I don't have that symptom but think it's another form of TMS.
I just read about it at Johns Hopkins:
True isolated occipital neuralgia is actually quite rare. However many other types of headaches —especially migraines — can predominately or repeatedly involve the back of the head on the one particular side, inflaming the greater occipital nerve on the involved side and causing confusion as to the actual diagnosis. We generally refer to these patients as having migraines involving the greater occipital nerve, rather than as having occipital neuralgia itself.
If a migraine patient has headaches exclusively at the back of the scalp at one side, it may be tempting to perform one of the above permanent procedures to quickly “fix” the problem. Since migraines are thought to be due to a problem in the patient’s brain, however, and not the nerve itself, after a procedure it is possible that these patients might discover that their headaches have moved to another location, or that there is some improvement in pain but continued episodes of nausea, light-sensitivity, etc. We therefore only rarely recommend these procedures in migraine patients, especially since there have been no scientific studies proving that they work over the long haul.
If a patient’s pain does not reliably improve with
occipital nerve blocks, we do not recommend proceeding with any of the more drastic measures.