Question: What causes the clinical manifestations of confusion, convulsions, cerebral hemorrhage, and coma in hypernatremia? Want Online Help? The high sodium in the brain cells pulls water out of blood vessels intothe brain cells causing them to swell. The high sodium in the blood vessels pulls water out of brain cells into the blood vessels causing brain cells to shrink. The high sodium in the blood vessels pulls potassium out of brain cells, which slows the synapses within the brain. The high sodium in the blood vessels draws chloride into the brain cells followed by water causing brain cells to swell.