There is rapid turnover of ATP in the brain. On the average, about half of the terminal phosphate groups turn over in a 3-second period. The level of creatine phosphate in brain is even higher than ATP, the creatine phosphate shuttle with mitochondria appears to have a central role in energy regulation in cns. If the glycogen reserve was the sole energy source, it would only be sufficient to sustain the brain for about a five-min period. This accumulation is greatest in those brain regions which are undergoing the greatest oxidative activity at the time when the tracer is administered.
Thiamine deficiency produces a gross neuropathy.
Death occurs in rodents within two weeks on a thiamine antagonist or a thiamine-lacking diet. In humans, peripheral neuropathy is not uncommon in alcoholics. Vitamin B12 deficiency can produce peripheral neuritis, paresthesias, spastic weakness. Diffuse spongy demylenation occurs.