Patients with plasma sodium concentrations below 115 meq/L with mild symptoms (fatigue, dizziness, confusion, lethargy, muscle cramps, gait disturbances) should have their sodium gradually corrected, not to exceed 10 - 12 meq/L over the first 24 hours to avoid osmotic demyelination.
More aggressive initial correction, at a rate of 1.5 - 2 meq/L per hour for the first 3 to 4 hours, is warranted in patients with seizures or other severe neurologic abnormalities (ie coma). However, the plasma sodium concentration should probably still be raised by less then 10 - 12 meq/L in the first 24 hours.
Source
Rose, B. MD "Treatment of hyponatremia" Up to Date. 12 May 2008.