Abstract
Attribution of CNS symptomatology to electrolyte disturbances must be viewed cautiously. Review of experimental work reveals that the CNS ion concentrations are controlled by special transport mechanisms constituting a blood-brain barrier to ions, and rendering the brain relatively insensitive to serum changes. However, alterations in serum Na may produce profound changes in CNS function as a consequence of shifts in water. Under conditions which are not yet fully understood, CNS symptoms may result from marked alterations in serum Mg and Ca. However, few, if any, CNS symptoms can be ascribed to disturbances in K metabolism without a coexistent alkalosis or acidosis.