Osmotic demyelination syndrome is a rare neurological complication. It has mainly been described in patients who have undergone rapid corrections in serum sodium levels. It should always be cautious when correcting electrolyte disorders in patients presenting to the emergency service. However, it has been reported associated cases of osmotic demyelination without hyponatremia corrections. It is necessary to have a low threshold for suspecting the diagnosis of osmotic demyelination syndrome by the neurological consequences associated and the absence of effective treatment. Here, we presented a case report of a patient with an episode of extrapontine osmotic demyelination, apparently without consequences. In addition, a full review of the topic is made.