Question

A young woman was brought into the emergency room because of repeated seizures. her roommate said that the woman had taken the drug ecstasy the night before, and that she had been drinking a lot of water. a blood test showed her plasma na+ was very low: 120mm (normal 135-145), and her plasma osmolality was 250mosmoles/kg (normal 280-296). why would her low osmolality and low na+ concentration disrupt her brain function and cause seizures? what might be a possible therapy for this person?

Answer 1

Electrolyte imbalance can affect the normal function of the brain. Sodium is an important electrolyte maintains homeostasis in the body. Its primary function is to regulate water retention. Low sodium usually decreases serum osmolality. This combination of deficiencies is called Hypotonic hyponatremia.

A sudden drop in sodium and plasma osmolality can cause seizures. Brain function is affected because the water in the body, because start to flow from the extracellular spaces into the intercellular spaces. This causes the brain cells to swell and thus affecting its normal function. 

Therapy for this type is IV therapy, particularly hypertonic saline to replace the sodium in the body and normalize plasma osmolality and diuretics are given to aid in water excretion. Therapy should be done slowly and should be closely monitored. More swelling can developed when it is done too quickly.