I've heard a lot of similar reports of chronic musculoskeletal problems and neurological/neuropathic pains, and not just brain zaps.
Disclaimer - not everyone's symptoms may have such a physical/musculoskeletal cause as mentioned below, but its worth investigating with the guidance of a healthcare professional for those of you experiencing many physical symptoms.
Some neck muscles are activated with "anxiety breathing". These are known as accessory muscles of respiration, and these neck muscles (such as the SCM and scalenes) can cause all sorts of symptoms. This seems to be due to these neck muscles interactions with nerve plexuses and arteries around the neck/cranium. A meditation technique like vipassana (a form of mindfulness using the breath as an anchor) is particularly helpful for those with anxiety, and may help reset the unhelpful breathing patterns.
Anxiety breathing can also cause respiratory alkalosis, an acute symptom of panic breathing. A primary symptom of which is tingling, typically starting in the face and progressing further.
In your case with arm symptoms and other physical pains, see Thoracic Outlet Syndrome, which a couple of us have had. I would definitely check it out, but try not to self-diagnose. TOS is primarily a hand/arm condition, but various symptoms affecting the head can be present.
TOS is difficult to diagnose and many doctors are not familiar with it, and unfortunately if somebody goes to a doctor with these "psychiatric" symptoms also present, many valid physical musculoskeletal issues can be ignored or waived away as many doctors would think that we are crazy. TOS's ability to cause neurological/psychiatric symptoms is still not clear. It has been shown with brain bloodflow imaging studies that the neck muscles involved in TOS can compress certain arteries that supply the brain with blood, and I would bet that chronic compression/irritation of the subclavian artery could affect the brain as well. Personally, my psychiatric symptoms got better as I treated the physical illness. There are certainly many reasons why treating physical illness will improve mental health though, and as a general guideline everyone should aim to be in better physical shape.
There are many ways to treat TOS, and I have had neck injections and surgery as well. That surgeon, a regional TOS expert (MD+PhD), has a theory that the scalene muscles primarily cause the head symptoms where they attach up into the back of the scalp. There are many cranial nerves there (see occipital neuralgia).
The brain zaps (also frequent in SSRI withdrawal, in people who have never taken ecstasy) are known to be an issue with cranial nerves rather than the brain itself, and the cranial nerves run all sorts of weird routes through the head/neck. The cranial nerves and cranial arteries both express serotonin receptors. See the condition occipital neuralgia again, known for causing visual disturbances similar to HPPD and migraine. Lidocaine injections can be helpful for occipital neuralgia. As yet another example, an ophthalmologist told me many years ago that many of these visual disturbances are caused by an artery spasming in the back of the head. Anyways, there can be many physical causes to strange symptoms that might appear at first glance to have a chemical/cellular cause.
In the case of someone with TOS, the goal would be to stretch/release the muscles and tissues that need to be stretched, and to strengthen the muscles that need to be strong so that they can hold proper posture. Correction of bad posture (especially forward head posture) is extremely important no matter who you are. I have no doubt that many of you are hunched over as hell as you read this.
Physical therapy is where I would start. They can be very helpful in accurately diagnosing and treating musculoskeletal/neuropathic pains. As you progress along with physical therapy, I'd be happy to offer some pointers and share my experiences with it. I did multiple stints of physical therapy, about a year for 2-3 times a week, and in that time I recovered the use of my hands. Which I lost the use of for about 2 years. Fun times.
Hang in there everybody,
CY
