (maybe all of us) will generalize. In most cases, migraines are treated the same regardless of type. (There are some exceptions; but this is "in general.") So since it involves the eye, they may have used the term "ocular migraine." I would have said "migraine with aura." For me, a true ocular migraine means significant potential (not extremely common to occur, but significant potential to occur) of vision loss as a result of the migraine. A visual aura associated with migraine doesn't carry nearly the same risk.
As for what websites may say, one must always evaluate the source of information. A journalist or another layperson or a physician whose specialty doesn't include headache under its banner (e.g. a surgeon trying to explain headaches) may write things on websites that are generalizations or assumptions or just flat-out false information. If you've ever seen Sanjay Gupta on CNN or Nancy Schneiderman on NBC talking about medical topics, they commonly talk about topics outside their area of expertise and say things incorrectly (It grates on my nerves; so I don't watch them.).
Now, on to your last question. Neuralgia has been known to occur spontaneously, after major trauma, or after seemingly totally benign trauma. That's not terribly uncommon. But it's difficult to prove that a given event caused the neuralgia. Most neuralgias of the face/head are treated similarly; so once again, the cause doesn't matter as much as the treatment. (Note, there are several important exceptions, such as tumors or vascular malformations that can cause neuralgia and obviously need to be treated much differently than more typical neuralgias.)
Hope this helps. In the end, it sounds like just a semantic issue--"ocular migraine" versus "migraine with visual aura."
I'm actually not a 'layperson' - medically speaking (I have a medical background - but not in neurology) - so I am a bit disappointed that two of my physicians referred to my visual 'events' as ocular migraines (I actually did experience somewhat of a visual 'loss' in addition to seeing shapes; when I looked up, there was a black area (which may equate to seeing nothing) out of one eye only. I guess it doesn't really matter what this event is called- as long as it's not dangerous (and hopefully doesn't return).
I think I can reasonably establish that the neuralgia is a direct result of the blow to my head, since the neuralgia-like pain/symptoms commenced almost immediately after my accident - and I had no history of this type of facial pain on that side of my face prior to this event. Unless, in your opinion, there's no possible connection between a heavy blow to the head (near the temple) and the onset of neuralgia, it would be an extraordinary coincidence if the two events were unrelated.
I want to clarify that it may well not be that your neurologist/ophthalmologist were trying to mislead you. It's common for even neurologists to call something "ocular migraine" when it really isn't--just because the person, for example, may have pain around the eye and some visual disturbance. It's kind of a misnomer--not intentional deception--just not strict adherence to diagnostic parameters. The black area you speak of may be what we call a "scotoma," which is consistent with a migraine aura as well.
I agree with your last paragraph. If the neuralgia started immediately after the injury and persists with the same qualities, it would be an incalculable coincidence if the two were unrelated.
Thank you for you comprehensive, well written response(s). I have some other questions (related to my neuralgia), but I'll accept this answer and submit as a new question.
Can you explain why/how this blow to the head caused neuralgia? It was a very hard, bullet-like impact. I have to assume that it must have struck near the area where the trigeminal 'branches' converge (otherwise, I don't quite understand why it triggered this ongoing (sometimes 'lighting-bolt' type) pain - which sends severe, shooting pain to jaw and at times, my eye - which is awful (and scary).
The jaw/tooth-like pain began the day the accident occurred; the sharper, shooting pain started within a day or so (at that time, it seemed like it was mostly shooting into my eye). I saw my ophthalmologist - and he ruled out any issues with the eye itself and referred me to my neurologist.
Shouldn't this have resolved by now (or at least have gone into 'remission')? It doesn't happen every day, although there's always some level of discomfort in the area. I'm taking medication to try to control this (I've tried several), but it hasn't been that effective. When I increase the dosage, it's slightly better, but the side effects make me feel terrible (and very sleepy).
Any thought on why this isn't resolving (it's been a few years).
I cannot say the head trauma did cause the neuralgia; but if it did, it's a matter of a phenomenon called "deafferentation." Deafferentation is essentially interruption of the nerve fibers, leading to hyperexcitability of the nerve cell bodies. It commonly happens with head trauma, as a result of surgery, as a result of dental procedures (If you had your wisdom teeth removed, your oral surgeon may have told you this was a possibility.), etc. A less likely mechanism in this specific case would be formation of a seroma (pocket of fluid) or scar tissue forming around some portion of the trigeminal nerve. In either case, the damage could occur anywhere along its course. It doesn't really matter where along its course, as the pain signal from one part of the nerve can propogate such that the brain could perceive it occurring anywhere along the course of the nerve. (This is called "referred pain." A classic example of referred pain is that people with gallstones often have pain in their back near their scapulas, even though the gallbladder is near the surface in the front. The same sensory nerve supplies both areas.)
The fact that it causes pain in the jaw, tooth, and eye areas definitely suggests it's specifically a trigeminal nerve-mediated phenomenon; but again, the actual site of injury could be anywhere along its course, from the nerve nucleus to the ganglia to the peripheral portions of the nerve.
Resolution of the symptoms is never guaranteed. Many people eventually have resolution of symptoms. Others have neuralgia the rest of their lives. Some get relief with medications or surgical procedures (if the specific pathology in the individual is amenable to surgical therapy) or rhizotomy (which itself can cause trigeminal neuralgia). Others get no relief from any specific therapy. We unfortunately don't have an easy way to predict for most patients who will have resolution of symptoms and who won't--or when the symptoms will resolve.
We would generally classify post-traumatic trigeminal neuralgia in the "atypical facial pain" group. Studies have shown that the two best medications for this (all comers, though it may not be the case for an individual patient) are tricyclic antidepressants (amitriptyline or nortriptyline) in doses of at least 150 mg or carbamazepime in doses of at least 1000 mg. Sleepiness is a very common side effect of tricyclic antidepressants. (We generally tell patients to take it at bedtime--It's a once daily drug--so they sleep through the sleepy side effect but get benefit the rest of the day.) It can also cause confusion. Importantly, it can cause cardiac arrhythmias; and at high doses (150 mg or greater is a fairly high dose), it can cause sudden cardiac death. Carbamezepime can cause problems with liver enzymes and low white blood cells (the cells that fight infection) and can cause dizziness/nausea and a potentially fatal rash (though rare). If you have tried these, you might consider discussing these options with your neurologist. (Please note that this is not a treatment recommendations--just information that may be useful in discussion with your neurologist.) Several other medications could be tried; and they have varying success in different patients.
Hope that helps.