read about your flashing pain in the right side of your head at the back. I suffer something similar. I get this flash of pain which can either happen once for a second or two, or there can be a rapid succession of flashes over about 10 seconds, then maybe every few minutes afterwards. I am always aware of having been sensitive to cold in my right ear and in my back before the onset of the pain. Applying heat seems to reduce the frequency, though not the intensity of the flashes. I find anti-inflammatory drugs usually either cure or greatly reduce the severity of the pain. The flash I get is sharp and focussed in the one small spot, though the spot can move up to the top of my head on the right hand side. It feels like your brain is being pierced with an icepick.Get it investigated.