For reasons no one can explain, strokes are on the upswing among young healthy people. The scary thing is that stroke can present in a bunch of different ways -- you may just have weird vision and a headache, not the classic one-side weakness and difficulty speaking -- and ER doctors may not know the best way to diagnose stroke in someone who looks very healthy.

Strokes, anxiety, and depression -- all brain diseases -- are happening more than they used to.

Is it the modern diet? Modern overuse of screens in our lives? The simple fact that we live longer?

No one knows. We know so little about the brain, even now. 

The article suggests three entirely unrelated causes: increased strenuous sports, drug use, and better diagnosis.

Yeah, I wondered what they meant by "strenuous".

And I wondered if the drugs they meant were prescribed or illegal.

And I still wonder if diet and screens have affects on the brain but have not been studied. 

Probably better diagnosis - many "headaches" were probably mini strokes.

Do any other symptoms accompany mini-strokes besides headaches?

Numbness, paralysis, aphasia (can't understand or speak words), weakness.  Maybe blackouts.  Except for paralysis, those are symptoms of bad migraines also, and I've had all of them at least once as part of a migraine headache.  Or maybe it was a minor stroke.  I've had CAT and MRI scans since, so if I did, no major obvious damage.

Are minor strokes the same as TIA's?

I would say so, except that by definition a TIA causes no permanent damage and a minor stroke does.  But the damage might not be noticeable.  http://www.webmd.com/stroke/tc/transient-ischemic-attack-tia-topic-overview

Migraines are vascular headaches where the blood vessels of the brain constrict for a while, then they expand, perhaps cycling.  First there are sensory problems with little pain, then those often go away and there is a flood of pain.  I had a doctor once look at my retina the day after a migraine headache and tell me he could see the blood vessels still pulsing.  Not sure a diagnosis like that is valid.  However, since the symptoms of a migraine can overlap a lot with a TIA, it seems plausible that the same lack of blood flow is causing both.  Or maybe people are just having TIAs and calling them migraines.

I've known a person with a TIA who did not have pain -- he had numbness and tingling and he briefly lost vision. So not all TIA's have migraine-like symptoms.

What about mobile device use and a lack of sleep as a cause? 

They certainly seem like contributing factors but I've seen no studies that say that mobile device use or lack of sleep can be causes of strokes.