Can you tell me which medical specialty would be best suited to consult on a 73 year old female who developed hypernatremia (due to diabetes insipidus ) following 12 weeks of hospitalization? She was originally hospitalized due to confusion which was assessed via MRI & brain biopsy -- no malignancy . Has been on vasopressin replacement therapy, but control of plasma sodium is only temporary. Confusion increasing. Peripheral edema and physical deconditioning are advancing.