Is it possible that the neurodegeneration we are witnessing due to the spike protein inducing a form of prion disease causing microglia to activate as phagocytes and "cannibalize" the brain? This process would be very similar to primary amoebic meningoencephalitis:

Initial symptoms include changes in taste and smell, headache, fever, nausea, vomiting, back pain, and a stiff neck. Secondary symptoms are also meningitis-like including confusion, hallucinations, lack of attention, ataxia, cramp and seizures. Some people have presented with a clinical triad of edematous brain lesions, immune suppression and fever. Clearly the process is much slower.