Before revision: Although the cause of idiopathic (also referred to as primary) NPH remains unclear, it has been associated with various vascular diseases including hypertension, diabetes mellitus, peripheral vascular disease, and coronary heart disease .
After revision: Although the cause of idiopathic (also referred to as primary) NPH remains unclear, it has been associated with various co-morbidities including hypertension, diabetes mellitus, Alzheimer's disease, and hyperlipidemia .