My mom recently was hospitalized after having multiple seizures and a possible mild stroke in conjuction with a mild heart attack. The doctors treating her have told us she had a critically low sodium level in her blood. In doing some rearch I have learned that this sodium deficiency supposedly can trigger seizures, strokes, heart attacks, anxiety, nervousness, sleeping disorders, chronic fatigue, renal failure, and depression disorders associated with stroke like symptoms. Is this true and if so,...... (which my mom now has most of these symptoms or was plagued by these symptoms prior to her being hospitalized).... then my queation is
1. What is the treatment for hyponatremia or related illness/disorder and
2. What is the prognosis for full recovery with the proper treatment and
3. What is the time frame for recovery

Note: My mama is 82 and was in generally excellent health with no history of seizures, diabetes or heart disease
Please help
Thank you