What Could Cause Severe Pains On The Left Side Of The Head?

hi there, I suffer with stabbing sharp pains in the left side of my head and lasts for a few seconds.got diagnosed with severe high blood pressure 18mths ago, which is now under control. since then I have had numerous mri s, ct scans. they found that I have lesions on my brain and shadowing. keep getting fobbed off by gp and neurologist saying its migraines.. is this right, because I have not felt right for last year. i m 41 female