Hypertension or high blood pressure has grown in epidemic proportions around the world. It is affecting not only individuals from affluent western countries, but also those living in third world developing countries and that too in rural areas. Changed lifestyles, obesity, lack of exercise, stress, use of alcohol and tobacco are said to be the risk factors causing high blood pressure. Due to genetic susceptibility, a person having a sibling or parent or a blood relative with hypertension is more likely to develop it. Recent studies have shown that even under nutrition can cause chronic cardiovascular diseases including hypertension.
People are usually aware of complications related to kidney and heart by hypertension, but are unaware about its effect on nervous system
In case of very high blood pressure (>180 or 200 mm. Hg) blood vessels of the brain can burst resulting in damage to part of the brain. This manifests as sudden paralysis of one side of face and or body, visual disturbances, loss of speech, loss of consciousness e.t.c. neurological problems depending on part of the brain affected. Massive intracerebral bleeding can be fatal. Volume of accumulated blood, due to rupture of vessels causes compression of brain substance. This can result in coma or disorientation and or convulsions. High blood pressure also contributes to stiffening and narrowing of blood vessels. Total blockade of blood vessels can cause heart attacks or stroke. Timely treatment can save the person’s life and stabilize him gradually. Medicines and physiotherapy form part of the treatment. Cure occurs within 6 weeks to 6 months. It depends on the size and state of blood vessel affected and that of surrounding blood vessels. For example, if a major blood vessel is involved and surrounding blood vessels are patent, perfusion of the concerned part is restored partially or totally, thus steadying the person.
Long standing high blood pressure damages blood vessels of the body including the brain. This affects the blood supply of various body parts. Damage to the tissues in the deep interior of the brain substance does not manifest dramatically as a stroke, i.e. sudden paralysis, neurological disturbances, e.t.c. But subtle behavioral changes occur in the individual. These include loss of memory, disorientation to time, space and or person, loss of basic social behavior, lack of personal hygiene, e.t.c. These are usually presumed to be age related changes. But the underlying cause is uncontrolled high blood pressure. Senile dementia, i.e. behavioral changes with aging is induced and aggravated by uncontrolled hypertension. These conditions can be diagnosed by scans of the brain. Timely treatment is beneficial.
Studies have shown that those people having diabetes with hypertension are more likely to develop damage to the peripheral nerves, (nerves that carry sensations from outside of the body to the brain) as compared to those who have diabetes alone. This manifests as tingling, numbness or loss of sensation in limbs.
Long standing high blood pressure damages the kidney causing kidney failure. This reduces the elimination of toxic waste products from the body, which accumulate in the body and also affect the brain after reaching there via the bloodstream. Electrolyte imbalance caused due to kidney failure causes muscle cramps, weakness and also affects functioning of the brain. Thus the individual suffers from disorientation and or altered consciousness and even coma.
Considering these harmful effects of high blood pressure on the brain, it is imperative that a person avoids developing it. If he or she has high blood pressure it is advisable to keep it controlled with dietary measures, regular exercise, adequate relaxation and regular intake of prescribed medicines.
Dr. Rachna Pande is a specialist in internal medicine.