Hypertension and cognitive function in the elderly

Abstract

Alzheimer's disease is the most prevalent and common form of cognitive impairment, ie, dementia, in the elderly followed in second place by vascular dementia due to the microangiopathy associated with poorly-controlled hypertension. Besides blood pressure elevation, advancing age is the strongest risk factor for dementia. Deterioration of intellectual function and cognitive skills that leads to the elderly patient becoming more and more dependent in his, her, activities of daily living, ie, bathing, dressing, feeding self, locomotion, and personal hygiene. It has been known and demonstrated for many years that lowering of blood pressure from a previous hypertensive point can result in stroke prevention yet lowering of blood pressure does not prevent the microangiopathy that leads to white matter demyelinization which when combined with the clinical cognitive deterioration is compatible with a diagnosis of vascular dementia. It is known from many large studies, ie, SHEP, SCOPE, and HOPE, that lowering of blood pressure gradually will not and should not worsen the cognitive impairment. However, if the pressure is uncontrolled a stroke which might consequently occur would further worsen their cognitive derangement. So an attempt at slow reduction of blood pressure since cerebral autoregulation is slower as age increases is in the patient's best interest. It is also important to stress that control of blood glucose can also be seen as an attempt to prevent vascular dementia from uncontrolled hyperglycemia. Vascular dementia is not considered one of the reversible causes of dementia. Reversible causes of cognitive impairment are over medication with centrally acting drugs such as sedatives, hypnotics, antidepressants, and antipsychotics, electrolyte imbalance such as hyponatremia, azotemia, chronic liver disease, and poor controlled chronic congestive heart failure. Criteria for the clinical diagnosis of vascular dementia include cognitive decline in regards to preceding functionally higher level characterized by alterations in memory and in two or more superior cortical functions that include orientation, attention, verbal linguistic capacities, visual spacial skills, calculation, executive functioning, motor control, abstraction and judgment. Patients with disturbances of consciousness, delirium (acute confusional states), psychosis, serious aphasia, or sensory-motor alterations that preclude proper execution of neuro-psychological testing are also considered to have probably vascular dementia. Furthermore, these are ten of the other essential cerebral or systematic pathologies present that would be able to produce a dementia syndrome.