The symptoms of tingling in the extremities resemble what my wife experienced after her chemo when the treatment damaged her neurons' myelin sheath. This causes

The symptoms of tingling in the extremities resemble what my wife experienced after her chemo when the treatment damaged her neurons' myelin sheath. This causes 'noisy' neuron signals to be transmitted (tingles, lack of sensation, etc.). If the same thing happened in the brain, I bet the noisy signals would lead to brain fogginess, forgetfulness, etc. Back then, she was taking omega-3 supplements and received shots of vitamin B12. After a year, it removed almost all the tingling, but some sensations never fully came back. This is not medical advice (and check with your doctor beforehand), but it feels like taking vitamin B12 and omega-3 supplements should be a pretty low-risk bet to try to improve your situation if you're experiencing the long COVID symptoms described in the article.