"Hollow" area in occipital region of brain noted by GP, but missed by radiologist...what could it be?

I had a GP look at my MRI results, which were "normal", save a 13mm non-enhancing pineal cyst. My question is not about the pineal cyst, though. The GP noted that there was a "hollow" in the occipital region on the left side (pictures can be found through my profile), and he thought that this may be associated with some of my symptoms, especially the vertical diplopia, and recommended I see a neurosurgeon.

My question is: what type of abnormal "growths" are most like to occur on the occipital lobe, near the back of the head/brain? Symptoms I've been experiencing include an essential tremor (favors the left hand); constant daily headaches that sometimes intensify to terrible headaches and some of which include nausea; I almost always have a headache upon wakening; feeling very light headed and nauseous whenever I exert myself (i.e. walking a mile at a decent speed); decreased sensitivity to touch, particularly on my left side; sinusitis or allergic rhinitis of some sort for the past 6 weeks (can barely breathe through my nose); muscle spasms and twitches--usually happens in my left eye every day or two, as well as in my left arm and left leg; left-sided facial weakness (not paralysis); a few floaters in my left eye, only; extreme fatigue, but insomnia at times; photosensitivity; teeth pain/gum soreness; vertical diplopia, particularly when reading and at night, and especially evident when viewing illuminated objects, like road signs.

Aside from giving me some suggestions on what might be going on that area (check out the pictures if you really want to see), can anyone recommend what I should do next? The radiologist did not comment on this "hollow" area, but from viewing "normal" MRIs online myself, it's pretty obvious that a chunk of the left side of my brain toward the back of my skull does not look normal...and I don't want to wait to deal with this, but the two neurologists I recently saw didn't want to look through my MRI images. They glanced at the first few and said it appeared normal, then didn't bother to look through the rest. I'm only being treated for migraines right now.

Thanks for help!